ObjectiveSurgeons have postulated on numerous occasions that cancer resection may participate in the dissemination of a malignancy. This randomized trial sought to determine whether a large volume of chemotherapy solution used perioperatively to flood the peritoneal cavity could eliminate microscopic residual disease and thereby improve survival of patients with gastric cancer. Summary Background DataSurgical treatment failures in patients with gastric cancer are confined to the abdomen in most patients. Resection site and peritoneal surface spread, along with liver metastases, are the most common areas of recurrence. Survival and quality of life of patients with gastric cancer would be improved if disease progression at these anatomic sites was reduced. MethodsIn a prospective randomized trial of 248 patients, intraperitoneal mitomycin C on day 1 and intraperitoneal 5-fluorouracil on days 2 through 5 were administered after gastric cancer resection. Patients who were thought to have stage 11 or stage Ill disease were randomized after resection to surgery alone versus surgery plus early postoperative intraperitoneal chemotherapy. After final pathologic examinations, there were 39 patients with stage 1, 50 with stage 11, 95 with stage 111, and 64 with resected stage IV cancer. ResultsThe 5-year survival of the surgery-only group was 29.3%, and the surgery-plus-intraperitoneal chemotherapy group was 38.7% (p = 0.219). In a subset analysis, the patients with stage 1, stage 11, and stage IV disease showed no statistically significant difference in survival. The 5-year survival rate of patients with stage Ill disease who underwent surgery only was 18.4% versus a survival rate of 49.1 % for patients who underwent surgery plus intraperitoneal chemotherapy (p = 0.011). ConclusionsIn a subset analysis, patients with stage Ill gastric cancer have shown a statistically significant improvement in survival when treated with perioperative intraperitoneal chemotherapy. Further studies in patients with gastric cancer with surgically directed chemotherapy are suggested.

Previous analysis of this prospective randomized trial and meta-analysis of published randomized trials of adjuvant intraperitoneal chemotherapy demonstrated improved survival in patients with advanced gastric cancer. Simple criteria applicable at the time of surgery for patient selection were sought in this analysis. From 1990 to 1995 a series of 248 patients with biopsy-proven gastric cancer were randomized intraoperatively to receive early postoperative intraperitoneal mitomycin C and 5-fluorouracil (125 patients) versus surgery only (123 patients). Gastric resection plus early postoperative intraperitoneal chemotherapy showed improved overall survival compared to surgery only (54% and 38%, respectively; p = 0.0278). There were statistically significant differences in patients with stage III (57% and 23%, respectively; p = 0.0024) and in those with stage IV (28% and 5%, respectively; p = 0.0098) gastric cancer. The improvement in survival rate was statistically significant for the subgroup of patients with gross serosal invasion (52% and 25%, respectively; p = 0.0004) and patients with lymph node metastasis (46% and 22%, respectively; p = 0.0027). The surgeons' impression about lymph node status was unreliable, but assessment of serosal invasion was accurate in 80% of cases. Gross serosal invasion with or without frozen section evaluation of lymph nodes can be used as the major selection criteria for early postoperative intraperitoneal chemotherapy of advanced gastric cancer.

BACKGROUND.Peritoneal carcinoma has been regarded as a uniformly lethal clini-

Purpose: The purpose of this study was to report the pharmacokinetics of heated intraoperative intraperitoneal mitomycin C (MMC) and to analyze the impact of heat, extent of peritoneal resections, and effect of intraoperative hyperthermic chemotherapy on the pharmacological properties of the peritoneal plasma barrier. Methods: Sixty patients with peritoneal carcinomatosis were included in a phase I/II study combining cytoreductive surgery with 2 h of heated intraperitoneal mitomycin C in an intraoperative lavage technique and one cycle of early postoperative 5-fluorouracil (5-FU) given on postoperative days 1–5. Three pharmacokinetic analyses were performed: (1) pharmacokinetics of heated intraoperative intraperitoneal MMC was determined for 18 patients by sampling peritoneal fluid, plasma, and urine during the 2-h procedure; (2) impact of peritoneal resections on MMC pharmacokinetics was assessed by comparing a group of patients who underwent ≤1 peritonectomy procedure (minimal surgery) to a group of patients who underwent ≥2 peritonectomy procedures (extensive surgery), and (3) effects of heated intraoperative intraperitoneal chemotherapy on the pharmacokinetics of early postoperative intraperitoneal 5-FU by comparing a group of patients treated with heated intraoperative intraperitoneal MMC to a control group who did not receive heated intraoperative intraperitoneal chemotherapy. Results: The mean dose of heated intraoperative intraperitoneal MMC per patient was 22.5 ± 7.1 mg (12.9 ± 3.8 mg/m²). Drug absorption from perfusate was 14.3 ± 2.7 mg. The mean aeras under the curve (AUC) for perfusate and plasma were, respectively, 340 ± 138 and 15 ± 4 µg/ml × min. The mean AUC peritoneal fluid/plasma ratio was 23.5 ± 5.8. Patients who underwent extensive peritoneal resections exhibited a significantly (p = 0.037; Wilcoxon rank test) increased peak plasma concentration of MMC, a significantly (p = 0.029) increased AUC of plasma concentrations and a significantly (p = 0.034) decreased peritoneal fluid/plasma AUC ratio. Pharmacokinetic studies of early postoperative intraperitoneal 5-FU showed no significant difference in plasma AUC, perfusate AUC and AUC ratio between patients who received and those who did not receive heated intraoperative intraperitoneal MMC. Conclusions: Heated intraoperative intraperitoneal chemotherapy achieves high peritoneal concentrations of MMC with limited systemic absorption. Systemic drug absorption during heated intraoperative intraperitoneal chemotherapy is increased when extensive peritoneal resections are performed, but such slight increases are unlikely to change the risk of systemic drug toxicities. Heated intraoperative intraperitoneal chemotherapy does not alter the pharmacokinetics of early postoperative intraperitoneal 5-FU.

Two main approaches are suggested to improve treatment results in resectable gastric cancer: extended lymphadenectomy and adjuvant antitumour therapy. Progress is to some extent stalled by the perception of gastric cancer as a pathophysiologically uniform disease; it has been demonstrated, however, that there are variants of gastric cancer associated with predominantly intra-abdominal spread or with haematogenous metastases. Recent clinicopathological studies have provided information about the mechanisms of this metastatic diversity. A review of clinical trials suggests that no single method of treatment can efficiently address all variants of gastric cancer spread, but new treatment strategies may be based on defining the pathophysiological variant of gastric cancer and selecting adjuvant therapy according to the most probable mode of tumour spread. Treatment should start with surgery which includes a 'reasonably' extended lymphadenectomy aimed at achieving an increased rate of curative resection and more accurate staging. Risk factors for peritoneal spread of tumour require the perioperative use of intraperitoneal chemotherapy. Subsequent adjuvant therapy may be indicated in patients at high risk of further cancer spread or occult metastases, as determined by pathological examination of the resected specimen.