Frequency of the hypercalcemia-leukocytosis syndrome in oral malignancies.

There have been a number of reports over the last 15 years of patients with cancer who develop both leukocytosis and hypercalcemia, particularly in patients with cancers of the oral cavity. In this study, the authors report the frequency of hypercalcemia and leukocytosis in 225 patients with oral malignancies. Ten patients (4.4%) had hypercalcemia, 11 patients (4.9%) had leukocytosis, and five (2.2%) had both hypercalcemia and leukocytosis. The occurrence of these two distinct paraneoplastic syndromes in the same patients was greater than could have been expected from chance alone (chi-square = 45.8, P less than 0.0001). This study demonstrates that although hypercalcemia and leukocytosis are relatively uncommon in oral cancers, when they do occur they are frequently associated. To the knowledge of the authors, this is the first report in which the frequency of the association hypercalcemia and leukocytosis is studied in detail in large numbers of patients with oral cancer.