Breast cancer is the most common invasive cancer in females and responsible for the highest death rate. It is uncommon in males.
Incidence and mortality
There are almost 12,000 new cases a year in Australia. The risk of being diagnosed before 85 is 1 in 9 for women and 1 in 722 for men. Each year, 2710 women and 10 men die of breast cancer.
Screening
Mammographic screening every two years is recommended for women aged 50-70 years, though it is available to women from 40 years of age. Younger women in high risk groups may be screened by Magnetic Resonance Imaging (MRI).
Symptoms and diagnosis
Symptoms include:
- new lumps or thickening in the breast or under the arm
- nipple sores
- discharge or turning in
- skin of the breast dimpling
- rash or red swollen breasts
- pain is rare.
Diagnostic options include imaging then biopsy by needling or removing the lump.
Staging
Staging includes knowing the size of the breast cancer and whether it has spread to the draining lymph nodes under the arm. Imaging of the chest liver with CT scan and bone scan includes the major sites of spread.
Causes
Increasing age, family history, inheritance of mutations in the genes BRCA2, BRCA1 and CHEK2 exposure to female hormones (natural and administered), obesity (diet and exercise) and excess alcohol consumption, are all associated with breast cancer, as well as some benign breast disease and past exposure to radiation.
Prevention
There is no proven method of prevention, however high risk women (very strong family history) can benefit from hormones such as tamoxifen, usually administered over five years. Bilateral prophylactic mastectomy can be considered in high risk women with gene mutations.
Treatment
Treatment depends on the extent of the cancer.
For localised breast cancer the most extensive surgical option would be removing the breast and lymph nodes under the arm. However, removing the lump and just a section of the breast, followed by radiotherapy, results in the same rate of survival. If the first draining lymph node can be identified using dye or a nuclear medicine scan it can be sampled and if negative further surgery avoided.
For tumours at greater risk of recurrence, ie. bigger, more aggressive looking, spread to the lymph nodes, additional treatment (adjuvant therapy) can be given after surgery. This can include hormone therapy of aromatase inhibitors or tamoxifen for women whose tumours have hormone receptors on their surfaces, chemotherapy and targeted therapies such as trastuzumab for those 25% of tumours which are HER2 positive (ie. have the target for trastuzumab on their surfaces).
Patients presenting with locally extensive cancer will have chemotherapy and radiotherapy initially to see if it will shrink the cancer to become operable.
If breast cancer returns after initial treatment, local disease may be treated with surgery, while more widespread disease will be treated with combinations of similar drugs to those listed for the adjuvant setting, as is the case for patients who present with widespread disease. Common chemotherapy drugs include anthracyclines and taxanes.
Patients with bone disease can receive bisphosphonates such as zoledronate to slow the erosion of bones, and receive local radiotherapy for pain.
Prognosis
If the cancer is limited to the breast, 98% of patients will survive (survival is considered as being free of cancer five years after the cancer is detected); this figure excludes those who die from other diseases. If the cancer has spread to the regional lymph nodes survival drops to 83%.
For more information, please contact The Cancer Council Helpline on 13 11 20 (cost of a local call).