Citations

TPS3634 Background: For patients with oligometastatic colorectal cancer (CRC), aggressive local therapy of isolated metastases, particularly in the liver, has been associated with long-term progression-free and overall survival (OS) primarily based on retrospective evidence. However, in patients with limited metastatic CRC that is deemed inoperable or those with additional disease outside of the liver or lungs, the role of local ablative therapies, including microwave ablation (MWA) and stereotactic body radiation therapy (SBRT), to render patients disease free is less clear. Despite the long history of treating oligometastatic CRC with local therapy, which is largely provider biased, questions remain regarding the benefit of extending the paradigm of metastatic directed therapy to patients with more extensive disease. This trial seeks to use a pragmatic multimodality approach that mirrors the current clinical dilemma. This study is designed to evaluate the safety and efficacy of adding total ablative therapy (TAT) of all sites of disease to standard of care systemic treatment in those with limited metastatic CRC. Methods: A022101/NRG-GI009 is a National Clinical Trials Network randomized phase III study planned to enroll 364 patients with newly diagnosed metastatic CRC (BRAF wild-type, microsatellite stable) without peritoneal metastasis or liver-only disease on baseline imaging. Patients receive first-line systemic therapy for 12-39 weeks. Patients with ≤4 sites of metastatic disease following initial systemic therapy that are amenable to any combination of surgical resection, MWA, and/or SBRT are then randomized 1:1, stratified by number of metastatic organ sites (1-2 vs. 3-4), timing of metastatic disease diagnosis (de novo vs. secondary), and presence of metastatic disease outside the liver/lungs in at least 1 site. Patients in Arm 1 will receive TAT consisting of treatment of all metastatic sites with SBRT, MWA, and/or surgical resection followed by standard of care systemic therapy. Patients in Arm 2 will continue with standard of care systemic therapy alone. The primary endpoint is OS. Secondary endpoints include event-free survival, treatment-related toxicities, and local recurrence with exploratory biomarker analyses. The study needs 346 evaluable patients combined in the 2 arms to demonstrate an improvement in OS with a hazard ratio of 0.7 to provide 80% power with a one-sided alpha of 5%. The trial utilizes a group sequential design with two interim analyses (25% and 50% of events) for futility. The trial activated in January 2023 and recruitment is ongoing. Support: U10CA180821, U10CA180882; https://acknowledgments.alliancefound.org. U10CA180820 (ECOG-ACRIN); U10CA180868 (NRG); U10CA180888 (SWOG); Clinical trial information: NCT05673148 .

TPS3650 Background: A total neoadjuvant therapy (TNT) approach improves compliance with chemotherapy and increases rates of tumor response compared to neoadjuvant chemoradiation (CRT) alone in those with locally advanced rectal cancer. Recent data indicate that optimal sequencing of TNT involves consolidation (rather than induction) chemotherapy to improve complete response rates. The use of FOLFIRINOX has shown to improve response and outcomes compared to CRT and surgery alone. Data have also shown that patients with clinical complete response (cCR) after TNT may be managed with a watch and wait approach (WW) instead of preemptive total mesorectal resection (TME). However, the optimal consolidation chemotherapy regimen to improve cCR rates has not been established, and a randomized clinical trial has not robustly evaluated cCR as a primary endpoint. We designed this NCI-sponsored study of chemotherapy intensification to address this and to increase cCR rates, provide opportunity for organ preservation, and survival outcomes. Methods: In this multigroup randomized, seamless phase II/III trial (1:1), up to 760 patients with LARC, T4N0, any