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 findings on the pre-treatment mammogram and local recurrence after breast-conserving therapy (BCT), and (b) to analyse the relationship between mammographical features, specific pathological characteristics and the need for re-excision.

Method: The size and outline of the lesion, the presence of suspect microcalcifications and signs of multifocality on pre-treatment mammograms of 39 patients with local recurrence after BCT and 126 randomly selected control patients without local recurrence were compared. Tissue slides of the primary tumour were reviewed to confirm the histological type and grade, the aspect of the margins, microscopic margin involvement, presence of vascular invasion and the presence and extent of an intraductal component.

Results: Among patients </=50 years of age, the proportion 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 >/=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 finding of an extensive intraductal component, vascular invasion and a higher histological grade by the pathologist. Patients with a non-circumscribed density or a scirrhous lesion needed re-excision more often (30 and 33%, respectively) than those with a well-circumscribed density (9%).

Conclusions: Although the number of patients was small, this study indicates that some mammographical features are associated with a higher risk of local recurrence after BCT and the need for re-excision. This was supported by the findings of the pathological review.