Abstract: Provided herein are various methods for treating a subject for local and/or regional recurrence of invasive breast cancer or a subject with invasive breast cancer, identifying a subject who will not be adequately responsive to radiation therapy, recommending a treatment to a subject, preventing an invasive breast cancer recurrence in a subject, preventing a local and/or regional recurrence of an invasive breast cancer in a subject, or modifying a treatment for a subject based on PDGFRb levels. In some embodiments, the methods are based on PDGFRb levels.

Abstract: Provided are embodiments for treating breast cancer comprising obtaining a tissue sample of a tumour from a breast cancer patient, determining an expression level of PD-1 in the sample, determining that the expression level is below a threshold level, providing intensified treatment to the subject. The intensified treatment can be intensified radiotherapy treatment.

Abstract: Methods for treating and/or prognosing breast cancer and breast cancer recurrence are provided. The method includes obtaining a tissue sample of a tumor from a breast cancer patient, determining an expression level of one or more markers (for example PD-1 and/or PD-L1) in the sample, and providing intensified treatment to the subject based on the level of (for example) PD-1 and/or PD-L1. The intensified treatment can be intensified radiotherapy treatment.