George, Manju

Introduction With the rapidly changing landscape of rectal cancer treatment, it is becoming increasingly challenging for clinicians to interpret and synthesise the vast amount of high-quality evidence being generated. A core outcome set (COS) for clinical trials in rectal cancer would help address issues surrounding outcome selection and reporting. The purpose of this research project is to develop a COS to be used in research comparing different treatment paradigms in the management of rectal cancer. Methods and analysis This will be a mixed-methods project, including a systematic review, semi-structured interviews and a Delphi consensus process. The project was designed in accordance with the COMET (Core Outcome Measures in Effectiveness Trials) Handbook, which provides a framework for COS development based on existing evidence. A multidisciplinary Study Advisory Group, composed of rectal cancer providers, methodologists and patients, will oversee the project. A systematic review will be performed to identify an inclusive list of outcomes reported by researchers in previous rectal cancer trials. Outcomes will be collapsed into various core areas and domains according to the OMERACT Filter V.2.0. Semi-structured interviews with rectal cancer survivors and their partners/caregivers will help identify additional patient-centric outcomes not captured in the systematic review. Finally, after a final list of outcomes is generated, patients and healthcare professionals will be invited to participate in a Delphi process to develop the final COS. Ethics and dissemination The study has received full approval with the Research Ethics Committee at the Integrated Health and Social Services Network for West-Central Montreal (health network responsible for the Jewish General Hospital) (REC: 2025-4377) and the Institutional Review Board of the Mount Sinai School of Medicine (IRB: STUDY-25-00515). The results of this study will be presented at national and international meetings and a manuscript will be submitted for publication in a high-impact surgery and/or oncology peer-reviewed journal. Trial registration number The study was registered in the COMET database in December 2023 ( https://www.comet-initiative.org/Studies/Details/2941 ). The full systematic review protocol, along with the search strategy and inclusion/exclusion criteria, was registered online in September 2023 (researchregistry.com; reviewregistry1705).

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 .

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 <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.

Abstract Background: For patients with liver-confined metastatic colorectal cancer (mCRC), local therapy of isolated metastases has been associated with long-term progression-free and overall survival (OS). However, for patients with more advanced mCRC, including those with extrahepatic disease, the efficacy of local therapy is less clear although increasingly being used in clinical practice. Prospective studies to clarify the role of metastatic-directed therapies in patients with mCRC are needed. Methods:The Evaluating Radiation, Ablation, and Surgery (ERASur) A022101/NRG-GI009 trial is a randomized, National Cancer Institute-sponsored phase III study evaluating if the addition of metastatic-directed therapy to standard of care systemic therapy improves OS in patients with newly diagnosed limited mCRC. Eligible patients require a pathologic diagnosis of CRC, have BRAF wild-type and microsatellite stable disease, and have 4 or fewer sites of metastatic disease identified on baseline imaging. Liver-only metastatic disease is not permitted. All metastatic lesions must be amenable to total ablative therapy (TAT), which includes surgical resection, microwave ablation, and/or stereotactic ablative body radiotherapy (SABR) with SABR required for at least one lesion. Patients without overt disease progression after 16-26 weeks of first-line systemic therapy will be randomized 1:1 to continuation of systemic therapy with or without TAT. The trial activated through the Cancer Trials Support Unit on January 10, 2023. The primary endpoint is OS. Secondary endpoints include event-free survival, adverse events profile, and time to local recurrence with exploratory biomarker analyses. This study requires a total of 346 evaluable patients to provide 80% power with a one-sided alpha of 0.05 to detect an improvement in OS from a median of 26 months in the control arm to 37 months in the experimental arm with a hazard ratio of 0.7. The trial uses a group sequential design with two interim analyses for futility. Discussion: The ERASur trial employs a pragmatic interventional design to test the efficacy and safety of adding multimodality TAT to standard of care systemic therapy in patients with limited mCRC.

255 Background: During the COVID-19 pandemic, Twitter has been instrumental in accelerating knowledge dissemination and forging collaborations within the medical community and amongst patient advocates. Tweetchats within Twitter are scheduled conversations on a specific topic. In oncology, Tweetchats have been used by cancer advocates to spread awareness and for patient and caregiver education. A colorectal cancer (CRC) specific tweetchat did not previously exist. This abstract describes the creation, and experiences with a CRC specific tweetchat. Methods: The #CRCTrialsChat tweetchat was created by a patient advocate for colorectal cancer patients, caregivers and clinicians to meet and exchange clinical trial-related information. Two gastrointestinal (GI) medical oncologists and two radiation oncologists were enlisted as moderators. The topic for each session is chosen by the patient advocate, who creates an outline and divides the content, which is designed to last a one hour session. The idea is to create engaging, technical, but easy to understand content. Each moderator then works on the answers to their assigned section, which is edited to fit tweet character limit. Sessions may also have guest moderators with expertise on a specific topic. Through tweeting, moderators answer specific questions that come up during the session and later. Results: To date, we have had four sessions covering the following topics: Clinical trial basics, CRC Updates from ASCO22, ClinicalTrialFinders and BRAF-mutated tumors. The content created has been simple and engaging, the format has functioned smoothly, and the reach of #CRCTrialsChat has been steadily increasing. After the most recent session on BRAF in September 2022, the @CRCTrialsChat has 281 followers, 17K impressions and 14.6K profile visits, a reflection of its excellent content. From a clinician perspective, this is a great format to interact with colleagues, discuss enrolling trials and also become familiar with using Twitter. Conclusions: A CRC clinical trial focused tweetchat is an engaging way to deliver trial-related content to an audience of clinicians, patients and caregivers. The current format appears to be an effective way to create and disseminate information. Future sessions will focus on ctDNA, molecular markers such as KRAS and HER2, and rectal cancer trials. Our hope is that #CRCTrialsChat will stimulate continued patient and clinician engagement, increase awareness of clinical trials, enhance trial participation and initiate patient-centric research and collaborations.