Ijaz, Hafsah

6559 Background: Recent findings that Black and Hispanic patients were significantly underrepresented in industry-sponsored prostate cancer trials warrant a detailed investigation across cancer types to assess the association between funding source and enrollment disparities. Methods: Phase II/III clinical trials in prostate, breast, colorectal, and lung cancers reporting age, gender, race/ethnicity, and reporting NIH or industry as the funding source were considered eligible for inclusion. For age, and gender analysis, all trials were considered eligible. For race/ethnicity analysis, trials recruiting from the United States (US) were considered eligible. Enrollment-incidence ratios (EIR) comparing trial proportion from age/gender or racial/ethnic subgroups against global cancer incidence in the corresponding group (from Global Burden of Disease) or US-population-based incidence in the corresponding racial/ethnic subgroup (from SEER 22), were computed. Trial-level EIRs were pooled using a random-effects model and subsequently stratified by funding source. A univariate meta-regression was conducted to assess the temporal changes in EIR by each funding category. Results: Of 42,390 studies initially identified, 2234 trials (1989-2021) met the eligibility criteria. Regarding age, 361 (16%) trials reported age categories by 65 years threshold. Of 698 trials recruiting from the US, 498 (71%) reported race, and 198 (28%) reported ethnicity. Regarding representation, older adults were under-represented (EIR: 0.66; 95% CI: 0.62-0.70) in the industry but not in NIH-sponsored clinical trials (0.79; 0.62-1.00). Regarding gender, no significant disparity was observed regarding the enrollment of men and women in colorectal and lung cancer clinical trials. In terms of race, there was a greater under-representation of Black patients in industry sponsored trials (0.29; 0.26-0.32) as compared to NIH-sponsored clinical trials (0.65; 0.57-0.74) [Pint <0.01]. Asian patients were significantly overrepresented in industry sponsored trials (3.17; 2.69-3.74) but not in NIH sponsored clinical trials (1.43; 0.85-2.41) [Pint <0.01]. Hispanic patients were significantly under-represented in both, industry (0.27; 0.22-0.34) and NIH-sponsored clinical trials (0.35; 0.22-0.55) [Pint 0.32]. Secondary analyses including trials recruiting exclusively from the US, and analyses by specific cancer types showed consistent results. Recruitment of older adults, men, and Black patients is decreasing over time. Conclusions: There is a consistent under-representation of older adults in industry-sponsored, and of Black and Hispanic patients in both industry-sponsored and NIH-sponsored clinical trials. The under-representation of Black patients is likely to be greater in industry-sponsored trials, which has worsened over the last three decades.

6557 Background: Trials that inadequately include underrepresented minority (URM) populations widen inequities in cancer care. We assessed reporting patterns, representation, and trends of URM representation in breast cancer (BC) trials. Methods: We analyzed all phase 2/3 trials for age disparity and trials recruiting from the US for racial/ethnic disparity amongst BC RCTs (1990-2021). Enrollment-incidence ratios (EIR), which compare trial proportions (TP) from age subgroups against global estimates of incidence in the corresponding age group (from Global Burden of Disease) and racial/ethnic subgroups against US-population-based incidence in the corresponding racial/ethnic group (from SEER 22), were calculated. Individual-trial EIRs were pooled using random-effects meta-analyses. EIRs of <0.80 indicated meaningful underrepresentation, while EIRs >1.20 indicated meaningful overrepresentation. Meta-regression was used to explore associations between key trial characteristics and EIR, and trends in EIR over the last three decades. Results: Of 842 global trials with 490,657 participants, 232 (27.6%) reported the number of participants in specific age strata and 144 (17.1%) reported outcomes by age. Only 60 trials recruited exclusively from the US. Of these, 41 (68.3%) reported race and 24 (40.0%) reported ethnicity, and 2 (3.3%) analyzed outcomes by race. Older adults aged ≥65 years (TP: 24.3%; EIR: 0.53 [95% CI: 0.47-0.60]) and Hispanic women (TP: 5.3%; 0.54; 0.40-0.75) were underrepresented across global trials and US-only trials respectively. Black women were significantly underrepresented in trials that led to FDA approval (0.38; 0.25-0.58) but not in US-only trials. Stratified analysis by BC subtype (with subtype-specific population incidence) showed underrepresentation of Black women in US-only trials for HER2+ BC (0.66; 0.47-0.93), Hispanic women in ER+ BC (0.42; 0.20-0.90), Asians in triple-negative BC (0.24; 0.11-0.53), and older women in HER2+ BC (0.35; 0.31-0.40) and triple-negative BC (0.36; 0.29-0.45). From 1990-2021, the representation of older women declined significantly (meta-regression coefficient for EIR: -0.4 per 10 years), while Black and Hispanic representation showed no significant change. Black (p = 0.02) and Hispanic representation (p = 0.05) worsened significantly in larger trials. Conclusions: Published reports of BC trials do not consistently report the inclusion of URM. Older and Hispanic women were consistently underrepresented, whereas Black women were underrepresented in large, practice-changing trials. [Table: see text]

