Peritoneal implants of ovarian serous borderline tumors. Histologic features and prognosis.

The clinicopathologic features of 56 cases of ovarian serous borderline tumors (SBT) associated with peritoneal implants were reviewed. Data from 368 person-years of follow-up (median follow-up, 6.0 years) were analyzed to investigate the possibility that the histologic features of implants of this type of tumor may correlate with the prognosis. Eighty-five percent of the 56 patients were clinically free of tumor at the time of death or at last contact. Thirteen percent of the patients died of tumor, and one patient (2%) was alive with widespread progressive tumor. The product-limit estimate of the probability of death from tumor (+/- standard error) was 4% (+/- 3%) at 5 years and 23% (+/- 9%) at 10 years. The following three histologic features of the implants correlated with an adverse prognosis: (1) invasion (P = 0.0004), (2) severe cytologic atypia in both invasive and noninvasive implants (P = 0.0008) and in noninvasive implants alone (P = 0.02), and (3) the presence of mitotic activity in both types of implants (P = 0.02) and in noninvasive implants alone (P = 0.02). The only other feature that correlated with the prognosis was the presence of residual tumor postoperatively as assessed by the surgeon (P = 0.01). The product-limit estimate of death of tumor in patients with at least one of these four adverse prognostic factors was 56% (+/- 20%) at 10 years. Whether or not the patients received radiation therapy, chemotherapy, or both had no statistically significant effect on the outcome. These data and the results of a stratified analysis suggest that patients may benefit from additional therapy if adverse prognostic factors are present, especially invasiveness or severe cytologic atypia. It is unlikely that additional therapy is necessary in patients without adverse prognostic features, because no deaths occurred in this group.