Citations

390216 Background: CDK4/6 inhibitors have become standard of care for advanced hormone receptor positive, HER2-negative (HR+/HER2-) breast cancer in combination with endocrine therapy (ET), with one approved for high-risk patients (pts) in the adjuvant setting. The PALLAS Trial investigated the addition of palbociclib to adjuvant ET in pts with stage II-III breast cancer. Stage IIA patients were specifically enrolled to evaluate the potential benefit of using palbociclib with adjuvant ET pts diagnosed at lower risk who may have more indolent disease. Methods: In the prospective, randomized, phase III PALLAS trial, pts with HR+/HER2- early breast cancer were randomly assigned to receive adjuvant ET for at least 5 years with or without 2 years of palbociclib (125 mg orally once daily, days 1-21 of a 28-day cycle). ET was of provider’s choice. Stage IIA enrollment was capped at 1,000 patients. While the primary end point of the overall study was invasive disease-free survival (iDFS) for the entire cohort, there was a preplanned analysis of recurrence and survival endpoints in the stage IIA cohort. Outcomes were compared between arms using stratified log-rank tests and Cox models (stratification factors: chemotherapy and age ≤ 50). Results: Among 5,796 pts enrolled at 406 centers in 21 countries worldwide between 9/1/2015 and 11/30/2018, a total of 1,010 stage IIA pts were enrolled. The protocol-defined number of events occurred at a median follow-up of 50 months for this subgroup (43.1 months for the overall study). Median age within this subgroup was 54 (range 29-85 yrs), and 410 (40.6%) were pre/perimenopausal, 506 (50.1%) T2/N0 (vs T0-1/N1), 272 (26.9%) grade 3 (vs. grade1/2), and 561 (55.5%) received chemotherapy. iDFS events occurred in 31 of 503 (6.2%) pts who received palbociclib plus ET and in 45 of 507 (8.9%) pts who received ET alone, resulting in a statistically nonsignificant difference in iDFS at 4 years (92.9% vs. 92.1%; hazard ratio, 0.75; CI, 0.48 to 1.19; P = .23). Nonsignificant differences were also observed for invasive breast cancer-free, distant recurrence-free, and locoregional cancer-free survival. No significant differences in iDFS were observed in subgroups including age group, receipt of chemotherapy, tumor grade, and clinical risk (T1/N1 vs. T2/N0).Conclusions: In this preplanned analysis of the stage IIA cohort of the PALLAS trial, the addition of adjuvant palbociclib to standard ET did not improve outcomes over ET alone, suggesting no benefit from the agent in reducing the incidence of early relapse in pts with lower-stage HR+/HER2- breast cancer. Future analyses will incorporate genomic risk and other molecular patterns from the extensive transPALLAS correlative program. Additional follow-up (10-year minimum) is also underway to assess the impact of palbociclib exposure on late recurrence in HR+ disease. Clinical trial information: NCT02513394.

AbstractData on diet and survival among people with metastatic colorectal cancer are limited. We examined dietary fat in relation to all‐cause mortality and cancer progression or death among 1149 people in the Cancer and Leukemia Group B (Alliance)/Southwest Oncology Group (SWOG) 80405 trial who completed a food frequency questionnaire at initiation of treatment for advanced or metastatic colorectal cancer. We examined saturated, monounsaturated, total and specific types (n‐3, long‐chain n‐3 and n‐6) of polyunsaturated fat, animal and vegetable fats. We hypothesized higher vegetable fat intake would be associated with lower risk of all‐cause mortality and cancer progression. We used Cox proportional hazards regression to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI). Over median follow‐up of 6.1 years (interquartile range [IQR]: 5.3, 7.2 y), we observed 974 deaths and 1077 events of progression or death. Participants had a median age of 59 y; 41% were female and 86% identified as White. Moderate or higher vegetable fat was associated with lower risk of mortality and cancer progression or death (HRs comparing second, third and fourth to first quartile for all‐cause mortality: 0.74 [0.62, 0.90]; 0.75 [0.61, 0.91]; 0.79 [0.63, 1.00];Ptrend: .12; for cancer progression or death: 0.74 [0.62, 0.89]; 0.78 [0.64, 0.95]; 0.71 [0.57, 0.88];Ptrend: .01). No other fat type was associated with all‐cause mortality and cancer progression or death. Moderate or higher vegetable fat intake may be associated with lower risk of cancer progression or death among people with metastatic colorectal cancer.

