Second Primary Lung Cancer after Breast Cancer: A Case Series

Abstract

Abstract Background: Breast cancer (BC) accounts for approximately 24.2% of all malignant tumours in women. Due to advances in chemotherapeutic agents and targeted treatment, survival of BC patients is increasing. Second primary cancers (SPC) are becoming more common, among which lung cancer (LC) has a latency of approximately ten years and may be related to risk factors such as exposure to BC radiotherapy. We present a case series of nine patients with SPC of the lung after BC (BC-LC), highlighting the clinical and molecular findings in a tertiary care hospital in Colombia. Case presentation: This is a retrospective case series report describing demographic, diagnostic, therapeutic and molecular profile data of patients with SPC of the lung diagnosed between 2014 and 2019 with a history of BC in a referred tertiary care hospital. Nine women with BC-LC were included. The mean age at BC diagnosis was 56.2 ± 10.8 years. All cases were ductal carcinoma, seven were triple negative, one was HER2 positive, and one was estrogen and progesterone positive. Adenocarcinoma was the only histological type of LC. All patients had received radiotherapy for BC, and the mean latency between the two diagnoses was 8.1 years. Conclusion: Our case series provides preliminary data on patients with BC-LC and contributes to the local epidemiology. Histology (ductal BC, adenocarcinoma of the lung) has a role in BC-LC patients and radiotherapy for BC. Adequate histological diagnosis of lung lesions in patients with BC is essential for appropriate approach and treatment.