Decline in pulmonary function in patients with breast cancer receiving dose-dense chemotherapy: a prospective study

Background: Prompted by complaints of dyspnea in breast cancer patients receiving adjuvant dose-dense chemotherapy (DDC), we sought to evaluate the possible association of DDC with pulmonary dysfunction. Patients and methods: A total of 34 consecutive patients receiving adjuvant DDC were enrolled. The chemotherapy regimen consisted of i.v. doxorubicin 60 mg/m(2) and cyclophosphamide 600 mg/m(2) (AC) every 14 days x4 with growth factor support followed by weekly i.v. paclitaxel 80 mg/m(2) x12. The following parameters were prospectively measured before and after the AC protocol (P1, P2) and at completion of paclitaxel treatment (P3): presence of dyspnea, blood pressure, pulse rate, hemoglobin, erythrocyte sedimentation rate, C-reactive protein level, cardiac ejection fraction, and pulmonary function. Repeated measures analysis was used to evaluate differences among the time points, and paired t-test was used to evaluate differences between consecutive time points. Results: Although only five patients (15%) complained of dyspnea, there was a significant decrease in mean carbon monoxide diffusing capacity (DLCO), in all patients from P1 (22.09 ml/min/mmHg) to P3 (15 ml/min/mmHg) and in 29 of 32 patients (90.6%) from P1 to P2 (15.96 ml/min/mmHg) (P < 0.001). Conclusions: DDC is associated with a statistical significant reduction in DLCO. Awareness of this potential toxicity may be important in women with preexisting lung disease.