Who Can Perform Adjuvant Chemotherapy Treatment for Gastric Cancer? A Multicenter Retrospective Overview of the Current Status in Korea.

Purpose: To investigate the current status of adjuvant chemotherapy (AC) regimens in Korea and the difference in efficacy of AC administered by surgical and medical oncologists in patients with stage II or III gastric cancers. Materials and Methods: We performed a retrospective observational study among 1,049 patients who underwent curative resection and received AC for stage II and III gastric cancers between February 2012 and December 2013 at 29 tertiary referral university hospitals in Korea. To minimize the influence of potential confounders on selection bias, propensity score matching (PSM) was used based on binary logistic regression analysis. The 3-year disease-free survival (DFS) rates were compared between patients who received AC administered by medical oncologists or surgical oncologists. Results: Between February 2012 and December 2013 in Korea, the most commonly prescribed AC by medical oncologists was tegafur/gimeracil/oteracil (S-1, 47.72%), followed by capecitabine with oxaliplatin (XELOX, 16.33%). After performing PSM, surgical oncologists (82.74%) completed AC as planned more often than medical oncologists (75.9%), with statistical significance (P=0.036). No difference in the 3-year DFS rates of stage II (P=0.567) or stage III (P=0.545) gastric cancer was found between the medical and surgical oncologist groups. Conclusions: S-1 monotherapy and XELOX are a main stay of AC, regardless of whether the prescribing physician is a medical or surgical oncologist. The better compliance with AC by surgical oncologists is a valid reason to advocate that surgical oncologists perform the treatment of AC for stage II or III gastric cancers.