Retrospective Genetic Testing and Imaging Surveillance in Breast Cancer Survivors

Two new analyses presented for breast cancer survivorship highlight how retrospective genetic testing and mammographic surveillance can improve follow-up care. A UK national study presented at the ESMO Breast Cancer 2026 congress examined whether efficiently delivered genetic testing can identify germline pathogenic variant (gPV) carriers among previously untested patients, enabling prevention, earlier screening, and family risk assessment, while a 2026 systematic review and meta-analysis found that mammographic surveillance significantly lowers mortality among survivors of breast cancer.

Hundreds of thousands of people diagnosed with cancer are still alive today but were never genetically tested, either because testing was not available or was not routinely offered at the time of their diagnosis. These patients are just as likely as those diagnosed today to carry a germline pathogenic variant (gPV) – a heritable genetic alteration – that increases cancer risk. The UK-only Retrospective Genetic Testing Programme used national health records to identify patients with breast and ovarian cancer eligible for genetic testing based on tumor characteristics, but who had never been offered it.

In the pilot phase, 3,525 patients diagnosed between 2015 and 2018 were invited to take part using a simple, home-based saliva test. By March 2026, 43.7% had accepted the invitation; completed testing revealed inherited cancer-related gene variants in 8.6% of patients with breast cancer and 10.1% with ovarian cancer. The findings highlight missed opportunities to deliver more personalized follow-up care, surveillance and to inform at-risk family members. The pilot focused on patient groups with a strong likelihood of hereditary cancer, including triple-negative, bilateral and young-onset breast cancer, as well as high-grade serous ovarian cancer.

A particularly important group for this approach are women who survived young-onset breast cancer and may now be approaching the age at which, if they carry a germline pathogenic variant in BRCA1 or BRCA2, their risk of ovarian cancer becomes very high, according to a professor of translational cancer genetics at the Institute of Cancer Research, London, UK. The study showed that a simplified approach to genetic testing – the BRCA-DIRECT pathway – is potentially feasible at scale, without increasing workload for healthcare professionals. By removing several traditional steps, including routine pre-test consultations for all patients, the pathway can be streamlined without compromising patient experience or engagement. The study also marks a step towards data-driven, automated identification of eligible patients through linked cancer registry and genetic laboratory data, allowing healthcare systems to proactively reach individuals who may otherwise be missed, rather than relying solely on clinician referral or patient self-advocacy. Based on the program's early outcomes and the integration of the BRCA-DIRECT pathway into routine care, the NHS is commissioning a broader range of direct-to-patient genetic tests, with potential expansion to prostate, pancreatic and colorectal cancer patients.

Separately, a 2026 systematic review and meta-analysis published in the Asian Pacific Journal of Cancer Prevention assessed surveillance techniques including mammography, ultrasonography, MRI, and digital breast tomosynthesis. Overall, 18 studies met the eligibility criteria. The pooled sensitivity, specificity, and accuracy of mammographic surveillance were 81%, 71%, and 76% respectively, and mammographic surveillance had a lower diagnostic accuracy in survivors of breast cancer than in the screening population. The lower diagnostic accuracy could be explained by unique challenges in post-treatment imaging; for example, interval cancer, scarring, and architectural distortion are more prevalent in survivors of breast cancer, and breast-conserving therapy, in particular, frequently produces post-surgical and radiation-induced changes that obscure subtle lesions. A 50% reduction in mortality risk was linked to mammographic surveillance, compared to individuals without surveillance. Adjunct imaging modalities, including MRI, can enhance early detection, and MRI showed better sensitivity (91%) and specificity (82%) than both mammography and ultrasonography. There was high heterogeneity between studies, which could have stemmed from variations in surveillance protocols, imaging frequency, and outcome definitions. Most included studies were conducted in high-income countries, limiting generalisability. The analysis nonetheless highlights the importance of mammographic surveillance in post-treatment care as an essential element of reducing mortality among survivors of breast cancer. Standardised surveillance protocols were suggested to improve post-treatment monitoring and patient outcomes. Researchers proposed that the integration of AI-driven image processing in mammographic surveillance may improve sensitivity and specificity.