Tumor doubling time: A selection factor for pulmonary resection of metastatic melanoma

Background and Objectives: Melanoma patients have a 20-27% rate of 5-year survival after surgical resection of pulmonary metastases. We evaluated tumor doubling time (TDT) and other prognostic factors in an attempt to identify candidates for pulmonary metastasectomy. Methods: Review of our large melanoma database identified 129 patients who underwent complete or partial resection of pulmonary metastases. At least two preoperative chest roentgenograms were available for 35 patients; these images were used by a single examiner to measure tumor width and length. The mean of the diameters was plotted against time on semilogarithmic paper: the slope of the line approximated tumor growth rate, and TDT was proportional to the inverse of the tumor growth rate. Results: For the 45 patients with a calculated TDT, median survival was 23.1 months and 5-year survival rate was 15.6% (7/45). By multivariate analysis, the only prognostically significant factors were TDT (P = 0.006) and type of pulmonary resection (P = 0.022). When TDT was <60 days, median survival was 16.0 months, and 5-year survival rate was zero; when TDT was greater than or equal to 60 days, median survival was 29.2 months (log-rank test; significant at P < 0.0001) and 5-year survival rate was 20.7% (6/29) (P < 0.0001). Conclusions: TDT is the most significant preoperative prognostic factor for patients undergoing pulmonary resection of metastatic melanoma. If TDT is <60 days, a preoperative neoadjuvant regimen of chemotherapy and biologic therapy is recommended. pulmonary metastasectomy should not be attempted if TDT cannot be increased to greater than or equal to 60 days by systemic therapy. (C) 1998 Wiley-Liss, Inc.