Riaz, Zaryab Bin

Purpose Neutropenic diet (ND) has historically been recommended to reduce infectious complications in patients with cancer. Although its use has declined over the past decade, recent studies, particularly in patients undergoing hematopoietic stem-cell transplantation (HSCT), have renewed concern regarding the safety of a liberalized diet (LD). We performed a meta-analysis of studies comparing ND with LD in patients with cancer. Methods We searched MEDLINE, Embase, and Cochrane databases from inception through January 2026. Comparative studies evaluating ND versus LD in adults or children with cancer were included. Primary outcomes were major infections and bacteremia/fungemia; secondary outcomes were pneumonia, diarrhea, and mortality. Random-effects meta-analyses were performed to calculate pooled relative risks (RRs) with 95% CIs. Results Fifteen studies including 4,320 patients met criteria for analysis. ND was not associated with significant differences in major infections (RR, 1.02 [95% CI, 0.88 to 1.18]; P = .795), bacteremia/fungemia (RR, 0.97 [95% CI, 0.78 to 1.22]; P = .805), pneumonia (RR, 0.98 [95% CI, 0.59 to 1.63]; P = .933), diarrhea (RR, 1.12 [95% CI, 0.96 to 1.31]; P = .159), or mortality (RR, 0.94 [95% CI, 0.77 to 1.15]; P = .632). Sensitivity analyses restricted to randomized controlled trials (RCTs) were consistent. In hematologic malignancy/HSCT studies (9 studies; 1,769 patients), no differences were observed across outcomes. In RCTs limited to these patients (6 studies; 855 patients), ND was associated with lower bacteremia/fungemia risk (RR, 0.67 [95% CI, 0.47 to 0.95]; P = .023), with no differences in other outcomes. Conclusion ND was not associated with reductions in major infections, pneumonia, diarrhea, or mortality compared with LD. These findings do not support routine implementation of ND for patients with short-term neutropenia or lower-risk cancer populations although selected high-risk patients, particularly those undergoing HSCT or experiencing prolonged neutropenia related to hematologic malignancies, may still warrant cautious dietary practices.

e18574 Background: ND has historically been recommended to reduce infectious complications in cancer patients (pts). While the adoption of ND has declined over the last decade, recent studies - particularly in pts undergoing hematopoietic stem cell transplantation (HSCT) - have raised uncertainty regarding the safety of LD. Herein, we performed a meta-analysis of studies directly comparing ND with LD in pts with cancer. Methods: We conducted a systematic search of MEDLINE, Embase, and Cochrane databases from inception through January 2026. Comparative retrospective and prospective studies were included if they were comparing ND with LD in adults or children with cancer. Primary outcomes were major infections and bacteremia/fungemia. Secondary outcomes were pneumonia, diarrhea, and all-cause mortality. Random-effects meta-analyses were performed to calculate pooled risk ratios (RR) with 95% confidence intervals (CI). The review followed PRISMA 2020 guidelines. Results: Fifteen studies enrolling 4,320 patients were included in the primary analysis. Six studies enrolled only adult patients, three were restricted to pediatric populations, and six included mixed adult and pediatric cohorts. Across these studies, ND was not associated with a significant reduction in major infections (RR 1.02, 95% CI 0.88–1.18; p=0.795), bacteremia/fungemia (RR 0.97, 95% CI 0.78–1.22; p=0.805), pneumonia (RR 0.98, 95% CI 0.59–1.63; p=0.933), diarrhea (RR 1.12, 95% CI 0.96–1.31; p=0.159), or all-cause mortality (RR 0.94, 95% CI 0.77–1.15; p=0.632). Sensitivity analyses restricted to RCTs showed consistent results. Subgroup analysis of hematological/HSCT studies (9 studies; 1,769 pts) also showed no differences across outcome. Analysis restricted to RCTs in hematologic/HSCT pts (6 studies; 855 pts) showed no differences in major infections, pneumonia, diarrhea, or mortality; however, ND was associated with a lower risk of bacteremia/fungemia (RR 0.67, 95% CI 0.47–0.95; p=0.023). Heterogeneity across studies was low to moderate. Conclusions: ND was not associated with reductions in major infections, pneumonia, diarrhea, or mortality compared with LD. A reduction in bacteremia/fungemia was observed in RCTs of hematologic malignancy and HSCT pts. Overall, these findings suggest that routine ND implementation is unnecessary for most cancer pts, although cautious dietary practices may remain reasonable in selected high-risk hematologic malignancy/HSCT populations.

