Incidence and clinical impact of chemotherapy induced myelotoxicity in cancer patients: an observational retrospective survey.

PURPOSE: To evaluate the frequency of chemotherapy-induced myelotoxicity in cancer patients, the related treatment (G-CSF, rHuEPO), and the occurrence of chemotherapy dose reductions, delays or discontinuations. PATIENTS AND METHODS: We retrospectively collected data from 1175 patients who completed at least four chemotherapy courses at 64 Italian Centres. Myelotoxicity was defined as anemia (Hb < 10 g/dL) and neutropenia (ANC < 1500/mm(3)). The study population was divided by age, in 664 adult patients aged < or =65 years and 511 elderly patients, aged > 65 years. The association between events during chemotherapy and myelotoxicity indices were assessed by logistic regression.
RESULTS: The median age of the patients was 64 years. Myelotoxicity was observed in 633 patients (53.9%), anemia (< 10 g/dL) in 263 (22.4%) and neutropenia in 530 (45.1%); 686 patients (58.5%) showed mild anemia (Hb < 12 g/dL). Dose reductions were observed in 199 patients (16.9%), dose delays in 338 (28.7%), and discontinuations in 157 (13.4%), with no significant difference between age groups. Myelotoxicity accounted for 20% of treatment withdrawals with no differences between age groups. G-CSF was administered to 53.4% of the neutropenic patients, and rHuEPO to 53.1% of the anemic patients. Logistic regression analyses showed a significant (P < 0.001) association between chemotherapy dose delays, dose reductions and myelotoxicity. Considering age strata, the association between dose reduction and myelotoxicity was significant. The risk of neutropenia in the adults was higher than in elderly (50.0% vs 38.7%).
CONCLUSION: Our results show that anemia and neutropenia occur in a substantial proportion of cancer patients receiving chemotherapy, and have an impact on chemotherapy dose delivery. G-CSF and rHuEPO are treatments widely used in about one half of neutropenic and anemic patients. Particular attention should be given to elderly patients, who are at high risk of myelotoxicity and should be carefully evaluated for the prophylactic use of G-CSF and monitored for the appropriate use of rHuEPO.