Objective: To investigate if the carbon monoxide-diffusing capacity (D(LCO)) could be the early indictor monitoring the bleomycin-induced lung toxicity (BILT) with retrospection of the influence of bleomycin cumulative dose on the pulmonary functions.
Methods: During June 1985 to October 2000, 42 patients with malignant tumor of ovarian germ cells received chemotherapy containing bleomycin in the department of Obstetrics and Gynecology of Peking Union Medical College Hospital. Twenty three patients (54.76%) among them had >or= 2 courses of chemotherapy with bleomycin and performed >or= 2 measurements of lung function. These 23 patients were included in the study. The forced expiratory volume in one second (FEV(1)), forced vital capacity (FVC), total lung capacity (TLC) and D(LCO) were measured and recorded as % of predicted. The D(LCO) was corrected by hemoglobin concentration [D(LCO) corrected = D(LCO) measured x (9.38 + Hb) divided by (1.76 x Hb)]. All the data were divided into 4 groups according to the cumulative dose of bleomycin (pre-treatment group, < 100 mg group, 101 - 200 mg group and > 201 mg group). The relationship between D(LCO) and bleomycin cumulative dose was examined by linear regression analysis and t-test.
Results: The values of FEV(1%)predicted in the 4 groups were 99.83 +/- 16.41 (14), 101.43 +/- 12.32 (42), 99.41 +/- 10.22 (23), and 90.96 +/- 13.63 (12), respectively. The FVC%predicted were 97.74 +/- 18.23 (14), 101.11 +/- 13.95 (42), 96.49 +/- 12.04 (23) and 89.63 +/- 18.20 (12), respectively. The TLC%predicted were 101.22 +/- 10.68 (13), 106.14 +/- 12.16 (40), 102.13 +/- 11.33 (23) and 95.05 +/- 14.06 (11), respectively. There were no statistical significant differences in the parameters among the 4 groups. The D(LCO%)predicted of the 4 groups were 93.27 +/- 12.75 (14), 94.51 +/- 12.50 (40), 80.93 +/- 10.05 (24) and 70.99 +/- 11.69 (15), respectively, and the D(LCO) of the last group (> 201 mg group) was significantly decreased as compared to that of the other groups (P < 0.05). A bleomycin dose-related fall in D(LCO) was observed, y = 100.59 - 0.11x, r = -0.649, P < 0.001.
Conclusion: The D(LCO) might be the most sensitive indicator of subclinical BILT. However, the cumulative dose of bleomycin did not show significant influence on the FEV(1), FVC and TLC.