Gastric cancer: current status of treatment

While carcinomas of the stomach is decreasing in incidence in the Dnited States, it is still a major cause of cancer death. But gastric neoplasms are not decreasing in some other geographic areas. According to some studies, 30% of all cancer in the U.S.S.R. originates in the stomach. The rate of gastric neoplasms is greatest in Japan, and over 54% of all cancer in the male population arises in the stomach. The peak age for development of stomach cancer is between 70 and 80 years; over 60% of all stomach cancer is diagnosed in patients between the ages of 60 and 70, while more than 10% is found in those over 80. The main hope for cure at this time rests with surgical treatment. However, despite increased use of surgery, the 5-year survival rate of approximately 13% for patients diagnosed during 1955-59 has not improved to any degree since that time. The major drugs commonly used to treat gastric cancer are 5-fluorouracil (5-FU) and mitomycin C. Controversy still exists concerning the optimum method for administering 5-FU, the most frequently used drug in the United States. The standard loading-course method was attended by a high risk of severe toxicity and drug-related deaths. Several variations of the loading course have evolved. Currently, the Mayo Clinic group uses a 5-day course of 13.5 mg 5-FU/kg repeated every 5 weeks, with therapy interrupted if stomatitis or diarrhea develops; with this regimen the drug-related mortality rate was reported to be less than 1%. Studies have shown that 5-FU plus radiotherapy can enhance survival in patients with locally unresectable diseases. The overall objective with 5-FU is 20-25% with an average of 4-5 months' duration of response. Despite the many patients treated with 5-FU, rarely has a systematic analysis been done of factors such as age, sex, disease-free interval, histologic grade of the tumor, or sites or metastases, which might predispose to a favourable or unfavorable response. In Japan the most commonly used drug for treatment of gastric cancer is mitomycin C, the second most frequently used drug in the United States. The overall objective response rate with mitomycin C is between 20 and 30%, with the higher response rates being reported in the Japanese data. The average duration of response ranges from 1 to 3 months. The nitrosoureas [1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), 1,3-cis(2-chloroethyl)-1-nitrosourea (CCNU), and methyl CCNU (MeCCNU)] have shown some evidence of activity against gastric cancer. BCNU has yielded an objective response rate of 18% (6/33) and an average duration of response of 4.5 months in gastric cancer patients, most of whom had no prior therapy. Adriamycin recently has been shown to have some antitumor activity, with an approximate response rate of 25%. Combination approaches have been more successful in stomach cancer than in any other gastrointestinal neoplasm. The Japanese have reported higher response rates with a combination of 5-FU, mitomycin C, and cytosine arabinoside...