129 Background: Androgen receptor pathway inhibitors (ARPIs) improve metastasis-free and overall survival in men with non-metastatic hormone-resistant prostate cancer (nmHRPC). Apalutamide and darolutamide were approved by the Federal Drug Administration in 2018 and 2019, respectively, based on pivotal clinical trials showing similar efficacy. However, no head-to-head comparisons exist in real-world settings. We compared prescription patterns and survival outcomes between apalutamide and darolutamide in men with nmHRPC using the Surveillance, Epidemiology and End Results (SEER)-Medicare data. Methods: We identified men aged ≥66 years with localized or locoregional prostate cancer between 2000 and 2021 using the SEER-Medicare linked database. Eligible patients initiated apalutamide or darolutamide between January 2019 and December 2021, defined by Medicare Part D claims. The index date was the first prescription of either agent. Men with distant metastases, prior malignancies and age ≤65 were excluded. Baseline demographics and clinical characteristics were compared using chi-square and Wilcoxon rank-sum tests. Survival was assessed using Kaplan-Meier analysis with log-rank tests. Cox proportional hazards regression was used to estimate adjusted hazard ratios (HRs) for mortality. Results: Among 582 men with nmHRPC, 435 (74.7%) received apalutamide and 147 (25.3%) received darolutamide. The mean age at diagnosis was 73.8 vs 74.1 years (p=0.95). Most patients were White (84.6% vs 81.0%, p=0.21) and resided in metropolitan areas (85.0% vs 88.4%, p=0.39). Darolutamide use was more frequent in the Northeast (42.9% vs 24.6%, p<0.001), while apalutamide was more common in the South (28.7% vs 15.6%, p<0.001). Patients receiving darolutamide had higher-grade tumors (68.0% grade III vs 51.3%, p=0.002) and a longer median time from diagnosis to prescription (93 vs 64 months, p<0.001). Kaplan-Meier curves and adjusted Cox models showed no significant difference in overall survival (HR 1.00; 95% CI 0.51–1.98; p=1.00). Age was independently associated with mortality (HR 1.05 per year; 95% CI 1.00–1.10; p=0.04). Conclusions: Apalutamide and darolutamide demonstrated comparable real-world survival outcomes in nmHRPC. Geographic and clinical factors influenced prescribing patterns, but survival did not differ between agents. Treatment choice may therefore be guided by patient comorbidities, tolerability, and clinician preference. Variable Comparison HR (95% CI) P-Value Treatment Darolutamide vs Apalutamide 1.00 (0.51,1.98) 1.00 Age at Diagnosis 1.05 (1.00, 1.10) 0.04* Race White vs Non-White 0.71 (0.28, 1.80) 0.47 Marital Status Married vs Unmarried 1.29 (0.60, 2.75) 0.51 Geographic Region -Midwest vs West 1.18 (0.34, 4.15) 0.79 -Northeast vs West 1.92 (0.92, 3.88) 0.07 -South vs West 1.01 (0.43, 2.36) 0.99

483 Background: Sarcomatoid dedifferentiation (sRCC) in metastatic clear-cell renal cell carcinoma (mccRCC) confers aggressive disease and poor prognosis. We maintain a living meta-analysis of first-line immune checkpoint inhibitor (ICI)–based combinations in mccRCC (Riaz et al., Eur Urol Oncol 2021), which demonstrated improved survival with ICI-based regimens over sunitinib. Here, we present an updated synthesis focused on the comparative efficacy of ICI combinations in the sarcomatoid subset. Methods: A systematic search of MEDLINE, EMBASE, and CENTRAL through October 2025 was performed as part of our living meta-analysis of first-line mccRCC therapy. Eligible phase III RCTs compared ICI combinations (IO/IO or IO/TKI) versus