Objective: Esophagectomy is a complex operation associated with significant morbidity for fit patients. Risk calculation is essential to guide pre-operative patient selection. This study used CT-derived body composition measures and age to develop a model for the prediction of postoperative mortality after minimally-invasive esophagectomy. Methods: Patients who underwent minimally-invasive esophagectomy from 2010 to 2022 were identified. Preoperative CT scans at the L3-vertebral level were analyzed to calculate skeletal muscle gauge (SMG) as the product of skeletal muscle index and density. Patient demographics, clinical characteristics, and outcomes were collected. Patients were grouped based on SMG (low muscle = bottom quartile vs normal muscle = top 3 quartiles) and age (>= 75 vs < 75 years). Ninety-day postoperative mortality was compared between risk groups. Results: Of 399 patients, mean age was 62.8 years. Anastomotic leak occurred in 8.3 %, pneumonia in 17.0 %, discharge to home in 81.5 % and 90-day mortality in 5.5 %. Ninety-day mortality by risk group showed 1.8 % mortality for patients < 75 years with normal muscle (n = 281), 10 % mortality for patients < 75 years with low muscle (n = 72), 5.6 % mortality for patients >= 75 years with normal muscle (n = 18), and 32 % mortality among patients >= 75 years with low muscle (n = 28). Conclusions: Low-risk patients (< 75 years with normal muscle), which comprised 70 % of our study cohort, had favorable outcomes with 1.8 % 90-day postoperative mortality. Contrastingly, patients >= 75 years with low muscle measures were at high risk with 32 % mortality. Predictive models including SMG and age can identify high-risk groups and predict postoperative mortality after minimally-invasive esophagectomy.

INTRODUCTION:Percutaneous cryoablation is a first-line therapeutic option for primary neoplasms and metastatic lesions of the musculoskeletal system. Treatment of abdominal wall tumors is challenging as surgical resection can be highly morbid and necessitate complex reconstructive surgery; the efficacy of cryoablation for abdominal wall tumors may be limited by inadequate posterior margins owing to the proximity of intra-abdominal organs. With laparoscopy and insufflation, peritoneal structures can be safely mobilized away from the abdominal wall, allowing for adequate deep margin freeze and visualization of the ice ball. We present two patients with abdominal wall soft tissue tumors treated with a novel approach of laparoscopic-assisted, percutaneous ultrasound-guided cryoablation. PATIENTS AND METHODS:Patient 1 is a 65-year-old female with metastatic extraskeletal myxoid chondrosarcoma, stable on systemic therapy, who presented with a new soft tissue metastasis to the abdominal wall. Resection would have necessitated a highly morbid complex abdominal wall reconstruction with mesh. Patient 2 is a 35-year-old female with a large abdominal wall desmoid tumor, diagnosed after miscarriage. Resection was relatively contraindicated owing to the morbidity of a complex abdominal wall reconstruction and concerns regarding potential future pregnancies after surgery. RESULTS:Both patients underwent procedures in the outpatient setting after discussion at multidisciplinary sarcoma tumor board. Laparoscopic enterolysis was performed to mobilize the bowel away from the abdominal wall, to allow direct visualization of the peritoneal aspect of the tumor, and to confirm adequacy of the posterior margin freeze of the lesion. Laparoscopic transversus abdominus preperitoneal (TAPP) blocks with local anesthetic were performed for postoperative pain control. Interventional radiology performed an ultrasound-guided cryoablation consisting of two freeze and thaw cycles. Both patients recovered well without complications and were without radiographic evidence of persistent or recurrent disease at 12 and 18 months postoperatively, respectively. CONCLUSION:We report a novel approach of laparoscopic-assisted cryoablation for the treatment of abdominal wall soft tissue tumors. This allowed for successful minimally invasive local control of these large tumors that would have otherwise required highly morbid resections with complex abdominal wall reconstruction and mesh repair.

