Should patients with primary mammographic-occult breast cancer undergo mammographic surveillance?
Hamdi Farah, Eva Molnar, Kian Chin, Fredrik WärnbergAbstract
Introduction
Mammographic screening enables early breast cancer detection but has reduced sensitivity in dense breast tissue and lobular subtypes. Mammographically occult primary cancers may raise concerns when patients are advised to continue mammographic surveillance. This study aimed to assess how local recurrences of initially mammographically occult cancers are detected during follow-up.
Methods
We conducted a retrospective study of patients who developed new or recurrent breast cancer between 2013 and 2023, identified from the National Breast Cancer Registry of the Västra Götaland Region, Sweden. Patients treated with breast-conserving surgery or mastectomy who subsequently developed ipsilateral or contralateral cancer were included. The primary endpoint was mammographically occult (mammo/occult) versus non-occult (mammo/non-occult) recurrence. The secondary endpoint was ultrasound-occult disease. Proportions were compared using the chi-square test.
Results
Baseline characteristics were similar between groups. Of 179 patients identified, 167 were included. Twenty-seven (16%) had primary mammo/occult cancers; of these, 7 (26%) were also mammo/occult at recurrence. Among 140 (84%) with primary mammo/non-occult cancers, 14 (10%) had mammo/occult recurrence. There was a significant association between primary occult status and occult recurrence (OR 4.7, 95% c.i. 1.9–11.6; P = 0.001). Concurrent mammographic and ultrasound occult disease was observed in 7/27 (26%) at primary diagnosis versus 14/29 (48%) at recurrence (P = 0.09).
Discussion
Primary mammographically occult cancers are associated with higher odds of occult recurrence. Improved understanding of recurrence patterns may help inform patient counseling and optimize follow-up strategies.