Impact of adjuvant therapy on locally advanced adenocarcinoma of the stomach.

From 1975 to 1988, 120 consecutive patients with locally advanced (T3/T4 or N1/N2) adenocarcinoma of the stomach underwent attempted curative resection. Seventy patients were treated with surgery alone while 50 patients also received adjuvant therapy consisting of either chemotherapy (5-FU/FAM) alone, radiation therapy alone, or chemotherapy+radiation therapy. Adjuvant therapy was tolerated relatively well with only one patient experiencing a grade 3 (RTOG/EORTC) toxicity, and none experiencing grade 4/5 toxicity. In patients with T3/T4 tumors, the median survival was 10 months for surgery alone as compared to 18 months for the adjuvant treatment group, and a 5-year survival of 10% versus 24% in the adjuvant therapy group (p = .01). In patients with lymph node positive disease, the median survival was 10 months in patients treated with surgery as compared to 15 months for those treated with adjuvant therapy, and a 5-year survival of 8% for surgery alone versus 16% for the adjuvant therapy group (p = .04). Patients having both T3/T4 tumor and positive lymph nodes had a median survival of 9 months with surgery versus 13 months for the adjuvant therapy group, and a 5-year survival of 4% versus 22% (p = .03) for the adjuvant group. Seventy-four patients were evaluable for pattern of relapse. Thirty developed locoregional recurrence; 17 of 38 (45%) in the surgery alone group and 13 of 36 (36%) in the adjuvant therapy group. The improvement in local control in the adjuvant group was totally accounted for by the group receiving both chemotherapy and radiation therapy, in which the recurrence rate was 19%. Statistically significant improvement in the 2-year local control rate was limited to patients with negative surgical margins who received radiation, 93%, versus those who did not, 55% (p = 0.03). The modest improvement in survival seen in patients receiving adjuvant therapy appears to be related to improved local control. No improvement in the rate of distant failure was seen. Chemotherapeutic regimens used seem to be critical in enhancing the effects of radiation in improving local control and survival. Results may be further improved by the extended use of intraoperative radiation.