PERITONEAL ADENOCARCINOMA (SEROUS) OF MULLERIAN TYPE - A SUBGROUP OF WOMEN PRESENTING WITH PERITONEAL CARCINOMATOSIS

Peritoneal adenocarcinoma (serous or other subtype) of Mullerian type (PAMT) is frequently misclassified as another primary tumor. Peritonea l carcinomatosis in women without evidence of a primary site may occur secondary to a number of processes. Confusion regarding the nomenclat ure has made it difficult to determine the incidence and natural histo ry of this unique malignancy. Other terms used for this tumor include mesothelioma, peritoneal papillary serous carcinoma, extra-ovarian ser ous carcinoma, and normal-sized ovarian carcinoma syndrome. Thirty-fou r patients (33 serous and one endometrioid) were identified with PAMT during 1976 through 1988. One hundred and thirty-seven patients underw ent primary cytoreductive surgery for a preoperative diagnosis consist ent with ovarian cancer. Twenty-nine (21.2%) were classified as PAMT ( 5 of the 34 had their initial surgery at other institutions). The mean age was 61.4 years. The primary symptoms and signs were abdominal pai n (68%) and ascites (52%). Twenty-five (73%) had a preoperative diagno sis of ovarian cancer while the postoperative diagnosis was unknown (4 4%), PAMT (29%), and ovarian cancer (27%). Univariate and multivariate survival analysis were performed. Survival was independent of age, re sidual disease, grade, ascites, type of chemotherapy, and second-look results. In patients with residual disease <1.5 cm, extended survival was found in those with ascites <1000 ml, residual disease in pelvis o nly, and small residual volume but statistical significance was not ob tained. Twenty-eight patients received greater-than-or-equal-to 4 cour ses of chemotherapy after primary surgery. Twelve of 21 patients (57%) who received cisplatin (CDDP) survived between 23 and 92 months, whil e no patient receiving other chemotherapeutic regimens survived more t han 25 months. The 2 and 3 year survival rate for CDDP was 47% and 33% vs. 14% and 0% for other regimens. Optimal cytoreductive surgery was not an independent prognostic factor as found in ovarian cancer, proba bly secondary to unresectable peritoneal carcinomatosis. PAMT is sensi tive chemotherapy but only the use of. CDDP was associated with long t erm survival. Based on these results, women with peritoneal carcinomat osis consistent with PAMT should receive a CDDP-based regimen after pr imary surgery.