e16094 Background: Standard of care for locally advanced esophageal cancer consists of chemoradiation (chemoRT) followed by esophagectomy. Fewer patients in older populations with locally advanced esophageal cancer undergo esophagectomy when compared to their younger counterparts. Furthermore, frail patients frequently forgo surgery after chemoRT. The current study examined the relationship between age, body composition, and treatment decision-making in locally advanced esophageal cancer. Methods: Patients with clinical stage T2-4, N0-2, and M0 adenocarcinoma or squamous cell carcinoma of the mid or distal esophagus diagnosed between 2010-2021 were included from 11 hospitals across our healthcare system. Treatment decision-points included receipt of chemoRT versus non-curative therapy, unresectable disease after chemoRT defined by metastatic disease or upper mediastinal lymphadenopathy, and receipt of surgery stratified by histology. Sociodemographic data including age, race, sex, insurance status, socioeconomic status, body composition data from CT imaging (skeletal muscle gauge [SMG]), and outcome data were collected. Skeletal Muscle Gauge was calculated as the product of skeletal muscle cross-sectional area at L3 normalized for height and muscle density. Fisher's exact test was used for categorical variables and Kruskal-Wallis for continuous variables. Results: 513 patients were included in the analysis, of which 399 (78%) had adenocarcinoma and 114 (22%) had squamous cell carcinoma. Median age was 66. Of the 513 patients, 472 (92%) underwent chemoRT (366 [78%] adenocarcinoma, 106 [22%] squamous cell carcinoma). Patients who were over the age of 75 were less likely to undergo chemoRT when compared to their younger counterparts (85% vs. 94%, p = 0.002). After the completion of chemoRT, 419 (89%) patients were deemed resectable, 330 adenocarcinoma and 89 with squamous cell carcinoma. Among resectable patients with adenocarcinoma, those > 75 years old and lower SMG were less likely to receive surgery (p < 0.001 and p =0.001). Age and body composition associated with lower receipt of surgery in locally advanced esophageal cancer patients was significant on both univariate and multivariate analyses. Conclusions: Patients over 75 are less likely to undergo chemoRT and surgical resection for locally advanced esophageal cancer. Among patients with resectable disease who have completed chemoRT, those with unfavorable body composition as measured by low SMG on CT imaging are also less likely to undergo surgical resection. These measures may be helpful in surgical decision-making in patients with locally-advanced esophageal cancer. Further study is warranted to more precisely define the relationship between age, body composition, and risk of surgery in esophageal cancer.

e16093 Background: Treatment for locally advanced esophageal cancer consists of chemoradiation (chemoRT) followed by esophagectomy. Studies have suggested Black patients were less likely to undergo surgery for esophageal cancer with inferior survival rates, attributing this to differences in access to surgery. These studies have not always accounted for differences in the natural history of adenocarcinoma and squamous cell carcinoma, which have strong racial correlations and different rates of surgical resection. The current study examined outcomes and patterns of care for patients with locally advanced esophageal cancer, both adenocarcinoma and squamous cell carcinoma, in relation to their sociodemographic characteristics. Methods: Patients with clinical stage T2-4, N0-2, and M0 adenocarcinoma or squamous cell carcinoma of the mid or distal esophagus diagnosed between 2010-2021 were included from 11 hospitals across our healthcare system. Treatment decision-points included receipt of chemoRT, unresectable disease after chemoRT defined by metastatic disease or upper mediastinal lymphadenopathy, and receipt of surgery stratified by histology. Age, race, sex, insurance status, socioeconomic status measured by social deprivation index (SDI), and outcome data were collected. Chi-squared test was used for categorical variables and Kruskal-Wallis for continuous variables. Results: 513 patients were included, of whom 472 patients underwent chemoRT (366 adenocarcinoma, 106 squamous cell). Female patients (n =97) were less likely to undergo chemoRT (84% vs. 94%, p = 0.003). Patients without insurance were less likely to undergo chemoRT (86% vs 93%, p = 0.023). After completing chemoRT, 419 patients (82%) were resectable. Surgery was performed in 262/330 patients (79%) with adenocarcinoma and 38/89 patients (43%) with squamous cell carcinoma, reflecting the differences in natural history by histology. Among 330 patients with resectable adenocarcinoma, higher SDI was associated with a lower rate of surgery, while there was no difference in the receipt of surgery based on sex, race or insurance status. There were no detectable social factors associated with receipt of surgery for squamous cell carcinoma. Conclusions: Within our healthcare system, female and Medicaid/uninsured patients are less likely to undergo chemoRT for locally advanced esophageal cancer. Further studies are needed to evaluate whether sex-specific bias plays a role in the receipt of chemoRT. Among patients with resectable locally advanced esophageal adenocarcinoma treated with chemoRT, those with high SDI are less likely to undergo surgery. Further studies are needed to assess which component factors of socioeconomic status most impact the receipt of surgery so they can be targeted. The previous findings that race impacts treatment of locally advanced esophageal cancer are not seen in our healthcare system when accounting for histology.

