Background: "Does this patient have cancer?" is a question frequently asked when confronted by patients with involuntary weight loss. The aim of this study was to assess the value of age, erythrocyte sedimentation rate (ESR), and anemia in the diagnosis of cancer as a cause of involuntary weight loss.
Methods: A retrospective study of 7850 patients admitted to the Department of Internal Medicine from January to September 2003 was performed. Especially selected were 431 patients with weight loss. Age, ESR, hemoglobin, and the discharge diagnosis were recorded.
Results: Twenty-four percent of the patients with involuntary weight loss had cancer. Age, ESR, and anemia were found not to be of value in the diagnosis of cancer (areas under the curve were 0.684, 0.690, and 0.766, respectively). When diagnostic tests for age, a high ESR, and anemia were used serially, the positive predictive value for a malignancy was 64% (CI: 27-90%); when the tests were utilized in parallel, the negative predictive value was 91% (CI: 85-100%).
Conclusions: Any patient admitted to our Department of Internal Medicine for involuntary weight loss had a 24% probability of having a malignancy. Neither age, nor ESR, nor anemia, used separately as a multilevel, diagnostic test or combined serially or in parallel, could exclude or rule in the diagnosis of cancer. However, they could increase (from 24% to 64%) or decrease (from 24% to 9%) the probability of cancer.