title: Cell proliferation patterns in human malignant melanoma, in vivo.
abstract: Cell kinetics were studied, in vivo, in 19 patients with metastatic melanoma by autoradiographic technics. Multiple tumor labeling indices (L.I.) were determined with intralesional H3-TdR in 19 patients and were correlated with the presence of melanin. Serial biopsies were obtained to derive percent labeled mitoses (PLM) curves for 9 individual patients. Duration of the S and G2 phases were calculated using 50 and 37% intercepts from the PLM curves, as well as by two computerized cell-cycle analysis programs, and the results were compared. Tumor L.I.s were found to be reproducible for distant metastases of similar size in the same patient. Tumor L.I.s had a bimodal distribution for the 19 patients examined. The two significantly distinct subgroups had L.I.s of 18.2 +/- 3.4% and 6.7 +/- 2.1%. The presence of melanin correlated with the higher L.I. subgroup. The difference in L.I. may reflect a higher growth fraction or a shorter germinative cycle in melanotic tumors. However, the presence of melanin did not correlate with a change in the duration of S or G2 phases. The sum of Ts and Tg2 was approximately 24 hours, regardless of the analytic method. These kinetic parameters are being monitored during chemotherapy for prognostic indicators.
mesh_terms: D001345:Autoradiography; D002453:Cell Cycle; D002455:Cell Division; D006801:Humans; D007399:Interphase; D007700:Kinetics; D008545:Melanoma / Q000473:pathology*; D008940:Mitotic Index; D012878:Skin Neoplasms / Q000473:pathology*; D013997:Time Factors