Uncertain benefit from surgery in patients with lung metastases from breast carcinoma.

Background: Isolated lung metastases have been reported to occur in 10-20% of all women with breast carcinoma. The authors described a series of patients who underwent surgery for lung metastases from breast carcinoma.
Methods: They reviewed the files of 125 consecutive patients who underwent surgery with a curative intent for lung metastases from breast carcinoma between 1972 an 1998 at a single institution. Survival curves were plotted by the Kaplan-Meier method. Prognostic factors were identified using the log-rank test and a Cox proportional hazards model for univariate and multivariate analyses, respectively.
Results: The median age at surgery was 53 years. There was a median of 1 resected metastasis (range, 1-16 resected metastases). The median size of the largest metastasis was 19 mm (range, 5-70 mm). The median disease-free interval (DFI) was 3 years. The median follow-up time after surgery was 8.5 years (range, 25 days to 22 years). The 3-year, 5-year, and 10-year probabilities of survival were 58% (95% confidence interval [95% CI], 49-67%), 45% (95% CI, 36-55%), and 30% (95% CI, 21-41%), respectively. The median survival time after surgery was 4.2 years. Complete resection was achieved in 96 patients. The quality of the resection (complete vs. incomplete) was not a statistically significant prognostic factor by univariate analysis and there was no significant difference between these two groups in terms of adjuvant postoperative therapy. The characteristics of the primary tumor and the number of metastases (one vs. two or more) had no detectable influence on survival. The size of the largest metastasis (> 20 mm or < or = 20 mm) and the DFI (< or = 3 years vs. > 3 years) were highly significant prognostic factors (P = 0.006 and P = 0.003, respectively). This was confirmed by multivariate analysis. Patients with a DFI < or = 3 years and/or the largest metastasis > 20 mm reportedly had a poor outcome (median survival, 2.6 years vs. 8.5 years for patients with none of these poor prognostic factors).
Conclusions: Resection of lung metastases from breast carcinoma was associated with a significant 5-year survival rate of 45%. Whether these encouraging findings resulted from the surgical procedure itself or the preoperative selection of patients remained uncertain. When surgery is considered in this setting, the size of the largest metastasis and the DFI should be taken into account.