Adjuvant treatment of gastric cancer in a long term follow-up

Abstract

BACKGROUND: Advanced gastric cancer carries a poor-prognosis. The best extent of the node dissection and the value of postoperative adjuvant treatments remain open questions. AIM: To study the efficacy of adjuvant chemoradiation and the prognostic value of some clinico-pathological variables in gastric cancer previously submitted to surgery. METHODS: Retrospective single institution study of 69 patients with histological diagnoses of gastric adenocarcinoma, consecutively submitted to radical surgery with curative intent in a five years period. Lymph node dissection was either D1 or D2 at the surgeon's description. All patients were submitted to adjuvant chemoradiation according to MacDonald et al.². Treatment discontinuation and early deaths were considered as serious toxic events. Clinical-pathological variables (the extent D level of the node dissection, T/N-stage, histological subtype, margin status, number of the dissected nodes) were correlated to the results. Overall survival was estimated according to the Kaplan-Meier method and the curves were compared by the log-rank test. RESULTS: Patients characteristics: 48 male/21 female, median age 56,4 y (30-79). In 25 patients, the extent of node dissection was D1, in 41 was D2 and D0 in 3. Staging (n): T2 (16); T3 (49); T4 (4); No (11); N1 (29); N2 (20); N3 (8); Nx (1). Histological subtype: intestinal (45), diffuse (19) and unknown (5). Margins were free in 57 patients, the median number of dissected nodes was 31 (0-120). They were treated with linear acelerator 6 MV photons, AP/PA fields with 45Gy in 5 weeks in 90% of the patients and the treatment was done in a mean time of 19,2 weeks. In the median follow-up of 19,3mo (8-52,5mo), 52 patients with more than 24 months of follow-up occurred 38 deaths. The median overall survival for all patients was 22,2 months. Seven (10%) patients presented serious toxic events and treatment was discontinued. Six (8,6%) refused to continue the treatment. The acute toxicity was predominantly gastrointestinal (63), neurological (2), hematological (3), stroke (1). Toxicity was considered GI/GII (52), GIII (10) and GIV (1). Recurrences were local (6); loco-regional (2); local and distant (5); regional (9); regional and distant (2) and only distant (4). There were two patients with progression of the disease and 11 were lost of the follow-up (16%). Twenty eight (40,5%) were alive without disease. In the 52 patients with longer follow-up the Kaplan Mayer analysis showed: better overall survival was observed in those patients presenting T2 versus T3/T4 tumors (not reached vs 17,3 mo, HR 0,35, 95%CI , P=0,03), N0N1 vs N2/N3 tumors (32,7 mo vs 14,5 mo, P=0,0041) and free vs compromised surgical margins (25,7 vs 17,2 mo, P=0,03). No difference in either T (P=0,430, Fisher exact test), N-stage (P= 0,077), or overall survival (27,1 mo vs 17,3 mo, P=0,28) were detected between patients submitted to D1 or D2 dissections. CONCLUSIONS: In this high-risk population of gastric cancer submitted to adjuvant chemoradiation, D2 dissection was not superior to D1 when chemoradiation was administered, in spite of the retrospective nature of these data and the low number of studied patients. Patients with compromised surgical margins have a very poor prognosis and the addition of chemoradiation seems not improve the survival of these patients.