Lymphopenia and clinical outcome of elderly patients treated with sunitinib for metastatic renal cell cancer.

Objective: Lymphopenia is associated with toxicity and outcomes in several cancer types. We assessed the association between pre-treatment lymphopenia, toxicity, and clinical outcomes in elderly patients with metastatic renal cell cancer (mRCC) treated with first-line sunitinib. Prognostic factors in these patients were also evaluated.

Patients And Methods: We reviewed the clinical records of 181 patients with mRCC aged ≥70 years treated with first-line sunitinib in 17 Italian Oncology Units from February 2006 to September 2011. Baseline lymphopenia was defined as lymphocyte counts <1000/μL.

Results: Twenty-nine (16%) patients had a baseline lymphocyte count <1000/μL (group A) and 152 (84%) patients had a lymphocyte count ≥1000/μL (group B). Although no differences between the two groups were reported in terms of overall response rate (P = 0.207), dose reductions (P = 0.740), discontinuation due to adverse events (P = 0.175) or overall incidence of grade 3-4 toxicities (P = 0.112), more patients in the lymphopenia group had grade 3-4 neutropenia (P = 0.017), grade 3-4 thrombocytopenia (P = 0.017) and grade 3-4 diarrhea (P = 0.006). In multivariate analysis, performance status and Heng score were predictors of progression-free survival (P = 0.015 and P = 0.0006, respectively), while performance status, Heng score, and lymphopenia were found to be significantly associated with overall survival (P = 0.007, P < 0.0001 and P = 0.023, respectively).

Conclusions: Sunitinib appears to be safe and active in elderly patients with lymphopenia. Lymphocyte count is an independent prognostic factor for overall survival in elderly patients with mRCC treated with first-line sunitinib.