sunitinib, including CheckMate 214, CheckMate 9ER, KEYNOTE-426, CLEAR/KEYNOTE-581, JAVELIN Renal 101, and IMmotion151. Extracted outcomes included overall (OS) and progression-free survival (PFS), and objective (ORR), complete (CR), and partial (PR) response rates. Random-effects meta-analyses generated pooled hazard ratios (HRs) for time-to-event outcomes and risk ratios (RRs) for response rates with 95% confidence intervals. Subgroup interaction analyses compared sarcomatoid versus non-sarcomatoid subgroups, with p < 0.1 considered significant. Results: Six phase III RCTs (n = 5,121; 624 sarcomatoid) were included. Across all ICI-based combinations, ICI therapy improved outcomes versus sunitinib in both sarcomatoid and non-sarcomatoid disease. In the pooled analysis, the OS interaction favored sRCC meeting the prespecified significance threshold for subgroup analyses (HR 0.53 vs 0.68; p-interaction = 0.06 < 0.10), while no significant interaction was seen for PFS. Response outcomes showed the strongest differential benefit, particularly with IO/TKI regimens. IO/IO results were directionally consistent but limited by smaller non-sarcomatoid samples. Conclusions: ICI-based combinations significantly improve survival and response outcomes versus sunitinib in mccRCC. Using a prespecified α = 0.10 for interaction testing, the pooled analysis showed a significant OS interaction and higher response rates in sRCC, indicating enhanced ICI sensitivity. These updated meta-analysis data support ICI regimens as the preferred first-line therapy for mRCC with sarcomatoid de-differentiation. Endpoint Regimen Subgroup (S = sarcomatoid; NS = non-sarcomatoid) Effect (95% CI) p-interaction PFS IO/IO S 0.51 (0.40–0.65) – IO/TKI S vs NS 0.48 (0.36–0.64) vs 0.46 (0.39–0.52) 0.81 OS IO/IO S 0.54 (0.07–4.42) – IO/TKI S vs NS 0.51 (0.17–1.48) vs 0.68 (0.30–1.58) 0.24 ORR IO/IO S 2.93 (0.49–17.37) – IO/TKI S vs NS 2.43 (1.84–3.21) vs 1.95 (1.67–2.28) 0.03 CR IO/IO S 3.81 (0.82–17.71) – IO/TKI S vs NS 5.93 (4.73–7.42) vs 2.85 (0.10–83.73) 0.007 PR IO/IO S 3.48 (1.70–7.11) – IO/TKI S vs NS 2.10 (1.78–2.47) vs 1.75 (1.18–2.61) <0.001

e17155 Background: Localized PCa is classified into six NCCN risk categories, each with specific treatment recommendations. However, treatment concordance across these categories and its variation by race in clinical practice remain unexplored. Therefore, we aim to describe patterns of guideline-concordant treatment receipt for localized PCa across risk groups and race. Methods: Surveillance, Epidemiology, and End Results (SEER) database (2018–2020) was queried to identify patients with localized PCa from 17 registries. Data regarding clinical T stage, Gleason patterns, PSA level, biopsy cores and initial treatment received (radiation, radical prostatectomy, systemic therapy) was obtained. Each patient was then stratified into one of six NCCN-based risk categories using a rule-based algorithm. Using the stratified risk category of each patient, treatment recommendations were obtained from the NCCN guidelines. Concordance was assessed by comparing the received treatment and guideline-recommended treatment. A focused bi-variate logistic regression analysis was performed adjusting for risk groups, and race. Odds ratio (OR) with 95% confidence intervals (CI) were computed to quantify the magnitude of guideline-discordant treatment receipt. Results: This analysis included 69,584 patients with localized PCa (White: 53,875 [77.4%]; Black: 11,265 [16.2%]; Asian/Pacific Islander: 4,133 [5.9%]; American Indian/Alaska Native: 