Older mRCC patients see greater toxicity from treatments but derive similar benefits

While age does not seem to affect outcomes, older patients with metastatic renal cell carcinoma (mRCC) seem to be more prone to treatment toxicities, a recent study has found.

The study included 838 mRCC patients who had been treated with first-line tyrosine kinase inhibitors (TKI), mammalian target of rapamycin inhibitors, or checkpoint immunotherapy (CPI). Outcomes such as overall survival (OS), time-to-treatment discontinuation (TTD), and progression-free survival (PFS) were compared across three age groups: ≥75, 65–74, and <65 years.

Older patients were given a lower TKI dose. The final daily median dose of pazopanib, for example, was 300 mg in patients ≥75 years of age, after adjusting for toxicities. In those aged 65–74 and <65 years, the doses were 400 and 600 mg, respectively. The corresponding doses for sunitinib after toxicity adjustments were 25, 37.5, and 50 mg (p<0.001 for both therapies). Older patients received fewer CPI treatments, though only numerically so (p=0.22).

In addition, dose reductions or interruptions occurred at a significantly greater frequency in patients aged ≥75 years than in those 65–74 or <65 years of age (76 percent vs 55 percent and 41 percent; p<0.001).

In contrast, age seemed to have no significant impact on outcomes. Median OS was similar between groups (p=0.5), as were TTD (p=0.9) and PFS (p=0.4).

“[O]lder age should not preclude patients with mRCC from therapy,” the researchers said. Instead, “[p]roactive dose modification/interruption, and patient and physician awareness may help to reduce toxicity while maintaining efficacy.”