Genetic Susceptibility to Radiation-Induced Skin Reactions in Racial/Ethnic Groups of Patients With Breast Cancer

OBJECTIVES:

- To develop and validate prediction biomarkers for radiation therapy (RT)-induced acute
and chronic skin reactions and quality of life in five racial/ethnic groups of breast
cancer patients, Whites*, Black/African Americans, Hispanic/Latinos, Asians/Native
Hawaiians/Pacific Islanders, and American Indians/Alaskan Natives. NOTE: *This stratum
is closed as of April 25, 2012.

- To develop polygenic models of RT-induced skin reactions with a comprehensive evaluation
of genome-wide nonsynonymous single nucleotide polymorphisms (nsSNPs).

- To evaluate the levels of DNA damage (Comet assay) and radiosensitivity (Cell Cycle G2
Delay assay) in lymphocytes before and after RT.

- To test the effect of gene-gene and gene-smoking interactions on RT-induced skin
reactions.

- To assess race-ethnic differences in RT-induced skin reactions, DNA damage, and
radiosensitivity and to determine if the gene effects are consistent across
race-ethnicity (gene-race/ethnic interactions).

OUTLINE: This is a multicenter study. Patients are stratified according to race/ethnicity
(Whites* vs Black/African Americans vs Hispanic/Latinos vs Asians/Native Hawaiians/Pacific
Islanders vs American Indians/Alaskan Natives). NOTE: *This stratum is closed as of April 25,
2012.

Patients undergo adjuvant radiotherapy after breast-conserving surgery.

Blood and urine samples are collected at baseline and last day of radiotherapy for
genotyping, DNA damage, cell cycle assays, urine cotinine, inflammatory immune response
biomarkers, and tumor-killing activity by BeadArray System, Comet assay, flow cytometry-based
assay, Cell-Cycle G2 Delay Assay, Oxygen Radical Absorbance Capacity (ORAC) assay, and ELISA.

Patients are assessed for acute toxicity by research staff using the ONS Criteria for
Radiation-Induced Acute Skin Toxicity at baseline, week 3, and at 1 and 2 months after
radiotherapy. Patients are also assessed for chronic toxicity by research staff using the
Chronic skin toxicity questionnaire (RTOG SOMA Criteria for RT- Induced Breast/Chest Wall
Late Skin Toxicity) at 6 and 12 months after completion of radiotherapy. Photographs of the
breast, chest wall, and contralateral breast are also taken at baseline, week 3, last day of
radiotherapy, and at 1, 2, 6, and 12 months after completion of radiotherapy.

Patients complete the Breast Cancer Risk Study Questionnaire, the Functional Assessment of
Cancer Therapy Breast (FACT-B), the Modified Skindex, and the B39 Quality-of-Life (QOL)
Questionnaire at baseline, last day of radiotherapy, and at 1, 2, 6, and 12 months after
radiotherapy.

DISEASE CHARACTERISTICS:

- Female patients newly diagnosed with breast carcinoma including ductal carcinoma in
situ (DCIS)

- Stage 0-IIIA disease

- Status post-lumpectomy, -quadrantectomy, or -mastectomy

- Plan to receive adjuvant radiation to the whole breast or chest wall and/or regional
lymph nodes

- No sites that cannot send blood/urine specimens to Wake Forest by overnight (next day)
express shipping

PATIENT CHARACTERISTICS:

- *This stratum is closed as of April 25, 2012.

- No patients who do not understand English and are unable to complete form with
assistance

PRIOR CONCURRENT THERAPY:

- Total dose > 40 Gy, dose per fraction > 1.8 - 2.0 Gy, use of 2D, 3D-conformal, or
intensity-modulated radiation therapy (IMRT) treatment techniques allowed; a daily
fraction of 2.7 Gy to the whole breast is suggested for hypofractionated regimens

- Concurrent and sequential boost techniques are allowed for both standard and
hypofractionated regimens

- Adjuvant hormonal therapy will be allowed prior to, during, and/or after radiotherapy
(RT) at the discretion of a medical oncologist

- Targeted therapies, such as Herceptin, will be allowed prior to, during, and/or after
RT at the discretion of the medical oncologist

- No prior radiation to the involved breast or chest wall

- No concurrent chemotherapy

- No patients who underwent breast reconstruction following mastectomy

- Placement of tissue expanders and implants are not allowed

- No patients who have undergone MammoSite® or any other form of brachytherapy as well
as those who will be treated with skin-sparing IMRT

- Patients may not be concurrently enrolled in a protocol that involves treatment of the
skin, i.e., applying lotions/moisturizers

- Protocols that do not involve treatment of the skin are allowed