6530 Background: Only a small fraction of patients with cancer participate in treatment trials. Patients identifying as members of racial and ethnic minority groups are consistently underrepresented in these trials. A recent systematic review reported that patients, regardless of race and ethnicity, are willing to enroll in trials if asked to participate by their treating clinician. Prospective and longitudinal data and metrics at the site- and clinician-level are necessary to understand whether patients are equitably considered for clinical trials. Methods: ASCO and Association of Community Cancer Centers (ACCC) developed a self-assessment for trial sites to record and gauge the number of patients across races and ethnicities screened, offered, and enrolled into clinical trials. Research sites, from across the US, were recruited through an open call to apply to participate in the ASCO-ACCC Pilot Project. There were 65 sites assigned to this pilot study, which tested the feasibility and utility of the site assessment. Sites were asked to enter 2019 and 2020 aggregate data for each step along the clinical trial enrollment continuum by select races and ethnicities (Black, Hispanic/Latinx, White) and overall. Results: 62 of 65 sites completed the study and represented a range of settings and practice types (61% academic, 26% hospital/health system, 13% independent). Only 2 sites (3%) were able to provide the data requested at each enrollment step in the assessment (table). Sites that collected the data did not do so routinely (table) and most had to compile data through multiple sources and/or manual extraction (40-100% across enrollment steps). Sites with missing data reported they did not collect data at all (36-64% across enrollment steps), did not collect data in a systematic way (0-29% across enrollment steps), or stated it would be too burdensome to manually review charts to extract data (12-29% across enrollment steps). Conclusions: Data collection and routine evaluation of participation metrics, by race and ethnicity, are necessary to assess and monitor equity and diversity in clinical trials. Most sites in this study did not collect, or routinely collect, data for screening, offering, and consenting patients to clinical trials. Without these data, sites are unable to evaluate and monitor whether their patients have equitable access to clinical trials or establish strategies to address any inequities. ASCO and ACCC will continue to partner with sites to better understand their processes and the feasibility of collecting such data in a systematic and automated way, such as through electronic health record systems. [Table: see text]

6514 Background: Tobacco use is a modifiable risk factor for adverse outcomes among patients diagnosed with cancer. Despite ASCO’s recommendation for assessment and treatment of tobacco use, integration into cancer care is suboptimal. Socioeconomic contexts influence access and utilization of tobacco treatment, but little is known about the relationship between neighborhood socioeconomic disadvantage (NSD) and tobacco assessment, assistance, and cessation among cancer patients enrolled in clinical trials. Methods: The NCI Cancer Patient Tobacco Use Questionnaire (C-TUQ) was centrally administered to participants enrolled in 10 ECOG ACRIN clinical trials (9 therapeutic, 1 imaging). We examined associations of NSD with patient-reported rates of receiving brief tobacco cessation support (i.e., Ask, Assist (counseling)) and cessation (past 30d quit attempts and duration). NSD was measured using the national Area Deprivation Index (ADI) based on participant’s zip code. Associations between ADI (low, intermediate, and high) and tobacco variables were evaluated using logistic regression and ANOVA. Results: 740 patients, completing the C-TUQ between June 2017-October 2021, can be classified as 402 (54%) never smokers, 81 (11%) current smokers, and 257 (35%) former smokers. Patients were 70% male; 94% white; 3% Hispanic; mean age 58.8 (SD 9.0). Cancer diagnoses were 36% leukemia; 19% lymphoma, 18% prostate, 11% breast; 9% melanoma, 7% myeloma, and 0.5% head and neck. Patients were categorized into high (33%), intermediate (34%) and low (33%) disadvantaged neighborhoods. Patients in high (vs. low) disadvantaged neighborhoods were more likely to report being asked about smoking (OR = 3.90; 95% CI (confidence interval), 1.61 to 9.46; p = 0.0062) but less likely to report receiving counseling to help quit smoking (OR = 0.20; 95% CI, 0.06 to 0.73; p = 0.0234). Patients from high disadvantaged neighborhoods had the shortest quit duration, followed by patients from intermediate and low disadvantaged neighborhoods (mean = 145.78, 187.66, and 210.98 months, respectively, p = 0.0372). Conclusions: Greater socioeconomic neighborhood disadvantage was associated with increased assessment of tobacco use but decreased tobacco treatment referral, and the shortest quit duration. More research is needed to promote increased referral to tobacco treatment for individuals with cancer from disadvantaged neighborhoods to promote and sustain cessation.

