Purpose: As reported earlier, a chemotherapy regimen that consisted of dacarbazine, vincristine, lomustine, and bleomycin (DOBC) combined with natural leukocyte interferon (IFN) has been administered with favorable results to patients with metastatic melanoma. In this study, lymphocyte subsets (CD4+ and CD8+) were analyzed before and during treatment to elucidate if alterations in the CD4+/CD8+ ratio had any prognostic value.
Materials and methods: Blood samples were systematically obtained from 54 patients with metastatic melanoma who received this chemoimmunotherapy. The frequencies of peripheral-blood lymphocyte subsets were monitored by flow cytometry using the monoclonal antibodies OKT4 (CD4+, T-helper cells) and OKT8 (CD8+, T-suppressor cells).
Results: Twenty-seven patients had a constantly increasing ratio, while the remaining 27 patients had a fluctuating or constantly decreasing ratio. The former group had a median survival time of 11.8 months, as compared with 6.5 months for the latter (P = .008, log-rank test). This difference was generated among patients who had an objective response. Responding patients with a constantly increasing ratio had a median survival time of 21.7 months, as compared with 10.2 months for patients with no constant increase in the ratio (P = .038, log-rank test). In nonresponders, no difference in survival was observed between the two groups.
Conclusion: The monitoring of early changes in the CD4+/CD8+ ratio can provide valuable information that predicts the prognosis of metastatic melanoma patients receiving chemoimmunotherapy.