There are over a dozen histologic variants of renal cell carcinoma (RCC); therefore, each tumor can vary widely based on genetic, pathologic, and clinical characteristics. The most common histologic variants of RCC include clear cell RCC, papillary RCC, and chromophobe RCC. In a recent study, results of which are now published in JAMA Network Open, researchers found that disease spread for metastatic RCC may vary based on histologic variant, and the location of disease spread is associated with overall survival.
The investigators used the International metastatic RCC Database Consortium (IMDC) database to collect data on 10,105 patients who started systemic therapy for metastatic RCC between 2002 and 2019. At diagnosis, patients had a median age of 60. Of the patients, 72.4% were men, and 84.5% underwent nephrectomy. Ninety-two percent of the patients had clear cell RCC, 7% had papillary RCC, and 2% had chromophobe RCC. Patients had a median of two metastasis sites. For clear cell RCC, lung (70%), lymph nodes (45%), bone (32%), liver (18%), and adrenal glands (10%) were the most common sites of metastasis. Sites of metastatic spread varied between subtypes. In clear cell RCC, metastasis was more commonly found in the lungs (70%), adrenal glands (10%), brain (8%), and pancreas (5%), while for papillary RCC, lymph node metastasis (69%) was more common. Liver metastases (34%) were most frequent in chromophobe RCC. For metastasis sites in clear cell RCC, median overall survival varied. For metastasis to the pleura, the median overall survival was 16 months, and for the pancreas, it was 50 months. In general, patients with papillary RCC usually had a lower overall survival compared to those with clear cell RCC, regardless of metastatic site.
"In this cohort study, sites of metastatic involvement differed on the basis of histologic subtype in metastatic RCC and were associated with overall survival. These data highlight the clinical and biological variability between histologic subtypes of metastatic RCC. Metastases to endocrine organs are infrequent but are associated with the longest median overall survival, whereas metastases to pleura, brain, liver, and bone are associated with poor overall survival," conclude the study authors, led by Shaan Dudani, MBChB, FRCPC, a medical oncology fellow at Tom Baker Cancer Centre and the University of Calgary Cumming School of Medicine in Calgary, Alberta, Canada. "These benchmark values are useful for patient counseling and study design. Further research to characterize differences in immune, molecular, and genetic profiles between metastatic sites and histologic subtypes is encouraged."
For More Information
Dudani, S, Velasco GD, Wells C, et al (2021). Evaluation of clear cell, papillary, and chromophobe renal cell carcinoma metastasis sites and association with survival. JAMA Netw Open, 4(1):e2021869. DOI:10.1001/jamanetworkopen.2020.21869
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