The purpose of this study is to compare the effects on low risk breast cancer receiving usual care that includes regional radiation therapy, with receiving no regional radiation therapy. Researchers want to see if not giving this type of radiation treatment works as well at preventing breast cancer from coming back.

This randomized phase III trial studies whether weight loss in overweight and obese women may prevent breast cancer from coming back (recurrence). Previous studies have found that women who are overweight or obese when their breast cancer is found (diagnosed) have a greater risk of their breast cancer recurring, as compared to women who were thinner when their cancer was diagnosed. This study aims to test whether overweight or obese women who take part in a weight loss program after being diagnosed with breast cancer have a lower rate of cancer recurrence as compared to women who do not take part in the weight loss program. This study will help to show whether weight loss programs should be a part of breast cancer treatment.

To examine whether rapamycin can reduce malignant markers and aberrant mammary stem/progenitor cells (MaSCs) number in surgical specimens

This study will evaluate the efficacy, safety, and pharmacokinetics of adjuvant atezolizumabwhen given in combination with trastuzumab emtansine compared with placebo andtrastuzumab emtansine for patients with residual invasive HER2-positive breast cancerfollowing neoadjuvant taxane-based and HER2-targeted therapy including trastuzumab, whoare at high risk of disease recurrence. The primary endpoint for this study is invasivedisease-free survival (IDFS).

To compare how often cancer recurs (comes back) after 3 weeks of radiation compared to 5 weeks of radiation in patients who receive radiation therapy delivered to the lymph nodes near the breast. The side effects that can develop during or after radiation treatment, including how often arm swelling (edema) happens, will also be studied

RATIONALE: Estrogen can cause the growth of breast cancer cells. Hormone therapy using tamoxifen citrate, goserelin acetate, leuprolide acetate, anastrozole, letrozole, or exemestane, may fight breast cancer by lowering the amount of estrogen the body makes. Everolimus may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. It is not yet know whether hormone therapy is more effective when given with or without everolimus in treating breast cancer. PURPOSE: This randomized phase III trial studies how well giving hormone therapy together with or without everolimus work in treating patients with breast cancer.

This randomized phase III trial studies how well doxorubicin hydrochloride and cyclophosphamide followed by paclitaxel with or without carboplatin work in treating patients with triple-negative breast cancer. Drugs used in chemotherapy, such as doxorubicin hydrochloride, cyclophosphamide, paclitaxel, and carboplatin, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. It is not yet known whether doxorubicin hydrochloride and cyclophosphamide is more effective when followed by paclitaxel alone or paclitaxel and carboplatin in treating triple-negative breast cancer.

This phase III trial compares the effect of active symptom monitoring and patient education to patient education alone in helping young women with stage I-III breast cancer stay on their hormone therapy medicines. The patient education tool contains interactive weblinks which provide patients with education material about breast cancer and side effects of therapy. Symptom monitoring is a weblink via email or text message with questions asking about symptoms. Hormone therapy for breast cancer can cause side effects, and may cause some women to stop treatment early. Asking about symptoms more often may help women keep taking hormone therapy medicines

We will assess physical functioning, daily physical activity with wearable activity monitors, biological markers (serum and salivary cortisol), diet, program adherence, as well as psycho-social measures of physical, mental, and spiritual wellbeing. In addition, BCS will be asked to describe their best day possible and their typical day. We will conduct a qualitative analysis from their responses to identify endorsement of themes.