BCSC Data Explorer

Glossary of Terms

Patient and exam characteristics

Age
Age at the exam.
Race/ethnicity
Reported by the woman.
Family history of breast cancer
One or more first-degree relatives (mother, sisters, or daughters) has had a diagnosis of breast cancer.
Current use of hormone therapy
Use of hormones prescribed for women after menopause. Also known as hormone replacement therapy.
Prior breast biopsy
The removal of cells or tissue for examination by a pathologist. Aspiration biopsy is the removal of a sample of tissue or fluid with a thin needle. From the BCSC database or reported by the woman.
Prior breast cancer
Past diagnosis of invasive breast cancer or ductal carcinoma in situ (DCIS). From the BCSC database or reported by the woman.
Indication for exam
Screening exams are performed for routine screening on a woman who does not have symptoms of a breast problem. Diagnostic exams are performed for additional evaluation of a recent screening exam, "short interval" follow-up of an earlier breast exam, or evaluation of a breast problem. Reported by the radiologist.
Time since last exam
From the BCSC database or reported by the woman.
Breast density
Density of breast tissue as it appears on a mammogram. Reported by the radiologist, using Breast Imaging and Reporting and Data System (BI-RADS®) categories.
Year
Year the exam was done.

Breast cancer diagnosis

Breast cancer
First diagnosis of invasive breast cancer or ductal carcinoma in situ (DCIS) in the BCSC database. Based on cancer registry reports.
Invasive or DCIS
Whether the breast cancer was invasive or ductal carcinoma in situ (DCIS). Invasive breast cancer is cancer that has spread from where it started in the breast into surrounding, healthy tissue. DCIS is a noninvasive condition in which abnormal cells are found in the lining of a breast duct. The abnormal cells have not spread outside the duct to other tissues in the breast.
Tumor stage
Stage of breast cancer at diagnosis. Classified using to the American Joint Committee on Cancer (AJCC), 6th edition.
Tumor size
Size of the breast tumor at diagnosis.
Tumor grade
Grade of the breast tumor at diagnosis.
Lymph node positive
The breast cancer had spread to the lymph nodes by the time of diagnosis.

Screening mammography performance and cancer rates

Screening mammogram classification (exam result and cancer status)
The mammogram result is based on the interpretation of the radiologist. A screening mammogram is defined as positive if the initial Breast Imaging Reporting and Data System (BI-RADS®) assessment was 0 (needs additional imaging evaluation), 4 (suspicious abnormality), 5 (highly suggestive of malignancy), or 3 (probably benign finding) with a recommendation for immediate follow-up. A negative screening mammogram is an initial assessment of 1 (negative), 2 (benign finding), or 3 (probably benign finding) without a recommendation for immediate follow-up. The follow-up period was one year after the screening mammogram or until the next screening mammogram, whichever occurred first. Cancer status is positive if a tissue diagnosis of invasive breast cancer or DCIS was made during follow-up. Cancer status is negative otherwise.
True positive
A positive mammogram with cancer diagnosed by the end of follow-up.
False positive
A positive mammogram with no cancer diagnosed by the end follow-up.
True negative
A negative mammogram with no cancer diagnosed by the end of follow-up.
False negative
A negative mammogram with cancer diagnosed by the end of follow-up.
Sensitivity
The probability of interpreting a mammogram as positive when breast cancer is present. Calculated as the number of true positives divided by the total number of cancers (true positives + false negatives) in the population.
Specificity
The probability of interpreting a mammogram as negative when breast cancer is not present. Calculated as the number of true negatives divided by the total number of non-cancers (true negatives + false positives) in the population.
Positive predictive value
The proportion of positive mammograms that result in a tissue diagnosis of breast cancer. Calculated as the number of true positives divided by the total number of positive mammogram results (true positives + false positives) in the population. Also known as PPV or PPV1.
Cancer rate
The number of breast cancers diagnosed during follow-up per 1,000 mammograms.
Cancer detection rate
The number of breast cancers correctly detected at mammography and diagnosed during follow-up per 1,000 mammograms.