Pathological Response after Neoadjuvant Treatment in Advanced Gastric Cancer: Impact on Survival
JJ Sola, C Beorlegui, A Panizo, FJ Pardo, G Aisa, JA Diaz-Gonzalez, JL Hernandez, J Aristu, MA Idoate. Clinica Universidad de Navarra, Pamplona, Navarra, Spain
Background: Combined modality treatment, i.e. neoadjuvant radiochemotherapy (ChRT) plus radical surgery, has been promoted to improve the outcome of patients with operable locally advanced gastric cancer. Grade and type of both tumoral and node response could be prognostic factors for global and disease-free survival (OS-DFS).
Design: Sixty one patients with locally advanced gastric cancer (cT3-4/N+) were treated with neoadjuvant ChRT plus radical surgery between 2000 and 2007. For each patient preoperative stage and type of tumor were recorded. Grade of pathological tumor response was performed according Becker's scheme. Type of node response was recorded using Millers' scheme for breast carcinoma. Major pathological response (MPR) was defined as Becker's grade 1 (ீ10% of residual tumor). Statistical studies were performed using SPSS v. 15.0.
Results: Forty patients (65%) received ChRT and the rest only chemotherapy (Ch). T- and N-stage down staging were observed in 75,4% and 46,4% of patients. There were significant differences between Ch and ChRT series in T down staging (57,1% vs. 86,1%, p=.014). Complete pathological response was achieved in 7 patients (12,1%), and grade Ia of response was observed in 9 (15,8%), all of them from ChRT group. MPR was observed in 30 patients (52,6%), 33,3% from Ch and 63,9% from ChRT series. Pathological evidence of node response was observed in 29 (52,7%) cases, with only 10 (18,2%) without residual tumor. Median follow-up was 27,3 months (4,8-93). Median OS and DFS were 45,7 and 36,5 months, respectively. Univariate analysis revealed significant differences in DFS for MPR, pN, node complete response and T down staging; there were differences in OS for pT, pN, T and N down staging, MPR and node complete response. In Cox multiple regression only pN (OR=8.85; 95% CI: 2.69-29.4; p<0.001) for DFS and N down staging (OR=4.65; 95% CI: 1.35-15.8; p=0.015) and MPR (OR=2.84; 95% CI: 1.10-7.4 p=0.033) for OS retain the differences.
Conclusions: Combined neoadjuvant ChRT were more effective than Ch alone to obtain complete or major pathological response in locally advanced gastric carcinoma, although there were no differences in DFS or OS between both groups. Major pathological response and N down staging were independent prognostic factors for OS while only pN was prognostic factor for DFS.
Tuesday, March 23, 2010 1:00 PM
Poster Session IV # 61, Tuesday Afternoon