Breast Cancer
The breast is made of three tissue types: Glandular tissue, fat and fibrous tissue.
Glandular tissue is made up of milk lobules and ducts. These end at the nipple and are all lined by glandular cells which are always dividing and renewing.
This process of division and renewal is under very tight control by the body. Cancer results when these cells lose this tight control and start dividing excessively.
These cells can sometimes develop the ability to invade neighbouring structures including the lymphatics (reaching the lymph nodes) and blood vessels thus spreading throughout the body and growing elsewhere (distant metastases).
All cancers result from the loss of control over dividing cells which is usually due to a combination of genetic abnormalities and environmental factors.
Genetic abnormalities do not necessarily mean that it has to run in the family but there is certainly an important role for inheriting faulty genes. Going through your family history and depending on the type of cancer and your age, you may be advised to see a clinical geneticist and / or have genetic testing which can have implications on your treatment and follow up.
We know that the lifetime chance of a woman having breast cancer in Australia is 1 in 8 and most of the cancers are what we call “sporadic” – that is without a family history.
Below is a list of factors that increase the risk of breast cancer and others that are protective against breast cancer. The list is to help you understand the risks that we know about rather than serve as a checklist to see what you could have done differently to avoid breast cancer. You may have none of these risk factors and yet get breast cancer. You may also have all of these risk factors but do not get breast cancer. You should, however, avoid whatever you can avoid from the risks such as prolonged use of hormone replacement therapy.
| Factors that increase the risk of breast cancer | Protective factors |
|---|---|
| Increasing age Female sex |
Younger age Male sex |
| Carrying certain genes (eg. BRCA1 & BRCA2) Family history of breast cancer Personal history of breast cancer (having had breast cancer in the past) |
No family history |
| Early menarche (<12) Late menopause (>55) Having no children or having children after age 30 |
Late menarche (>14) Early menopause (<45) Giving birth before age 30 Having more children (>5) Breastfeeding (>16 months) |
| Using the oral contraceptive pill (risk goes back to normal 2 years after stopping this) Using hormone replacement therapy (HRT) – especially >5yrs |
No exogenous hormones No use of the contraceptive pill or implanted devices No use of hormone replacement therapy (HRT) |
| Increased breast density on mammogram | Recreational exercise |
| Increased bone density (which reflects greater exposure to estrogen) | Healthy body mass index (BMI) after menopause (<23) |
| Previous breast biopsies | Aspirin – more than 1/wk for >6 months |
| History of high-risk breast lesions (eg. ADH) Regular alcohol (2-5 drinks/day) |
For more details on breast cancer risk factors follow this link:
Cancer stage depends on how far the cancer has spread as well as its size.
- Stage 1 – small cancer. No lymph node involvement.
- Stage 2 – small cancer with lymph node involvement or larger cancer without lymph nodes.
- Stage 3 – larger cancer with lymph nodes.
- Stage 4 – cancer has spread beyond the breast and lymph nodes.
Cancer grade refers to how aggressive the cancer cells look under the microscope. The closer the cells resemble the normal breast cells, the lower the grade and the less aggressive the cells.
- Grade 1 (well differentiated – cancer cells look more similar to normal breast cells): low grade, less aggressive. Unlikely to require chemotherapy.
- Grade 2 (moderately differentiated): moderately aggressive. May or may not require chemotherapy.
- Grade 3 (poorly differentiated – cancer cells look very different compared to normal breast cells): more aggressive. More likely to require chemotherapy.
All cells in the body, have protein receptors on their surfaces or inside the cells.
These are “receivers” similar to TV antennas that the cells use to communicate with other cells. There are thousands of receptors on each cell.
Breast cancer cells may express receptors for the hormones estrogen (called estrogen receptors: ER) or progesterone (called progesterone receptors: PR).
When a breast cancer cell expresses these ER and PR, it usually has a better prognosis and can also be treated with endocrine therapy.
One of the other receptors that may be expressed on breast cancer cells is a so-called growth factor receptor by the name of Her-2.
Cancers that express Her-2 receptors are usually more aggressive but with the advent of target therapies such as Herceptin, prognosis is much better.
Thankfully, most breast cancer is diagnosed early. Early breast cancer has an excellent prognosis with a high 10-year survival rate. Therefore, most patients with early breast cancer can be cured. The risk of recurrence depends on the type, grade and stage of cancer and this dictates treatment and follow up.
With advances in management, survival rates are increasing even for advanced breast cancer.
While this question is often on patients’ minds, doctors can only at best provide estimates of survival on a case to case basis.
