Currently, there are 2.5 million to 2.7 million breast cancer survivors in the United States. According to the American Cancer Society, as many as 10 to 20 percent of these women already or will eventually develop recurrent breast cancers. The risk of breast cancer recurrence of an individual depends on a variety of factors, including patient age, inherited susceptibility, stage of the original tumor, type of treatment for original tumor (e.g. surgery or radiation therapy) and other lifestyle factors such as obesity and alcohol consumption.
Types
Breast cancer recurrence is categorized according to its relative location to the original tumor. If the recurrence occurs at or close to the original site, it is often classified as true recurrence or marginal miss recurrence, respectively. If the recurrent tumor is located within the same breast but at a distinct site, it is often referred to as "elsewhere in the breast" and represents a new primary site. Recurrence can also occur in the other breast and other organs and is often referred to as metastasis.
Statistics
The statistics on breast cancer recurrence have evolved over time, according to the book "DeVita, Hellman, and Rosenberg's Cancer: Principles and Practice of Oncology" (Eighth Edition, Lippincott Williams & Wilkins, 2008). In the 1980s and the 1990s, the local recurrence rates were reported to be 8 to 19 percent in the 10 years following the initial diagnosis and treatment. In the early 21st century, the 10-year rates of recurrence are often reported to be between 2 and 7 percent, which is consistent with recent improvement in the treatment of breast cancer.
Time Frame
For patients undergoing breast-conserving therapy, the annual incidence rate of local recurrence is 1.3 to 1.7 percent between year two and year seven following treatment. This rate is reduced to 0.4 percent per year at 10 years after treatment. On the other hand, for patients undergoing mastectomy, most local recurrences occur in the three to five years following surgery, according to "DeVita, Hellman, and Rosenberg's Cancer: Principles and Practice of Oncology."
Roughly 20 percent of breast cancer survivors who have finished five years of additional cancer treatment after their initial therapy will have a recurrence within 10 years of their treatment, according to the American Cancer Society (ACS). Overall, 11 percent of women will suffer a recurrence at five years and 20 percent at 10 years, the ACS says.
Other Considerations
The risk of recurrence depends on the hormone receptor status of the cancer. According to the ACS, the five-year recurrence rate for women with hormone receptor-positive tumors is twice as high as that of those with hormone receptor-negative tumors.
Patients with a BRCA1 or BRCA2 mutation have a 26 percent chance of developing contralateral breast cancer, compared to 3 percent in those who do not have mutation. A woman's risk of developing breast cancer is significantly increased if she inherits mutations in BRCA1 and BRCA2 genes.
The five-year recurrence risk in patients with ductal carcinoma in situ (DCIS) ranges from 12 to 15 percent.
Prevention/Solution
Tamoxifen and additional chemotherapy have been shown to reduce the risk of recurrence by 40 to 50 percent. Several genetic tests exist that enable identification of women who would benefit from tamoxifen or additional chemotherapy. For instance, Oncotype Dx has been shown to correctly identify people with early breast cancer who would benefit from additional chemotherapy.
References
- Study Quantifies Risk of Breast Cancer Recurrence
- Devita, Hellman & Rosenberg's Cancer: Principles & Practice of Oncology, 8th Edition
- Clarke M, Collins R, Darby S, et al. Effects of radiotherapy and of differences in the extent of surgery for early breast cancer on local recurrence and 15-year survival: an overview of the randomised trials. Lancet 2005;366(9503):2087
