Hypofractionated Radiation Therapy After Mastectomy in Preventing Recurrence in Patients With Stage IIa-IIIa Breast Cancer

PRIMARY OBJECTIVES:

I. To evaluate whether the reconstruction complication rate at 24 months post radiation is
non-inferior with hypofractionation.

SECONDARY OBJECTIVES:

I. To evaluate the incidence of acute and late radiation complications, based on Common
Terminology Criteria for Adverse Events (CTCAE) 4.0 toxicity.

II. To evaluate the local and local regional recurrence rate. III. To compare reconstruction
complication rates based on reconstruction method (autologous +/- implant versus [vs] implant
only) and timing of reconstruction received (immediate vs. intent for delayed).

TERTIARY OBJECTIVES:

I. To evaluate reconstructed breast photographic cosmetic scores with hypofractionated
radiation compared to standard fractionation 24 months after radiation.

II. To evaluate reconstructed breast photographic cosmetic scores 24 months after radiation
based on the method and timing of reconstruction received.

III. To estimate the incidence of arm lymphedema by treatment arm. IV. To compare physical
well-being, psychosocial well-being, sexual well-being, satisfaction with
breast/nipples/abdomen, and satisfaction with overall outcome between the treatment arms at
24 months after radiation.

V. To estimate patient satisfaction with trial participation by treatment arm as measured by
the Was It Worth It Questionnaire at 24 months after radiation.

VI. To compare the direct and indirect patient costs for radiation therapy by treatment arm.

VII. To compare patient reported total health care service utilization 12 months after the
completion of radiation.

VIII. To compare the economic impact of treatment. IX. To analyze polymorphisms in MDM2 and
in genes including TP53, ATM, TGFB1, IL4, IL6, and IL10 and determine correlations with a
higher likelihood of adverse radiation reactions (radiation sensitivity) and with toxicities.

X. To analyze polymorphisms in MDM2 and in genes including TP53, ATM, TGFB1, IL4, IL6, and
IL10 to determine correlations with secondary endpoints such as local-regional control.

OUTLINE: Patients are randomized to 1 of 2 groups.

GROUP I: Patients undergo radiation therapy daily on Monday-Friday for 5-6 weeks.

GROUP II: Patients undergo hypofractionated radiation therapy daily on Monday-Friday for 3-4
weeks.

After completion of study, patients are followed up for 5 years.

Inclusion Criteria:

- Histologically confirmed invasive carcinoma of the breast of any of the following
histologies (ductal, lobular, mammary, medullary, or tubular); in-situ disease alone
is not allowed

- Patients will be staged according to the TNM staging system; pathologic stage T0N1-2a,
T1N1a-2a, T2N1-2a, T3N0-2a, all M0 status; pathological stage for all patients not
receiving neoadjuvant chemotherapy; higher of the clinical or pathological T and N
stage, if receiving neoadjuvant chemotherapy; patients with pathological N0 at the
time of mastectomy are only eligible if biopsy-proven clinically N1 or N2 disease is
documented prior to induction chemotherapy

* Note: All patients with clinical, radiographic or pathological T4, N3 or involved
internal mammary disease (N1b, N1c, and N2b) will not be eligible to enroll

- No prior radiation therapy to the chest, neck or axilla

- No prior history of ipsilateral breast cancer (invasive disease or ductal breast
carcinoma in situ [DCIS]); lobular carcinoma in situ (LCIS) and benign breast disease
is allowed

- No history of prior or concurrent contralateral invasive breast cancer; benign breast
disease, LCIS or DCIS of contralateral breast is allowed

- No active collagen vascular diseases, such as: systemic lupus erythematous,
scleroderma, or dermatomyositis

- Negative inked histologic margins from mastectomy pathology (no invasive cells at
margin)

- No significant post mastectomy complications in the ipsilateral breast requiring an
unplanned re-operation or admission for intravenous (IV) antibiotics; re-operation for
margins evaluation, nodal completion and routine reconstruction is acceptable

- Radiation oncologist intends to treat all target volumes and respect all normal
tissues in accordance with the dosimetric constraints described (simulation before
registration recommended)

- Radiation oncologist is planning to treat regional lymph nodes including internal
mammary nodes and meet acceptable protocol dosimetric requirements

- Radiation oncologist is NOT planning to utilize a chest wall/scar boost

- Patient must have undergone immediate reconstruction at the time of mastectomy or be
planning to undergo reconstruction within 18 months after radiation

- If a tissue expander is utilized it needs to be a fluid filled expander, NO air
expander (unless completely deflated) during radiation therapy

- For patients with diabetes, hemoglobin A1C test must have been performed =< 90 days
prior to registration

- No co-existing medical conditions with life expectancy < 5 years

- No other malignancy within 5 years of registration with the exception of basal cell or
squamous cell carcinoma of the skin treated with local resection only or carcinoma in
situ of the cervix

- Negative serum or urine beta-human chorionic gonadotropin (HCG) in women of
child-bearing potential =< 7 days prior to registration; a female of childbearing
potential is a sexually mature female who has not undergone a hysterectomy or
bilateral oophorectomy and has not been naturally postmenopausal for at least 12
consecutive months

- Women of child-bearing potential must agree to utilize a form of birth control or
agree to undergo sexual abstinence during radiation therapy

- Eastern Cooperative Oncology Group (ECOG) (Zubrod) performance status 0-1