PURPOSE:Although the 21-gene Oncotype DX assay predicts chemotherapy (CT) benefit in hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer (BC), some patients decline CT despite their physician recommendations. We examined factors associated with CT declination and its impact on overall survival (OS) among patients with early-stage disease and high recurrence scores (RS). METHODS:Patients aged 18 years and older diagnosed with clinical stage I-II HR-positive/HER2-negative BC who underwent definitive surgery between 2018 and 2022 and had RS > 25 were identified in the National Cancer Database. Multivariable logistic regression was used to identify factors associated with CT declination. Multivariable Cox proportional hazards regression was used to examine the association between CT declination and OS in a 1:5 propensity score-matched cohort. RESULTS:Among 30,326 patients with RS > 25, 10.9% declined CT. 15.5% of patients who declined CT also declined hormonal therapy. Higher RS was associated with lower odds of CT declination (adjusted odds ratio [aOR], 0.97; 95% CI, 0.96 to 0.97). A more recent year of diagnosis and Hispanic race (aOR, 0.83; 95% CI, 0.70 to 0.98) were associated with lower odds of CT declination, while older age and Black race (aOR, 1.29; 95% CI, 1.15 to 1.45) were associated with higher odds. Patients on Medicaid (aOR, 1.53; 95% CI, 1.31 to 1.79) and Medicare (aOR, 1.19; 95% CI, 1.05 to 1.34) had higher odds of declination compared with those on private insurance. Having pathologic Nodal 1 (pN1) disease was associated with lower odds of declination than pN0 disease. Notably, CT declination was associated with an increased risk of death (aHR, 1.43; 95% CI, 1.20 to 1.69). CONCLUSION:Despite a decrease in CT declination over time, disparities persist, and declination is associated with worse OS. Further research is needed to understand these disparities and improve cancer care delivery and outcomes.

629 Background: GLP1 Receptor Agonists (GLP1) are widely used for type 2 diabetes (DM2) and obesity in adults. However, data on modern utilization and associated health outcomes, including all-cause mortality, in breast cancer (BC) patients is limited. We evaluated these endpoints in a BC population from a large US national healthcare database. Methods: Using Truven MarketScan, a commercial insurance claims database which includes over 270 million patients, we extracted eligible invasive BC patients diagnosed between 2014 and 2023 who were ≥ 18 years old, completed definitive BC surgery (index date), received GLP1 for at least 3 continuous months, and had available mortality data. Overall survival (OS) was defined as the time from BC surgery to death from any cause; patients alive at the time of analysis or lost to follow-up were censored at last contact date. Propensity score matching (1:1 ratio) was used to match patients who received GLP1 with those who did not, based on clinical prognostic factors (age; sex; deyo comorbidity index (CI); receipt of immunotherapy, chemotherapy, adjuvant endocrine therapy; DM2; weight category; stroke; myocardial infarction (MI)/coronary artery disease (CAD); heart failure); Kaplan-Meier estimates and log-rank tests were used to compare OS between groups and hazard ratios (HR) were estimated using multivariable Cox proportional hazards models. Results: In 137,493 BC patients, 7,249 (5.3%) received a GLP1 and over half (n=4,019; 55.4%) initiated it after BC surgery. The median follow up time in GLP1 users was 32 (IQR 15-57) months. In GLP1 users the median age was 59 (IQR 53-64) years; 5,860 (80.8%) had DM2 and 1,825 (25.2%) had a CI ≥3; in those with weight data available (n=4,687), 4,609 (98.3%) were in the overweight or obese category. A total of 3,828 (52.8%) received GLP1 concurrent with anti-cancer systemic therapy (chemotherapy, immunotherapy, or adjuvant endocrine therapy). The median duration of GLP1 use was 2.1 (IQR 0.8-6.1) years. GLP1 use increased over time (3.2% in 2014, 5.2% in 2018, 7.2% in 2023). Semaglutide was the most common agent prescribed across all years (35.8%) and exhibited the greatest annual increase in use after 2018. In the propensity score matched cohort, OS was significantly higher in GLP1 users vs non-users (n=7,248 per group): 5 year OS 95.8% GLP1 vs. 89.5% non-users (adjusted HR 0.41, 95% CI: 0.34-0.49, p<0.001). Conclusions: We describe one of the largest observational studies on real-world GLP1 prescription patterns and associated mortality in a BC cohort. Use of these agents is increasing over time in BC patients. Our research supports other emerging epidemiologic data suggesting a potential all-cause mortality benefit with these incretin mimetics in this population. Prospective studies are warranted to clarify the biological mechanisms underlying this association, including metabolic health implications and effects on BC tumor biology.

