We hear over and over, “mammograms save lives.” Multiple studies performed showed that women who have annual mammograms have a significantly decreased chance of dying due to breast cancer verses women who do NOT have annual mammograms. What does that really mean? Do mammograms magically cure or prevent breast cancer? Is it by the mere event of having a mammogram that the cancer will be cured? Is it that by having annual mammograms, one will prevent breast cancer?
It is first important to consider how breast cancer is classified in order to determine the likelihood of curing a breast cancer once it is diagnosed. The classification of a breast cancer is complex and very involved, but some of the major concepts will be highlighted here. The two biggest questions that need answered when a breast cancer is diagnosed are the following: (1) how big is the tumor; and, (2) has the tumor spread to any of the lymph nodes or other areas of the body beyond the breast? The answers to these questions help determine the classification or stage of the breast cancer. Typically four (4) stages are used: 1 , 2, 3 ,4 (or I, II, III, IV for the Roman numeral people). Stage 1 breast cancer has the best survival rate whereas stage 4 breast cancer has the lowest survival rate. Patients with small tumors and NO involvement of lymph nodes or other areas beyond the breast are within the stage 1 and stage 2 end of the spectrum. Patients with large tumors and involvement of lymph nodes and others of the body beyond the breast are within the stage 3 and stage 4 end of the spectrum. So, in summary, when a breast cancer is diagnosed when it is very small and has not spread beyond the breast, that is the type of breast cancer with the highest rate of cure/survival.
Prior to the use of mammograms, women typically got diagnosed with breast cancer after her or her doctor felt a lump within the breast tissue. These types of breast cancer tended to be very large and were usually classified within the stage 3 and stage 4 types of breast cancer, which as just described above, have lower rates of survival and cure. Mammograms, however, changed this. Mammograms can detect breast cancer BEFORE it is large enough to be felt or before it can spread beyond the breast. Therefore, mammograms can detect breast cancer in the stage 1 or stage 2 spectrum, which as just described above, has the higher rates of survival and cure.
So, in summary, mammograms reduce breast cancer deaths (or, in other words, increase chances of surviving breast cancer) because they detect breast cancer in the earlier stages when it can be better treated. If just mammograms have made this big of an impact, it is great to think about how advanced imaging techniques like breast MRI (which can detect breast cancers even smaller than mammograms) can further help women have the very best opportunity for early detection of breast cancer, and therefore, the best opportunity for a cure.