Whatever drugs are used, chemotherapy should start as soon as possible. Waiting 40 to 60 days allows the tumor cell population to double. Primary stomach cancer appears to be more responsive to chemotherapy than metastatic cancer.
Adjuvant Chemotherapy Despite many ongoing North American clinical trials evaluating the use of chemotherapy as an adjuvant therapy after surgery, there is not yet any conclusive proof of its effectiveness, although early results suggest that further clinical trials should be conducted to improve response and survival.
The Japanese have reported major benefits in adjuvant programs, but stomach cancer is different in Japan. The cancer is less differentiated and the surgery is more aggressive. Patients usually have fewer tumor cells left after the operation, which may explain the better results of adjuvant therapy.
Biological Therapy Trials evaluating the use of radioactive tagged monoclonal antibodies or toxins
such as ricin to kill cancer cells while sparing normal tissues are under way. Results so far have not been encouraging, and more studies will have to be done to discover whether there is any benefit. The use of interferon or PALA in combination with chemotherapy merits further clinical trials, and some of the preliminary results are encouraging.