The National Surgical Quality Improvement Project (NSQIP) dataset was used to identify perioperative variables associated with the length of stay (LOS) and early discharge among cancer patients undergoing colectomy. Patients who underwent non-emergent right colectomy for colon cancer from 2012 to 2019 were identified from the NSQIP and colectomy-targeted databases. Postoperative LOS was analyzed based on postoperative day (POD) of discharge, with patients grouped into Early Discharge (POD 0–2), Standard Discharge (POD 3–5), or Late Discharge (POD ≥ 6) cohorts. Multivariable ordinal logistic regression was performed to identify risk factors associated with early discharge. The NSQIP query yielded 26,072 patients: 3684 (14%) in the Early Discharge, 13,414 (52%) in the Standard Discharge, and 8974 (34%) in the Late Discharge cohorts. The median LOS was 4.0 days (IQR: 3.0–7.0). Thirty-day readmission rates were 7% for Early Discharge, 8% for Standard Discharge, and 12% for Late Discharge. On multivariable regression analysis, risk factors significantly associated with a shorter LOS included independent functional status, minimally invasive approach, and absence of ostomy or additional bowel resection (all p < 0.001). Perioperative variables can be used to develop a model to identify patients eligible for early discharge after right colectomy for colon cancer. Efforts to decrease the overall median length of stay should focus on optimization of modifiable risk factors.

