Immunohistochemical assessment of tumor vascularity in recurrent Clark II melanomas using antibody to type IV collagen.

Thin melanomas, measuring 0.76 mm or less, are generally associated with an excellent prognosis. However, a certain subset of these seemingly innocuous lesions have been reported to develop recurrences. Therefore, the predictive values of currently accepted prognostic indicators have been questioned in thin melanomas. Several studies concerning tumor vascularity in melanoma and certain non-melanocytic malignancies suggest that the degree of vascularization correlates with growth rate and biologic aggressiveness. In the present study, we determined the vascularity of a small group of Clark level II melanomas that resulted in recurrence, and compared these results to an equal number of nonrecurrent lesions with similar prognostic indicators. Blood vessels were labeled by immunoperoxidase staining techniques for Type IV collagen, and quantified by image analysis. No statistical difference was found between the two groups when mean blood vessel counts and percent vascular area were measured. The recurrent tumors had a mean PVA of 4.68 compared to 4.34 for the nonrecurrent group (p = 0.677). The mean blood vessel count beneath the recurrent group was 29.6 per 400 x field, and the corresponding value for the nonrecurrent group was 31.8 (p = 0.681). Our data is preliminary within this limited group of tumors, yet it suggests that tumor vascularity is not a distinctive prognostic indicator by which eventual outcome can be predicted in thin Clark level II malignant melanomas.

High levels of interleukin-6 are associated with low tumor burden and low growth fraction in multiple myeloma.

Interleukin-6 (IL-6) is a multifunctional cytokine postulated to play a central role as a growth factor for multiple myeloma (MM). We evaluated the spontaneous secretion of IL-6 in supernatants of Ficoll-Hypaque--enriched bone marrow (BM) cultures from 35 patients with MM. The levels of IL-6 were correlated with biological and clinical characteristics of the disease. High levels of IL-6 production defined a subgroup of patients with low tumor burden as determined by lower serum beta 2-microglobulin (B2M) (P = .02) and lower percentage of myeloma cells infiltrating the bone marrow (P = .003), higher synthetic rates of monoclonal protein (P = .006), and low proliferative compartments as measured by the percentage of Ki-67--positive myeloma cells. Patients with high proliferative fractions (Ki-67--positive myeloma cells > 20%) had significantly lower levels of IL-6 when compared with patients with low proliferative fractions (P = .005). Our findings do not support IL-6 as a major growth factor for MM, but demonstrate an association of high levels of IL-6 secretion with low tumor cell burden and low proliferative fraction.