Introduction The germinal center (GC) in lymph nodes plays an important role in immune responses; however, their relevance to the effects of immune checkpoint inhibitor (ICI) remains unclear. The relationship between GC and ICI efficacy is investigated in this study. Materials and methods This investigation included 16 non-small cell lung cancer (NSCLC) patients with postoperative recurrence who were treated with immune checkpoint inhibitors (ICI) between January 2016 and April 2022. Patients were categorized into two groups based on the presence of GC in the lymph nodes. Additionally, the association between the number of lymph nodes dissected during pulmonary resection and ICI efficacy was evaluated. Results Sixteen patients were included with eight GC+ patients and eight GC- patients. The presence of GC positively influenced ICI efficacy, with the objective response rate (ORR) being significantly higher in the GC+ group (62.5%) compared to the GC- group (12.5%) (p=0.039). Disease control rate (DCR) was also more favorable in the GC+ group (100%) compared to the GC- group (50%) (p=0.021). Additionally, patients with fewer lymph nodes dissected at surgery had a better progression-free survival (median: 15.7 months) than those with more lymph nodes dissected (median: 7.4 months) (p=0.027). Conclusion GC in the lymph nodes can enhance the efficacy of ICI in treating NSCLC. Moreover, the number of dissected lymph nodes has emerged as a crucial prognostic factor that influences the effectiveness of treatment. These findings underscore the importance of considering lymph node characteristics in personalized ICI therapy for NSCLC.

Background The optimal duration of immune checkpoint inhibitor (ICI) therapy for maximum benefits remains unclear. Recently, the long-term follow-up data from clinical trials suggest the existence of a durable response (DR) that maintains the therapeutic effect even after ICI discontinuation. The study aimed to explore how the characteristics of ICI therapy influence the effectiveness of subsequent treatments in patients with advanced non-small-cell lung cancer (NSCLC). Methods The medical records of 134 patients with NSCLC who received ICIs before December 31, 2022, were retrospectively reviewed. We evaluated the impact of pretreatment ICIs on survival after completion of ICI administration. Results Among the 116 included patients, long ICI use (≥180 days) was the only independent prognostic factor for post-ICI overall survival (OS) in the multivariate analysis (HR: 0.382, 95% CI: 0.206-0.708, p=0.002). Patients who received ICIs for < 180 days showed significantly improved survival with subsequent chemotherapy (SC) compared to those who received only best supportive care (BSC) (p<0.001). However, among patients treated with ICIs for ≥ 180 days, no significant difference in OS or post-ICI OS was observed between the SC and BSC groups (p=0.188). In patients who discontinued ICIs due to PD, the impact of ICI treatment duration on survival outcomes differed. Among those with short ICI use, the SC group showed significantly better post-ICI OS compared to the BSC group (p=0.007). However, in patients with long ICI use, there was no significant difference in post-ICI OS between the SC and BSC groups (p=0.913). Regarding OS, no statistically significant differences were observed between the SC and BSC groups, regardless of ICI treatment duration. The 2-year OS was 47.6% in the SC group and 46.0% in the BSC group among patients with short ICI use (p=0.549), and 93.3% vs. 66.7% among those with long ICI use (p=0.136). Similarly, in patients who discontinued ICIs without PD, survival outcomes varied depending on ICI duration. Among those with short ICI use, the BSC group had a 2-year post-ICI OS of 21.1%, which was lower than that of the SC group (50.0%; p=0.08). The 2-year OS was also significantly higher in the SC group (64.3%) compared to the BSC group (31.6%; p=0.008). In contrast, no significant differences were observed in post-ICI OS (p=0.104) or OS (64.3% vs. 31.6%; p=0.104) between the SC and BSC groups among patients with long ICI use. Conclusion The achievement of a DR through prolonged ICI use may reduce the need for immediate subsequent chemotherapy in selected patients.

