Pulmonary toxicity syndrome in breast cancer patients undergoing BCNU-containing high-dose chemotherapy and autologous hematopoietic cell transplantation.

We performed a retrospective review to investigate pulmonary toxicity syndrome (PTS) in a cohort of breast cancer patients undergoing BCNU-containing high-dose chemotherapy (HDC). Our aim was to characterize presentation, identify risk factors, determine outcome following therapy, and find any association with differences in survival. We reviewed the data of 152 patients with stage II or III or metastatic breast cancer treated with cyclophosphamide 5625 mg/m2, cisplatin 165 mg/m2, and BCNU 600 mg/m2 followed by autologous peripheral blood hematopoietic cell transplantation. During follow-up, PTS was diagnosed when the following criteria were met: (1) presentation with typical clinical symptoms of PTS, (2) an absolute carbon monoxide diffusion capacity (DLCO) decline of 10% compared with pre-HDC DLCO, and (3) no clinical evidence of active pulmonary infection. Patients were then treated with a course of corticosteroid therapy. The incidence of PTS for all 152 patients was 59%, with a median onset at 45 days (range, 21-149 days) post-HDC. The median absolute DLCO decrement was 26% (range, 10%-73%) at diagnosis of PTS. There was no significant correlation between patient age, stage of breast cancer, pre-HDC chemotherapy regimen, pre-HDC chest wall radiotherapy, tobacco use, prior lung disease, or baseline pulmonary function test results and the development of PTS. We did observe an interesting association between PTS and the development of a noncholestatic elevation of transaminases. Of PTS patients treated with prednisone therapy for a median of 105.5 days (range, 44-300 days), 91% achieved resolution of their PTS without pulmonary sequelae. At 3 years, the overall survival (OS) of stage II or III patients who developed PTS was 84% (95% confidence interval [CI], 73%-95%); of metastatic breast cancer patients with PTS, the OS was 58% (95% CI, 38%-78%). These values were not significantly different from those of patients who did not develop PTS (91% [95% confidence interval [CI], 81%-100%] and 53% [95% CI, 32%-74%], respectively). No significant differences in disease-free or event-free survival were observed between patients with and without PTS. The incidence of PTS in breast cancer patients treated with a BCNU-containing HDC regimen can be remarkably high. Treatment with a course of corticosteroid therapy is successful in the vast majority.