Certain Factors Help Predict Invasive Breast Cancer
A new study published in the Journal of the National Cancer Institute suggests that two factors can help predict the risk of developing future invasive cancer in women with noninvasive breast cancer. This could help women and their doctors make more informed treatment choices.
Ductal carcinoma in situ (DCIS) refers to cancer in the breast's milk ducts that has not spread. It is the most common type of noninvasive breast cancer, accounting for about one out of every five new breast cancer cases in the U.S. DCIS is not deadly, but it raises your risk for future invasive cancer.
Some women with DCIS are treated with lumpectomy alone. In a lumpectomy, the tumor and surrounding tissue are removed. Studies have shown that 5 to 10 percent of women with DCIS treated by lumpectomy alone develop an invasive form of breast cancer within five years. But research to identify which of these women are at higher risk has had mixed results.
Method of cancer detection and biomarkers predict risk
To determine risk factors for invasive cancer in women with DCIS, researchers interviewed 1,162 California women who had been diagnosed with DCIS an average of seven-and-a-half years prior. The women were ages 40 and older when they were diagnosed. They underwent lumpectomy for treatment.
In the time since DCIS diagnosis, 15 percent had developed an invasive cancer. But women whose original DCIS was found when a lump was felt by their doctors were more than twice as likely to develop a subsequent invasive cancer as women whose DCIS was found by mammography.
In addition, analysis of DCIS tissue found that several biomarkers predicted risk for developing invasive breast cancer. A biomarker is a substance that is produced by the body and indicates a specific process, condition, or disease. Risk was more than double in women with high levels of three biomarkers (p16, cyclooxygenase-2, and Ki67).
All told, women without high levels of the three biomarkers whose DCIS was detected by mammography had a 4 percent risk for invasive cancer over eight years. But women who had all three biomarkers or whose DCIS was detected when a lump was felt by their doctors had a 20 percent risk.
The study authors think that this information will enable doctors to better predict the risk level of developing invasive cancer later for women who are treated with lumpectomy. Those who are at high risk may be better candidates for additional treatment.
Lowering your risk after breast cancer
All forms of breast cancer raise your risk for new cancer. But there are ways to help lower your risk. Talk with your doctor about these tips:
Maintain a healthy weight. Being overweight can boost your risk for breast cancer coming back or a new cancer forming.
Get active. Research suggests that regular exercise can help lower your risk for a new breast cancer or the original cancer returning. The American Cancer Society suggests that women with breast cancer exercise about four hours per week to improve their quality of life and fitness level, and possibly reduce the risk for new cancer.
Consider preventive medicines. Ask your doctor if you might be a good candidate for preventive medicines, such as aromatase inhibitors and selective estrogen receptor modulators (SERMs), which lower the risk for recurrence of certain breast cancers or for new cancers developing.
Avoid hormone replacement therapy. Most experts agree that the higher risk for a subsequent cancer outweighs the benefits of hormone replacement therapy in women who have had breast cancer.