Background: The effect of lymph node dissection (LND) on the efficacy of immune checkpoint inhibitor (ICI) remains unclear. The purpose of this study was to examine the difference in the effect of ICI between patients with non-small cell lung cancer (NSCLC) according to the extent of LND performed in surgery prior to postoperative recurrence. Methods: A total of 134 patients with postoperative recurrence (surgery group, n=26) or unresectable advanced lung cancer (non-surgery group, n=108) who were treated with ICIs between January 2016 and December 2022 were included for analysis. In the surgery group, 16 patients underwent systematic LND, whereas the remaining 10 patients underwent selective LND. Progression-free survival with ICI treatment (ICI-PFS) and overall survival (OS) were compared between the surgery and non-surgery groups and between the systematic and selective LND groups using the inverse probability of treatment weighting (IPTW) method to adjust for patient background characteristics. Results: In the IPTW-adjusted analysis, the 2-year PFS rate with ICI treatment was 31.2% in the surgery group and 27.3% in the non-surgery group (P=0.19); the corresponding 2-year OS rates were 69.6% and 62.2%, respectively (P=0.10). In the surgery group, the 2-year PFS rates under ICI were 20.0% in the systematic LND group and 45.7% in the selective LND group (P=0.03). Conclusions: IPTW-adjusted analysis indicated no difference in prognosis between patients with postoperative recurrence and those with advanced unresectable lung cancer. However, in patients with postoperative recurrence, the extent of LND was a significant predictor of ICI-PFS. These findings suggest that systematic LND may reduce the efficacy of ICI, indicating that preoperative ICI administration may be warranted.

In cases of right upper and lower bilobectomy, careful manipulation is required to avoid lung torsion, as only the right middle lobe remains in the right thoracic cavity. We report a case of successful right upper and lower bilobectomy with no torsion of the middle lobe. Our technique prevents postoperative lung torsion by fixing the lung to the chest wall and pericardial fat with silk threads. In situations where lung torsion is a concern after lung resection, fixing the remaining lungs with silk thread is effective in preventing lung torsion.

Background: Even if lung cancer is detected at an early stage, surgery may be difficult in patients with severe comorbidities, like interstitial pneumonia (IP). Radiation therapy cannot be performed due to the high risk of acute IP exacerbation. Therefore, an effective alternative, such as photodynamic therapy (PDT), is required. To prove that acute exacerbation is not induced after PDT in peripheral lung cancer, we investigated the effects of PDT on IP rat models. Methods: Bleomycin (BLM) was administered intratracheally. Seven days after administration, left thoracotomy was performed. Talaporfin sodium was injected, and diode laser irradiation (664 nm, 150mW, 100J/cm2) was performed. Seven days after PDT, the whole blood and left lungs were collected. A total of 23 rats, comprising BLM + PDT (n = 4), BLM + non-PDT (n = 10), non-BLM + PDT (n = 2), non-BLM + non-PDT (n = 5), and two rats that died immediately after PDT were observed. Serum levels of Krebs von den Lungen-6, surfactant proteinD, lactate dehydrogenase, and serum C-reactive protein were measured. Fibrosis and macrophage scorings, and the collagen fibers percentage were examined by staining with hematoxylin and eosin, Elastica van Gieson, anti-alpha smooth muscle antibody, and anti-CD68 antibodies. Results: There was no remarkable difference in the values of each marker in fibrosis and macrophage scores with or without PDT. In case of death, fibrosis was mild, and PDT was not affected. Conclusions: In IP rat models, PDT did not induce lung fibrosis or acute exacerbation.

