Statistics
According to the National Cancer Institute (NCI) there will be more than 192,000 cases of breast cancer diagnosed in 2009, and 40,000 people (mostly women) will die from the disease. The American Cancer Society (ACS) says about one in five breast cancer survivors (20 percent) who have completed 5 years of adjuvant treatment (additional cancer treatment given after the primary treatment to lower the risk that the cancer will come back) will have a recurrence within 10 years following treatment. There are a number of variables that determine the risk of a breast cancer recurrence.
Cancer Stages
The ACS reports that Dr. Abeena Brewster and colleagues at the M.D. Anderson Cancer Center in Houston, Texas, investigated the risk of breast cancer recurrence in approximately 3,000 women with various stages of the disease. The women received treatment at the center over a 16-year period that ended in 2001. Brewster and colleagues concluded that the more advanced stage of the cancer, the greater the risk of recurrence.
The five-year recurrence rate was 7 percent for stage I, 11 percent for stage II and 13 percent for stage III breast cancers.
Cancer Grades
The grade of breast cancer cells also has an impact on the chance of recurrence. A grade describes how the cells appear under a microscope. They are rated on a scale from one to three. The cells are more apt to multiply quickly if they are of a higher grade. The five-year recurrence rate for a grade 1 tumor is about 9 percent while the chances of a grade 3 tumor reappearing is 14 percent.
Hormone Receptor Standing
The odds of breast cancer coming back within five years of diagnosis are also affected by the hormone receptor status of the malignancy. The five-year recurrence rate for hormone-receptive positive cancers was 13 percent and 7 percent for hormone receptor negative tumors. The NCI says 75 percent of breast cancer tumors are estrogen receptive positive.
Types of Recurrence
Breast cancer is most likely to return to the same area where the initial cancer was detected. This is called a local recurrence.
A regional recurrence is more serious because it typically means the cancer has moved beyond the breast. However regional recurrence occurs in only 2 percent of all breast cancer cases.
A distant recurrence means the breast cancer has spread (metastasis) to other areas of the body, most frequently striking the bone, lung or liver.
According to the National Breast Cancer Coalitioni, some 6 percent of breast cancer patients have metastatic disease at the time of the initial diagnosis. Nearly half of those first diagnosed with non-metastatic breast cancer will eventually suffer from metastatic disease.