T with node positive disease (any T, N+) or T3N0 requiring abdominoperineal resection or coloanal anastomosis and distal margin within 12 cm of anal verge will be enrolled. Stratification factors include tumor stage (T4 vs T1-3), nodal stage (N+ vs N0) and distance from anal verge (0–4; 4–8; 8–12 cm). Patients will be randomized to receive neoadjuvant long-course chemoradiation (LCRT) followed by consolidation doublet (mFOLFOX6 or CAPOX (control arm)) or triplet chemotherapy (FOLFIRINOX (experimental arm)) for 3–4 months. LCRT in both arms involve 4500 cGy in 25 fractions over 5 weeks +900 cGy boost in 5 fractions with a fluoropyrimidine. Patients will undergo assessment 8–12 (±4) weeks post-TNT completion. The primary endpoint for the phase II portion will compare cCR between treatment arms. A total number of 312 patients (156 per arm) will provide statistical power of 90.5% to detect a 17% increase in cCR rate, at a one-sided alpha = 0.048. The primary endpoint for the phase III portion will compare disease-free survival (DFS) between arms. A total of 285 DFS events will provide 85% power to detect an effect size of hazard ratio 0.70 at a one-sided alpha of 0.025, requiring enrollment of 760 patients (380 per arm). Secondary objectives include overall survival, organ preservation time, time to distant metastasis, and adverse event rates. This study has accrued 587 patients as of January 2025, and is investigating exploratory correlatives (e.g., ctDNA). Support: U10CA180821, U10CA180882, U24 CA196171. https://acknowledgments.alliancefound.org. Clinicaltrials.gov ID: NCT05610163. Clinical trial information: NCT05610163 .

3624 Background: Increasing chemotherapy completion and reducing chemotherapy adverse events (AE) are critical to improve survival after colon cancer diagnosis. Sex, as a biological variable, may impact chemotherapy treatment differently, and thus further investigation is needed to examine sex differences in chemotherapy completion and adverse events among patients with colon cancer. Methods: Among an NCI-sponsored trial conducted among patients with stage III colon cancer (CALGB/SWOG 80702), all patients received standard adjuvant chemotherapy FOLFOX (fluorouracil, leucovorin, and oxaliplatin). To signal chemotherapy completion, we utilized relative dose intensity (RDI) calculated as the ratio of the delivered dose intensity to planned dose intensity; and reduced RDI (RDI <85%) was considered as a clinically significant deviation from standard FOLFOX. From clinicians’ records of NCI’s Common Terminology Criteria for Adverse Events (CTCAE), we primarily focused on clinically significant AE such as neutrophils decrease, nausea, platelets decrease, hypertension, peripheral neuropathy, diarrhea, fatigue, gastritis, creatinine increase, gastric ulcer, myocardial ischemia, and cerebral ischemia; and severe AE was defined as the occurrence of any above AE with CTCAE grade ≥3. Using multivariable logistic regression that adjusted for body surface area (BSA) and other clinicopathological confounders, we estimated adjusted odds ratios (OR) for the associations of sex with reduced RDI and severe AE. Results: Of 2201 patients, mean (standard deviation [SD]) age was 60.9 (10.9) years, 1019 (46.3%) were female, 1750 (79.5%) were White, 172 (7.8%) were Hispanic, 964 (43.8%) experienced reduced RDI, and 1156 (52.5%) had severe adverse events. Compared to males, females were at significantly higher risks of experiencing reduced RDI (OR [95% CI]: 1.57 [1.27-1.93], P <0.001) and severe AE (OR [95% CI]: 1.73 [1.41-2.12], P <0.001). Conclusions: Our findings suggested females are more likely than men to experience reduced RDI and severe AE during colon cancer chemotherapy. Clinical Impact: In the era of precision medicine, sex (as a biological variable) should be considered in optimizing colon cancer chemotherapy to improve completion and reduce toxicities. Clinical trial information: NCT01150045 .