末梢肺へ経気管支的に光線力学的治療(photodynamic therapy: PDT)を行った際の肺実質への影響を調査するため,ハイブリッド犬の正常肺に対してPDTを行い肺組織への影響を病理学的に検討した.二頭のハイブリッド犬に対し経気管支鏡的に側射型プラスチックレーザープローブを左右後葉の末梢気管支へ挿入しPDTを施行した.タラポルフィンナトリウム投与後,左右後葉支へ50 J/cm2および100 J/cm2のレーザー照射を行い,7日後に肺を摘出し病理学的にPDTの影響を検討した.PDT施行部に一致して肺胞出血や肉芽の形成,線維芽細胞の増殖やマクロファージの浸潤などが認められた.周囲の気管支軟骨や肺胞上皮,臓側胸膜へは影響を認めなかった.PDTの効果範囲は約15 mmだった.末梢肺へのPDTは既存構造への影響は少なく安全に施行可能と考えられた.

BACKGROUND: This study aimed to investigate the efficacy of adjuvant chemotherapy for pathologic stage I non-small cell lung cancer (NSCLC) with high risk for recurrence. METHODS: Prospectively collected data from 1278 patients with pathologic stage I NSCLC according to eighth edition staging guidelines who were undergoing lobectomy were retrospectively analyzed. Factors associated with high risk for recurrence were determined using the multivariable Cox proportional hazards model for recurrence-free survival (RFS). Survival was compared between patients who received adjuvant chemotherapy and those who did not. RESULTS: In multivariable analysis, age (=70 years), invasive component size (>2 cm), visceral pleural invasion, lymphatic invasion, and vascular invasion were identified as independent factors for RFS. In patients with high-risk factors for recurrence such as pathologic T1c or T2a or lymphovascular invasion (high-risk group; n = 641), adjuvant chemotherapy resulted in significantly longer RFS and overall survival (n = 222; 5-year RFS, 81.4%; 5-year overall survival, 92.7%) than in patients who did not receive adjuvant chemotherapy (n = 418; 5-year RFS, 73.8%; P = .023; 5-year overall survival, 81.7%; P < .0001). In patients without any high-risk factors for recurrence (low-risk group; n = 637), RFS was not significantly different between those who received adjuvant chemotherapy (n = 83; 5-yeat RFS, 98.1%) and those who did not (n = 554; 5-year RFS, 95.7%; P = .30). CONCLUSIONS: Adjuvant chemotherapy may improve survival in patients with pathologic stage I NSCLC who have factors associated with high risk for recurrence, such as pathologic T1c or T2a or lymphovascular invasion. (C) 2022 by The Society of Thoracic Surgeons

OBJECTIVE:We aimed to determine the influences of surgical procedures on the postoperative death of octogenarians with clinical Stage IA non-small cell lung cancer excluding cT1mi.METHODS:We compared overall survival and the cumulative incidence of death due to all and other causes among 1 130 279, and 191 consecutive patients aged ≤79 and ≥80 years after lobectomy, segmentectomy and wedge resection at three institutions. Death due to other causes was defined as death due to any cause except non-small cell lung cancer.RESULTS:The median followup was 53 months. The 5-year overall survival rates for patients aged ≥ 80 and ≤ 79 years after lobectomy, segmentectomy and wedge resection were respectively, 78.0% (95% confidence interval, 63.8%-87.2%) versus 91.2% (95% confidence interval, 89.0%-92.9%), 68.1% (95% confidence interval, 45.2%-83.1%) versus 90.0% (95% confidence interval, 84.6%-93.5%), and 62.7% (95% confidence interval, 44.0-76.7%) versus 84.4% (95% confidence interval, 76.3%-89.9%) (P < 0.01 for all). The cumulative incidence of death due to other causes after wedge resection was similar between patients aged ≥ 80 and ≤ 79 years (P = 0.45), but significantly higher in those aged ≥ 80, than ≤ 79 years after lobectomy or segmentectomy (P = 0.00015 and 0.00091, respectively).CONCLUSIONS:The influence of wedge resection on death due to other causes was lower than that of lobectomy or segmentectomy in patients with non-small cell lung cancer aged ≥ 80 years. Wedge resection might be a useful option for octogenarians even if they can tolerate lobectomy/segmentectomy to avoid postoperative death due to causes other than non-small cell lung cancer.

