Adjuvant Therapy for Gastric Carcinoma Patients in the Past 15 Years: a Review of Western and Oriental Trials

Background: The early detection of gastric carcinoma is neither feasible nor practiced around the world, except on a limited basis in Japan. Thus, because gastric carcinoma is detected later in most patients throughout the world, those who undergo curative resection still remain at high risk for relapse. Adjuvant therapy therefore has a potentially important place in the treatment of these patients. It has been extensively investigated in the Orient, North America, and Europe. The authors reviewed the results of these trials to determine the current status of adjuvant therapy.

Methods: All randomized studies published in the world literature since 1984 were reviewed. These studies were divided into those performed in the West and those performed in Asia and also by the type of therapy investigated (chemotherapy, chemoimmunotherapy, or radiotherapy). These findings were then summarized and tabulated.

Results: In the process of evaluating the results of these studies, the authors uncovered some marked differences in the methodologies employed. For example, the use of no treatment control is a norm in the West, whereas a treatment control is commonly used in Asia. In addition, there is a greater emphasis on chemoimmunotherapy in Asia than in the West. Furthermore, results of Western studies suggest that postoperative adjuvant therapy is ineffective, whereas the results of the Asian trials do not give a clear indication. Despite this, most Asian patients receive postoperative or perioperative adjuvant chemoimmunotherapy.

Conclusions: Postoperative chemotherapy as an adjuvant to potentially curative resection of gastric carcinoma remains investigational despite more than 30 years of investigation in the West. Newer therapeutic combinations or strategies (preoperative chemotherapy or chemoradiotherapy) have the potential to benefit the high risk patients.