Anemia as an independent prognostic factor for survival in patients with cancer: a systemic, quantitative review.

Anemia is common in cancer patients, although the prevalence is influenced both by the type of malignancy and the choice of treatment. Individual studies have compared the survival of patients with and without anemia and have shown reduced survival times in patients with various malignancies, including carcinoma of the lung, cervix, head and neck, prostate, lymphoma, and multiple myeloma. The objective of this study was to systematically review, to summarize, and to obtain an overall estimate of the effect of anemia on survival in patients with malignant disease.A comprehensive literature review was carried out using the MEDLINE data base and reviewing the reference lists from published studies. Two hundred papers were identified. Of these, 60 papers that reported the survival of cancer patients according to either hemoglobin levels or the presence of anemia were included. Among these papers, 25% related to patients with lung carcinoma, 17% related to patients with head and neck carcinoma, 12% related to patients with multiple myeloma, 10% related to patients with prostate carcinoma, 8% related to patients with cervicouterine carcinoma, 7% related to patients with leukemia, 5% related to patients with lymphoma, and 16% related to patients with other types of malignancies.The relative risk of death increased by 19% (95% confidence interval, 10-29%) in anemic patients with lung carcinoma, by 75% (37-123%) in anemic patients with head and neck carcinoma, by 47% (21-78%) in anemic patients with prostate carcinoma, and by 67% (30-113%) in anemic patients with lymphoma. The overall estimate increase in risk was 65% (54-77%).Anemia is associated with shorter survival times for patients with lung carcinoma, cervicouterine carcinoma, head and neck carcinoma, prostate carcinoma, lymphoma, and multiple myeloma.