Background. Complex segmentectomy creates several intricate intersegmental planes; however, it has not been fully established in lung cancer treatment. We compared the oncologic outcomes of complex segmentectomy and lobectomy through a large cohort, multicenter database using propensity score-matched analysis. Methods. We retrospectively analyzed data from 1517 patients with clinical stage I lung cancer with a solid component size 2.0 cm or less, who underwent surgical resection at 3 institutions between 2010 and 2018. Complex segmentectomy (n = 240) and location-adjusted lobectomy (n = 851) as well as surgical results were analyzed for all patients and their propensity scorematched pairs. Results. The prognosis of patients undergoing complex segmentectomy was not significantly different from that of patients undergoing lobectomy (5-year cancer-specific survival [CSS] rate, 96.4% versus 97.2%, P = .69; and 5-year recurrence-free interval [RFI] rate, 95.8% versus 93.4%, P = .19). This trend was also identified in subanalyses for pure solid tumors. However, there were major differences in clinicopathologic features between the 2 groups. After propensity score-matched analysis, proper matching of patients was ascertained. In 219 propensity score-matched pairs, long-term outcomes were similar between patients undergoing complex segmentectomy (5-year CSS, 96.0%; 5-year RFI, 95.5%) and lobectomy (5-year CSS, 97.8%; 5-year RFI, 95.9%). Propensity score-adjusted multivariable analysis for RFI revealed that prognosis associated with complex segmentectomy was comparable to the prognosis obtained with lobectomy (hazard ratio = 0.98; 95% confidence interval, 0.33-2.40; P = .98). Conclusions. Complex segmentectomy provides acceptable oncologic outcomes in clinical stage I lung cancer treatment. (C) 2021 by The Society of Thoracic Surgeons

Objective: Anatomical resection with lymph node dissection is the standard treatment for early non-small cell lung cancer, whereas wedge resection is considered as a compromise. We aimed to determine whether wedge resection without lymph node dissection could be a treatment option for patients aged >= 80 years. Methods: We assessed 669 patients with clinical stage IA non-small cell lung cancer, whole tumour sizes <= 2 cm and a consolidation to tumour ratio of >0.5 who underwent RO resection at three institutions between 2010 and 2016. We selected 58 of them who were aged >= 80 years and analysed their clinicopathological findings and prognosis after surgical procedures over a median follow-up of 38 months. Propensity scores for surgical procedures were calculated using age, gender, smoking status and solid tumour size on computed tomography. Results: Three-year overall and recurrence-free survival rates after wedge resection and after segmentectomy + lobectomy for patients aged >= 80 years did not significantly differ (overall survival: 88.9% [95% confidence interval, 69.4-96.3%] vs. 75.5% [95% confidence interval, 51.5-88.8%], P = 0.95; recurrence-free survival: 85.2% [95% confidence interval: 65.2-94.2%] vs. 68.0% [95% confidence interval, 44.4-83.2], P = 0.57). Multivariable Cox regression analysis of overall survival with propensity scores revealed that surgical procedure was not an independent predictor of a poor prognosis (hazard ratio: 0.86 (0.28-2.6), P = 0.78) in patients aged >= 80 years. Conclusions: Wedge resection might be an alternative to lobectomy or segmentectomy with lymph node dissection for patients aged >= 80 years with early non-small cell lung cancer.

We are developing a diffused light irradiation probe using a small diameter flexible plastic optical fiber and aiming at a photodynamic therapy in a narrow area by uniform light irradiation. In a narrow area, a direct transmission light irradiation probe could not manipulate the irradiation area, and a diffused light irradiation probe is required. The conventional diffused light irradiation probe made of quartz, has a hard tip, and could not be inserted into a curved path. We developed a light diffuser made by a small diameter plastic optical fiber and completed a small diameter and flexible diffused light irradiation probe.

