Surgical treatment of breast fibroadenomas.

Introduction: Fibroadenoma is a benign tumour with a prevalence of 9-22% and the third most common palpable breast tumour. Management is primarily conservative, but treatment varies due to a lack of national guidelines. We aimed to estimate the proportion of women diagnosed with fibroadenoma who underwent surgical excision in Denmark between 2011 and 2014, including regional differences in age, tumour size and year of surgery.

Methods: In this nationwide registry-based cohort study, we identified all patients who underwent surgical excision of a fibroadenoma from 1 January 2011 to 31 December 2014, using the Danish National Register of Pathology. This registry provided information on age and region. Operation rates were calculated using population data from Statistics Denmark.

Results: We identified 1,843 patients. The mean size of surgically removed fibroadenomas was 25.5 mm, and the mean age at surgery was 37 years. Patients > 50 years had a significantly higher proportion of small fibroadenomas (less-than 20 mm) removed than younger patients (p less-than 0.01). The overall operation rate was 20.6 per 100,000 women per year, highest in the 18-25-year age group (56.8 per 100,000 per year). Significant regional variation was found (p less-than 0.01), with the North Denmark Region having the highest operation rate (43.6 per 100,000 per year).

Conclusions: Despite conservative management being recommended in Denmark during the study period, many fibroadenomas were surgically removed, and considerable regional variations were recorded. National guidelines are needed to ensure uniform, evidence-based treatment and reduce overtreatment.

Funding: None.

Trial registration: nr. SABN 3-3013-1306/1.