PURPOSE:Late effects of chemotherapy in older breast cancer (BC) survivors remain understudied. We evaluated the long-term impact of taxane chemotherapy on patient-reported neuropathy, balance problems, and falls among older BC survivors. METHODS:Using Texas Cancer Registry-Medicare linked data, BC survivors age 65 years or older at diagnosis, with local or regional disease diagnosed between 2012 and 2013 were identified. Survivors completed questionnaires including patient-reported outcomes and clinical characteristics between April 2018 and October 2019. Rao-Scott chi-square tests and multivariable logistic regression models evaluated associations between taxane chemotherapy and neuropathy in the past 7 days, and balance problems and fall outcomes in the past 12 months. RESULTS:Among 1,493 BC survivors, the majority were non-Hispanic White (80.8%), had hormone receptor-positive BC (78.1%), and had localized disease (75.6%). 26.5% received chemotherapy, and 89% of those received a taxane. Survivors who received chemotherapy were more likely to report neuropathy (61.8% v 36.0%, P < .01). Those who received paclitaxel had worse neuropathy than survivors treated with docetaxel (73.3% v 55.7%, P < .01). Although taxane use was not significantly associated with falls (adjusted odds ratio [aOR], 1.2 [95% CI, 0.83 to 1.64]), those treated with a taxane were more likely to report balance problems than those who did not receive chemotherapy (aOR, 1.6 [95% CI, 1.13 to 2.24]). Although Black BC survivors were more likely to report neuropathy (aOR, 1.8 [95% CI, 1.10 to 3.07]), Hispanic (aOR, 1.5 [95% CI, 1.01 to 2.31]) survivors were more likely to receive a provider intervention to prevent falls or treat balance problems relative to White survivors. CONCLUSION:Older BC survivors who received taxane chemotherapy were more likely to report neuropathy and balance problems but not falls. Future research should evaluate effective fall prevention and balance interventions in this population.

530 Background: Adjuvant abemaciclib (2 years) is approved in combination with endocrine therapy (ET) for node-positive high-risk early HR+ BC. Although it improves invasive disease-free and overall survival, its long duration and toxicities increase treatment complexity. As adjuvant regimens become more intensive, long-term adherence is critical for real-world effectiveness. However, data outside clinical trials are limited. We examined treatment patterns and factors associated with adherence to abemaciclib in a younger population of patients with early BC. Methods: We conducted a retrospective cohort study using the Merative MarketScan Commercial Claims and Encounters database. Patients aged 18-64 years with early BC who received abemaciclib between 2017 and 2024 were identified. Index date was the date of the first abemaciclib claim. We included patients who underwent breast surgery within one year before the index date and had continuous enrollment for 6 months before and one year after index date. We excluded patients with metastatic disease prior to the index date. Medication adherence was assessed using the proportion of days covered (PDC), with adherence defined as PDC ≥80%. Multivariable logistic regression was used to examine factors associated with abemaciclib adherence at one and two years. Results: Among 640 patients (median age 51 years) treated with adjuvant abemaciclib (median follow up 1.5 years), 55% were adherent to therapy at one year. Adherence declined from 100% in month 1, to 66%, 57%, 55%, and 50% in months 2, 6, 12, and 24 (p<0.001). Overall, 84.5% of patients initiated abemaciclib at 150 mg, and 47.2% had no dose adjustments during treatment. On multivariable analysis of one-year adherence, patients prescribed lower abemaciclib doses (50 or 100mg) were less likely to be adherent compared to those prescribed 150 mg (aOR=0.52; 95%CI 0.31–0.90). Adherence to ET was also associated with higher abemaciclib adherence (aOR=3.63; 95%CI 2.55–5.18). Polypharmacy was associated with reduced abemaciclib adherence among patients taking two (aOR=0.56; 95%CI 0.37–0.85) or ≥3 drug classes (aOR=0.51; 95%CI 0.34–0.78) compared with 0–1 drug class. Patients with high-deductible health plans (HDHP) had higher odds of adherence compared to those with PPO insurance (aOR=2.10; 95%CI 1.23–3.59). At two years (n=213), younger age and adherence to ET were significantly associated with greater abemaciclib adherence. Conclusions: Abemaciclib adherence was low, 55% in year 1, and 50% in year 2. Although lower abemaciclib doses and polypharmacy were associated with lower odds of adherence, ET adherence was associated with higher odds. Adherence in HDHP patients may reflect demographics (White, young, higher income). These findings highlight the need for close patient monitoring and strategies to support long-term adherence to adjuvant treatment.

e18546 Background: Acute promyelocytic leukemia [APL] has historically been associated with significant early mortality, but it is now one of the most curable leukemias, with long-term survival rates >90%. Early recognition and prompt treatment initiation are critical to prevent early death. Although early mortality remains a significant challenge, the impact of weekend admission on hospitalization outcomes of patients with APL is unclear. We evaluated the association between weekend versus weekday admission and inpatient outcomes among patients with APL. Methods: Retrospective cohort analyses were conducted using data from the National Inpatient Sample (NIS) collected between 2017 and 2021. Using ICD-10 CM codes, adult (≥18 years) inpatient hospitalizations with a diagnosis of APL were identified. Multivariable logistic and linear regression models were used to examine the association between day of admission and inpatient outcomes among hospitalized patients with APL. Results: Among 4,959 hospitalizations with a diagnosis of APL, 19% of admissions occurred on a weekend. Patients admitted on weekends were more likely to be male (49% vs 43%, p=0.027), non-Hispanic Black (19% vs 11%, p<0.01) and insured by Medicare (72% vs 59%, p<0.001). There was no significant difference in weekend admissions by age. After multivariable adjustment, patients admitted over the weekend had higher odds of in-hospital mortality compared to those admitted during a weekday (Adjusted odds ratio [AOR] 1.80, 95% CI, 1.20 – 2.40). Weekend admission was associated with length of stay (LOS) >5 days (AOR 2.60, 95% CI, 1.80 – 4.50) relative to 5 days or less. Additionally, patients admitted over the weekend had $3,579 (95% CI, $43.6 – $78,964.5) higher total hospital charges compared to those admitted during a weekday. Conclusions: Our findings demonstrate a weekend effect on hospitalization outcomes among patients with APL, with weekend admissions associated with higher in-hospital mortality, longer hospital stays, and increased hospital costs. Further investigation is needed to identify the underlying causes of these differences and implement strategies to attenuate them. Impact of weekend admission on inpatient outcomes among hospitalized patients with acute promyelocytic leukemia. Weekend Admission Unadjusted Adjusted Mortality OR (95% CI) No Reference Reference Yes 1.23 (0.56–2.60) 1.80 (1.20–2.40) Length of stay OR (95% CI) 5 days or less Reference Reference More than 5 days 2.30 (1.20-3.60) 2.60 (1.80-4.50) Total Charges ß (95% CI) 49.05 (-654.35-178643.76) 3578.8 (43.64-78964.54) AOR=Adjusted odds ratio; CI=confidence intervals. Model adjusted for age, gender, race/ethnicity, median household income national quartiles, hospital region, hospital location, Charlson comorbidity index, insurance type, admission type and length of stay. Boldface indicates statistical significance.

Abstract Background The use of preventive therapy in women at high risk for invasive breast cancer is associated with a significant reduction in breast cancer risk, however, uptake remains suboptimal outside of clinical trials. We conducted a pilot study of a behavior-change intervention to encourage high-risk women to take preventive therapy. Methods Women aged 35–69 with a history of lobular carcinoma in situ (LCIS) or atypical hyperplasia (AH) receiving care at MD Anderson Cancer Center, Houston, Texas, were eligible. Following cognitive testing, the tool was field-tested using a pre-post design, comparing patients seen before its integration into clinical practice (pre-implementation cohort) with those seen after implementation (post-implementation cohort). Participants completed self-administered questionnaires assessing knowledge, treatment preferences, decisional conflict, shared decision-making and acceptability; clinicians completed surveys on their experiences with the tool. Descriptive analyses and standard tests of association were performed. Results Of the 48 women who participated, 21 were in the post-implementation cohort. The majority of participants were White (75%) and non-Hispanic (81%), with a median age of 53 years. Most participants (90%) reported never needing help with reading health materials and were comfortable searching for health information online (81%). Women in the post-implementation cohort had higher knowledge about breast cancer preventive therapy compared to those in the pre-implementation cohort. However, only 38% correctly understood that side effects such as hot flashes and vaginal symptoms occur infrequently. After discussing with their clinician, 57% of women in the post-implementation cohort stated an intent to take preventive therapy compared to 70% in the pre-implementation cohort. Both groups reported low decisional conflict. The majority of women in the post-implementation cohort had positive perceptions of the tool. Furthermore, clinicians gave high ratings for the tool’s acceptability (median 4, IQR: 3.75–4.5), feasibility (median 4; IQR: 4-4.5) and appropriateness (median 4, IQR: 4-4.5), and found it somewhat/very helpful (100%) to patients with making decisions about preventive therapy. Conclusion Our findings suggest that the behavior-change tool was associated with improved patient knowledge about preventive therapy and had good acceptability. Future research should focus on enhancing patient education about the likelihood and management of side effects, measuring treatment initiation and adherence and identifying effective strategies to integrate these tools into clinical practice to support informed decision-making.

