Patterns of response after preoperative treatment in gastric cancer

To analyze the rate of pathologic response in patients with locally advanced gastric cancer treated with preoperative chemotherapy with and without chemoradiation at our institution.

From 2000 to 2007 patients were retrospectively identified who received preoperative treatment for gastric cancer (cT3-4/ N+) with induction chemotherapy (Ch) or with Ch followed by concurrent chemoradiotherapy (45 Gy in 5 weeks) (ChRT). Surgery was planned 4-6 weeks after the completion of neoadjuvant treatment. Pathologic assessment was used to investigate the patterns of pathologic response after neoadjuvant treatment.

Sixty-one patients were analyzed. Of 61 patients, 58 (95%) underwent surgery. The R0 resection rate was 87%. Pathologic complete response was achieved in 12% of the patients. A major pathologic response (<10% of residual tumor) was observed in 53% of patients, and T downstaging was observed in 75%. Median follow-up was 38.7 months. Median disease-free survival (DFS) was 36.5 months. The only patient-, tumor-, and treatment-related factor associated with pathologic response was the use of preoperative ChRT. Patients achieving major pathologic response had a 3-year actuarial DFS rate of 63%.

The patterns of pathologic response after preoperative ChRT suggest encouraging intervals of DFS. Such a strategy may be of interest to be explored in gastric cancer.