311 0.5%]). In terms of risk groups, patients in higher risk categories had increased odds of discordance compared to the lower risk groups (Table). In terms of race, Black men had significantly higher odds of receiving guideline-discordant therapy (OR:1.67, 95% CI:1.58–1.76), while no statistically significant difference was observed with American Indian/Alaska Native men (OR:1.21, 95% CI: 0.92–1.61) and Asian/Pacific Islander men (OR:1.05, 95% CI:0.97–1.14) compared to White men. Conclusions: Population level data, based on limited sample size in some groups, suggests that treatment concordance with NCCN guidelines varies by risk group and race in localized PCa. Black patients, and those with higher risk groups were more likely to receive guideline-discordant therapy. These findings highlight the need for strategies and prospective studies at individual patient level to evaluate and enhance guideline adherence to promote personalized care for these patients. Variable Discordant Treatment (%) OR (95% CI) White 22168 (41.1) REF Black 5653 (47.5) 1.67 (1.58-1.76) * Asian/Pacific Islander 1822 (44.1) 1.05 (0.97-1.14) American Indian/Alaska Native 191 (61.4) 1.22 (0.92- 1.61) Very Low Risk 770 (9) REF Low Risk 146 (2) 0.16 (0.13-0.19) * Favorable Risk 35 (0.4) 0.03 (0.02-0.04) * Unfavorable Risk 15125 (83.2) 36.30 (33.72-39.25) * High/Very High Risk 13441 (50) 7.32 (6.83-7.86) * * p <0.05.

134 Background: Prostate cancer patients with visceral metastases at diagnosis are often treated using one-size-fits-all approach. For example, CHAARTED criteria treats any visceral metastasis as high volume. Therefore, we aimed to assess overall survival (OS) by site of visceral involvement in patients with metastatic PCa. Methods: Surveillance, Epidemiology, and End Results (SEER) database (2010-2021) was queried to obtain case listing data on metastatic PCa patients from 17 registries. The patients were categorized into three groups based on visceral metastasis at diagnosis: lung metastasis, liver metastasis, and others. Kaplan-Meier survival analysis was performed to estimate median OS with 95% confidence interval (CI). Log-rank test was conducted to assess if survival was significantly different among the groups. Cox proportional hazard regression analysis was performed to assess the magnitude of difference among the groups. P-value <0.05 established statistical significance. Results: This analysis included 21,007 metastatic PCa patients (lung: n=319; liver: n=123; brain: 107; bone: 20538). Metastatic PCa population with lung metastasis exhibited a median OS of 60 months (95% CI: 48-72) compared to 24 months (95% CI: 12-36) in population with liver metastases and to 36 months (95% CI: 36-36) in population with other metastases. The difference in OS among the groups was statistically significant (p < 0.001). Compared to population with lung metastasis, those with liver (HR: 1.91; 95% CI: 1.41-2.57) but not those with other metastases (1.16; 0.97-1.39) had significantly worse OS adjusting for Gleason score, PSA and race (Table). Conclusions: In metastatic PCa, patients with lung-only metastasis have significantly better overall survival and should be considered differently in prognostication to liver metastases. Consideration of site of visceral metastasis is critical for treatment intensification decisions. Limitations of this analysis include lack of accounting for confounding relationships at individual patient level. Variable Hazard Ratio (95% CI) Metastases (Lung) REFERENCE Metastases (Liver) 1.91 (1.41-2.57) Metastases (Other) 1.16 (0.97-1.39) Gleason score≥8 REFERENCE Gleason score <8 0.68 (0.64 -0.72) PSA - ng/dL 1.01 (1.00 – 1.01) Race (White) REFERENCE Race (Black) 0.99 (0.94 – 1.05) Race (Asian or Pacific Islander) 0.70 (0.64 – 0.76)