692 Background: Sarcomatoid mRCC exhibits poor prognosis and limited response to vascular endothelial growth factor pathway inhibition. Therefore, we assessed the efficacy of ICI combination therapy in this patient population using data from contemporary trials. Methods: MEDLINE and EMBASE were searched to identify phase III randomized controlled trials (RCTs) comparing the efficacy of ICI combinations with sunitinib monotherapy in patients with sarcomatoid mRCC. Patient important outcomes of interest included overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and complete response (CR). Precomputed hazard ratios (HR) with 95% confidence intervals (CI) for survival outcomes and binary outcome data for response rates (expressed as relative risk [RR] were meta-analyzed using a DerSimonian-Lairds random-effects method. Mixed treatment comparisons among different ICI combinations were made using a network-meta-analysis within the Bayesian framework. The surface under the cumulative ranking curves (SUCRA) were computed to assess the relative treatment rankings. Results: Six RCTs with a total of 618 patients were considered eligible for inclusion. ICI combination therapy was significantly associated with improved OS (HR: 0.56; 95% CI: 0.43-0.72) and PFS (HR: 0.50; 0.40-0.62), increased ORR (RR: 2.42; 1.92-3.06), and CR (RR: 4.23; 2.00-8.93) when compared to sunitinib in patients with sarcomatoid mRCC (Table). The results were consistent with Hartung-Knapp adjustment. Mixed treatment comparisons using current data revealed no statistically significant differences among different ICI combinations. However, the combination of nivolumab-ipilimumab was consistently ranked higher (rank 2 for OS, ORR, and CR) and may potentially be more efficacious than other counterparts. Conclusions: Current evidence suggests improved survival, delayed disease progression and increased response rates with the use of ICI combination therapy in patients with sarcomatoid mRCC. [Table: see text]

531 Background: Neoadjuvant cisplatin-based chemotherapy (NAC) is established in the management of MIBC. Pathologic complete response (pCR, ypT0N0) and downstaging (<ypT2N0) are associated with long term survival in patients with MIBC. Several trials have evaluated neoadjuvant immunotherapy (NAI) and chemoimmunotherapy (NACI) for MIBC. We aimed to conduct a meta-analysis of available trials to compare the incidence of pathological response with NAC, NAI and NACI in MIBC patients undergoing radical cystectomy. Methods: Phase II/III clinical trials assessing neoadjuvant systemic therapies (NAC, NAI, or NACI) in patients with MIBC undergoing radical cystectomy were identified through a systematic search of MEDLINE and EMBASE. Outcomes of interest included pCR and pathological downstaging. A DerSimonian and Laird random-effect meta-analysis was conducted to estimate pooled incidence of events using the Freeman-Tukey transformation. Clopper-Pearson method was used to estimate the associated 95% confidence intervals (CI). Results: Of the 5357 records initially identified, 28 trials with a total of 2138 patients were considered eligible for inclusion. Neoadjuvant chemotherapy was assessed in 15 trials (1535 patients), NAI in 5 (288 patients), and NACI in 8 (315 patients). The pooled incidence of patients experiencing a pCR was 30.91% (95% CI: 26.54%-35.45%) with NAC, 30.92% (23.22%-39.14%) with NAI, and 42.25% (36.6%-48.0%) with NACI. The difference in pCR among these therapies was statistically significant (p <0.05). Similarly, the pooled incidence of achieving pathological downstaging was 40.91% (34.26%-47.72%) with NAC, 38.84% (26.73%-51.64%) with NAI, and 62.88% (57.22%-68.39%) with NACI. Consistently, there was statistically significant effect modification by the choice of neoadjuvant systemic therapy (p <0.01). The results were consistent across different clinically important subgroups (Table). Conclusions: NACI may achieve better pCR and pathological downstaging than NAC and NAI alone in MIBC patients which may potentially be associated with long-term survival. Definitive data from phase III trials are pending. [Table: see text]

