Background and objective: In patients with follicular lymphoma and mantle cell lymphoma circulating lymphoma cells can be detected by quantitative real-time PCR with a high sensitivity and reproducibility. With this study we wanted to ascertain whether a continuous molecular remission achieved in patients with mantle cell lymphoma and follicular lymphoma has an impact on survival of these patients.
Patient and methods: We conducted these investigations in 32 patients (24 with follicular lymphoma and 8 with mantle cell lymphoma) who were treated in a randomized trial with chemotherapy plus/minus rituximab (MCP, R-MCP). A further ten patients had follicular lymphoma (stage I and II) in long-term complete remission after radiation therapy.
Results: Up to 18 years after initial diagnoses of a stage I or II follicular lymphoma circulating t(14;18) positive cells could be detected in the peripheral blood. In advanced stage follicular lymphoma patients molecular remissions could only be achieved when they were treated with combined chemo-immunotherapy (MCP+R). A significantly higher relapse-free survival correlates with sustained molecular remission. In contrast, the frustrating clinical results obtained from the treatment of patients with mantle cell lymphoma corresponded to an achievement of only short molecular remissions in very few patients.
Conclusions: The consequent application of quantitative real-time PCR will further improve current treatment strategies in lymphoma patients. Especially, individual treatment options can be developed for patients who do not respond to a standard chemotherapy or progression of disease is recognized, if results of molecular monitoring will be confirmed in large prospective studies.