This phase III trial compares the effect of radiation therapy combined with hormonal therapy versus hormonal therapy alone in treating patients with low risk, early stage breast cancer with Oncotype Dx Recurrence =< 18. Oncotype DX is a laboratory test which results in a score that is used to help predict whether breast cancer will spread to other parts of the body or come back. Radiation therapy uses high doses of radiation to kill cancer cells and shrink tumors but may result in some side effects. Hormones called estrogen and progesterone may contribute to the growth of breast tumor cells. Hormone therapy, also called endocrine therapy, may stop the growth of tumor cells by blocking or removing these hormones. This clinical trial may help researchers understand if patients with low-risk, early stage breast cancer who have Oncotype recurrence score of =< 18 can safely omit radiation therapy and only be treated with hormonal therapy without losing any radiation treatment benefit.

This phase I/II trial tests the safety, side effects, and best dose of decitabine and cedazuridine (ASTX727) in combination with itacitinib and how well they work in treating patients with myelodysplastic/ myeloproliferative neoplasm. Cedazuridine is in a class of medications called cytidine deaminase inhibitors. It prevents the breakdown of decitabine, making it more available in the body so that decitabine will have a greater effect. Decitabine is in a class of medications called hypomethylation agents. It works by helping the bone marrow produce normal blood cells and by killing abnormal cells in the bone marrow. Itacitinib may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Giving decitabine and cedazuridine in combination with itacitinib may work better in treating patients with myelodysplastic/myeloproliferative neoplasm.