Incidental discovery of second primary lung tumors in breast cancer patients: an institutional case series.

BACKGROUND

Guidelines recommend biopsy of first breast cancer recurrence. Our group recently showed that only half of patients in Washington diagnosed with metastatic breast cancer (MBC) between 2008 and 2017 underwent biopsy.

METHODS

Oncologists in our group identified patients in which a lung malignancy was diagnosed in patients with a breast cancer history.

RESULTS

We identified eight illustrative cases. Lung findings were typically identified on a CT obtained for staging or radiation planning. In five cases, patients were treated curatively for two early-stage malignancies. In two cases, patients with MBC were found to have early-stage lung adenocarcinomas. In one case, MBC and metastatic lung cancer were diagnosed synchronously.

CONCLUSIONS

While imaging can raise suspicion for breast cancer recurrence, relying on radiologic appearance to infer that a lesion (1) is malignant and (2) represents spread of the known primary risks treating both the primary tumor and the newly detected condition inappropriately.