The relationship between findings on pre-treatment mammograms and local recurrence after breast-conserving therapy for invasive breast cancer

Aims: This study was planned (a) to determine the correlation between findi ngs on the pre-treatment mammogram and local recurrence after breast-conser ving therapy (BCT), and (b) to analyse the relationship between mammographi cal features, specific pathological characteristics and the need for re-exc ision. Method: The size and outline of the lesion, the presence of suspect microca lcifications and signs of multifocality on pre-treatment mammograms of 39 p atients with local recurrence after BCT and 126 randomly selected control p atients without local recurrence were compared. Tissue slides of the primar y tumour were reviewed to confirm the histological type and grade, the aspe ct of the margins, microscopic margin involvement, presence of vascular inv asion and the presence and extent of an intraductal component. Results: Among patients less than or equal to 50 years of age, the proporti on with a mammographically occult tumour was 48% of the patients with local recurrence and 26% of the control group (P = 0.05). In the age group great er than or equal to 50 years, 67% of the patients with local recurrence had a non-circumscribed lesion compared to 9% of the control group (P<0.001). Suspect microcalcifications on the mammogram were associated with the findi ng of an extensive intraductal component, vascular invasion and a higher hi stological grade by the pathologist. Patients with a non-circumscribed dens ity or a scirrhous lesion needed re-excision more often (30 and 33%, respec tively) than those with a well-circumscribed density (9%). Conclusions: Although the number of patients was small, this study indicate s that some mammographical features are associated with a higher risk of lo cal recurrence after BCT and the need for re-excision. This was supported b y the findings of the pathological review.