Soft tissue sarcomas (STSs) comprise a heterogenous group of rare and aggressive tumors arising from mesenchymal tissues that can occur anywhere in the body.1 Although relatively rare, accounting for <1% of all malignant tumors, ∼10% of patients have metastasis present at diagnosis and nearly 50% of the patients with STS will ultimately develop distant metastases.2 Treatment with curative intent of STSs consists of wide resection with negative margins and typically neoadjuvant and/or adjuvant radiation therapy to decrease the risk of local recurrence. While the average size of a STS at presentation is 10 cm, ∼10% of patients present with large tumors that are >20 cm.3 Depending on the anatomic location, larger tumor size can make margin negative resection more technically challenging (Fig. 1). In some cases, large sarcomas or those that have been treated with neoadjuvant radiation may contain an internal fluid cavity as a result of tissue necrosis or hemorrhage.4 The added mass effect from a sizeable internal fluid cavity can complicate safe dissection around the tumor, thereby increasing the risk of positive margins. Unexpected positive margins after STS resection have been associated with increased local recurrence rates as high as 35%, an almost 4-fold increase from that expected with negative margins, and a rate of future metastatic spread near 49%.5 In addition, in this setting, unintentional rupture of the fluid cavity and tumor spillage results in a grossly contaminated resection bed. This paper will outline a technique for controlled intraoperative decompression of soft tissue tumors with internal fluid cavities, which can facilitate dissection around the tumor and improve visualization during resection while simultaneously decreasing risk of inadvertent rupture.FIGURE 1: Axial imaging positron emission tomography/computed tomography of high-grade neoplasm of the lower extremity with associated fluid cavity exhibiting mass effect on adjacent critical structures.TECHNIQUE Preoperative advanced imaging of the mass is recommended to best characterize the local anatomic and adjacent neurovascular structures, as well as the contents of any internal fluid cavity. Magnetic resonance imaging with and without contrast is the imaging study of choice to obtain, however, computed tomography scan with contrast or a positron emission tomography/computed tomography scan can also provide useful information (Fig. 1). Intraoperatively, a standard oncologic approach and dissection are performed based upon the anatomic location of the tumor. Once a superficial portion of the soft tissue mass has been exposed for decompression, a 0-silk suture is placed in purse string fashion in the tissue adjacent to the tumor capsule. A scalpel is then used to penetrate the capsule within the bounds of the purse string suture. Next, an 18 or 22 Fr chest tube attached to suction is inserted into the internal fluid cavity (Fig. 2). Note, the use of a chest tube is recommended over a standard Yankauer suction device due to the propensity of the latter to become clogged with debris. Once sufficient decompression has been performed, the suction device is extracted from the wound, and the purse string suture is tied securely. It is important to note that by function of achieving partial exposure and puncture of the tumor in order allow for decompression, this technique effectively intentionally performs an R1 resection to decrease risk of accidental R2 resection due to accidental spillage and rupture of noncompressed tumors, thus theoretically allowing for a lower, more consistent overall risk of local recurrence.FIGURE 2: Insertion of chest tube through incision with circumferential purse string suture.Alternatively, if the fluid cavity is close to the skin surface, decompression can be performed percutaneously before a formal surgical approach. This can be done initially with a large bore needle or through a technique similar to that described above. Subsequently, the skin surrounding the percutaneous approach may be excised en bloc with the tumor. Before proceeding with en bloc resection of the mass, the field should be thoroughly irrigated with or without use of adjuvant cleaning solutions such as hydrogen peroxide per surgeon preference. At this point, the field may be reprepped in sterile fashion if necessary, and the planned wide resection of the tumor is then performed with improved mobilization and visualization of the tumor and surrounding anatomic structures. CASE EXAMPLE A 57-year-old morbidly obese male with past medical history of a T4 N0 M0 G3 dedifferentiated liposarcoma of the right lower extremity extending from the knee joint to the hip joint (Fig. 3). Due to the size of the tumor, associated fluid collection, and adjacency to bone and critical structures, this was considered a complex tumor which would entail a resection with high degree of difficulty and a significantly elevated risk of local recurrence even if appropriate R1 or R0 resection was successfully performed.FIGURE 3: Clinical photograph of the mass in patient right thigh.To allow for mobilization of the patient’s tumor away from the femur and femoral neurovascular structures (Fig. 1), the above-described decompressive procedure was performed over the cystic mass through the skin and capsule at the right thigh. A total of 9 L of liquified material and old hematoma were evacuated through the purse string approach which led to decompression of ∼50% of the volume of the tumor. The vastus intermedius, which contained the mass, was dissected circumferentially in its entirety from the hip joint to the knee joint. There was an anticipated focal positive margin along the anteromedial femur after resection, which did not appear to infiltrate the cortex. Saucerization was performed at this location using curettes, followed by cauterization and irrigation with hydrogen peroxide. The patient experienced delayed wound healing but did not require reoperation. He subsequently underwent targeted adjuvant radiation therapy to the medial aspect of the tumor bed in the right thigh, including the medial cortex of the right femur at the location of previous saucerization. Due to morbid obesity, periosteal stripping, and adjuvant radiation therapy the patient was deemed at high risk for impending pathologic fracture of the femur. Prophylactic intramedullary nailing of the femur was performed without complication 7 months following initial surgery. He developed distant metastasis to the lung 9 months status postresection for which he has received intermittent systemic chemotherapy and focal radiation therapy. On surveillance scans 17 months after initial surgery, there was evidence of cortical disruption and local recurrence at site of right femoral saucerization. This patient, however, remains alive with disease at the time of this description. COMPLICATIONS Intraoperative spillage can still be a risk with this method if the initial poke-hole incision into the purse string entry is made too large or if inappropriate externally applied pressure is placed on the fluid collection while draining. Leakage may also occur if closure of the purse string suture is inadequate and/or all fluid is not completely drained before closure. These complications can be avoided by careful attention to the size of suction device that will be used for decompression and ensuring the entry incision is no larger than required in addition to reliable closure of the purse string suture and maximal decompression of the fluid cavity. When applicable, draining the tumor percutaneously will provide a more secure closure of this hole and provide less chance of leakage. EXPECTED OUTCOMES The suction device decompression technique is expected to improve the safety and feasibility of resection in select large STSs with internal fluid cavities by facilitating dissection around the mass and improving visualization of adjacent neurovascular structures. In addition, drainage of the fluid cavity may reduce the risk of inadvertent rupture and gross tumor spillage. In doing so, preresection decompression can, as illustrated in this technique paper, improve patient safety and facilitate surgical attempts at resecting tumors that had relative contraindications to wide resection or limb salvage. Furthermore, while tumor decompression presents an additional operative step, this technique can reduce overall surgical time. CONCLUSIONS The described method for meticulous surgical decompression by closed suction drainage of large intratumoral fluid collections facilitates wide resection of soft tissue neoplasms. This technique provides a safe, simple, and effective method for facilitating STS decompression and resection which has previously not been reported in the orthopedic and surgical oncology literature.