4020 Background: In previously treated patients (pts) with advanced extra-pancreatic NET (epNET) or pancreatic NET (pNET), cabozantinib (cabo) demonstrated improved progression-free survival compared to placebo (pbo) in the CABINET trial (NCT03375320). Here we present HRQOL data from CABINET. Methods: Pts with previously treated unresectable, locally advanced or metastatic epNET or pNET were randomized (2:1) in separate cohorts to receive cabo 60 mg daily vs pbo. HRQOL was an exploratory endpoint measured using the EORTC QLQ-C30, QLQ-GI.NET21, Patient Global Impression of Change (PGIC), and PRO-CTCAE questionnaires. Optional participation was by paper surveys at baseline and every 12 weeks (wks) until disease progression or new anticancer therapy. Mean changes from baseline were compared between treatment arms at wk12 using general linear mixed models. Minimally important within-arm improvements and between-arm differences were defined as 8 points on the C30 Global Health Status (GHS)/QOL Scale. PGIC was dichotomized as improved vs unchanged/worsened and compared using Chi-squared tests. Rates of pt-reported adverse events (AEs) by PRO-CTCAE were baseline-adjusted and compared using Fisher’s exact tests. Results: 172 pts (113 cabo, 59 pbo) with epNET and 81 pts (53 cabo, 28 pbo) with pNET consented for survey participation. Pts completed 524 (82%) of 640 expected surveys across baseline, wk12, and wk24. For epNET, C30 GHS/QOL was significantly improved at wk12 in pts receiving cabo (mean change 9.5, standard error (SE) 2.2, p < 0.001) but not pbo (mean change 0.2, SE 3.1, p = 0.95) resulting in significantly different mean changes from baseline between arms (p = 0.02). For pNET, C30 QHS/QOL was significantly improved at wk12 in pts receiving cabo (mean change 8.0, SE 3.0, p = 0.008) but not pbo (mean change 6.8, SE 4.4, p = 0.12); mean changes from baseline did not statistically differ between arms (p = 0.82). No significant differences in mean changes from baseline at wk12 in C30 Physical, Role, Emotional, Cognitive and Social Function were observed between arms in the epNET or pNET cohorts. In both cohorts at wk12, pts on cabo reported improved overall status as measured by PGIC more often than those on pbo (epNET: 38% vs 19%, p = 0.04; pNET: 57% vs 18%, p = 0.006). Rates of pt-reported AEs were statistically significantly higher in cabo for diarrhea (68% vs 53%), hand-foot syndrome (57% vs 26%), mouth or throat sores (47% vs 27%), and dysgeusia (67% vs 37%) [all p < 0.05]. GI.NET21 data will be presented. Conclusions: Although cabo is associated with pt-reported AEs consistent with its known safety profile, global HRQOL was maintained. A higher proportion of patients receiving cabo reported improved overall status. Results support cabo as a treatment option for pts with previously treated advanced NET that preserves patient HRQOL. Clinical trial information: NCT03375320 .

Observational studies have demonstrated that aspirin and/or PTSG2 inhibitor (e.g., celecoxib) use, before or after colon cancer (CC) diagnosis, is associated with a lower risk of recurrence. However, a randomized trial of adjuvant celecoxib therapy in stage III CC did not show improved survival compared to placebo treatment. We therefore hypothesized that immune microenvironment features may identify patient subgroups with stronger survival benefits from anti-inflammatory celecoxib treatment. Drawing from an NCI-Intergroup trial (Cancer and Leukemia Group B [now Alliance for Clinical Trials in Oncology]/SWOG 80702) for patients with stage III resected CC that compared 3 versus 6 months of adjuvant fluorouracil, leucovorin, and oxaliplatin ± 3 years of celecoxib, we conducted tissue-based tumor microenvironment profiling on 1,098 resected tumors using a custom 9-plex, T-cell multiplex immunofluorescence assay coupled with digital image analysis and supervised machine learning. The Kaplan-Meier method was used to describe disease-free survival, based on T cell density, and log-rank testing was performed. Cox proportional hazards