Background. The prognosis of patients with cT1N0 lung adenocarcinoma is better when tumors include mixed ground glass opacity (GGO), compared with pure solid tumors. However, whether the prognosis of patients with mixed GGO tumors is favorable regardless of the solid component size remains unknown. Therefore, we aimed to determine the prognostic role of the solid component size in mixed GGO. Methods. We retrospectively analyzed the clinicopathological findings and prognoses of 856 patients with mixed GGO tumors based on solid component size during a median follow-up of 45 months, among 1215 patients with cT1N0 lung adenocarcinoma according to the TNM Classification of Malignant Tumors, Eighth Edition, who underwent R0 resection at 3 institutions between 2010 and 2015. Results. Four-year recurrence-free survival rates were significantly worse for patients with mixed GGO cT1c tumors (solid component size: 2-3 cm; 81.5%; 95% confidence interval [CI], 72.8%-87.7%) than for those with cT1mi+1a tumors (0-1 cm; 96.8%; 95% CI, 94.2%-98.2%) and cT1b (1-2 cm; 95.3%; 95% CI, 92.1%-97.2%) (both P < .001), although that for cT1b tumors was comparably favorable to those of T1miw+1a tumors. Multivariable Cox regression analysis of recurrence-free survival revealed that a solid component size of 2 cm to 3 cm (cT1c) vs less than or equal to 2 cm (cT1mi+1a+1b) was an independent prognostic factor (hazard ratio, 4.16; 95% CI, 2.24-7.72; P < .001). Conclusions. The prognostic impact of a solid component size less than or equal to 2 cm and greater than 2 cm significantly differs after complete resection of GGO-mixed T1N0 lung adenocarcinoma. The prognosis of patients with solid components less than or equal to 2 cm is favorable, whereas the behavior of those solid components greater than 2 cm is more aggressive. (C) 2020 by The Society of Thoracic Surgeons

Objectives: Recurrence risk of resected lung adenocarcinoma is represented by pathological stage (pStage), histological subtype, and potentially by EGFR mutation. However, the relationship among these factors and their combined impact on prognosis are unclear. Materials and Methods: Using a multicenter database, we retrospectively investigated the prognostic impact of EGFR mutation status in relation to pStage and histological subtype in resected pN0-1M0 lung adenocarcinoma. Results: Among 1155 pN0-1M0 adenocarcinoma cases, pStage 0 and IA1-IB were confirmed predominantly in EGFR-positive cases. AIS, MIA, and lepidic predominant adenocarcinoma were also more frequently found in EGFR-positive cases and showed no/little recurrence regardless of EGFR mutation status. The 5-year recurrence-free survival (RFS) of papillary, acinar, solid, and micropapillary predominant adenocarcinoma was stratified by pStage (IA1-IB, IIA-IIIA) or histological malignant subtype (intermediate or high malignant subtype), and more finely subdivided by EGFR mutation status. Positive EGFR mutation cases showed worse RFS in both classifications. Low malignant subtype and pStage IA1-IB intermediate malignant subtype showed low frequency of recurrence. Whereas, in pStage IA1-IB high malignant subtype and pStage IIA-IIIA cases, EGFR-positive cases showed poorer 5-year RFS than EGFR-negative (49.6% and 75.6%, respectively, hazard ratio [HR] = 1.84, 95% CI = 1.38-7.42, p < 0.01) and multivariate analysis indicated positive EGFR mutation status was significantly related to poorer PRF (HR = 2.005, 95% CI = 1.029-3.906, p = 0.041). Conclusion: EGFR mutation harbored primarily in early-stage or low-malignant histological subtypes with no/little recurrence. In pN0-1M0 adenocarcinoma with higher risk of recurrence, positive EGFR mutation cases showed worse RFS. EGFR mutation status enables better stratification of recurrence risk when considering pStage and histological malignant subtype.