Objectives Patients undergoing oesophagectomy frequently experience malnutrition, which in combination with the catabolic effects of surgery can result in loss of muscle mass and function. Safe swallowing requires preservation of muscle mass. Swallowing dysfunction puts postoperative patients at risk for aspiration and pneumonia. Modified Barium Swallow Study (MBSS) enables assessment of postoperative swallowing impairments. The current study assessed incidence and risk factors associated with swallowing dysfunction and restricted diet at discharge in patients after oesophagectomy in a high-volume surgical centre. Methods Patients with an MBSS after oesophagectomy were identified between March 2015 to April 2020 at a high-volume surgical centre. Swallowing was quantitatively evaluated on MBSS with the Rosenbek Penetration-Aspiration Scale (PAS). Muscle loss was evaluated clinically with preoperative hand grip strength (HGS). Univariable and multivariable logistic and linear regression analyses were performed. Results 129 patients (87% male; median age 66 years) underwent oesophagectomy with postoperative MBSS. Univariate analysis revealed older age, preoperative feeding tube, lower preoperative HGS and discharge to non-home were associated with aspiration or penetration on MBSS. Age and preoperative feeding tube remained as independent predictors in the multivariable analysis. Both univariate and multivariable analyses revealed increased age and preoperative feeding tube were associated with diet restrictions at discharge. Conclusions Swallowing dysfunction after oesophagectomy is correlated with increased age and need for preoperative enteral feeding tube placement. Further research is needed to understand the relationship between muscle loss and aspiration with the goal of enabling preoperative physiological optimisation and patient selection.

We sought to derive and validate a prediction model of survival and recurrence among Western patients undergoing resection of gastric cancer. Patients who underwent curative-intent surgery for gastric cancer at seven US institutions and a major Italian center from 2000 to 2020 were included. Variables included in the multivariable Cox models were identified using an automated model selection procedure based on an algorithm. Best models were selected using the Bayesian information criterion (BIC). The performance of the models was internally cross-validated via the bootstrap resampling procedure. Discrimination was evaluated using the Harrell’s Concordance Index and accuracy was evaluated using calibration plots. Nomograms were made available as online tools. Overall, 895 patients met inclusion criteria. Age (hazard ratio [HR] 1.47, 95% confidence interval [CI] 1.17–1.84), presence of preoperative comorbidities (HR 1.66, 95% CI 1.14–2.41), lymph node ratio (LNR; HR 1.72, 95% CI 1.42–2.01), and lymphovascular invasion (HR 1.81, 95% CI 1.33–2.45) were associated with overall survival (OS; all p < 0.01), whereas tumor location (HR 1.93, 95% CI 1.23–3.02), T category (Tis-T1 vs. T3: HR 0.31, 95% CI 0.14–0.66), LNR (HR 1.82, 95% CI 1.45–2.28), and lymphovascular invasion (HR 1.49; 95% CI 1.01–2.22) were associated with disease-free survival (DFS; all p < 0.05) The models demonstrated good discrimination on internal validation relative to OS (C-index 0.70) and DFS (C-index 0.74). A web-based nomograms to predict OS and DFS among gastric cancer patients following resection demonstrated good accuracy and discrimination and good performance on internal validation.

Introduction: Mobile applications offer innovative opportunities for patient engagement and preoperative education. Among patients undergoing elective colorectal surgery, we evaluated the impact of patient enrollment in an interactive mobile app on perioperative enhanced recovery after surgery (ERAS) metric completion rates, postoperative opioid consumption, and length of stay. Methods: Data were prospectively collected on consecutive patients undergoing elective colorectal surgery managed on standard ERAS protocols. Enrolled mobile app patients received daily electronic reminders and educational material starting 7 days preoperatively through 30 days post-discharge. Patients not enrolled in the app received surgeon-specific education at preoperative clinic appointments. Perioperative clinicopathologic variables were collected, including ERAS metric completion rates. Daily postoperative morphine milligram equivalents (MME) requirements were analyzed. Results: A total of 111 patients enrolled in the mobile app, while 58 did not enroll (designated “non-users”). No significant differences in demographics, procedure, approach, or ostomy creation (all p >0.20) were noted. More mobile app users had a cancer diagnosis (68% vs 38%; p = 0.002). Mobile app users demonstrated increased rates of preoperative antibiotic completion (81% vs 73%) and preoperative clear liquid carbohydrate loading (88% vs 71%). Daily MME requirements were not significantly lower for app users on postoperative day (POD) 0, POD1, or POD2. Median LOS was 3 days in both cohorts. The 30-day readmission rate was lower among app users (6% vs 14%; p = 0.10). Conclusion: Enrollment of patients undergoing elective colorectal surgery in a mobile education app was associated with non-significantly increased rates of ERAS metric completion and decreased 30-day readmission rates. Postoperative narcotic use was not significantly impacted.

