Serous ovarian tumors of low malignant potential with peritoneal implants

Between 1956 and 1985, 82 patients with metastatic low-grade serous ovarian carcinoma, subsequently reclassified by pathologic review as serous ovarian tumors of low malignant potential with peritoneal implants, were seen at the authors' institution. Median age was 34 years (range, 17-64 years). Original stage distribution was as follows: 32 Stage II, 46 Stage III, and four Stage IV. Peritoneal implants in 72 patients were classified as benign (22 patients), noninvasive (37), or invasive (13). For ten patients, implants were clinically documented but histologic material was unavailable. The most common sites of peritoneal implants included the pelvic peritoneum (42), omentum (33), uterus (33), and fallopian tube (26). All patients underwent primary surgery. Postoperative therapy consisted of radiotherapy in 18 patients, single-agent chemotherapy in 37 patients, combination chemotherapy in 25 patients, and no therapy in two patients. Second-look laparotomy documented response to chemotherapy in 42% of patients with no gross residual disease and in 80% of patients with macroscopic residual disease (40% complete response, 40% partial response). Disease-free survival rates were 95% at 5 years and 91% at 10 years. The International Federation of Gynecologists and Obstetricians (FIGO) stage, extent of residual disease, type of postoperative treatment, and type of peritoneal implants had no effect on survival. Based on a comparison of the present study's findings with those in the literature, the authors propose possible explanations for differences in survival by type of peritoneal implants and outline recommendations for clinical management until further studies elucidate the role of postoperative therapy.