40 Background: Previously we have reported enrollment disparities in PCa clinical trials. Funding source can influence minority representation in clinical trials. Hence, we aimed to evaluate the impact of source of funding on enrollment disparities in PCa clinical trials. Methods: MEDLINE and EMBASE were searched to identify phase II/III PCa trials. All relevant trials reporting age by 65 years were considered eligible for inclusion. Trials recruiting from the United States (US) were considered eligible for analysis by race and ethnicity. The trial proportions of age, or racial/ethnic subgroup category and the global incidence in the corresponding age subgroup (from the global burden of disease database), or the US-population-based incidence in the corresponding racial/ethnic subgroup (from SEER 21 database) were used to compute enrollment incidence ratio (EIR) at each trial. EIRs with corresponding 95% confidence intervals (CI) were then meta-analyzed using a random-effects model and stratified by sources of funding (industry, US-government, and others [academic and non-US govt]). A univariate meta-regression was conducted to assess the temporal changes in EIR by each funding category. Results: Of 127 trials recruiting from the US, 89 (70%) reported race, and 35 (27%) reported ethnicity. Among those, 57 (64%), 14 (16%), and 18 (20%) trials reported industry, US-government, and other sources of funding, respectively. Of those reporting ethnicity, 23 (66%), 4 (11%), and 8 (23%) trials reported industry, US-government, and other sources of funding, respectively. Among the 287 eligible trials, 49 trials (17%) reported age by 65 years. Of those, 36 (73%), 6 (12%), and 7 (13%) reported industry, US-government, and other sources of funding, respectively. In terms of racial/ethnic enrollment, Black patients were significantly under-represented in industry funded trials (0.33; 0.27-0.41). No significant disparity was observed in US-government funded trials (0.75: 0.57-1.00). The P-value of interaction was <0.0001. Hispanics were significantly under-represented in industry funded clinical trials (0.56; 0.43-0.74). The number of US-government funded trials reporting Hispanics were small (<10) which precluded any meaningful statistics. No significant disparity was observed in terms of older adults (EIR: 1.00; 95% CI: 0.95; 1.05) overall and by funding sources. Black patients’ representation in industry funded PCa trials has significantly decreased over the last three decades. No significant change was observed in US-government funded PCa trials over the last three decades (P:0.004). Conclusions: Black and Hispanic men with PCa are likely to be under-represented in industry sponsored clinical trials. Black patients’ representation in industry sponsored trials has declined over time, thus widening the cancer-care inequities in these patients.