BACKGROUND:For locally advanced esophageal squamous cell carcinoma (ESCC), chemoradiation (ChemoRT) followed by surgery offers the best chance of cure, with a 35-50% pathologic complete response (pCR) rate. Given the morbidity of esophagectomy and the possibility of pCR with ChemoRT, a 'watch and wait' strategy has been proposed, particularly for squamous cell carcinoma. The ability to accurately predict which patients will have pCR from ChemoRT is critical in treatment decision making. This study assessed positron emission tomography (PET) in predicting pCR after neoadjuvant ChemoRT for ESCC.METHODS:ESCC patients treated with ChemoRT followed by surgery were identified. Maximum standard uptake value (SUV), metabolic tumor volume, total lesion glycolysis, and first-order textual features of standard deviation, kurtosis and skewness were measured from PET. Univariable and multivariable generalized linear method analyses were performed. A metabolic complete response (mCR) was defined as a post-therapy PET scan with maximum SUV < 4.0.RESULTS:Twenty-seven patients underwent ChemoRT followed by surgery, with overall pCR seen in 11 (41%) patients and radiographic mCR seen in 12 (44%) patients. Final pathology for these 12 patients revealed pCR (ypT0N0M0) in 5 (42%) patients and persistent disease in 7 (58%) patients. Univariate analysis did not reveal PET parameters predictive of pCR.CONCLUSION:Treatment of ESCC with ChemoRT often results in a robust clinical response. Among patients with an mCR after ChemoRT, disease persistence was found in 58%. The inability of PET to predict pCR is important in the context of a 'watch and wait' strategy for ESCC treated with ChemoRT.

BACKGROUND:Prognostic nomograms for patients with resected extremity soft tissue sarcoma (STS) include the Sarculator and Memorial Sloan Kettering (MSKCC) nomograms. We sought to validate these two nomograms within a large, modern, multi-institutional cohort of resected primary extremity STS patients.METHODS:Resected primary extremity STS patients from 2000 to 2017 were identified across nine high-volume U.S. institutions. Predicted 5- and 10-year overall survival (OS) and distant metastases cumulative incidence (DMCI), and 4-, 8-, and 12-year disease-specific survival (DSS) were calculated with Sarculator and MSKCC nomograms, respectively. Predicted survival probabilities stratified in quintiles were compared in calibration plots to observed survival assessed by Kaplan-Meier estimates. Cumulative incidence was estimated for DMCI. Harrell's concordance index (C-index) assessed discriminative ability of nomograms.RESULTS:A total of 1326 patients underwent resection of primary extremity STS. Common histologies included: undifferentiated pleomorphic sarcoma (35%), fibrosarcoma (13%), and leiomyosarcoma (9%). Median tumor size was 8.0 cm (IQR 4.5-13.0). Tumor grade distribution was: Grade 1 (13%), Grade 2 (9%), Grade 3 (78%). Median OS was 172 months, with estimated 5- and 10-year OS of 70% and 58%. C-indices for 5- and 10-year OS (Sarculator) were 0.72 (95% CI 0.70-0.75) and 0.73 (95% CI 0.70-0.75), and 0.72 (95% CI 0.69-0.75) for 5- and 10-year DMCI. C-indices for 4-, 8-, and 12-year DSS (MSKCC) were 0.71 (95% CI 0.68-0.75). Calibration plots showed good prognostication across all outcomes.CONCLUSIONS:Sarculator and MSKCC nomograms demonstrated good prognostic ability for survival and recurrence outcomes in a modern, multi-institutional validation cohort of resected primary extremity STS patients. External validation of these nomograms supports their ongoing incorporation into clinical practice.

