New evidence may help improve management of rare kidney cancers

CHICAGO — Researchers have identified relapse patterns of nonclear cell renal cell carcinomas — an understudied group of rare kidney cancers — that are distinct from the more common clear cell renal cell carcinomas.

The findings may help improve the management of patients with nonclear cell renal cell carcinomas (non-ccRCC), who represent approximately 20% of kidney cancer patient populations, Vivek Narayan, MD, MSCE, assistant professor of medicine at the Hospital of the University of Pennsylvania, told HemOnc Today.

According to Narayan, the disease biology and clinical behavior of non-ccRCC is unique from clear cell renal cell carcinomas (ccRCC). However, the natural history of non-ccRCC following curative-intent nephrectomy is poorly defined.

“Despite the knowledge or the recognition that non-ccRCC is a distinct type of kidney cancer, the management of this cancer is largely informed by evidence and experience with how we manage clear cell kidney cancer patients,” Narayan said. “Particular gaps in knowledge are how to best conduct surveillance and how to best manage patients after nephrectomy surgery.”

To address this, Narayan and colleagues conducted a retrospective study to investigate the postoperative natural history of non-ccRCC among patients who underwent nephrectomy. The researchers used data from the ASSURE study (ECOG-ACRIN E2805) — the largest randomized controlled clinical trial for adjuvant therapy in patients with kidney cancer — to compare relapse patterns of non-ccRCC with ccRCC.

Results of the ASSURE study showed that rates of DFS and OS did not significantly differ between the subset of patients with non-ccRCC (n = 403) and the overall study population.

Over a 5-year follow-up period, the rate of disease recurrence was similar among patients with non-ccRCC (RR = 34.6%; 95% CI, 29.8-39.4) and those with ccRCC (RR = 39.5%; 95% CI, 36.9-42.1). However, patients with non-ccRCC were more likely to relapse in the abdomen (26.4% vs. 18.2%) and less likely to relapse in the chest compared with patients with ccRCC (13.7% vs. 20.9%).

“That suggests some distinct patterns of relapse in nonclear cell and clear cell patients,” Narayan said.

The results, he added, could have important implications for operative techniques and postoperative surveillance in patients with non-ccRCC.

“While it is tough to inform the optimal approach from a retrospective study, some hypotheses that we raised include the need for more intensified abdominal surveillance among patients who have nonclear cell histologies, and the need to consider more extensive local surgery,” Narayan said. “This should be validated in other datasets to further strengthen these hypotheses.” – by Stephanie Viguers

Reference:

Narayan V, et al. Abstract 4564. Presented at: ASCO Annual Meeting; June 1-5, 2018; Chicago.

Disclosures: Narayan reports receiving consulting or advisory fees from Exelixis and research funding from Bristol-Myers Squibb and GlaxoSmithKline.