132 Background: Distant metastasis at the time of prostate cancer (PCa) diagnosis is associated with increased morbidity and mortality. This study aimed to assess the impact of sociodemographic characteristics on distant metastasis at the time of PCa diagnosis. Methods: The Surveillance Epidemiology and End Results (SEER) database (2000-2021), including PCa patients from 17 registries, was queried. Patients with late-stage diagnosis (LSD) were defined as those who were initially diagnosed with stage IV disease, indicating distant metastasis. Sociodemographic predictors included race, ethnicity, age, marital status, residential status, and median household income. Multicollinearity was assessed using variance inflation factors (VIF). Univariable logistic regression was performed to identify significant predictors of LSD, which were further analyzed in multivariable logistic regression using a maximum likelihood estimation approach. Odds ratios with 95% confidence intervals (CI) were computed with a p-value of <0.05 indicating a statistically significant association. Results: Of the 1,089,736 PCa patients diagnosed, 64,983 (6%) had an LSD. The majority were white (80%), non-Hispanic/Latino (HL) (91%), aged ≥65 years (60%), married (75%), residents in metropolitan areas (88%), and had an annual house income of ≥$70,000 (70%). Multivariable logistic regression identified Black (OR: 1.24; 95%CI: 1.22-1.27), Asian or Pacific Islander (1.35; 1.30-1.40), and American Indian/Alaska Native (1.70; 1.53-1.89) to have higher odds of LSD compared to White patients (Table). In addition, HL ethnicity compared to non-HL (OR: 1.45; 95% CI: 1.42-1.49), age ≥65 compared to <65 (1.68; 1.65-1.71), unmarried status compared to married (1.88; 1.85-1.91), residency in non-metropolitan areas compared to metropolitan (1.10; 1.07-1.12), and household income <$70,000 compared to ≥$70,000 (1.03; 1.01-1.05) had a significant association with LSD. Conclusions: Older, non-White (Black, Asian/Pacific Islander, American Indian/Alaska Native), Hispanic/Latino, unmarried men, residents of non-metropolitan areas, or those with lower annual household incomes have higher odds of late-stage diagnosis. Interventions targeting early detection in these at-risk groups may improve prostate cancer outcomes in the US. Variable Odds Ratio (95% CI) p-value Race (Black vs White) 1.24 (1.22-1.27) <0.01 Race (Asian or Pacific Islander vs White) 1.35 (1.31-1.40) <0.01 Race (American Indian/Alaska Native vs White) 1.70 (1.53-1.89) <0.01 Ethnicity (Hispanic/Latino vs non-/Hispanic/Latino) 1.45 (1.42-1.49) <0.01 Age (≥65 vs <65) 1.68 (1.65-1.71) <0.01 Marital status (unmarried vs married) 1.88 (1.85-1.91) <0.01 Residence status (non-metropolitan vs metropolitan) 1.10 (1.07-1.12) <0.01 Household income (<$70,000 vs ≥$70,000) 1.03 (1.01-1.05) <0.01

Introduction Prognostication in myelofibrosis (MF) currently relies on manual assessment of clinical, pathological, and laboratory variables, which is inefficient and error-prone. The potential of large language models (LLMs) and rule-based programming to automate data extraction and prognostication in these patients remains unexplored and merits investigation. Methods Patients with MF were identified from a retrospective chart review. Data regarding clinical (age, constitutional symptoms, transfusion requirements), laboratory (hemoglobin, circulating white blood cell, platelet, and blast counts), and pathological (grade of bone marrow fibrosis, chromosomal analyses, cytogenetics) features was extracted from the latest free-text clinical notes and pathology reports using the generative pretrained transformer-4 (GPT-4) model in a zero-shot setting with the prompting parameters set to generate deterministic responses. The patients were randomly sampled into development (15%) and test (85%) sets, with the documents of patients in the development set used for iterative prompt engineering. The finalized prompts were used for data extraction in the test set. Rule-based programming was used for post-processing of the extracted data and ascertaining prognosis via Dynamic International Prognostic Scoring System (DIPSS), DIPSS-plus (DIPSS+), and Mutation-enhanced International Prognostic Scoring System-70 (MIPSS-70). Automatically extracted data and prognostic categories were compared with the manually generated human annotations. Mean accuracy, precision, and recall with 95% confidence intervals (CI) were computed. Detailed error and sensitivity analyses were conducted to assess performance. Results The study included 100 patients (development: 15; test: 85) with 100 clinical notes (development: 15; test: 85) and 90 pathology reports (development: 13; test: 77). The mean age of these patients was 70 (SD: 10.6); 55 (55%) patients were men, and 93 (93%) patients were White. In the development set, the mean accuracy, precision, and recall for data extraction from clinical notes were 94% (95% CI: 90-98%), 92% (84-99%), and 99% (97-100%). For data extraction from pathology reports, the mean accuracy, precision, and recall were 96% (93-100%), 98% (92-100%), and 83% (63-100%). For prognostication, the mean accuracy, precision, and recall were 87% (79-94%), 80% (73-87%), and 100% using DIPSS (accuracy: 80%; precision: 73%; recall: 100%), DIPSS+ (accuracy: 93%; precision: 83%; recall: 100%) and MIPSS-70 (accuracy: 87%, precision: 83%; recall: 100%). In the test set, the mean accuracy, precision, and recall for data extraction from clinical notes were 96% (95% CI: 93-98%), 91% (87-96%), and 98% (97-100%). For data extraction from pathology reports, the mean accuracy, precision, and recall were 95% (92-98%), 93% (87-99%), and 90% (80-100%). For prognostication the mean accuracy, precision, and recall were 95% (94-96%), 89% (88-90%) and 99% (96-100%) using DIPSS (accuracy: 94%; precision: 89%; recall: 100%), DIPSS+ (accuracy: 95%; precision: 88%; recall: 95%) and MIPSS-70 (accuracy: 94%, precision: 90%; recall: 100%). Error analyses identified incorrect extractions by GPT-4 were related to the circulating blasts and constitutional symptoms variables from the clinical notes. Sensitivity analyses excluding the associated variables improved overall accuracy from 94% to 97% and 96% to 97% in the development and test sets, respectively. Similarly, incorrect extractions from the pathology reports were related to the CALR gene mutation variables. Sensitivity analyses excluding the associated variables improved the overall accuracy from 96% to 98% and 95% to 97% in the development and test sets, respectively. Conclusion LLMs and rule-based programming can accurately extract data from the electronic health records and prognosticate MF patients via DIPSS, DIPSS+, and MIPSS-70. The automated approach could significantly streamline clinical and research workflows, providing an efficient and less resource-intensive alternative to manual prognostication.

