Thus far, the routine use of chemotherapy after surgery has not been shown to improve survival for patients with stomach or gastric cancer in whom all visible cancer was removed surgically. This is the conclusion that researchers at M.D. Anderson Cancer Center in Houston drew after their review of studies published on stomach cancer over the last 15 years. However, the researchers also point out that chemotherapy used after surgery (adjuvant chemotherapy) may become more beneficial with the development of new, more effective chemotherapy drugs.
Very early-stage cancer of the stomach can often be cured with surgery alone. However, patients with more advanced disease, stage II and III stomach cancer, often experience a recurrence of the cancer (return of cancer) after surgery. This is because some patients will already have small amounts of cancer that spread away from the stomach. Undetectable areas of cancer are referred to as micrometastases and cannot be detected with any of the currently available tests. It is the presence of micrometastases that causes the relapses that follow treatment with surgery alone. An effective treatment is needed to cleanse the body of micrometastases in order to improve the cure rate achieved with surgical removal of the cancer. Efforts are currently underway to find such a therapy.
Various chemotherapy drugs and drug combinations have been used to try to prevent this recurrence and increase survival time. Evaluations of these treatment regimens over the last 15 years have produced contradictory results. More extensive surgery to remove lymph nodes to which the cancer has potentially spread has also been used, but has not in general been shown to increase survival time for patients with stage II and III disease.
To determine which patients benefit from adjuvant chemotherapy and which do not, the Houston researchers reviewed 76 studies on stomach cancer. They found that, when all visible cancer is removed by surgery, adjuvant chemotherapy regimens have not shown to improve the duration of survival when compared to treatment with surgery alone. The researchers concluded that if more effective chemotherapy drugs are needed, chemotherapy utilized before or after surgery will be able to decrease the risk if cancer recurrence. Patients with stage II or III cancer of the stomach are urged to consider participation in 1 of the many clinical trials (research studies) testing new potentially more effective chemotherapy regimens given before or after surgery. (Cancer, Vol 86, No 9, pp 1657-1668, 1999)