The aim of the present study was to investigate epidermal growth factor receptor (EGFR) mutations as a prognostic factor for postoperative patients with positive EGFR mutations treated with postoperative platinum-based adjuvant chemotherapy (PBAC), and whether two common EGFR mutations exhibit different responses to PBAC. A total of 110 patients who underwent complete surgical resection were enrolled, and overall survival (OS) and disease-free survival (DFS) were investigated based on EGFR mutation status and PBAC. The 3 year OS rate in patient groups were as follows: Patients with EGFR mutations (MT) undergoing PBAC, 89.3%; MT patients without PBAC, 83.3%; wild-type (WT) patients with PBAC, 82.3%; and WT patients without PBAC, 62.2%. Statistically significant differences were observed between WT patients based on PBAC (P=0.026). No statistically significant differences were observed between MT patients with PBAC and MT patients without PBAC. On the basis of mutation subtypes, the 3 year OS rate of patient groups were as follows: Patients with in-frame deletions in exon19 (19 del) with PBAC, 92.3%; patients with 19 del without PBAC, 85.7%; patients with the point mutation L858R inexon21 (21L858R) with PBAC, 86.7%; and patients with 21L858R without PBAC, 81.5%; the respective 3-year DFS rates were 53.8, 14.3, 40.2 and 26.9%. Statistically significant differences were observed in the DFS rates in 19 del patients, which was dependent on PBAC (P=0.040). EGFR mutation-positive patients exhibited a decreased benefit from PBAC for increasing in survival rate compared with WT patients. It may be necessary to consider postoperative strategies based on EGFR mutations and their subtype in the future.

Rationale: Wasting of the subcutaneous adipose tissue (SAT) is one of the clinical characteristics of patients with pulmonary emphysema, although visceral fat accumulation has been also reported. The capacity of SAT to store the surplus lipid would determine the overflow of lipid, resulting metabolic disorders like visceral fat accumulation. The aim of this study is to explore subcutaneous and vesceral adipocytes in patients with pulmonary emphysema. Methods: We evaluated formalin-fixed, paraffin-embedded human subcutaneous and visceral adipose tissue samples obtained from smokers with pulmonary emphysema and from healthy smokers. The adipocyte size w determined on hematoxylin & eosin-stained paraffin sections by quantifying the actual area of discrete adipocytes. The subcutaneous and visceral fat area were assessed using cross-sectional CT scans at the umbilicus level. Results: The areas of SAT were significantly decreased in smokers with pulmonary emphysema as compared to healthy smokers, even though the average adipocyte sizes were similar, suggesting reduced number of subcutaneous adipocytes in smokers with pulmonary emphysema. The areas of visceral adipose tissue were similar between smokers with pulmonary emphysema and healthy smokers, even though the average viseceral adipocyte sizes in smokers with emphysema tended to be increased as compared to healthy smokers, suggesting reduced number and subsequent hypertrophy of viseceral adipocytes in smokers with emphysema. Conclusion: This study showed the reduced number of subcutaneous adipocytes and hypertrophy of visceral adipocytes due to impaired capacity of SAT to store the surplus lipid in patients with pulmonary emphysema.