531 Background: ILC has a distinct biology and is considered less chemosensitive than invasive ductal carcinoma (IDC). O-Dx RS can guide adjuvant CT decisions for patients with HR+/HER2- breast cancer (BC); however, pivotal trials largely included patients with IDC. Patients with high RS have been shown to benefit from CT. Whether this genomic risk threshold is applied to patients with ILC in real-world practice is not well understood. We evaluated contemporary CT use by O-Dx RS and its association with overall survival (OS) in patients with ILC. Methods: Patients ≥18 years with HR+/HER2- ILC diagnosed from 2018-2022 who underwent surgery, had pT1-T3, pN0-N1 disease, and known O-Dx RS were identified in the NCDB. Baseline characteristics were compared by RS groups: 0-10 (low), 11-25 (intermediate), and >25 (high). Multivariable logistic regression models identified factors associated with CT use in the overall cohort and stratified by RS. We evaluated the association between CT use and OS within each RS group, adjusting for covariates using propensity score matching (by year of diagnosis, age, pT, pN). Results: A total of 30,393 patients with early-stage HR+/HER2- ILC and O-Dx score were identified. Among them, 21% had low, 72% intermediate, and 7% high RS. Overall, 9.2% received CT, including 2.4% of those with low RS, 5.5% of intermediate RS, and 66% of high RS. CT use did not change over time (p=0.47). On multivariable analysis in all patients, higher RS was the key determinant of CT use (RS 11-25 vs 0-10: aOR=2.98, 95%CI 2.49-3.58; RS >25 vs 0-10: aOR=333.4, 95%CI 266.8-416.7), while older age was associated with lower CT use (aOR=0.91, 95%CI 0.91-0.92). In multivariable models stratified by RS, clinicopathologic features, including younger age, larger tumor size, higher nodal stage, and higher grade, were associated with CT use in low and intermediate RS groups (i.e., pN1 aOR=18.64 for RS 0–10; aOR=7.37 for RS 11–25; both p<0.001), whereas in high RS group, age had similar effect; however, tumor size and nodal status had significant but attenuated effects. In propensity-matched cohorts within RS groups, CT use was not associated with different OS in low RS (5-year OS 98% vs 100%, p=0.29) or intermediate RS (5-year OS 97% vs 97%, p=0.68) groups; however, in high RS group, CT use was associated with improved OS (5-year OS 96% vs 90%; p=0.01). Conclusions: In clinical practice, CT use in patients with ILC is guided by O-Dx RS but influenced by age and clinicopathologic risk. CT use conferred no OS benefit in patients with low or intermediate RS but was associated with OS benefit in high RS. Despite this, one-third of patients with ILC with high RS did not receive CT. These findings support RS-guided adjuvant CT decision-making in ILC and suggest that increasing CT use in patients with high RS may improve outcomes.

e20703 Background: mNSCLC is associated with poor survival, with 5-year rates < 15%. Concurrent IPF further worsens prognosis and increases the risk of hospitalization due to respiratory complications. However, factors associated with in-hospital mortality among patients with mNSCLC, especially those with IPF, remain poorly understood. We examined patient- and hospital-level predictors of in-hospital mortality among patients with mNSCLC with and without IPF. Methods: Retrospective cohort analyses were conducted using data from the National Inpatient Sample (NIS) from 2017 to 2021. Adult (≥18 years) inpatient hospitalizations with a diagnosis mNSCLC were identified using ICD-10 CM codes and stratified by the presence of a concurrent diagnosis of IPF. Descriptive analyses and standard tests of association were performed. Multivariable logistic regression models were used to examine the factors associated with in-hospital mortality among patients with mNSCLC, stratified by IPF status. Results: Of 1,564,000 hospitalizations with mNSCLC, 13.6% had a concurrent diagnosis of IPF. In-hospital mortality was higher among patients with IPF compared to those without IPF (58% vs 42%, p < 0.001). Among patients with IPF, being non-Hispanic Black (NHB) (Adjusted odds ratio [AOR] 1.80, 95% CI 1.20–2.60) or Hispanic (AOR 1.60, 95% CI 1.20–3.10) was associated with higher odds of in-hospital mortality compared to being non-Hispanic White (NHW). While age ≥65 years was associated with higher mortality odds relative to age < 65 (AOR 2.25, 95% CI 1.40–3.79), having private insurance was associated with lower odds compared to being on Medicare (AOR 0.43, 95% CI 0.35–0.78). Patients who received care at urban teaching hospitals had lower risk of mortality than those treated at rural hospitals (AOR 0.34, 95% CI 0.20–0.80). Notably, those with acute respiratory failure (ARF) were more likely to have in-hospital mortality than patients without ARF (AOR 1.86, 95% CI 1.24–2.85). However, among patients without IPF, NHB race was associated with lower odds of in-hospital mortality compared to NHW race (AOR 0.23, 95% CI 0.10–0.60). Across both cohorts, prolonged length of stay ( > 5 days), endotracheal intubation, and higher comorbidity burden were associated with increased mortality. Conclusions: Our findings demonstrate that hospitalized patients with mNSCLC and concurrent IPF experience high in-hospital mortality, with notable disparities identified by age, race and ethnicity, insurance status and hospital type. The differences in mortality outcomes by care setting suggest that health system-level factors may influence survival in this vulnerable population. Further investigation into the drivers of these disparities is needed to shape clinical interventions and inform policy decisions to improve outcomes.

