Lymphatic spread among women with primary peritoneal carcinoma.

BACKGROUND AND OBJECTIVES

Our knowledge regarding the pathologic lymphatic spread pattern of primary peritoneal carcinoma (PPC) is limited. The aim of this study was to compare the incidence and the pathologic patterns of pelvic and para-aortic lymph node metastases among women with PPC and those with papillary serous ovarian carcinoma (PSOC).

METHODS

We conducted a prospective study over the last 4 years among women with FIGO stage III and IV PPC and PSOC who had optimal primary cytoreductive surgery (<1 cm residual). The same surgeon performed pelvic and para-aortic lymphadenectomy on all the patients using a similar technique. The same pathologist reviewed all lymph nodes and recorded nodal involvement with cancer, diameter of the largest nodal tumor, capsular integrity, and pattern of immune response (lymphocyte predominant, germinal cell predominant, unstimulated, or lymphocyte depletion). Both groups were compared in their characteristics, FIGO stage, tumor grade, number of lymph nodes, proportion of lymph nodes with metastases, and the pathologic characteristics of the positive lymph nodes.

RESULTS

Eleven women had PPC and 27 had PSOC. Patients with PPC were older than those with PSOC (mean age: 63.2 years +/- 11.0 vs. 57.4 +/- 13.4, P = 0.181). There was no difference in FIGO stage or tumor grade between both groups. There was no difference among the mean numbers of pelvic and para-aortic lymph nodes between women with PPC and those with PSOC (10.8 +/- 7.3 vs. 11.0 +/- 6.7 and 3.0 +/- 3.3 vs. 3.4 +/- 2.1, P = 0.768 and 0.706, respectively). The incidences of pelvic, para-aortic, and pelvic and/or para-aortic lymph node metastases were similar among women with PPC and those with PSOC (72.7% vs. 66.6%, P = 0.701, 72.7% vs. 48.1%, P = 0.172, and 72.7% vs. 77.8%, P = 0.736, respectively). Similarly, pelvic and para-aortic nodal tumor size, capsular integrity, and immune response were similar in both groups. The incidence of significant complications related to lymphadenectomy was low among women with PPC and those with PSOC (9.1% vs. 7.4%, respectively).

CONCLUSIONS

PPC and PSOC exhibit similar pathologic lymphatic spread patterns. Pelvic and para-aortic lymphadenectomy should be considered among women with PPC in whom the tumor could be optimally cytoreduced.