Telomere length shortening of peripheral blood mononuclear cells in solid-cancer patients undergoing standard-dose chemotherapy might be correlated with good treatment response and neutropenia severity.

This study evaluated the telomere length changes (DeltaTL) of peripheral blood mononuclear cells before and after repetitive standard-dose nonmyeloablative chemotherapy and the association of DeltaTL with treatment response and myelosuppression severity. TL was measured with Southern blot analysis in 32 solid-cancer patients without bone marrow metastasis. The mean TL before chemotherapy (t0 TL) and after the 2nd (t1 TL), 4th (t2 TL) and 6th cycle (t3 TL) was 8.49, 8.33, 8.08 and 8.10 kb, respectively. TL became significantly decreased after 4 (p = 0.005) and 6 (p = 0.026) cycles of chemotherapy. The mean value of DeltaTL before and after completion of chemotherapy (t0 TL - t3 TL) was 0.46 kb. DeltaTL has a significant correlation with good treatment response (r = 0.448, p = 0.005) and the frequency of severe neutropenia (r = 0.417, p < 0.05). Consequently, TL of peripheral blood mononuclear cells was decreased by the repetitive nonmyeloablative standard-dose chemotherapy in solid-cancer patients without bone marrow metastasis, and DeltaTL was associated with good treatment response and neutropenia severity. Copyright 2007 S. Karger AG, Basel.