499 Background: The impact of socioeconomic status on gastrointestinal (GI) cancer mortality in the United States (US) is not well-established. We hypothesized that socially vulnerable populations have disproportionately higher mortality rates. Hence, we assessed the association of the social vulnerability index (SVI) with GI cancer mortality across US counties. Methods: Social vulnerability indices were obtained from the agency for toxic substances and disease registry (ATSDR) from 2014-2018 to compute percentile ranking scores (PRS: ranging from 0-1) for each US county. PRS were further categorized into quartiles (Q: 1st: 0-0.25 [least vulnerable]; 4th:0.75-1.00 [most vulnerable]). The wide-ranging online data for epidemiological research (WONDER) database was queried to abstract county-level age-adjusted mortality rates (AAMR) per 100,000 person-years (PY) for populations diagnosed with GI cancers. AAMRs were then linked with quartile rankings. Rate ratios (RR) of AAMRs between 4th and 1st Q were subsequently estimated with 95% confidence intervals using population-weighted, Poisson regression. Results: A total of 3142 counties were included in this analysis. The AAMR for overall deaths (OD) and premature deaths (PD; defined as death at age <65) in the GI cancer population was 53.8 and 17.7 per 100,000 PY. A gradient increase in GI cancer-related mortality was observed from 1st Q to 4th Q (OD: 49.2 vs 59.3; PD: 14.1 vs 21.3). This stepwise increase in AAMR over the quartiles was consistent across gender, different racial/ethnic subgroups, and rural/urban categories of counties. The AAMRs for OD were significantly higher in the 4th Q as compared to the 1st Q for gastric (RR: 1.67 [95% CI, 1.51-1.86]), hepatocellular including intrahepatic biliary (1.52 [1.45-1.61]), colorectal (1.21 [1.16-1.26]) and biliary (1.17 [1.06-1.28]) cancer. Similarly, significantly higher AAMRs for PD were observed in 4th Q vs1st Q for gastric (1.81 [1.60-2.05]), hepatocellular including intrahepatic biliary (1.78 [1.58-2.00]), biliary (1.64 [1.35-1.99]), colorectal (1.29 [1.21-1.39]) and pancreatic (1.16 [1.07-1.25]) cancer. However, no significant differences were observed for esophageal and small intestinal cancers. Men with gastric (1.58 [1.41-1.78]) and hepatocellular cancer (1.54 [1.43-1.66]), non-Hispanic Black population (1.54 [1.31-1.80]) with hepatocellular cancer, and Hispanic population with colorectal cancer (1.50 [1.31-1.72]) were observed to have higher overall mortality in the 4th Q compared to the 1st Q. The findings were similar for premature mortality. Conclusions: Population-level data suggests that the US counties with higher socio-economic adversities may be at an increased risk of GI cancer-related mortality. Investigations using patient-level data are required to probe the impact of socioeconomic vulnerabilities on cancer-related mortality.

23 Background: Identification of factors associated with enrollment disparities in clinical trials can narrow cancer care inequities. Funding source can influence minority representation in clinical trials. Therefore, we aimed to assess the impact of funding sources on enrollment disparities in colorectal (CRC) clinical trials. Methods: CRC phase II/III randomized controlled trial (RCTs) identified through MEDLINE and EMBASE from each database’s inception through 2022 were considered eligible. Trial level enrollment incidence ratios (EIR) were computed; defined as the ratio of trial proportions of a gender, age, or racial/ethnic subgroup category and the global incidence in the corresponding gender/age subgroup (from the global burden of disease database), or the US-population-based incidence in the corresponding racial/ethnic subgroup (from SEER 21 database). EIRs were then meta-analyzed using a random-effects model for each funding source category (US- government, industry, others). Temporal trends were analyzed using a univariate meta-regression. Results: Using data from 287 RCTs, women were significantly under-represented in the industry sponsored trials (EIR: 0.85 [95% CI: 0.83 - 0.88]) but not in US-government sponsored trials (0.92 [0.84-1.00]). A total of 87 RCTs reported age proportions; older adults (above 65 years) were significantly under-represented in the industry sponsored (0.84 [0.74-0.96]) and as well as in US-government sponsored CRC trials (0.52 [0.44-0.61]). Only 56 and 15 trials reported race and ethnicity, respectively. Limited data on racial/ethnic enrollment revealed significant under-representation of Black (0.45 [0.36 -0.57]) and Hispanic (0.45 [0.31-0.66]) patients across industry sponsored CRC trials. In contrast, no significant disparity was observed in the inclusion of Asian race in the industry sponsored trials. The number of US-government sponsored trials reporting racial/ethnic subgroups were small ( < 10) which precluded any meaningful statistics. Trends show that the representation of women has improved ( P: 0.02) while the representation of Black ( P: 0.007) and Hispanic patients ( P: 0.04) has worsened over the last three decades in industry sponsored CRC trials. Conclusions: The reporting of race/ethnicity is suboptimal in CRC trials especially in those sponsored by US government. Older adults may be under-represented regardless of funding source. Women, Blacks and Hispanics may be under-represented in industry sponsored CRC clinical trials. While representation of women appears to be improving, representation of Black and Hispanic patients has worsened in industry sponsored CRC clinical trials over the last three decades.