EAU 2018: The role of histologic subtypes in follow-up scheme of postsurgical kidney cancer patients
In this abstract, the authors evaluated their own institutional RCC recurrence data to help better inform the surveillance strategy. This was a retrospective review of 2047 patients treated surgically for RCC between 1987 and 2016 at a single institution. Patients were stratified based on metastatic status at the time of diagnosis, cM0 or cM1.
They presented a lot of data, the highlights of which are below.
Overall, 10% of patients were cM1 and 24% experienced oncologic progression (OP). Of patients with chRCC (chromophobe), ccRCC (clear cell), p1RCC (papillary type 1) and p2RCC (papillary type II), the percentage presenting with metastatic disease and developing OP was 3%, 12%, 3%, 7% and 7%, 26%, 11%, 22% of patients, respectively (all p<0.01).
On MVA analyses, in patients who were cM0, ccRCC and p2RCC, pT and pN stage and Fuhrmann grade were predictors of progression (all HR>2, all p<0.05). However, it may be a typo, but for tumor size and age, the HR was 1.0 (CI 1-1) and yet this was listed as significant – this calls into question the accuracy of the analysis. Conversely, no predictor of OP was identified in cM1 patients.
When comparing proportions among OP sites (abdomen vs. chest. vs. bone vs. brain), in cM0 patients, imbalances in histology type were found for patients with chest and bone progression. Among cM0 chRCC patients, no OP to chest was recorded, but the 80% of them progressed to bone, at a median time of 20 months. 13% and 10% of cM0 p1RCC or p2RCC progressed to bone (8 and 9 months, respectively).
Based on these findings, the authors note that there is a differential recurrence pattern for patients with cM0 disease based on histologic subtype - for chRCC cM0 patients, oncologic follow-up should focus more on bone scans than chest CT scans. For patients with cM0 ccRCC, p1RCC and p2RCC, follow-up scheme should include both chest CT scan and bone scan, although the proportion of patients with single bone involvement is inferior to that with lung-only dissemination.
However, unfortunately, they did not go into much more specifics. A major limitation of this study, and all other studies in this area, is the quality of metastatic evaluation during the study period – both bone and CT scans evolved rapidly during this time frame. With increased quality, capture of metastases likely increased. Also, CT scans can capture bone metastases – so recommending increased bone scans may not necessarily be needed, if all the bone metastases are in the field of the CT scan. These considerations were unfortunately not accounted for.
Speaker: A. Nini
Co-Author(s): Cianflone F., Lucianò R., Larcher A., Carenzi C., Cazzaniga W, Matloob R., Montorsi F., Doglioni C., Gianolli L., Rigatti P., De Cobelli F., Del Maschio A., Gandaglia G., Briganti A., Salonia A., Picchio M., Freschi M., Nicoletti R., Capitanio U., Bertini R.
Written by: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto, Twitter: @tchandra_uromd at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark