Internal Medical Treatment of Gastric Cancer, February 12, 2001

Internal Medical Treatment of Gastric Cancer, February 12, 2001

Gastric cancer has the highest incidence and mortality rate among all cancers in China. Qinghai, Ningxia, and Gansu are high-incidence areas, while Jiangsu, Shanghai, Zhejiang, and Fujian have relatively higher incidence, and southern provinces have comparatively lower rates. Pathology: protruding, ulcerated, and flat types—these are early stages; polypoid and ulcerated types—these are mid-to-late stages. Pathological cytological classification: adenocarcinoma, mucinous adenocarcinoma, poorly differentiated adenocarcinoma, undifferentiated adenocarcinoma, adenosquamous carcinoma, squamous cell carcinoma, etc.

Treatment principles: Stage I—radical surgery; Stages II and III—radical surgery plus chemotherapy (preoperative and postoperative chemotherapy); Stage IV—primarily chemotherapy, with minor palliative surgeries possible when necessary, such as relieving obstruction or jaundice. Radiotherapy is generally not recommended because it is too sensitive to the gastric mucosa and difficult to achieve therapeutic goals. The recurrence rate of early-stage gastric cancer within two years after surgery is 50%, so 3–4 rounds of chemotherapy are required within the first 1–2 years post-surgery. According to ASCO statistics, the 5-year survival rate for gastric cancer surgery is: Stage I—63%, Stage II—22%, Stage III—5%, and Stage IV—0%. Chemotherapy: Single-drug chemotherapy: MMC, 5-Fu, ADM, epirubicin (EPⅠ), DDP, VP-16, carmustine (BCNU), CCNU, MTX—single-drug PR ranges from 20% to 30%. Combination chemotherapy: Overall effectiveness is about 30%–50%. The most commonly used regimens currently are: MFA—MMC, 5-Fu, ADM, with an effectiveness of 33% and a median survival of 6–7 months; MFC—MMC, 5-Fu, Ara-c, with an effectiveness of 30% and a median survival of 6 months; FAB—5-Fu, ADM, BCNU, with an effectiveness of 38% and a median survival of 6–8 months. Gastric cancer treatment typically involves chemotherapy in 3-week cycles, with three cycles constituting one course. Usage of these drugs: MMC 4–10 mg, 1–2 times per week; 5-Fu 500 mg, 3–5 times per week; ADM 30 mg, 1 time every 3 weeks; VP-16 100 mg, 1–3 times per week; Ara-c 100 mg, 1–3 times per week; BCNU 100 mg, 1–2 times per week; DDP 20 mg, 1–3 times per week (with hydration). Generally, the first week is for medication, followed by 2–3 weeks of rest, forming one cycle. Three cycles make up one course. It is recommended to undergo 3–4 courses within the first two years after surgery.