Adjuvant chemotherapy benefit according to T/N stage in small bowel adenocarcinoma: a large retrospective multicenter study
Menée en France à partir de données portant sur 354 patients atteints d'un adénocarcinome de l'intestin grêle (âge médian : 63,5 ans), cette étude rétrospective multicentrique analyse l'efficacité, en fonction du stade TNM de la maladie et du point de vue de la survie sans maladie et de la survie globale, d'une chimiothérapie adjuvante
Background: Small bowel adenocarcinoma (SBA) is a rare cancer and the role of adjuvant chemotherapy (AC) for localized disease is still debated. Methods: This retrospective multicenter study included all consecutive patients who underwent curative surgical resection for localized SBA between 1996 and 2019 from 3 French cohorts’ study. Prognostic and predictive factors of AC efficacy were analyzed for disease-free survival (DFS) and overall survival (OS). The inverse probability of treatment weighting method (IPTW) was applied in the Cox regression model using the propensity score derived from multivariable logistic regression. Results: A total of 354 patients were included: median age, 63.5; duodenum location, 53.5%; tumor stage I, II, III in 31 (8.7%), 144 (40.7%) and 179 (50.6%) patients respectively. The AC was administered in 0 (0%), 66 (48.5%), and 143 (80.3%) patients with stage I, II and III, respectively (p < .0001). In the subgroup analysis by IPTW method, a statistically significant DFS and OS benefit in favor of AC was observed in high-risk stage II (T4 and/or <8 lymph nodes examined) and III (T4 and/or N2) but not for low-risk stage II (T3 and ≥8 lymph nodes examined) and III (T1-3/N1) tumors (p-value for interaction tests <0.05). Furthermore, tumor location in jejunum/ileum vs duodenum was also a significant predictive factor of response to AC in stage II and III tumors (p value for interaction tests <0.05). Conclusions: In localized SBA, AC seems to provide a significant survival benefit for high-risk stage II and III tumors, and for jejunum/ileum tumor locations.