The purpose of this study is to examine the impact of a lifestyle intervention. The study will examine the Stay on Track program, dietary and activity patterns, body composition, biomarkers and quality of life in breast cancer patients undergoing radiation therapy.

Research Design. The investigators will be conducting an randomized trial in 60 women undergoing radiation treatment for breast cancer to examine the feasibility of a 12-week lifestyle intervention that addresses diet and physical activity and to explore the impact on behavioral, biological and psychosocial outcomes.

Procedure Summary. Patients who are eligible are consented by the research coordinator, after which a baseline assessment will be scheduled. The baseline assessment requires 60 minutes and includes questionnaires, height/weight, dual energy x-ray absorptiometry (DEXA), and phlebotomy. Participants will also wear the Fitbit for one week to establish baseline activity level. After the baseline assessment, women are then randomly assigned to: the 12-week "Stay on Track" lifestyle intervention or the 12-week self-guided control. Both groups complete a post-intervention and a 3-month follow-up visit identical to their baseline assessment. Self-guided controls can utilize their Fitbit and will receive informative binders 24 weeks' post-intervention.

Inclusion Criteria:

1. > 18 years of age;
2. confirmed primary non-metastatic breast adenocarcinoma;
3. planned lumpectomy/segmentectomy/partial mastectomy surgery for primary breast cancer;
4. planning to undergo adjuvant whole breast radiation therapy following a lumpectomy;
5. Have a Karnovsky Performance Score of 70 or above (see Appendix)
6. Patient's Body Mass Index (BMI) is greater than determine by the treating physician, not currently meeting physical activity guidelines: moderate physical activity for at least 30 minutes at least five days a week AND 2 weekly sessions of resistance exercise;
7. have access to a mobile phone with capacity for text messaging (either unlimited or aware and accepting of text messaging charges);
8. understand and speak English;
9. physically able to engage in the intervention;
10. accepting of randomization (Note that anti-estrogen therapy is allowed.)

Exclusion Criteria:

1. Patients who have metastatic disease;
2. Patients with a history of prior malignancy within the past 3 years, other than non-melanoma skin cancer.
3. Patients with serious orthopedic, cardiovascular, or pulmonary conditions, have serious psychiatric or cognitive problems.
4. Patients who have received chemotherapy for their breast cancer.
5. Patients with prior radiotherapy to primary site or adjacent site that results in overlapping radiation fields.

Female Breast Cancer