The standard technique for examining patients for breast cancer is a mammography, which is an X-ray of the breast, along with a tissue biopsy, which is the removal and examination of a sample of tissue.
But mammograms are not 100 percent accurate, the detection of cancer can be prevented by healthy compact tissue. According to the American Breast Cancer Surveillance Consortium, mammography sensitivity for breast cancer is about 87 percent.
Some women, especially those living in poor isolated communities without hospitals or other facilities, also do not have access to mammograms. And other women simply don’t get regular breast cancer screenings.
A biopsy is also not an infallible method. Although the technique can provide information about the tumor, it has its limitations. Doctors can only examine a small area and the full size of the tumor may elude them. A tissue biopsy is also invasive and painful.
Taken together, the drawbacks of a diagnosis with mammograms and biopsies mean that some patients go undiagnosed before the cancer has grown and spread.