Gastric Cancer

Abstract

The objective of induction chemotherapy in the treatment of gastric cancer has been to reduce the risk of local recurrence and distal recurrence after gastrectomy. Results of early studies in treating both early and advanced gastric cancers have been very encouraging so that a prospective randomized trial is presently being conducted.

Traditionally, the common objective of induction chemotherapy has been to reduce risk of distant disease recurrence. The rationale for a risk-based approach to definitive local treatment individualized at diagnosis (and not after assessment of response to induction chemotherapy), avoiding unnecessary and potentially toxic concomitant chemoradiotherapy for selected patients.

Giving chemotherapy before other treatment has many theoretical advantages. Induction chemotherapy can result in down-staging tumors, thus increasing the rate of more conserving or radical surgery.

In cases of more advanced disease, induction chemotherapy can render inoperable tumors resectable. Other advantages of induction therapy include the ability to obtain information about tumor response, which can be used to study the biologic effects of chemotherapy and assess long-term disease-free and overall survival.

Induction chemotherapy as a component of primary treatment has been shown in several studies and meta-analyses to decrease the incidence of metastatic disease developing.

Now the terms induction, primary, preoperative, basal, and neoadjuvant are all used to describe chemotherapy given as initial therapy.

Gastric cancer is the second leading cause of cancer-related death worldwide, accounting for more than 20 deaths per 100,000 population annually in East Asia, Eastern Europe, and parts of Central and South America.

Gastric cancer is also the second most frequent cause of cancer death after lung cancer in Japan (despite the markedly higher curability obtained by early detection and surgery than in Western countries), because advanced or recurrent gastric cancer shows a poor prognosis. The development of effective standard chemotherapy is much needed.

The prognosis of patients with advanced gastric cancer who do not undergo surgery or who undergo non-curative therapeutic chemotherapy alone is unlikely to have sufficient impact to effect long-term survival.

Combined induction chemotherapy and radical surgery may be a more effective approach in treatment of unresectable cancers. However, one prerequisite of preoperative chemotherapy is that it should not cause such serious impairment of vital functions as to subvert the performance of invasive surgery under general anesthesia. To achieve a good local response without severe toxicity, chemotherapy must obtain a high drug concentration in the tumor yet have a low level in the peripheral blood. Since around the 1950s (Taguchi T, Nakamura H, editors. Arterial infusion chemotherapy. Tokyo: Japanese Journal Cancer and Chemother Publishers; 1994. ISBN 0385-0684), many reports attest to the clinical benefit of regional chemotherapy for several malignancies such as head and neck cancer, soft parts sarcoma, and metastatic liver cancer.