Cytologic assessment before and after intraperitoneal hyperthermic chemotherapy for peritoneal carcinomatosis

OBJECTIVE: A phase I/II clinical trial of surgical cytoreduction combined with intraperitoneal hyperthermic chemother npy (IPHC) for patients with disseminated peritoneal carcinoma was begun in December 1991. The use of peritoneal cytology to assess this treatment modality was the objective of this study. STUDY DESIGN: Adult patients with primary intraabdominal cancer with peritoneal dissemination underwent surgical debulking and intraoperative, two-hour, heated abdominopelvic perfusion with mitomycin C (MMC). Peritoneal washings were sent before and after IPHC, and the use of peritoneal cytology in this setting was reviewed retrospectively. RESULTS: Twenty patients (9 female, 11 male) with adenocarcinoma (19) and one with epithelial mesothelioma, all with bulky peritoneal disease, were treated. Pre- and post-IPHC cytologic specimens were available for 18 cases. Cytology was tumor negative in three cases before and after IPHC. Conversion to negative post-IPHC cytology was seen in 6 of 15 cases and correlated with total or near-total tumor debulking (Fisher's exact test, P=.002). For 13 patients with follow-up greater than or equal to 6 months, 6 patients with both negative post-IPHC cytology and tumor less than or equal to 1 g were alive at 6 months; of 7 patients with residual gross tumor or positive post-IPHC cytology 5 had died within 6 months (P=.02). CONCLUSION: Some patients undergoing IPHC with tumor-positive peritoneal cytology will convert to negative cytology following IPHC. This correlates with total or near-total tumor debulking and is associated with improved survival.