BACKGROUND:Trastuzumab has greatly improved outcomes in patients with human epidermal growth factor receptor 2-positive breast cancer. To reduce costs and increase access, biosimilar products were approved after trials demonstrated short-term safety similar to that of reference trastuzumab. However, real-world data on cardiac safety are limited. OBJECTIVES:We evaluated the adoption of biosimilar trastuzumab and compared heart failure (HF) risk between users of reference and biosimilar trastuzumab. METHODS:Patients aged ≥18 years with breast cancer who received trastuzumab from 2018 to 2024 were identified in the IQVIA PharMetrics Plus Closed Health Plan Claims database. Patients who underwent surgery within the first year after cancer diagnosis were selected as a proxy for early-stage disease. Healthcare Common Procedure Coding System Level II codes were used to identify reference and biosimilar trastuzumab use, and International Classification of Diseases codes were used to identify HF diagnoses. Patients with an HF diagnosis before breast cancer surgery were excluded. Multivariable cause-specific Cox proportional hazards regression was used to examine the association of reference vs biosimilar trastuzumab use with HF risk. RESULTS:Among 5,135 patients identified, 43.9% received reference trastuzumab. Use of biosimilar trastuzumab increased from 0% in 2018 to 71.3% in 2024 (P < 0.001). The overall rate of HF was 5.9% (5.5% among reference trastuzumab users vs 6.3% among biosimilar trastuzumab users; P = 0.26). In multivariable analysis, there was no statistically significant difference in HF risk between patients treated with biosimilar trastuzumab and those treated with reference trastuzumab (adjusted HR [aHR]: 1.16; 95% CI: 0.92-1.46). Patients with a Charlson Comorbidity Index score ≥2 had a higher risk of HF than those with a score of 0 (aHR: 1.52; 95% CI: 1.11-2.08). Compared with patients aged 18 to 54 years, those aged 65 to 74 years (aHR: 1.61; 95% CI: 1.19-2.19) and ≥75 years (aHR: 1.95; 95% CI: 1.29-2.96) had a higher risk of HF. CONCLUSIONS:As biosimilar trastuzumab use continues to increase, our findings provide reassurance regarding its cardiac safety in the management of early-stage human epidermal growth factor receptor 2 breast cancer. Additional studies with longer follow-up are needed to confirm these findings and evaluate long-term cardiac outcomes.

"HSR25-169: Sociodemographic Disparities in Survival Outcomes Among Adolescent and Young Adult Patients With Lung Cancer: Insights From a SEER Database Analysis" published on 28 Mar 2025 by National Comprehensive Cancer Network.

To assess the long-term impact of the COVID-19 (C19) pandemic, we examined treatment patterns and delays in early-stage breast cancer (BC). Patients ≥ 18 years with clinical stage I–III BC diagnosed between 2019 and 2022 were identified in the National Cancer Database. Patients were categorized as pre-C19 (2019), early-C19 (2020), late-C19 (2021), and post-C19 (2022). Descriptive statistics assessed changes in early-stage BC treatment patterns and time-to-treatment initiation. Multivariable logistic regression was used to identify factors associated with treatment delays > 60 days. A decline in BC cases was observed during the pre- to early-C19 period, it was more pronounced among patients with stage I disease. While surgery as initial treatment decreased from pre- to post-C19, chemotherapy use increased. The early-C19 period was associated with lower odds of any treatment initiation delays > 60 days (adjusted odds ratio [aOR] = 0.87; 95