Background and Objectives Caval leiomyosarcomas (cLMS) are rare soft tissue sarcomas historically associated with high recurrence rates and poor prognosis. While radical resection remains the mainstay of therapy for cLMS, new systemic therapies have presented opportunities for multimodality treatment. We examined the clinical outcomes of patients with cLMS treated with modern, multimodality approaches, and compared their outcomes to those of patients with noncaval retroperitoneal LMS (ncLMS). Methods A retrospective, single-institution review identified all patients diagnosed with primary retroperitoneal LMS from 2012 to 2018. Radiographic and pathologic review distinguished patients with cLMS and ncLMS. Standard clinicopathologic variables and response to chemotherapy (when applicable) were analyzed. Primary endpoints were overall (OS) and progression-free survival (PFS). Results Eleven patients with cLMS were identified. Median tumor size was 7.5 cm (IQR, 5.0-14.3 cm); all patients had Stage II/III disease. Seven patients received neoadjuvant chemotherapy. Nine cLMS patients underwent R0/R1 resection; two did not complete resection. Six patients received adjuvant systemic therapy. Twenty patients with ncLMS were treated during the same period. No statistical intergroup differences were noted in tumor size, pathologic grade, stage, or resection margin status. Patients with ncLMS were less likely to receive neoadjuvant (10% vs. 64%) and adjuvant chemotherapy (30% vs. 55%). Two-year OS (81% vs. 78%; p = NS) and PFS (55% vs. 46%; p = NS) were comparable between cLMS and ncLMS patients. Conclusions Multimodality treatment with systemic therapy and aggressive surgical resection may achieve equivalent survival outcomes for patients with cLMS versus similar ncLMS. We recommend that all patients with cLMS be evaluated for multidisciplinary treatment. Genomic and proteomic expression profiling may identify novel or targetable mutations.

Prognostic nomograms for patients undergoing resection of retroperitoneal sarcoma (RPS) include the Sarculator and Memorial Sloan Kettering (MSK) sarcoma nomograms. We sought to validate the Sarculator and MSK nomograms within a large, modern multi‐institutional cohort of patients with primary RPS undergoing resection.

454 Background: Sarcopenia has been associated with post-operative complications and length of stay (LOS) in patients undergoing esophagectomy. A variety of methods exist to measure muscle mass and strength, with few comparisons between methods. We compared hand-grip strength (HGS), muscle mass and intramuscular adipose tissue as predictors of post-operative outcomes. Methods: Patients with esophageal cancer undergoing esophagectomy were identified between January 2015 – June 2019 at Levine Cancer Institute. Skeletal muscle index (SMI) and skeletal muscle density (SMD), a measure of intramuscular adipose tissue, were derived from CT. HGS was measured using a dynamometer. Uni- and multivariable GLM analyses were performed. Results: 115 patients (100 male, 15 female) underwent esophagectomy with an average age of 64.3 +/- 9.8. The analysis was stratified by sex due to significant differences in HGS, SMI, and SMD. Among men, univariable analysis revealed a significant association between pre-operative HGS <25 kg and increased risk of post-operative pneumonia ( p=0.02), ventilation >48hrs ( p=0.02), LOS ( p=0.002), discharge to home ( p=0.001), and one-year mortality ( p=0.005). All associations except discharge home remained significant in multivariable analyses (Table). Among women, no factors analyzed were significantly associated with postoperative outcomes. Conclusions: HGS is a more powerful predictor of postoperative complications and LOS than either muscle mass or intramuscular adipose tissue among men undergoing esophagectomy. HGS is cost-effective and easily incorporated into routine clinical care, allowing for preoperative intervention to optimize patients for esophagectomy. To better understand the implications in women, additional research with a larger cohort is needed. [Table: see text]