How is breast cancer treated?
Most breast cancer is treated with a combination of surgery and other adjunctive therapies called “adjuvant” treatment.
When this adjuvant treatment is given before surgery it is called “neo-adjuvant”. This is sometimes done for larger cancers and certain cancer types.
I like to list the available therapies as the “weapons” we have in the fight against breast cancer. You will not necessarily need all of these weapons for your breast cancer. The timing and use of each of these weapons depends on your particular cancer. These weapons include: surgery, chemotherapy, radiotherapy, endocrine therapy and target therapy. Below is an outline of each of these weapons:
- This is often but not always the first treatment.
- Surgery is usually performed by removing the cancer (lumpectomy / Wide local excision) with or without reshaping the breast or performing a breast reduction (Oncoplastic surgery).
- Sometimes removing the whole breast (mastectomy) is necessary or preferred. This can be done with or without immediate or delayed reconstruction (making a “new breast” with an implant or with your own tissue).
- Surgery also includes removing a group of lymph nodes called the sentinel nodes (sentinel node biopsy) or removing all of the axillary (armpit) lymph nodes (axillary dissection) at the same time as the breast surgery.
- Usually after surgery, there is at least a 4-week break before other adjuvant treatment(s) can commence.
- If chemotherapy is indicated, this is usually the next step following surgery.
- Chemotherapy is the use of drugs to kill rapidly dividing cells which may have spread beyond the breast even if we cannot detect these with any imaging.
- We know that certain tumour characteristics are associated with an increased risk of spread of these cells. Having these tumour characteristics are indications for the use of chemotherapy.
- The duration of treatment and the drugs used as well as the side effects of the drugs are complex and are considered on a case by case basis by the medical oncologists.
- Chemotherapy commonly takes 4-6 months.
- Once again, after the conclusion of chemotherapy, a 4-week break is given before other adjuvant therapy can commence.
- If chemotherapy is not used, this is the next step after surgery. If chemotherapy is used, radiotherapy follows chemotherapy (after a 4-week break)
- Radiotherapy is the use of x-rays to the breast (+/- the lymph nodes) to reduce the risk of recurrent cancer in the same breast.
- It is usually required after a lumpectomy but is also sometimes indicated after a mastectomy.
- Radiotherapy is commonly administered over 3-5 weeks and is usually given every weekday (Mon to Fri). The radiation itself is given over a couple of minutes. Patients can usually fit this around their work schedule.
- Planning, duration and side effects are all discussed in detail by the Radiation Oncologist.
- Breast cancers that express ER and PR (see above) respond to endocrine therapy.
- Endocrine therapy is a group of drugs that block these receptors, or reduce the body’s production of female hormones. They include drugs that suppress ovarian function in pre-menopausal females.
- Endocrine therapy is usually given orally and is usually well tolerated.
- Duration of treatment is usually 5 years but may extend to 10 years.
- These are prescribed by the medical oncologist.
Other drugs that can be used in the treatment of breast cancer target specific receptors on the cancer cells. The most common of these drugs is Herceptin which targets the Her-2 receptor (see above). These are prescribed by the medical oncologist.
The role of target therapy is evolving rapidly and is the subject of many trials including immunotherapy drugs.
Your treatment team includes: surgeon, medical oncologist, radiation oncologist, breast care nurse as well as other members of the multidisciplinary team such as the radiologist, pathologist and clinical geneticist.
Being diagnosed with breast cancer can be devastating news. However, it is important to put things into perspective and look at the positives such as early diagnosis, likelihood of cure and availability of excellent healthcare in Australia.
I often advise my patients to resist negative thoughts by reminding themselves that they have presented with this problem to their doctor. It has now become the doctor’s problem rather than their own.
Follow up is usually by the surgeon alternating with the medical oncologist and may be shared with your local doctor (Shared Care)
- Every 3-6 months in the first three years.
- Every 6-12 months in the next two years.
- Annually thereafter.
- Your breast imaging (mammogram +/- ultrasound) should be performed on an annual basis indefinitely.
After the first 5 years of follow up, you may be discharged to your GP for annual examination and surveillance imaging. However, you may return to Breastscreen for your annual mammogram. You may also continue your surveillance through your surgeon.
Breast cancer treatment is advancing every day which is we continue to embrace changes that will benefit our patients. The most “up to date” treatments have to be studied and trialled to ensure their safety and efficacy. One way to access the most “up to date” treatments is to be part of these trials. Feel free to discuss this with your surgeon or oncologist. To see if you are eligible for any current trials, follow this link:
For more information about breast cancer follow these links: