RATIONALE: Studying samples of tumor tissue in the laboratory from Native American women with breast cancer may help doctors identify and learn more about biomarkers related to breast cancer in these patients. It may also help doctors learn more about the prognosis of these patients.

PURPOSE: This laboratory study is looking at biomarkers in Native American women with breast cancer.

OBJECTIVES:

• Evaluate a selected panel of molecular markers in tissue specimens from Native American women with breast cancer.
• Determine which molecular markers provide independent prognostic information with respect to traditional prognostic factors in these patients.
• Compare and contrast the prevalence of positivity in Native American women with breast cancer with an age- and stage-matched cohort of Caucasian women with breast cancer enrolled on clinical trial NCCTG-77-30-51 or the Mayo Breast Cancer Registry.

OUTLINE: Immunohistochemistry is performed on tumor samples to analyze the following molecular markers: estrogen receptor, progesterone receptor, c-erbB2, p53, Ki-67, Bcl-2, Bax, cyclin D-1, and insulin-like growth factor-1R.

DISEASE CHARACTERISTICS:

• Diagnosis of primary adenocarcinoma of the breast in Native American women

• Prior surgical treatment for breast cancer within the Aberdeen or Phoenix areas of the Indian Health Service or the Alaska area of the Native Health Service between 1990-2000

  • Paraffin-embedded tissue available

• Paraffin-embedded tissue available from Caucasian women with breast cancer enrolled on NCCTG-77-30-51 or the Mayo Breast Cancer Registry

PATIENT CHARACTERISTICS:

Age

• 18 and over

Sex

• Female

Native American women with primary adenocarcinoma of the breast with prior surgical treatment for breast cancer within the Aberdeen or Phoenix areas of the Indian Health Service or the Alaska area of the Native Health Service between 1990-2000.