Impact of radiation therapy dose, fractionation, and immunotherapeutic partner in a mouse model of hormone receptor-positive mammary carcinogenesis.

ABSTRACT:

Background

Hormone receptor-positive (HR+) breast cancer responds poorly to immune checkpoint inhibitors (ICIs). In some settings, radiation therapy (RT) has been shown to mediate immunostimulatory effects and promote ICI sensitivity.

Methods

We investigated whether hypofractionated RT may be successfully combined with ICIs in a mouse model of multifocal, metachronous HR+ mammary carcinogenesis. We hypothesized that focal RT targeting the first detectable (primary) tumor combined with ICIs may generate effective immunity, delaying the development of new lesions.

Results

Focal RT in various doses and fractionations limited primary tumor growth, with an optimum for a 20-Gy × 2 regimen (ablative in approximately 90% of mice). The degree of primary disease control, howeve

SUBMITTER: Buque A 

PROVIDER: S-EPMC12058254 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature