Study: Collecting duct carcinoma

Collecting duct carcinoma is a rare and highly aggressive variant of renal cell carcinoma that frequently presents with advanced disease, has few effective treatment options, and is associated with a poor prognosis.

Because of its rarity, most reports in the literature suffer from few patient numbers and little more than clinical anecdotes for treatment recommendations. In this report by Tokuda and colleagues, the collective experience of 281 institutions in Japan with collecting duct carcinoma are summarized as the result of a survey conducted from 2001 to 2003.

From 120 cases initially identified during the survey from 66 institutions, 81 cases were confirmed as collecting duct carcinoma based on independent histologic analysis. Mean patient age was 58.2 years, 71.6% of patients were male, and 65.4% of patients presented with symptoms related to their tumor. Median primary tumor size was 6 cm and 97.5% of tumors were grade 4. Of those that underwent a lymph node dissection during resection of the primary tumor, 44.2% had positive lymph nodes, and 32.1% of patients had distant metastasis at presentation. Surgery was utilized as a primary therapy in 98.8%. With a median follow-up of 15 months, the 1 year, 5 year, and 10 year disease free survival was 69%, 34.3% and 13.7%, respectively, further emphasizing the aggressive nature of this tumor type. Primary tumor stage was organ confined (T1-T2) in 39%, T3a in 31%, T3b-c in 18.5%, T4 in 7.4%, and not available in 5%. Many varied adjuvant therapies were applied in appropriate patients, with no obvious responses except for one patient who had a partial response to a gemcitabine/carboplatin regimen.

Collecting duct carcinoma is a rare and aggressive variant of renal cell carcinoma. Therapeutic advances in this tumor type remain hampered by the rarity of the tumor that prevents the conduct of clinical trials that could evaluate potentially effective therapies. As a consequence, we are still relegated to clinical anecdotes as guides to therapeutic intervention in patients.

Written by Christopher G. Wood, MD - UroToday

Tokuda N, et al., J Urol 176: 40-43, 2006