By Dr. Elise Dubuc
Breast cancer: Risks, Symptoms, Diagnosis.
Breast cancer is the most frequently diagnosed cancer among Canadian women representing 25% of all cancers affecting this population. One in 8 women will get breast cancer in her lifetime. The good news is that breast cancer mortality has decreased by 44% since the 1980s. This decrease is likely due to both increased mammography screening and the use of more effective treatments. It is recommended that average-risk women between the ages of 50 and 74 have a screening mammogram every two years. In Quebec, the recommended screening program has been chosen to stop at age 70. Overall, the five-year survival rate for women with breast cancer is relatively high, at 87%. On the other hand, survival varies enormously according to the cancer stage, ranging from nearly 100% for cancer discovered early to 22% for stage 4 cancers. More than 80% of all breast cancers are diagnosed at stage 1 or 2.
The risk of breast cancer is more significant for women who have already had breast cancer. It also includes those who had ductal or lobular carcinoma in situ if there is a first-degree family history or two female relatives or more in the 2nd degree who have had breast or ovarian cancer. With a first-degree relative with a history of breast cancer, the risk doubles; the more first-degree relatives affected, the greater the risk. The risk is not as high with 2nd-degree female relatives.
Other factors that can increase risk include women who had their period early (age 11 or earlier), late menopause (over age 55), a late or no pregnancy, who had radiotherapy (chest, neck and armpit area), who have dense breasts, or take combined hormonal contraceptives for more than ten years.
Alcohol consumption, even moderate, and physical inactivity are also risk factors. Obesity increases the risk of breast cancer by 2.5 times in postmenopausal women.
Gene mutations are changes in a gene that can make you more susceptible to certain cancers. These genetic mutations are passed down hereditarily from parent to child. Only a small number of breast cancers (between 5% and 10%) are attributable to a genetic mutation.
Women with BRCA1 or 2 gene mutations have up to an 85% risk of developing breast cancer and getting cancer at a younger age, before menopause. These mutations are rare, affecting approximately 1 in 500 people, but are more common in the Ashkenazi Jewish population. Genetic testing may be recommended if several family members have had breast and ovarian cancer, especially at a young age, if members have had cancer in both breasts or if a male member has had breast cancer. It is always preferable to initially test the members affected by breast or ovarian cancer and to test the unaffected members only if the mutation is found in the affected members.
Some rare inherited genetic syndromes are associated with breast cancer, such as Li-Fraumeni, ataxia telangiectasia, and Cowden and Peutz-Jeghers syndromes.
Breast Cancer Symptoms
Breast cancer may not present any signs or symptoms at the first signs of the disease, which is why mammography screening is so important. Symptoms appear when the breast tumour is large enough to feel the lump when touched. Breast cancer can present as a firm or hard lump different from the rest of the breast tissue. This lump may seem attached to the skin or nearby breast tissue and does not go away during the menstrual cycle. It can be tender but usually not painful. Breast pain or mastalgia is often associated with non-cancerous breast conditions such as fibrocystic changes.
Other symptoms associated with breast cancer are thickening or hardening of the breast tissue, lump in the armpit, change in the shape or size of the breast, and changes in the nipples, such as an inverted nipple inside or a discharge from the nipple without it being compressed.
Breast cancer can be diagnosed following a mammogram screening or following the appearance of symptoms. Mammography will detect a mass or abnormal area and guide a biopsy to remove tissue and cells to make the diagnosis with certainty in the laboratory. An ultrasound may also be done to characterize a mass better or guide a biopsy.
If a cancer is diagnosed, an analysis of hormone receptors and the HER2 gene will be carried out to determine which treatments will be the most effective for this particular tumour.
The cancer stage describes the extent of cancer at the time of its diagnosis. The stage will be determined by imaging examinations and certain targeted biopsies, making it possible to develop a treatment plan.
Your health practitioner will suggest a treatment plan depending on the stage and type of cancer, menopausal status, hormone and HER2 receptors, and overall health status. It may include surgery, chemotherapy, radiotherapy and hormone therapy.