8525 Background: Despite increasing evidence of favorable outcomes after segmentectomy for indolent lung cancer, such as ground glass opacity-dominant tumors, the adaptation of segmentectomy for radiologically aggressive lung cancer remains controversial. We attempted to elucidate oncologic outcomes after segmentectomy for radiologically aggressive lung cancer. Methods: Data from a multicenter database of 1353 patients with completely resected clinical Stage IA1–IA2 lung cancer at three institutions were retrospectively analyzed to identify radiologically aggressive lung cancer and compare outcomes of segmentectomy versus lobectomy in patients with radiologically aggressive lung cancer using propensity score matching. Results: Multivariable analysis showed that consolidation to maximum tumor (C/T) ratio on preoperative high-resolution computed tomography ( P= 0.037) and maximum standardized uptake value (SUVmax) on 18-fluorodeoxyglucose positron emission tomography/computed tomography ( P= 0.029) were independent predictors of recurrence-free survival (RFS). The criteria for radiologically aggressive lung cancer were determined as C/T ratio ≥ 0.8 or SUVmax ≥ 2.5, for which 522 patients were identified. RFS and overall survival (OS) were significantly worse in patients with aggressive lung cancer (5-year RFS, 83.3%; 5-year OS, 89.4%) than in those without the same (5-year RFS, 97.0%; P< 0.0001; 5-year OS, 97.3%; P< 0.0001). Among patients with aggressive lung cancer, no significant difference in RFS and OS was found between those undergoing lobectomy (n = 392) (5-year RFS, 81.3%; 5-year OS, 88.3%) and segmentectomy (n = 130) (5-year RFS, 90.0%; P= 0.33; 5-year OS, 92.3%; P= 0.76). Among the 111 pairs propensity matched for age, sex, smoking history, solid tumor size, C/T ratio, SUVmax, tumor location, clinical stage, and histology, similar RFS and OS were found between those undergoing lobectomy (5-year RFS, 83.3%; 5-year OS, 88.3%) and segmentectomy (5-year RFS, 90.9%; P= 0.92; 5-year OS, 94.5%). Conclusions: For radiologically aggressive small-sized lung cancer, oncologic outcomes of segmentectomy were equivalent to those of lobectomy.

The aim of this study was to evaluate the feasibility of a combination therapy of photodynamic therapy (PDT) and airway stent placement using a transparent silicone stent (gold studded stent [GSS]). Laser irradiation (664 nm, continuous wave) was performed through the GSS using a straight and cylindrical fiber 1.0 cm away from a power meter. There are two types of GSS: the TD type for the trachea and the BD type for the bronchus. Laser outputs were set to 150 mW, 180 mW, 210 mW, 240 mW, 270 mW, and 300 mW. The laser powers passing through the both types of GSS were measured three times for each outputs and the averages were calculated. Based on the results, animal experiment was performed using two female pigs. Under general anesthesia, a GSS (BD type) was inserted into trachea of pigs, and PDT using NPe6 as a photosensitizer was performed by 100 J/cm2 laser irradiation on parts of the trachea with and without a GSS. Immediately after and 1 week after PDT, pig tracheas were harvested and histological analysis was performed. Histological analysis of areas with or without the stent showed edematous changes between the cartilage and submucosal layer immediately after PDT, and necrotic changes 1 week later. The effectiveness of NPe6-PDT for pigs’ trachea covered by the stent was same as trachea without the stent. The use of a GSS may enable PDT to be effective even in the area covered by the stent.

Background. Quantitative computed tomography (CT) histogram analysis of tumors is reported to help distinguish between invasive and less invasive lung cancers. This study aimed to clarify whether CT histogram analysis of tumors can be used to classify patients with clinical stage 0 to IA non-small cell lung cancer according to pathologic lymph node (pN) status. Methods. Predictive factors associated with pN metastasis were identified from the derivation dataset including 629 patients with clinical stage 0 to IA non-small cell lung cancer who underwent complete resection with lymph node dissection (surgeries between 2008 and 2013). The validation dataset including 238 patients (surgeries between 2014 and 2015) were subsequently reevaluated. Clinicosurgical factors, including CT histogram analysis of tumors (CT value percentiles 2.5, 25, 50, 75, and 97.5, skewness, and kurtosis) were assessed. Results. Seventy-three patients (12%) in the derivation cohort and 35 patients (15%) in the validation cohort had positive nodes. The pN status significantly affected survival in the entire population: 5-year overall survival of 93.1% vs 71.1% and 5-year disease-free survival of 85.9% vs 43.1% for negative vs positive (both P <.001). On multivariate analysis in the derivation cohort, the 75th percentile CT value (P < .001), age (P = .003), and comorbidities (P = .006) were significantly associated with pN metastasis. The area under the curve and the cutoff level of the 75th percentile CT value relevant to pN metastasis were 0.729 and 1.5 HU, respectively, and the threshold value provided accuracy of 71% for the validation cohort. Conclusions. Histogram analysis of CT imaging metrics of tumors contributes to noninvasive prediction of pN metastasis in patients with clinical stage 0 to IA non-small cell lung cancer. (C) 2019 by The Society of Thoracic Surgeons

