2109 - Efficacy and Safety of Total Neoadjuvant Therapy in Elderly Patients with Locally Advanced Rectal Cancer: A Real-World Study
Presenter(s)
X. Ke1, Y. Zhang1, M. Song1, S. Li1, J. Geng1, Z. Liu1, H. Wang1, R. Du1, X. Zheng1, D. Dong1, X. Zhu1, Y. Cai1, Y. Li1,2, and W. Wang1; 1Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing, China, 2State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Beijing Key Laboratory of Carcinogenesis and Translational Research, Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing, China
Purpose/Objective(s): Although total neoadjuvant therapy (TNT) has become the standard recommendation for locally advanced rectal cancer (LARC), elderly patients remain underrepresented in related clinical trials. Concerns regarding treatment tolerability have further limited the adoption of TNT in this population in real-world clinical practice. This study aimed to evaluate the efficacy and safety of TNT in elderly patients with LARC.
Materials/Methods: We conducted a retrospective analysis of patients aged =60 years with LARC who received long-course chemoradiotherapy-based TNT between July 2016 and June 2024. Patients were stratified into younger-elderly (YE, 60-69 years) and older-elderly (OE, =70 years) groups. Propensity score matching (PSM) was performed to balance baseline characteristics of the two groups. Treatment compliance, complete response (CR) rate, survival outcomes, and treatment-related toxicities were evaluated.
Results: A total of 171 elderly patients were included (113 YE and 58 OE). All patients completed planned neoadjuvant chemoradiotherapy (NCRT). For systemic chemotherapy, 80 (46.8%), 76 (44.4%), and 15 patients (8.8%) completed 1-2, 3-4, and >4 cycles of neoadjuvant capecitabine and oxaliplatin (CAPEOX) chemotherapy, respectively. CR rate was 39.2% (67/171), including a pathological complete response (pCR) rate of 17.0% (29/171) and a clinical complete response (cCR) rate of 22.2% (38/171). R0 resection rate was 97.2%. After a median follow-up of 31.6 months (IQR: 20.8-48.2), the 3-year overall survival (OS), cancer-specific survival (CSS), locoregional recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were 95.8%, 97.0%, 93.2%, and 82.8%, respectively. In the overall cohort, grade 3-4 treatment-related acute toxicities occurred in 6.4% during NCRT and 9.4% during systemic chemotherapy. No grade 5 adverse events (AEs) were observed. After PSM, CR rates were comparable between YE and OE groups (43.1% vs. 36.2%, P= 0.57), and the two groups also achieved similar 3-year CSS (96.0% vs. 98.1%, P= 0.22). Regarding treatment-related toxicities, the incidence of grade 3-4 acute AEs did not differ between the YE and OE groups during NCRT (5.2% vs. 3.4%, P=1.00) and systemic chemotherapy (12.1% vs. 8.6%, P= 0.51). However, YE patients experienced a lower incidence of grade 2-4 acute toxicities (NCRT: 46.6% vs. 67.2%, P= 0.04; systemic chemotherapy: 39.7% vs. 58.6%, P= 0.06), predominantly hematologic.
Conclusion: Long-course chemoradiotherapy-based TNT, followed by surgery or watch-and-wait, demonstrated favorable oncologic outcomes and acceptable toxicities in elderly patients with LARC aged =60 years. Compared with younger-elderly (60-69 years) patients, older-elderly (=70 years) patients may also benefit from TNT.