Circulating Tumor Cells in Stage IV Melanoma Patients.

BACKGROUND: Management of stage IV melanoma patients remains a challenge. In spite of promising new therapies, many patients develop resistance and progression. The aim of this pilot study was to determine if circulating tumor cells (CTCs) are associated with shortened (180-day) progression-free survival (PFS) after a baseline CTC assessment in stage IV melanoma patients. STUDY DESIGN: A baseline CTC assessment was performed in 93 stage IV melanoma patients using a commercially available immunomagnetic system. The presence of 1 or more CTC was considered a positive result. A Cox multivariable regression model was used to evaluate the association between presence of CTCs at baseline and PFS, after adjusting for covariables. Kaplan-Meier curves and a log-rank test were used to summarize and compare unadjusted PFS for patients stratified by CTC positivity. RESULTS: Median follow-up was 17 months; mean age was 55 years. Thirteen of 93 (14%) patients had no evidence of disease (NED) at baseline CTC assessment. One or more CTC was detected in 39 of 93 (42%) of patients at baseline; CTCs were not associated with primary melanoma features or NED status. Twenty-eight of 93 (30%) patients progressed within 180 days of baseline draw, with 20 of 39 (51%) of the CTC-positive patients relapsing compared with 8 of 54 (15%) of the CTC-negative patients. In adjusted Cox models, a significant association was found suggesting worse PFS within 180 days for CTC-positive patients at baseline (vs CTC-negative) (hazard ratio 4.69, 95% CI 1.59 to 13.77, p = 0.005). CONCLUSIONS: One or more CTCs at baseline were associated with progression within 180 days in stage IV melanoma patients. This information warrants further study of CTCs as a means of identifying patients at high-risk for disease progression.

Prognostic Value of Circulating Tumor Cells Identified Before Surgical Resection in Nonmetastatic Breast Cancer Patients.

BACKGROUND: Circulating tumor cells (CTCs) can be identified in approximately 25% of nonmetastatic breast cancer patients, and data are emerging regarding their prognostic significance. We hypothesized that CTCs identified before resection of the primary tumor would predict worse outcomes in nonmetastatic breast cancer patients. STUDY DESIGN: We performed CTC enumerations on 509 patients with nonmetastatic breast cancer as part of an IRB-approved study. The CTCs (per 7.5 mL blood) were identified using the CellSearch System (Janssen). The presence of ≥1 CTC meeting morphologic criteria for malignancy was considered a positive result. Log-rank test and Cox regression analysis were applied to establish the association of CTCs with relapse-free and overall survival. RESULTS: Median follow-up was 48 months and mean age was 53 years. Fifty-nine percent of patients (299 of 509) had tumors larger than 2 cm, and 46% (234 of 509) had positive lymph nodes. One hundred sixty-six patients received neoadjuvant chemotherapy (NACT) before CTC assessment, and 343 patients were chemonaïve. One or more CTC was identified in 43 of 166 (26%) NACT treated patients, and in 81 of 343 (24%) chemonaïve patients. Circulating tumor cells were not associated with tumor size, grade, or lymph node status (p = NS). Detection of 1 or more CTCs predicted decreased relapse-free (log-rank p < 0.001, hazard ratio [HR] 2.72, 95% CI 1.57 to 4.72; p < 0.001) and overall survival (log-rank p = 0.02, HR 2.29, 95% CI 1.12 to 4.67; p = 0.03) at 48 months of follow-up. CONCLUSIONS: One or more CTCs identified before resection of the primary breast tumor predicted worse relapse-free and overall survival, irrespective of primary tumor size, grade, or lymph node positivity.