Radiation Therapy in Treating Post-Menopausal Women With Early Stage Breast Cancer Undergoing Surgery

PRIMARY OBJECTIVE:

I. For select patients with early stage breast cancer undergoing wide local excision
followed by single fraction radiation therapy (SFRT), we will evaluate rates of
observer-rated toxicity, cosmetic outcomes and patient satisfaction, objective measures of
toxicity and quality of life as well as delivery of intended dose.

SECONDARY OBJECTIVE:

I. Locoregional control reported at five years.

OUTLINE:

Patients undergo wide local excision breast surgery and SFRT over 60-100 minutes once
negative margins are obtained.

After completion of study treatment, patients are followed at 1 week, 1 month, 3 months, and
then every 6 months for 2 years.

Inclusion Criteria:

- Core needle biopsy (e.g. Mammotome, core, stereotactic, ultrasound guided) showing
invasive mammary cancer (with or without concomitant ductal carcinoma or lobular
carcinoma in situ) or ductal carcinoma in situ; acceptable histologic types of
invasive mammary cancer include ductal, tubular, mucinous, papillary, cribriform and
"NOS" (not otherwise specified); invasive lobular cancer is excluded

- Age >= 50 years and postmenopausal with no menses for at least one year prior to
study enrollment

- Age > 70 years with invasive breast cancer clinical size =< 3 cm OR Age 50 - 70 years
with invasive breast cancer clinical size =< 1.5 cm OR Age >= 50 years and
postmenopausal with any grade ductal carcinoma in situ (DCIS) clinical extent =< 1.5
cm (clinical tumor size will be determined by pre-operative breast
imaging-mammography, ultrasound and/or magnetic resonance imaging; in cases of
multiple measurements, the largest recorded single dimension will be used to
determine eligibility)

- Hormone receptor status

- Estrogen or progesterone receptor positive or

- Estrogen and progesterone receptor negative and clinical tumor size =< 1.0 cm

- Human epidermal growth factor receptor 2 (HER2)/neu negative on the core biopsy
analysis defined as 0 or 1+ by immunohistochemistry or not amplified by fluorescent
in situ hybridization analysis

- Tumor >= 0.5 cm from skin as defined by breast ultrasound

- Unicentric tumor

- Axillary lymph nodes negative by pre-operative physical examination in all cases and
pathologic examination from surgery for invasive disease

- Negative surgical margins, defined as no margin-labeling ink on tumor cells from
margin evaluation

Exclusion Criteria:

- Initial core biopsy showing invasive lobular cancer

- Estrogen receptor and progesterone receptor negative tumor with clinical size > 1 cm

- Any Her 2+ breast cancer (immunohistochemistry 3+; or amplified by fluorescence in
situ hybridization [FISH])

- Cancer in a patient with a known inherited susceptibility mutation in breast cancer
(BRCA)1 or BRCA2

- Multicentric breast cancer (two foci of known cancer in the breast separated by
greater than 5 cm, or in separate quadrants

- Clinically or pathologically positive axillary lymph nodes

- Any prior breast cancer

- Prior breast radiation therapy