Intraperitoneal adjuvant immunochemotherapy in operable gastric cancer with serosal involvement

Since the peritoneal cavity is the most common site of initial recurrence in patients after surgery for gastric cancer, an intraperitoneal (IP) adjuvant treatment was tested in patients with resected gastric cancer with serosal involvement. Between March 1986 and September 1991, 44 consecutive patients with resected T3/T4-N0/N+ gastric cancer were given an IP combination, including cisplatin or carboplatin, etoposide, and alpha interferon-2b. The overall survival of these patients was compared with that observed in 47 historical controls (admitted to the same institutions from 1983 to 1986) with similar prognostic characteristics, who had not received adjuvant treatment after surgery. No major complication relating to the IP route was observed. Mild to moderate abdominal pain occurred in nine patients. Grade 3-4 myelotoxicity occurred in 14 patients. Interferon had to be reduced in five patients and suspended in one because of severe fatigue. Emesis occurred in 23/28 patients given cisplatin and 9/16 given carboplatin. At the time of this analysis (September 1992) median follow-up was 42 months (range 12-78) in the group receiving IP treatment, and 97 months (range 74-128) in the historical controls. There had been 20 deaths among treated patients compared with 36 in the control group. The 5-year estimated survival rate was significantly better in the patients who received IP adjuvant treatment (44% +/- 9 versus 23% +/- 6; P = 0.016). Using the Cox proportional hazard model with a backward procedure to correct for the influence of prognostic pretreatment variables, IP treatment again afforded a significant advantage in terms of survival (P = 0.04). Adjuvant IP immunochemotherapy appears to improve prognosis compared with historical controls in patients having operable gastric cancer with serosal infiltration.