3580 Background: Monoamine oxidases (MAOs), including MAOA and MAOB, are mitochondrial enzymes responsible for catalyzing monoamine oxidation. Increased expression of MAOs were found in several cancer types and high MAOB was associated with worse disease stage and poorer survival in CRC. Positive and negative correlations of MAOB expression with mesenchymal type and epithelial type gene expressions, respectively, have been reported. Hence, we investigated whether MAOB expression is predictive for targeted therapies in mCRC. Methods: 430 mCRC pts treated with either bevacizumab (BEV, n = 224) or cetuximab (CET, n = 206) in combination with first-line chemotherapy within the CALGB/SWOG 80405 trial were included in the analysis. MAOB RNA was isolated from FFPE tumor samples and sequenced on the HiSeq 2500 (Illumina). Overall survival (OS) and progression-free survival (PFS) were compared between groups of pts categorized by tertiles of MAOB expression into high (H), medium (M) and low (L). Hazard ratios (HR) and 95% confidence intervals (CI) were computed from multivariable Cox proportional hazards model, adjusting for age, sex, location, number of metastases, KRAS, MSI status, and treatment with FOLFOX or FOLFIRI. Sensitivity analyses were conducted after stratifying by sex. Logrank P-values describe differences without adjustment for patient characteristics. Results: In CET-treated pts, MAOB-L showed significantly longer OS (median 39.2 vs 30.9 vs 15.9 months, logrank P = 4.7E-05, L vs H (as reference) adjusted HR 0.42, 95% CI [0.27, 0.65]) and PFS (median 13.2 vs 11.8 vs 7.6 months, logrank P = 0.006, L vs H adjusted HR 0.59 [0.40, 0.88]) compared to MAOB-M and MAOB-H, respectively. Similar results were observed when evaluating MAOB expression as a continuous variable. In BEV-treated pts, no significant differences were observed when comparing MAOB expression tertiles; however, pts with lower MAOB expression had significantly better OS, but not PFS, when evaluating MAOB as a continuous variable (Cox LRT P = 0.015, covariate adjusted). In CET-treated pts, the effect of MAOB expression was observed in male but not female pts (OS: median 40.3 vs 30.9 vs 16.1 months by MAOB-L, M, H, respectively, logrank P = 6.8E-05, L vs H adjusted HR 0.33 [0.19, 0.59]; PFS: median 13.8 vs 12.6 vs 7.9 months, logrank P = 0.001, L vs H adjusted HR 0.46 [0.28, 0.79]). A significant interaction was observed between MAOB expression and treatment for OS ( P = 0.010) in males and females combined, but only in males ( P = 0.018) when stratified by sex. Conclusions: Our results suggest that pts with MAOB-L tumors may have greater benefit from CET-based treatment and that targeting MAOB may be a promising strategy to improve patient outcomes. Further validation studies are warranted to develop a novel personalized approach based on MAOB expression in mCRC pts. Clinical trial information: NCT00265850.

3553 Background: Higher levels of plasma 25-hydroxyvitamin D [25(OH)D)] are associated with better outcomes in mCRC, but underlying biologic mechanisms are unknown. Key components of the VitD metabolic pathway include CYP27B1 (encodes 1-α-hydroxylase, converts 25(OH)D to active calcitriol), VitD receptor (VDR), and CYP24A1 (encodes 24-hydroxylase, degrades calcitriol and 25(OH)D into excreted metabolites). Since these factors may affect 25(OH)D levels and potentially mediate VitD activity in mCRC, we examined the relationship between tumoral gene expression (GEx) of CYP27B1, VDR, and CYP24A and pt outcome in a study nested in a randomized phase III trial of first-line chemotherapy plus biologics in mCRC pts, CALGB/SWOG 80405. Methods: We determined GEx of CYP27B1, VDR, and CYP24A1 by RNA sequencing (RNA-Seq) of archival tumor samples using the Illumina TruSeq platform. Primary endpoints were overall (OS) and progression-free survival (PFS). Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for prognostic and molecular characteristics. Results: 562 pts with RNA-Seq data were included. Pts with higher CYP27B1 expression (>median) were less likely to have BRAF wild type (WT) (79% vs 90%) compared to pts with lower expression (p=0.0007). Pts with higher VDR expression (>quartile 1 [Q1]) were younger (median age 59 vs 62 years; p=0.03), more likely to have left-sided (63% vs 46%; p=0.0005) and BRAF WT tumors (89% vs 70%; p<0.0001), and less likely to have RAS WT tumors (70% vs 80%; p=0.02) compared to pts with lower VDR. Pts with higher CYP24A1 expression (>median) were more likely to have left-sided tumors compared to pts with lower expression (63% vs 54%; p=0.03). On multivariable analysis, pts with higher CYP27B1 expression had significantly improved OS (HR 0.84; 95% CI, 0.75-0.93; p=0.002) and PFS (HR 0.89; 95% CI, 0.80-0.99; p=0.04). Higher VDR expression (up to Q1) was associated with significantly improved PFS (HR 0.69; 95% CI, 0.53-0.91; p=0.007) but not OS (HR 0.85; 95% CI, 0.66-1.09; p=0.20). Above Q1, this improvement attenuated. Higher CYP24A1 GEx was not associated with improved OS (HR 0.98; 95% CI, 0.88-1.08; p=0.66) or PFS (HR 0.98; 95% CI, 0.89-1.08; p=0.68). We found no significant interactions between GEx of CYP27B1, VDR, or CYP24A with baseline plasma 25(OH)D levels (p for interaction ≥0.10 for all). Conclusions: Our findings suggest an association between GEx of VitD pathway markers, particularly CYP27B1 and VDR, and survival in pts with mCRC, lending biologic plausibility to a role of VitD in CRC pathogenesis. Future studies are needed to confirm these findings and elucidate underlying mechanisms of action. Clinical trial information: NCT00265850 .