Clinical Significance of Radiologically Detected Small Indeterminate Extra-Mammary Lesions in Breast Cancer Patients

Rachel Yanlin Chen; Rui Ying Goh; Hoi Ting Leung; Stephanie Cheng; Veronique Kiak Mien Tan; Clement Luck Khng Chia; Jerry Tiong Thye Goo; Marc Weijie Ong

doi:10.4274/ejbh.galenos.2022.2022-1-2

Clinical Significance of Radiologically Detected Small Indeterminate Extra-Mammary Lesions in Breast Cancer Patients

Eur J Breast Health. 2022 Jul 1;18(3):252-257. doi: 10.4274/ejbh.galenos.2022.2022-1-2. eCollection 2022 Jul.

Authors

Rachel Yanlin Chen¹, Rui Ying Goh¹, Hoi Ting Leung¹, Stephanie Cheng², Veronique Kiak Mien Tan², Clement Luck Khng Chia¹, Jerry Tiong Thye Goo¹, Marc Weijie Ong¹

Affiliations

¹ Department of General Surgery, Khoo Teck Puat Hospital, Yishun, Singapore.
² Division of Surgery and Surgical Oncology, National Cancer Centre Singapore, Outram, Singapore.

Abstract

Objective: Patients with breast cancer who have indeterminate extra-mammary lesions, for example in lung, liver or bone, without other metastatic lesions pose a clinical dilemma regarding subsequent management. This study aimed to investigate the prevalence, characteristics and outcomes of such lesions detected on initial staging imaging, and address the clinical significance of these incidental findings.

Materials and methods: Medical records of patients with newly diagnosed breast cancer who underwent computed tomography scans and bone scintigraphy between January 1, 2015 and June 30, 2021 were reviewed. Patients with indeterminate extra-mammary lesions on imaging were included. Patients with obvious metastatic disease were excluded. Lesion characteristics, breast cancer staging, duration of follow-up and natural history of disease progression were analysed.

Results: The study included 52 patients with indeterminate lesions on pre-operative imaging. The median follow-up duration was 14 (range: 6-41) months. The most common site of occurrence of indeterminate lesions was the lung (60.9%) followed by the liver (26.1%). Forty-six had lesions that remained stable (88.5%), while six (11.5%) had progression to metastatic disease. Out of these six, only two (3.8%) developed metastasis in the same site as the original indeterminate lesion, whereas the remaining four developed metastases in other sites.

Conclusion: Patients with breast malignancy found to have indeterminate extra-mammary lesions without obvious distant metastasis on initial staging scans are associated with a small risk of subsequently developing metastatic disease. Although most of these lesions remain quiescent, surveillance imaging is recommended because a small but significant proportion of patients with such lesions eventually harbour actual metastatic disease.

Keywords: Breast cancer; extra-mammary; indeterminate lesion; metastatic.