The use of sentinel lymph node biopsy in the treatment of breast ductal carcinoma in situ: A Danish population-based study.

OBJECTIVES: The risk of axillary metastases in breast cancer patients with only ductal carcinoma in situ (DCIS) is low. Thus, axillary staging with sentinel lymph node biopsy (SLNB) should only be used according to the current guidelines to avoid over-treatment and unnecessary morbidity. In the present study, the use of SLNB in patients with DCIS was evaluated nationally and compared across Danish departments.

MATERIAL AND METHODS: A register-based study was conducted using the Danish Breast Cancer Group database. The use of SLNB in DCIS patients according to year of diagnosis, age at diagnosis, size of lesion, Van Nuys classification, palpability, location and department of surgery was evaluated. The chi-squared test was used to test differences between the groups.

RESULTS: Data from 2618 Danish female patients diagnosed with DCIS between 2004 and 2015 were included; 54.3% of patients underwent SLNB. The use of SLNB increased from 26.6% in 2004 to 65.1% in 2015. A total of 1877 (71.7%) patients underwent breast-conserving surgery (BCS), and 577 (22.0%) underwent mastectomy, of which 43.9% and 86.0% respectively had a concomitant SLNB. The SLNB was performed in 23.8% of 454 patients not included by the guidelines. The use of SLNB in combination with BCS differed significantly between departments ranging from 19.7% to 63.8%. A significant difference in the use of SLNB with BCS and mastectomy according to department capacity (high-volume departments versus low-volume departments) was observed.

CONCLUSION: The use of SLNB in patients with DCIS and adherence to the Danish national guidelines varies among Danish breast surgery departments. To optimise the axillary treatment of patients with DCIS, an improved compliance to the national DCIS guidelines is necessary.