PURPOSE:Triple-negative breast cancer (TNBC) is a clinically aggressive subtype associated with poorer survival outcomes. We examined the patterns and trends in neoadjuvant chemotherapy (NACT) use, pathologic complete response (pCR), and overall survival (OS). Furthermore, we evaluated the association between pCR and OS in a large cohort of patients. METHODS:Patients aged 18 years and older with stage I-III TNBC diagnosed between 2010 and 2021 were identified in the National Cancer Database. Trends in NACT use, pCR, and OS were assessed using the Cochran-Armitage test for time trends. Multivariable logistic regression was used to evaluate the factors associated with NACT use and pCR. The impact of pCR on OS was examined using a multivariable Cox proportional hazards model with propensity score (PS) adjustment and matching. RESULTS:The rate of NACT receipt increased from 19.1% to 56.4% (P < .001) between 2010 and 2021. Among those who received NACT, pCR rates increased from 19.6% to 40.3% between 2010 and 2021 (P < .001). Notably, 3- and 5-year OS rates increased among those with residual disease, while OS remained stable among those who achieved a pCR. Compared with non-Hispanic White patients, Black patients were less likely to receive NACT (adjusted odds ratio [aOR], 0.88 [95% CI, 0.85 to 0.91]) or achieve pCR (aOR, 0.90 [95% CI, 0.85 to 0.95]). Among patients treated with NACT, having a pCR was associated with a lower risk of death (adjusted hazard ratio, [aHR], 0.26 [95% CI, 0.24 to 0.29]). CONCLUSION:The use of NACT among patients with TNBC has dramatically increased in the past decade. Although TNBC is more prevalent in Black patients, they were less likely to be treated with NACT and less likely to achieve a pCR. Further research is needed to elucidate the underlying disparities and advance drug development to enhance outcomes.

e16156 Background: Esophageal cancer has a poor prognosis with a 21.6% five-year relative survival and demographic variations have been reported with esophageal cancer. This study aims to identify trends in demographic-specific disparities in mortality among esophageal cancer admissions. Methods: This is a retrospective longitudinal trends study using the Nationwide Inpatient Sample (NIS) database (2008-2021). We identified hospitalizations with esophageal cancer using ICD-9 and ICD-10 codes. The study highlights disparities in mortality outcomes stratified by age, gender and race categories. Results: There were 527,128 hospitalizations of esophageal cancer patients between 2008 and 2021. Over the period, the mean age at hospitalization increased from 66 years to 67 years (P < 0.001). Majority of the admissions were elderly patients (≥65 years) and Caucasians (P < 0.001). Most patients had Medicare and were in large and urban teaching hospitals (P < 0.001). The overall inpatient mortality rate declined from 10.2% in 2008 to 8.7% in 2019, followed by an increase to 9.2% in 2021 (P trend = 0.018). While the young adult population (< 45 years) showed a trend towards rising mortality, it was not statistically significant (P trend = 0.17). Significant reductions in mortality were observed only in patients aged ≥65 years (P trend = 0.004). In the gender subgroup analysis, males experienced a notable decline in mortality (P trend = 0.014). Among racial groups, only Caucasians showed a significant improvement in mortality trends (P trend = 0.006) over the study period. Conclusions: Inpatient mortality among esophageal cancer admissions has improved overall; however, significant demographic-related disparities were identified. Coordinated efforts to reduce these disparities will be essential in attaining sustained improvements in outcomes for esophageal cancer. Disparities in outcomes of esophageal cancer hospitalizations: A trend study (2008-2021). Mortality rate, % 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 P- Trend value Overall 10.19 9.55 9.05 9.16 9.46 9.22 8.94 9.05 8.97 8.94 8.68 8.66 9.15 9.19 0.02 Young (<45 years) 7.37 5.87 5.98 11.43 8.76 6.1 10.16 5.34 7.22 9.62 10.14 8.96 9.68 8.1 0.17 Middle-aged (45- 64 years) 10.02 8.01 8.77 8.83 8.8 8.42 8.38 8.66 8.54 8.73 7.99 8.13 8.77 9.03 0.48 Elderly (>65 years) 10.48 10.89 9.46 9.28 10 9.97 9.28 9.51 9.34 9.05 9.06 8.99 9.36 9.32 0.004 Females 8.09 8.41 8.34 9.28 9.17 7.93 8.16 7.52 7.83 8.76 7.96 7.83 8.39 8.8 0.61 Males 10.79 9.89 9.26 9.13 9.54 9.59 9.14 9.47 9.27 9 8.87 8.91 9.35 9.29 0.01 Whites 10.56 9.62 9.26 9.15 9.23 8.92 8.73 8.93 8.86 8.72 8.28 8.54 9.18 9.21 0.006 Blacks 11.09 9.5 8.99 9.6 10.54 10.71 9.93 8.15 8.89 10.09 9.3 9.73 8.12 9.5 0.27 Hispanics 9.23 9.2 7.04 12.16 10.38 8.06 9.39 8.4 8.6 9.61 9.51 8.81 9.56 9.58 0.87

