Lymphopenia and clinical outcome of elderly patients treated with sunitinib for metastatic renal cell cancer.
e15615 Background: Lymphopenia is associated with toxicity and outcome in several cancer types. We assessed the association of pre-treatment lymphopenia with toxicity and clinical outcome of elderly patients with metastatic renal cell cancer treated with first-line sunitinib. We evaluated the prognostic factors in these patients. Methods: We reviewed the clinical files of 181 patients aged >70 years with mRCC treated with first-line sunitinib in seventeen Italian Oncology Units from February 2006 to September 2011. Baseline lymphopenia was defined as lymphocyte counts <1,000/µL. Results: Twenty–nine patients (16.0%) had a baseline lymphocyte counts <1,000/µL, and 152 (84%) ≥1,000/µL. No difference between the two groups was reported in overall response rate (p = 0.207), dose reductions (p = 0.740); discontinuations due to adverse events (p = 0.175), overall incidence of grade 3-4 toxicities (p = 0.112) even if more patients in the group with lymphopenia 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 appeared safe and active in elderly patients with lymphopenia. Lymphocyte counts is an independent prognostic factor for OS in elderly patients with mRCC treated with first-line sunitinib.