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

ObjectiveLymphopenia 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 MethodsWe 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.ResultsTwenty-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).ConclusionsSunitinib 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.