e16565 Background: Nutritional deficiencies are common in esophageal cancer patients after esophagectomy. Patients frequently present with weight loss due to obstruction. Cancer therapies (chemoradiation and esophagectomy) further compromise nutrient intake through alterations in appetite, gastrointestinal function, and the catabolic effects of therapy. We aimed to understand and identify risk factors associated with post-esophagectomy weight loss. Methods: Patients undergoing minimally-invasive esophagectomy via laparoscopic and thoracoscopic techniques with intra-thoracic anastomosis between January 2015 and July 2019 were identified. Post-operative weight loss at 3- and 6-months post-surgery was calculated as percent change from preoperative weight. Univariate and multivariable generalized linear method (GLM) analysis was performed. Results: 176 patients (145 male, 31 female) underwent esophagectomy, with a median age of 64 [IQR 57-71] and median 3-month postoperative weight loss of 7.9% [IQR 1.5-12.3%]. The majority of patients were Caucasian (89%), histologically diagnosed adenocarcinoma (90%), and received neoadjuvant chemoradiation (71%). Median preoperative BMI was 28.3 [IQR 25.5-32.5]. Preoperative enteral feeding tubes were placed in 86 patients (49%). Five patients (2.8%) were converted to open surgery (laparotomy) and anastomotic leaks occurred in 12 (6.8%) patients. The median length of stay was 9 days [IQR 8-13]. Among a subset of 147 patients with data available, the median 6-month postoperative weight loss was 10% [IQR 5.3-15.0%]. On multivariable analysis, greater preoperative BMI and anastomotic leak were associated with increased weight loss at 3 and 6 months post-esophagectomy. Conclusions: Significant postoperative weight loss is common among minimally-invasive esophagectomy patients. Higher preoperative BMI and postoperative anastomotic complications are significantly associated with increased postoperative weight loss at 3 and 6 months. Need for preoperative feeding tube and conversion to open surgery were further associated with postoperative weight loss. [Table: see text]

Intraoperative radiation therapy (IORT) is used for high grade or recurrent malignancies in locations where negative resection margins may be difficult and locoregional recurrence risk is significant. One IORT option is radioisotope-impregnated, bioabsorbable brachytherapy mesh that can be customized and conformed to the tumor bed at risk. Promising early results with brachytherapy mesh are limited to case reports. We analyzed our institutional experience with low-dose rate brachytherapy mesh, focusing on procedure-related toxicities and long-term oncologic outcomes. Patients undergoing brachytherapy mesh placement at a single institution from 2014-2019 were identified and clinicopathologic and radiation data collected. All patients underwent preoperative planning for 103Pd or 131Cs impregnated brachytherapy mesh placement at the time of oncologic resection due to concern for high-risk surgical margins. Primary endpoints were brachytherapy-related toxicities, locoregional recurrence-free survival (RFS), defined as time to radiographic recurrence within the brachytherapy treatment field, and overall survival (OS). Six patients were identified. Histologies included recurrent colorectal cancer (CRC; n = 2), renal cell carcinoma (RCC; n = 1), squamous cell carcinoma (SqCC; n = 1), and high-grade soft tissue sarcoma (STS; n = 2). All 6 had microscopically positive (R1) resection margins. Locations of brachytherapy mesh implant included retroperitoneum (RP; n = 2), pelvic side wall (n = 2), and neck (n = 2). Two patients received 131Cs mesh; 4 received 103Pd mesh. The prescribed dose range was 50–60 Gy at 5–6 mm (131Cs) and 33–90 Gy at 5–8 mm (103Pd) to cover an average tumor resection bed area of 62 cm2 (range, 15–81) based upon single plane implant geometry. One patient developed delayed wound complications related to concurrent free flap reconstruction, ultimately requiring debridement and mesh removal 5 months post-implant. No other patients experienced brachytherapy-related toxicities. At a mean follow-up of 34 months, 2 patients have developed locoregional recurrence, at 39- and 52-months post-brachytherapy, respectively. One patient died in the follow-up period, at 16 months after resection due to distant metastasis without locoregional failure. Median RFS for the cohort was 27.9 months (range, 6.9 – 55.8); median OS was 28.7 months (6.9 – 69). IORT via brachytherapy mesh placement at time of resection for high-risk malignancies appears feasible and effective across multiple sites and histologies. Locoregional disease control rates after R1 resections were adequate and treatment-related toxicities were minimal.Tabled 1Abstract 2644; TablePt #HistologyPrior EBRT (Gy)LocationIsotopeSource Activity (mCi)Brachy Dose DeliveredArea (cm2)1RCCn/aRP103Pd17590 Gy at 8 mm802CRC45RP131Cs13950 Gy at 5 mm813STS72Neck103Pd12890 Gy at 5 mm724SqCC60Neck131Cs9560 Gy at 6 mm155CRC50Pelvis103Pd8633 Gy at 5 mm756STSn/aPelvis103Pd7060 Gy at 5 mm48 Open table in a new tab