Breast cancer survivors have a 2-fold higher risk of developing a second breast cancer, compared to women without breast cancer, matched for age, breast density, and use of mammography [ 3].
Both groups were also matched for main breast cancer-related criteria.
With appropriate local and systemic therapy, women treated with chemotherapy during pregnancy have clinical outcomes that are no worse than those of nonpregnant patients matched for age and breast cancer stage [ 12].
This resulted in 302 confirmed matched records for breast cancer registration.
For each cancer case, we selected two controls, who had not been diagnosed with breast cancer, matched for age, ethnicity and time of screening.
These breast cancer brain metastatic specimens and breast tumors were matched for patient age upon primary tumor detection and the ER status of the primary tumor.
Patients undergoing primary surgery for breast cancer and controls matched for age, menopausal and hysterectomy status were prospectively recruited.
Our retrospective study showed no disease and overall survival differences between male and female breast cancer patients matched for year of diagnosis, age, tumor size, nodal stage, tumor grade, estrogen receptor, progesterone receptor and HER2 expression.
In a Finnish study among 2,548 women < 40 years old diagnosed with carcinoma of the breast during 1967 to 1989, there were 91 eligible patients with subsequent deliveries (≥ 10 months after the diagnosis) – for whom 471 control individuals were matched for stage, age, and year of breast cancer diagnosis.
Specimens were matched for each donor to have both tumor-free and tumor-containing breast tissues.
