The results of a mammogram are usually accurate, but the results may not be properly analyzed. A false positive can mean that someone will have to go have an unnecessary biopsy and a false negative can mean someone will have breast cancer unnoticed. Not treating breast cancer at an early stage can result in serious health problems. While many women do have regular mammograms, there are still women who end up having later stages of breast cancer due to mistakes in reading the mammogram results.