Prise en charge des hyperplasies canalaires atypiques sur macrobiopsies : une désescalade possible ?

Atypical ductal hyperplasia diagnosed from core needle biopsies is associated with 11 to 35% underestimated rates of carcinoma, leading in most of the cases to excisional biopsies. On the other hand, patients with atypical ductal hyperplasia have a relative higher risk for breast cancer, which requires a specific follow-up after eliminating underestimation. Various criteria have been proposed to avoid an excisional biopsy. However, underestimation rate in the most favourable subgroup was still 3% to 8%. Although prospectively validated, one study reported an acceptable upgrade of 2% in a subgroup of patients but this proposal of atypical ductal hyperplasia management has not been assessed in other centres, which limits its strength as a recommendation. Compared to the general population, the relative risk of subsequent breast cancer after atypical ductal hyperplasia diagnosis either on excisional biopsy or core needle biopsy is lower than 5. Annual MRI is not recommended, except where approved by oncogenetic consult when there is a familial breast cancer risk. As suggested by the breast group of the Massachusetts General Hospital in Boston, MRI follow-up between the age of 25 to 30 years could also be discussed in multidisciplinary staff meeting for patients who developed atypical hyperplasia before 30 years. The consensus for the follow-up of patients with atypical ductal hyperplasia is an annual mammogram for a period of 10 years in France but this duration is not specified in the English literature. In contrast, some data highlight that the relative risk of breast cancer persists after 10 years, suggesting that a specific follow-up should be maintained beyond 10 years, which raises issues about breast irradiation. To conclude, de-escalation strategies at initial diagnosis are still controversial, and as extending the specific follow-up over 10 years should be discussed.