models were used to examine unadjusted and adjusted associations between T cell density and disease-free survival (DFS). Two-sided P values ≤0.05 were considered statistically significant. We found that higher CD3+ T cell density was associated with longer DFS with an adjusted hazard ratio (HR) of 0.69 (95% confidence interval [CI] 0.52-0.91) for patients with densities in the highest tertile as compared the lowest tertile (P=0.01). T cell subset analysis showed that stromal regulatory T helper cells (HR 0.42 comparing highest to lowest tertile, CI 0.31-0.58, P&lt;0.001) and stromal memory cytotoxic T cells (HR 0.55 comparing highest to lowest tertile, CI 0.42-0.74, P&lt;0.001) were most strongly associated with longer DFS. Compared to the placebo group, adjuvant celecoxib use associated with improved DFS for patients with low but not high stromal CD3+ T cell density (adjusted HRs of 0.45 [CI 0.31-0.65] for lowest tertile and 1.13 [CI 0.73-1.74] for highest tertile; Pinteraction=0.01). This association was also seen when the analysis was restricted to microsatellite stable tumors (HR 0.50 [CI 0.32-0.80] for lowest density tertile and 1.50 [CI 0.87-2.59] for highest density tertile; Pinteraction=0.01). T cell subset analysis showed that DFS benefit for celecoxib use most strongly associated with stromal memory helper T cell density (HR 0.38 [CI 0.26-0.56] for lowest density tertile and 1.26 [CI 0.80-1.97] for highest density tertile; Pinteraction&lt;0.001). Together, these results show that while higher T cell infiltration is associated with improved DFS, lower T cell infiltration is associated with improved DFS for patients treated with celecoxib. This unexpected finding may inform immunomodulatory treatment strategies for CC. Citation Format: Yasutoshi Takashima, Chao Ma, Qian Shi, Andressa Dias Costa, Tyler Twombly, Juha P. Väyrynen, Melissa Zhao, Ardaman Shergill, Pankaj Kumar, Felix Couture, Philip Kuebler, Smitha Krishnamurthi, Benjamin Tan, Eileen M. O'Reilly, Anthony F. Shields, Shuji Ogino, Charles S. Fuchs, Jeffrey A. Meyerhardt, Jonathan A. Nowak. Prognostic and predictive role of T cell infiltration in stage III colon cancer (CC) treated with celecoxib: CALGB/SWOG 80702 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5858.

Abstract Background The treatment of locally advanced rectal cancer now includes “watch-and-wait” (WW) management for patients who exhibit a clinical complete response (cCR) to total neoadjuvant therapy (TNT). We assessed patients’ knowledge and preferences regarding WW with the goal of incorporating patient input into clinical trial design. Methods Rectal cancer patients in advocacy groups (COLONTOWN/Rectalburgh and Fight CRC) were surveyed regarding perceptions about treatment strategies, tolerable risks of treatment failure, and preferences on clinical trial design. Surveys were initially distributed in 2019, with the shift toward WW prompting re-survey of select questions in 2023. Results All respondents preferred enrollment in trials that incorporated patient input. Most respondents (76%) preferred treatment that incorporated chemotherapy escalation over radiation escalation. Furthermore, when presented with a hypothetical patient who developed a cCR after chemoradiation (without the option for WW), 58% of patients chose surgical treatment (with 100% risk of permanent ostomy and 80% chance of cure) over omission of surgery (with &lt;80% chance of cure). In contrast, when the hypothetical patient developed a cCR after TNT (with an option for WW), 82% of patients opted for selective WW over surgery. Conclusions This work successfully integrated patient advocacy groups as a resource for obtaining patient input. Surveys revealed patients had a strong preference for chemotherapy escalation, for selective WW when offered, and for incorporation of input into future clinical trial design. These findings describe how well-informed patients approach complex medical decision-making and serve as a starting point for future studies seeking to incorporate patient voices.