Introduction: It is unknown whether adjuvant chemotherapy increases the risk of falls in older breast cancer (BC) survivors. We evaluated the long-term impact of chemotherapy receipt on patient reported balance problems and falls among older BC survivors. Methods: Using the Texas Cancer Registry (TCR)-Medicare linked data, BC survivors aged 65 years and older at diagnosis, with local/regional disease, and diagnosed between 2012–2013 were identified. Self-administered questionnaires collected information on patient-reported outcomes (including treatment side effects), demographic and clinical variables between April 2018 and October 2019. Rao-Scott Chi-square tests were used to examine the association between chemotherapy receipt after initial cancer diagnosis and patient-reported falls in the 12 months prior to survey completion, balance problems and receipt of fall prevention interventions (such as assistive devices or physical therapy). Multivariable logistic regression models were used to evaluate the factors associated with patient-reported falls and balance problems. Results: Of the 1,493 BC survivors who completed the survey, majority were non-Hispanic white (83.8%), with a history of hormone receptor positive (HR+) BC (77.1%) and localized stage disease (76.6%). 28.3% received adjuvant chemotherapy, and 89% of those received a taxane. Patients who received chemotherapy were more likely to report severe numbness/tingling (12.3% vs 5.1% p <0.0001). However, falls in the past 12 months (32.0% vs 32.9%, p = 0.77), and balance problems (50.3% vs 49.8%, p = 0.86) were similar between chemotherapy vs non-chemotherapy treated groups. In adjusted analysis, taxane use was not significantly associated with falls (aOR: 1.15; 95% CI 0.87–1.52), but older age and higher comorbidity scores were. Patients treated with a taxane were more likely to report problems with balance and walking than those who did not receive chemotherapy (aOR: 1.36; 95% CI 1.04–1.78). Black (aOR: 1.64; 95% CI 1.00–2.69) and Hispanic (aOR: 1.69; 95% 1.14–2.50) BC survivors were more likely to receive an intervention from their health care provider to prevent falls or treat balance problems compared to White survivors. Conclusion: Chemotherapy use is associated with persistent numbness/tingling more than 5 years after treatment in older BC survivors and patients treated with taxanes are more likely to report balance and walking problems than survivors who did not receive chemotherapy. However, these persistent symptoms and chemotherapy use were not associated with a higher risk of falls among older breast cancer survivors. Citation Format: Inimfon Jackson, Kaiping Liao, Susan K. Peterson, Liang Li, Daria Zorzi, Holly M. Holmes, Mariana Chavez Mac Gregor, Sharon H. Giordano. Late effects of chemotherapy on patient-reported falls among older breast cancer survivors [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr PS15-07.

We examined neoadjuvant chemotherapy (NACT) use, pathological complete response (pCR) and the association with overall survival (OS) among patients with early-stage HER2-positive breast cancer (BC). Patients ≥18 years with stage I-III HER2-positive BC from 2010–2022 who had surgery and chemotherapy were identified. Of 195,023 patients treated with chemotherapy, 37.7% received NACT. NACT use increased from 18.6% in 2010 to 63.4% in 2022 (p < 0.001) and pCR rates rose from 21% to 47.6% (p < 0.001). Black patients were less likely to receive NACT (aOR = 0.96;95%CI 0.93–0.99) or achieve pCR (aOR = 0.86;95%CI 0.82–0.90) than White patients. pCR was associated with a reduction in the risk of death (aHR = 0.45;95%CI 0.42–0.48). 3-year OS increased from 91% in 2010 to 95% in 2019 for patients without a pCR (p < 0.001), and from 97% to 99% for patients with pCR (p = 0.002). Further research is needed to understand and address racial and ethnic disparities in treatment access and outcomes.