We studied the concentration change of talaporfin sodium in human skin by in silico pharmacokinetics model for quantitative evaluation of skin photosensitivity risk. Talaporfin sodium is clinically applied with light shading in a room of less than 500 lux for two weeks. Although it doesn’t prescribe a hospitalization, basically two weeks of hospitalizations are conducted. In order to reduce patient burden and medical costs, it is necessary to obtain the scientific evidence on the safety of skin photosensitivity. We performed a clinical study of the talaporfin sodium fluorescence measurement in skin tissue using our developed transdermal fluorescence measurement system. This clinical study was conducted at Tokyo Medical University Hospital and Nippon Medical School Hospital. Talaporfin sodium concentration change was evaluated by measuring talaporfin sodium fluorescence using a blue LED (wavelength 409 ± 16 nm) for excitation of the Soret band absorbance peak. We investigated the time range where the skin photosensitivity risk is high after administration, by using an in silico pharmacokinetics model to predict the continuous photosensitizer concentration change in skin tissue.

8500 Background: The role of adjuvant chemotherapy for pathological stage I non-small cell lung cancer (NSCLC) is controversial. The purpose of this study was to investigate the effect of adjuvant chemotherapy for pathological stage I NSCLC with high-risk factors for recurrence. Methods: Prospectively collected data from 1,278 patients with pathological stage I (8th edition) NSCLC undergoing lobectomy were retrospectively analyzed. High-risk factors for recurrence were determined by multivariable Cox proportional hazards model for recurrence-free survival (RFS). RFS, overall survival (OS), and cancer-specific survival (CSS) were compared between patients who received adjuvant chemotherapy and those who did not. Results: In multivariable analysis, age (≥70 y; hazard ratio [HR], 2.14), invasive component size ( > 2 cm; HR, 1.60), visceral pleural invasion (HR, 1.81), lymphatic permeation (HR, 1.67), and vascular invasion (HR, 2.78) were identified as independent factors for RFS. In patients with high-risk factors for recurrence such as invasive component size of > 2 cm, visceral pleural invasion, lymphatic permeation, or vascular invasion (high-risk group; n = 641), RFS was significantly different between patients who received adjuvant chemotherapy (n = 222; 5-y RFS, 81.4%) and those who did not (n = 418; 5-y RFS, 73.8%; P = 0.023). OS and CSS were also significantly better in patients who received adjuvant chemotherapy (5-y OS, 92.7%; 5-y CSS, 95.0%) than in those who did not (5-y OS, 81.7%; P < 0.0001; 5-y CSS, 89.5%; P = 0.012). In patients without any high-risk factors for recurrence (low-risk group; n = 637), RFS was not significantly different between patients who received adjuvant chemotherapy (n = 83; 5-y RFS, 98.1%) and those who did not (n = 554; 5-y RFS, 95.7%; P = 0.30). OS and CSS were also not significantly different between patients who received adjuvant chemotherapy (5-y OS, 98.0%; 5-y CSS, 100%) and those who did not (5-y OS, 95.6%; P = 0.35; 5-y CSS, 99.4%; P = 0.52). Conclusions: Adjuvant chemotherapy may improve survival in patients with pathological stage I NSCLC who have high-risk factors for recurrence such as invasive component size of > 2 cm, visceral pleural invasion, lymphatic permeation, or vascular invasion.