LBA14 Background: CALGB/SWOG 80702 previously showed that the addition of celecoxib to standard adjuvant chemotherapy with FOLFOX did not significantly improve disease-free survival (DFS) in patients with stage III colon cancer. Here, we evaluated the prognostic and predictive value of ctDNA in identifying a subpopulation of patients who may benefit from celecoxib. Methods: In the subset of patients with adequate biospecimens who participated in CALGB/SWOG 80702, a randomized phase III trial of 3 versus 6 months of adjuvant 5-FU, leucovorin, oxaliplatin (FOLFOX) +/- celecoxib, ctDNA assessment was performed using a clinically validated, tumor-informed 16-plex mPCR-NGS assay (Signatera(TM), Natera, Inc.) after surgery and before the start of adjuvant therapy (baseline). The Kaplan-Meier method was used to describe the distribution of survival time based on ctDNA positivity and log-rank testing was performed. Cox proportional hazards models were used to examine unadjusted associations between ctDNA positivity and disease-free (DFS) and overall survival (OS). Two-sided P values equal to or less than 0.05 were considered statistically significant, except for interaction P values (tested with a likelihood ratio). Results: In total, 1,011 of the 2,526 patients who participated in 80702 had ctDNA testing results from baseline; 189 were ctDNA positive (18.7%). ctDNA positivity associated with male sex, higher T stage, and N2 (versus N1) stage. ctDNA positivity was significantly associated with worse DFS (hazard ratio [HR] 6.52 [95% confident interval (CI) 5.09-8.34; p<0.0001] and OS (HR 6.28 [95% CI 4.63-8.51; p<0.0001]). Three-year DFS was 86.6% in ctDNA-negative cases and 36.8% in ctDNA-positive cases. Among patients who were ctDNA negative, celecoxib use was not significantly associated with worse DFS as compared to placebo (HR 0.75 [95% CI 0.54-1.05; p=0.095]) with a three-year DFS of 87.7% versus 85.5%, respectively. Among ctDNA-positive patients, celecoxib significantly improved DFS compared to placebo (HR 0.59 [95% CI 0.42-0.85; p=0.004]) with a three-year DFS of 44.1% versus 26.6% (P interaction = 0.25). Similar results were seen for overall survival with a hazard ratio of 0.86 (95% CI 0.56-1.33; p=0.49) for ctDNA negative cases and 0.63 (95% CI 0.41-0.96; p=0.028) for ctDNA-positive cases for celecoxib versus placebo (P interaction = 0.28). Conclusion: In a randomized phase III adjuvant therapy trial for stage III colon cancer, ctDNA was highly prognostic of DFS and OS. ctDNA positivity also appeared predictive of the benefit of adjuvant celecoxib for DFS and OS. These results suggest a potential role for ctDNA in determining which patients should consider celecoxib in addition to standard FOLFOX adjuvant therapy. Clinical trial information: NCT01150045 .

666 Background: In the phase 3 CABINET trial (NCT03375320), cabozantinib (CABO) significantly prolonged median progression-free survival (PFS) compared to placebo (PB) in patients with advanced, previously treated, progressive extrapancreatic NET (epNET) [HR 0.38 (95% CI, 0.25-0.59, P<0.0001)] and pancreatic NET (pNET) [HR 0.23 (95% CI, 0.12-0.42, P<0.0001)] (Chan et al., NEJM, 2024). In this analysis, we focus on outcomes of patients with epNET arising in the GI tract. Methods: Patients with locally advanced or metastatic epNET or pNET were randomized 2:1 in separate cohorts to receive CABO 60 mg daily vs PB. The epNET cohort included patients with tumors arising in the GI tract (not including pancreas), lung, unknown primary, and other rare primary sites. In this subgroup analysis of the epNET cohort, patients with GI NET were included. Eligibility included progression by RECIST within 12 months (mo) prior to registration, ≥ 1 prior systemic therapy. Primary endpoint: PFS by blinded independent central review (BICR). Secondary endpoints: objective response rate, overall survival, safety. Results: 116 of the 203 patients in the epNET cohort had GI NET (CABO, n=70; PB, n=46). Median age was 66 yrs; females: 46%; G1/G2/G3/unknown grade: 35%/57%/6%/2%. ECOG performance status: 0/1-2: 43%/57%. White race: 86%. The most common primary tumor locations were ileum/cecum (54%), small intestine with location not specified (20%); non-cecum colon or rectum (11%), stomach (4%); duodenum (3%); jejunum and nonspecified midgut site (3% each). Prior systemic therapies included somatostatin analogs (SSA) (100%), everolimus (59%); Lu-177 dotatate (77%); temozolomide +/- capecitabine (16%). In patients with GI NET, CABO was associated with improved PFS by BICR compared to PB (stratified HR, 0.50; 95% CI: 0.28-0.88, 1-sided stratified log-rank P=0.007). Median PFS with cabozantinib was 8.5 mo (95% CI, 6.0-16.7) compared to 5.6 mo (95% CI, 3.9-11.0) with PB. CABO demonstrated potential benefit in patients with midgut GI NET and across clinical factors including grade, functional status related to hormone secretion, concurrent SSA use, and prior therapy with Lu-177 dotatate or everolimus. The most frequent grade 3/4 adverse events attributed to therapy with CABO included hypertension (19%), diarrhea (13%), fatigue (10%). Conclusions: CABO is associated with improvement in PFS compared to PB in patients with advanced GI NET. Potential benefit was observed across clinical factors including grade, functional status, concurrent SSA, and prior treatment. The safety profile for CABO in patients with GI NET is consistent with that previously reported. Support: U10CA180821, U10CA180882; U10CA180820 (ECOG-ACRIN), U10CA180868 (NRG Oncology), U10CA180888 (SWOG); Exelixis; https://acknowledgments.alliancefound.org . Clinical trial information: NCT03375320 .

TPS309 Background: Patients with oligometastatic colorectal cancer (CRC) often experience long-term progression-free survival and overall survival (OS) following aggressive local treatment of isolated metastases, especially in the liver. However, the effectiveness of local ablative therapies, such as microwave ablation (MWA) and stereotactic body radiation therapy (SBRT), in patients with inoperable limited metastatic CRC or those with additional metastases outside the liver or lungs, remains uncertain. Despite the historical use of local therapy for oligometastatic CRC, often influenced by provider bias rather than strong evidence, questions persist about the potential benefits of applying this approach to patients with more extensive disease. This trial aims to address this clinical challenge by evaluating the safety and efficacy of adding total ablative therapy (TAT) of all disease sites to standard systemic treatment in patients with limited metastatic CRC. Methods: A022101/NRG-GI009 is a randomized phase III study within the National Clinical Trials Network, set to enroll 364 patients with newly diagnosed metastatic CRC (BRAF wild-type, microsatellite stable). Patients with liver-only metastatic disease are excluded. Pre-registration during first-line systemic therapy induction is encouraged. Eligible lesions must be treatable with surgical resection, MWA, and/or SBRT. Patients without significant radiographic progression after 12-39 weeks of first-line systemic therapy, with 4 or fewer disease sites post-induction chemotherapy, will be randomized 1:1. Randomization will be stratified by the number of metastatic organ sites (1-2 vs. 3-4), timing of metastatic disease diagnosis (de novo vs. secondary), and the presence of metastatic disease outside the liver/lungs in at least one site. Patients in Arm 1 will receive TAT, targeting all metastatic sites with a combination of surgical resection, MWA, and/or SBRT, followed by standard systemic therapy. Patients in Arm 2 will continue with standard systemic therapy alone. The choice of systemic therapy is at the discretion of the medical oncologist and may include continued therapy, maintenance chemotherapy, or observation. The primary endpoint is OS, with secondary endpoints including event-free survival, treatment-related toxicities, and local recurrence. Exploratory biomarker analyses will also be conducted. The study requires 346 evaluable patients across the two arms to demonstrate an OS improvement with a hazard ratio of 0.7, providing 80% power with a one-sided alpha of 5%. The trial employs a group sequential design with two interim analyses (at 25% and 50% of events) to assess futility. The trial began in January 2023, and patient recruitment is ongoing. Clinical trial information: NCT05673148 .