Characteristics of second primary lung malignancy in patients with known breast cancer

As breast cancer survival improves, the incidence of additional malignancies will likely rise. Identification of a lung nodule in a patient with known breast cancer poses a challenging diagnostic problem. This study outlines the management of such patients and identifies factors that correlate with survival.

From 1977 through 2002, 35 patients with known breast cancer were identified with an additional primary lung cancer. Data were collected from a retrospective chart review. Median and 2- year survival were determined by the Kaplan-Meier method and Cox regression analysis identified independent predictors of survival.

Nineteen patients (54%) were asymptomatic at the time of diagnosis and had their lung cancer discovered during workup and/or follow-up of their breast cancer. The diagnosis of lung cancer was made by preoperative biopsy in 23 patients (82%). Nineteen patients (54%) were successfully treated with surgery. Mean follow-up was 2.3 years. Median survival for all patients was 1.8 years. Factors associated with a statistically significant improvement in survival included asymptomatic presentation of lung cancer (P = 0.003), absence of tobacco use (P = 0.021), and stage I lung cancer (P = 0.009). Multivariate analysis revealed that tobacco use (RR = 3.6, P = 0.047) and advanced stage of lung cancer (II-IV) at the time of diagnosis (RR = 2.2, P < 0.001) were independent predictors of decreased survival.

The presentation of a lung nodule in patients with breast cancer warrants a comprehensive evaluation to differentiate between primary lung and metastatic breast cancers, as diagnosis and resection of an early stage lung cancer is associated with improved survival.