Prognostic significance of hematological profiles in melanoma patients

Cancer-related inflammation may play an important role in disease progression and patient outcome, and could be easily monitored through indirect parameters routinely evaluated at diagnosis. Here, we investigated if peripheral blood cells and the ratios of neutrophils to lymphocytes (NLR) and of lymphocytes to monocytes (LMR) as surrogate markers of cancer related inflammation are associated with disease progression and survival of melanoma patients at any stage of the disease. Records of 1,182 melanoma patients included in an Institutional tumor registry in the period 2000-2010, were reviewed. Among them, 584 patients with a cutaneous or unknown primary melanoma and available pre-operative blood tests were analyzed. Survival was estimated with the Kaplan-Meier method, and analyzed using Log-rank test, Cox regression and multivariate Cox proportional hazard models. We found that patients presenting with distant metastases had higher leukocytes, neutrophils and monocytes, and lower lymphocytes compared to Stage I-III patients. Furthermore, at a single-patient level, hematological profiles changed on disease progression from regional to distant metastatic, with significantly increased circulating leukocytes, neutrophils and monocytes, and decreased lymphocytes. Peripheral blood cell counts were not associated with survival of patients with a localized or regionally metastasized melanoma. Instead, in Stage IV patients, leukocytes (p=0.001), neutrophils (p=0.0002), monocytes (p=0.002), NLR (p<0.0001) and LMR (p=0.005) were all significantly associated with survival, independently of other known prognostic factors. These results suggest that cellular components of peripheral blood do count for survival of patients with advanced melanoma. What's new? Inflammation plays a role in all aspects of tumorigenesis and progression, to the extent that for certain malignancies peripheral blood markers of systemic inflammation can potentially predict patient outcome. In this analysis of melanoma patients in various stages of disease, the presence of distant metastases was found to be associated with changes in blood cell counts, specifically in absolute cell numbers and relative frequencies. In Stage IV patients, a distinct hematological profile, characterized by elevations in monocytes and in neutrophil-to-lymphocyte ratios, was strongly linked to increased risk of mortality, independent of existing established predictors of patient outcome.