Introduction: Lobular carcinoma in situ (LCIS) is regarded as a non-obligate precursor of invasive breast cancer (IBC). Hence, the optimal management of LCIS found on minimally invasive breast biopsy remains a subject of debate. The aim of this study was to evaluate the correlation of biopsy findings with postoperative histology and to identify risk factors for upstaging to IBC.
Material and methods: Twenty-seven patients with pure LCIS diagnosed on image-guided biopsy (vacuum-assisted or core-needle) underwent subsequent surgery. Clinical, radiological and histological features were compared to the final pathology after surgical excision. Rates of upstaging were calculated and statistical analysis of high-risk factors was performed.
Results: Median age of patients (mean ± SD, range) was 56 years (56.6 ±9.7, 36–74), while median size of LCIS was 15 mm (15.3 ±5.9, 6–28). Final examination demonstrated IBC foci in 29.6% of lesions (8/27). Upstaged patients were younger (median, mean ± SD: 48.5, 50.9 ±13.0 vs. 56, 59.1 ±7.1) and had larger lesions (17, 18.6 ±6.6 vs. 14, 13.8 ±5.2 mm) but without statistical significance. Palpable tumours, BIRADS 5 lesions, masses and pleomorphic LCIS had a significantly increased rate of upstaging. Guidance of the procedure (ultrasound vs. stereotactic) was significantly associated with the upstaging risk, while the importance of the biopsy technique (core-needle vs. vacuum-assisted) was not confirmed. After excluding pleomorphic LCIS and mass-forming classic LCIS, there was no risk of upstaging for lesions with BIRADS 4 mammographic abnormalities.
Conclusions: Pleomorphic histology, mass formation and BIRADS 5 category reflect more aggressive behaviour of LCIS and identify patients who need subsequent surgery. For other patients, close follow-up could be a safe alternative.