Port site metastasis after surgery for renal cell carcinoma: harbinger of future metastasis

Port site metastasis is a rare occurrence after minimally invasive treatment for renal cell carcinoma. However, its prognostic implications are unclear because reports in the literature are heterogeneous in detail and followup. We clarify the significance of port site metastasis in cancer specific survival and broaden our understanding of this phenomenon.

A MEDLINE® search for published studies of renal cell carcinoma port site metastasis was performed. Contributing factors to port site metastasis, stage, Fuhrman grade, pathology, port site metastasis treatment method, followup protocol and long-term outcomes were collected. The corresponding authors of each publication were contacted to fill in details and provide long-term outcomes. We added 1 case from our recent experience.

A total of 16 cases from 12 authors (including ourselves) were found. Of the 12 authors 8 were available for correspondence and 9 cases were updated. Eventual outcomes were available for 11 of the 16 cases and survival curves showed poor prognosis with a 31.8% overall 1-year survival rate. Of the 16 cases 12 were radical nephrectomy and 4 were partial nephrectomy, and 13 involved multiple metastases in addition to the port site metastasis. Nine of the cases had no identifiable technical reason for port site metastasis formation such as specimen morcellation, absence of entrapment or tumor rupture. These tumors were uniformly aggressive, Fuhrman grade 3 or higher.

Port site metastasis after minimally invasive surgery for renal cell carcinoma is a rare occurrence with a poor prognosis. In most cases port site metastasis is not an isolated metastasis but instead is a harbinger of progressive disease. While technical factors can have a role in port site metastasis formation, it appears that biological factors like high tumor grade also contribute.