e16546 Background: Survival outcomes for patients with renal cell carcinoma (RCC) have improved in recent years. However, the risk of developing second primary malignancy (SPM) in RCC survivors remains underexplored. SPM pose significant challenges in cancer survivors, impacting long-term morbidity and mortality. Therefore, we aim to evaluate and discuss incidence and risk of SPM in RCC patients using a large population-based dataset. Methods: We analyzed the Surveillance, Epidemiology, and End Results (SEER) database, comparing secondary cancer rates among RCC cases diagnosed from 2000 to 2021. The histologic code for RCC in the SEER database is 8312/3. A second primary malignancy was defined as a malignancy developing at least six months after the initial RCC diagnosis. We used the SEER Multiple Primary Standardized Incidence Ratios (MP-SIR) session to obtain the p-value, observed/expected (O/E) ratios, absolute excess risk (AER) per 10,000. Results: 43,477 Renal Cell Carcinoma cases from 2000-2021 met our inclusion criteria and were included in our study. Of these cases, 5,931 (13.6%) developed second primary malignancies. The mean age of SPM was 70.45 years. The risk of developing SPM was significantly higher than the general population, with an O/E ratio of 1.27 (CI 1.23-1.30, AER 42.67, p < 0.05). Most common SPM included Brain (O/E ratio 1.33 CI 1.02-1.72, p < 0.05), Pancreas (O/E ratio 1.18 CI 1.01-1.36, p < 0.05), Liver (O/E ratio 1.67 CI 1.4-1.97, p < 0.05), Lung (O/E ratio 1.27 CI 1.18-1.36, p < 0.05), Prostate (O/E ratio 1.16 CI 1.09-1.23, p < 0.05, Thyroid (O/E ratio 2.7 CI 2.29-3.17, p < 0.05), Multiple Myeloma (O/E ratio 1.42 CI 1.17-1.71, p < 0.05), AML (O/E ratio 1.6 CI 1.23-2.03, p < 0.05), CML (O/E ratio 1.77 CI 1.2-2.51, p < 0.05). Conclusions: Compared to the general population, there is a statistically significant increased risk of secondary primary malignancies in RCC patients. These findings highlight the importance of ongoing surveillance, risk stratification, and tailored follow-up strategies to improve early detection and intervention for SPM in RCC survivors.

12058 Background: Greater than 60% of Head and neck cancer (HNC) patients have advanced cancer at the time of presentation. They have unique physical and psychological symptoms due to the cancer’s anatomical location and multimodal treatment-related toxicities. Early integration of palliative care (PC) in their management can improve health-related quality of life. We examined the trends and predictors of PC utilization among hospitalized advanced HNC patients in the US. Methods: A retrospective longitudinal study was conducted using the NIS database (2008-2021). Using joinpoint regression and multivariable logistic regression, trends and factors associated with PC receipt were assessed. Results: The overall prevalence of palliative care utilization among 326,265 hospitalizations with advanced HNC was 11%. Over the period, palliative care utilizations increased from 3,651 to 16,982 per 100,000 advanced HNC admissions (p-trend <0.001) with an average annual percentage increase of 9.7%. Females with metastatic HNC had higher odds (Adjusted odds ratio (AOR): 1.11; 95% CI: 1.04-1.19) of receiving palliative care compared to males. There was similar likelihood of utilizing palliative care across racial groups. Patients in teaching hospitals had 46% higher likelihood (AOR: 1.46; 95% CI: 1.33-1.60) of palliative care use in comparison to patients in non-teaching hospitals. Large hospitals had higher palliative care use compared to small hospitals (AOR: 1.12; 95% CI: 1.01-1.25). Admissions in the south and west had higher likelihood of palliative care use relative to those in the North-east region. Patients covered by Medicaid had higher odds of palliative care receipt compared to those covered by Medicare. Relative to patients who had a routine discharge home or with self-care, those discharged to facilities or with home health care were four-fold more likely (AOR: 4.35; 95% CI: 3.98-4.75) to receive palliative care. Those who died during hospitalization were also more likely to use palliative care (AOR: 21.4; 95% CI: 19.1-24.0). Non-elective admissions had higher likelihood of palliative care receipt relative to elective visits. Conclusions: Although palliative care utilization has improved over the years, it remains suboptimal. Tailored interventions addressing sociodemographic and hospital-level disparities will promote equitable access and meet the unique needs of this patient population. Predictors of PC use. Variables AOR (95% CI) Age “60 years and above“ vs “Less than 60” 1.0 (0.93-1.07) Gender Female vs Male 1.11 (1.04-1.19) Race Non-Hispanic Black vs Non-Hispanic White 1.02 (0.93-1.13) Hispanic vs Non-Hispanic White 1.10 (0.97-1.25) Non-Hispanic Others vs Non-Hispanic White 0.92 (0.82-1.03) Hospital region Midwest vs Northeast 1.09 (0.97-1.23) South vs Northeast 1.23 (1.10-1.37) West vs Northeast 1.37 (1.22-1.55) Hospital Teaching Status Teaching vs Nonteaching 1.46 (1.33-1.60)