4591 Background: EV-302 and CheckMate 901 demonstrated significant survival benefit with enfortumab vedotin-pembrolizumab (EVPembro) and gemcitabine-cisplatin-nivolumab (GemCisNivo) as 1L therapy, respectively, in patients (pts) with la/mUC. However, whether these treatments are cost-effective or not remains unclear. Methods: A three-state Markov model (progression-free, progression and death) was developed. State utilities were derived from published literature. State transition probabilities were informed from point-probabilities and hazard ratios for OS and PFS obtained from the latest follow-up of eligible trials. Average sales price (2024 USD) for individual treatments (excluding ancillary charges) were obtained from the center of medicare and medicaid services (US payer’s perspective). Treatment strategies were modeled in accordance with the dose/schedule reported in the eligible trials. Pts who received GemCis or Gem-carboplatin (GemCarbo) and did not progress were modeled to receive Avelumab maintenance. Half-cycle corrected costs and utilities were accrued over a 10-year lifetime horizon and were discounted at 3%. Monte Carlo simulation was used to estimate quality adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs). A willingness-to-pay threshold (WTP) of 100,000$ per QALY was used. Results: In cisplatin-eligible pts, GemCisNivo demonstrated a 0.8 QALY gain over GemCis at an ICER of 21,127 ($/QALY). GemCisNivo was also associated with an incremental net monetary benefit (INMB) of 63,099$ relative to GemCis. EVPembro demonstrated a 2.4 QALY gain over GemCis at an ICER of 915,283 and a 1.6 QALY gain over GemCisNivo at an ICER of 1,406,308. In cisplatin-ineligible pts, EVPembro demonstrated a 2.4 QALY gain over Gem-carboplatin (GemCarbo) at an ICER of 934,761. Price threshold analyses demonstrated that EVPembro is likely to be cost-effective at a cost of 12,344$ for cisplatin-eligible and 13,374$ per cycle for cisplatin-ineligible pts (original cost: 35,665.60$ per cycle). Sensitivity analysis using a total of 12 cycles for EVPembro showed cost-effectiveness at an ICER of 69,594 relative to GemCisNivo in cisplatin-eligible pts, and at an ICER of 53,099 relative to GemCarbo in cisplatin-ineligible pts. Conclusions: In terms of US payer’s perspective, GemCisNivo is most likely to be cost-effective in cisplatin-eligible pts at the WTP of 100,000 $/QALY. Limiting the number of cycles for EVPembro may render it as a cost-effective 1L treatment in la/mUC pts regardless of cisplatin-eligibility status.

229 Background: We aim to investigate non-cancer cause of death in adults within 2 years after initial diagnosis of mGU cancers including bladder cancer (BC), kidney cancer (KC), and prostate cancer (PC). Methods: Surveillance, Epidemiology, and End Results (SEER) database (2004-2020) was searched to obtain data on death caused by cardiovascular diseases (CVD), kidney diseases (KD), respiratory diseases (RD), liver diseases (LD), diabetes mellitus (DM), and sepsis in adults (>20y of age) diagnosed with mGU cancers. Standardized mortality ratios (SMRs) with 95% confidence interval (CI) were calculated within 2y of initial diagnosis. SMR was defined as the observed deaths from each category divided by the expected number of deaths in the age-matched US population for the same period. SMR >1 indicated increased while <1 indicated decreased mortality. Stratification factors included age (<50y, 50-70y, >70y), race (White, Black, Asian/Pacific Islander), ethnicity (Hispanic, non-Hispanic), chemotherapy, and radiotherapy. Results: This study including 77,246 mGU cancer patients showed that the greatest risk of early death was observed to be caused by sepsis (SMR: 4.21, 95% CI: 3.64-4.84) followed by CVD (1.70, 1.62-1.80), KD (1.58, 1.31-1.90), LD (1.58, 1.16-2.09), DM (1.56, 1.32-1.82), and RD (1.38, 1.22-1.56). Patients aged <50y observed the highest risk of mortality caused by sepsis (61.76, 30.83-110.5) followed by KD (28.06, 9.11-65.48) and CVD (5.63, 3.60- 8.84). However, patients aged 50-70y were more likely to die by RD (2.47, 1.94-3.09) and LD (2.01, 1.38-2.82). The results were consistent for Black patients; sepsis (6.59, 5.04-8.46) followed by RD (2.01, 1.41-2.78) and KD (1.64, 1.04-2.46). Asian/Pacific Islanders were more likely to die from CVD (2.52, 2.13- 3.00) and DM (2.21, 1.21-3.71). Hispanics were more likely to die from LD (3.11, 1.66-5.32) and non-Hispanics from sepsis (4.28, 3.68-4.96). This risk of death due to sepsis was increased with chemotherapy (7.06, 5.22-9.33) and radiotherapy (4.92, 3.58-6.61). Detailed results are available in Table. Conclusions: Sepsis remained the leading cause of early non-cancer-deaths in mGU cancers consistently across all subgroups. Younger adults were more likely to die from CVD and KD, Black patients from RD, and Hispanics from LD. [Table: see text]