Is there a subset of patients with Paget's disease of the breast in whom you would omit radiation after a central lumpectomy?

I would approach treatment following the same principle as low-risk DCIS. If there's no evidence of invasive or underlying DCIS, I would engage in discussions regarding the potential for radiotherapy or observation, with or without anti-estrogen therapy.

Breast Paget’s disease without underlying DCIS or invasive breast cancer is extremely rare, and I would remain suspicious of a pathological miss. If indeed negative, observation would be appropriate. However, our focus as a field should prioritize patients where radiotherapy is indicated.

In the last 20 years focusing on the omission of RT has likely led to many unnecessary breast cancer failures. The lack of compliance with hormones and the wide acceptance of hypofractionated and partial breast radiotherapy have made radiation therapy convenient for patients with minimal side effects.

A central lumpectomy is almost always associated with a very large negative margin and observation. If this is the case for Paget's associated DCIS, then it is the most appropriate course.