Breast Cancer Management
BREAST CANCER MANAGEMENT
Once the diagnosis of breast cancer is made, the treatment options are discussed with the woman and her family. Treatment options for breast cancer are diverse. The best possible treatment should take into account the woman’s physical, emotional, psychological and rehabilitation needs. The treatment of breast cancer also requires a team of healthcare staff such as the surgeon, oncologist, radiotherapist, pathologist, radiologist, plastic surgeon and counselor. Each person has an equally important role in the management of the disease and the person.
Treatment can be divided into
Local treatment, by surgery and/or radiotherapy, to control the disease in the breast and the lymph nodes in the armpit on the same side of the breast.
Systemic treatment, by chemotherapy and hormone therapy to control the cancer cells which may have spread outside the breast and armpit.
The type of treatment advised by the doctor depends on the stage at which the cancer is diagnosed.
Stage 0, 1 and 2 are considered early breast cancer and the primary treatment is surgical. Stage 3 and 4 are late breast cancer. In Stage 3, we can operate first (if operable) or give chemotherapy first to shrink the cancer, and then operate after chemotherapy. Stage 4 cancer is advanced and cure is less likely, thus treatment is systemic ie chemotherapy or hormonal therapy, and surgery is done to remove an ulcerating breast cancer.
Currently, the options for local treatment of breast cancer are:
modified radical mastectomy where the breast is removed with all the lymph nodes under the armpit, but the underlying muscles are left behind, After a modified radical mastectomy, radiotherapy to the chest wall is not required if the tumour is small, lymph nodes are not involved and the margins are clear. Reconstruction of the breast can be carried out at the same time as the mastectomy.
breast conservation surgery where the tumour is removed with a margin of normal tissue, the lymph nodes under the armpit are removed, and the rest of the breast is treated with radiotherapy (this is also termed a wide local excision / lumpectomy with axillary lymph node clearance). Breast conservation surgery is appealing to women because it does not involve loss of the breast, but it is suitable only for small tumours less than 4 cm, depending on the size of the breast.
Clinical studies have shown no difference in the survival between women treated with modified radical mastectomy and breast conservation surgery. There is a small risk of tumour recurring in the breast after conservation surgery of 10% over 10 years; however if the tumour recurs, a mastectomy can be done without any difference in survival.
After breast conservation surgery, radiotherapy must be done to the rest of the breast.
After breast surgery, the skin of the breast area may feel tight, and the muscles of the arm and shoulder may be stiff. Exercises are important to regain movement and strength in the arm and shoulder. Because the nerves are cut during surgery, there may be numbness and tingling in the chest, underarm, shoulder and arm. These feelings usually go away within a few weeks or months. Removing the lymph nodes may also give rise to swelling of the arm (lymphedema), and it is easier for infection to occur in the arm. The arm and hand on the treated side need to be protected from injury.
This method is only suitable for women with early breast cancer, where the lymph nodes are clinically not involved.
In most centres in Malaysia, the sentinel lymph node biopsy technique is not available. Hence all the lymph nodes are removed in most cases. Sentinel lymph node biopsy is an expensive technique especially when the radionuclide technique is used. Also, since the majority of women in Malaysia present with Stage 2 breast cancer, this technique is not suitable for most of them.
Another new technique in recent years, which is still on clinical trials is intra-operative radiotherapy. In this technique, which is also meant for very early stage breast cancer, a lumpectomy is done, the woman gets radiotherapy at the time of surgery or within a few days of surgery, only around the tumour bed, so that the woman need not go to the hospital every day for radiotherapy for 4 – 6 weeks. However this is still being evaluated and in Malaysia, this technique has not been carried out.
In Stage 4 breast cancer, where the cancer has spread to other parts of the body, local treatment may not be required, unless it is to remove a breast tumour which is bleeding, ulcerated or infected. In such situation systemic treatment is required to control the disease.
Even in early breast cancer, cancer cells could have spread through the blood stream, giving rise to what is known as micro-metastases, in a certain percentage of women. These micro-metastases may be present in other organs in the body such as the lungs, liver and bones. Months or years after the treatment of cancer, they may be reactivated and grow to become obvious metastases in these organs. Systemic treatment is required to eliminate these micro-metastases. The larger the tumour, the more likely that micro-metastases are present. If the lymph nodes in the armpit are involved, then the chance of micro-metastases is even higher. Hence tumour size, lymph node involvement and survival are all related. Local treatment will have little bearing on the treatment of such micro- metastases.
Chemotherapy (treatment with anticancer drugs) can kill cancerous cells in the body, but it affects normal cells as well. If administered after local treatment in early breast cancer (Stage 1 and 2), it is known as adjuvant chemotherapy. If administered in Stage 3 cancer to shrink the tumour before local treatment, it is known as neo-adjuvant chemotherapy. If administered in Stage 4 breast cancer, where local treatment is only for palliation, it is called primary chemotherapy.
Clinical studies have shown that adjuvant chemotherapy definitely increases the survival of patients with breast cancer where the lymph nodes are involved. However recent studies have shown that even without lymph node involvement, chemotherapy has a beneficial effect. However whether or not chemotherapy is required in this group of “node-negative” patients is controversial. Other factors that measure the aggressiveness of the tumour, such as size and grade of tumour, and age of patient need to be considered.
Chemotherapy consists of a combination of drugs injected through a vein, usually at three-weekly intervals, for duration of 4 to 8 cycles, depending on the type of drugs. Common side effects are nausea, vomiting, loss of hair, and a drop in the red cell count, white cell count and platelets in the blood.
After surgery, the tissues are sent for test to check whether the cancer cells are sensitive to hormones. Hormones secreted by the endocrine glands can affect the growth of breast cancer. The cells in the tumour can be hormone receptor positive, that is, they contain hormone receptors, or negative. Hormone therapy with tamoxifen, an anti-oestrogen drug in the form of tablets taken for five years has been shown to improve survival in women with breast cancer that is oestrogen receptor positive. It has little side- effects, although it may cause weight gain, hot flushes and irregular periods in younger women. There is also a fear of inducing uterus cancer (but the risk is very small and the benefit of tamoxifen far outweigh this risk) with prolonged use. Tamoxifen has been shown to reduce the risk of breast cancer in the opposite breast. A large study in the United States has shown that Tamoxifen can be used to prevent breast cancer as there was a 45% reduction in breast cancer incidence in women on Tamoxifen. However these results were not repeated in similar studies in Europe, and further information is required before Tamoxifen can be routinely prescribed as a breast cancer chemo-preventive agent.
In recent years, instead of Tamoxifen, a new group of drugs called the aromatase inhibitors (of which there are three drugs ie Aromasin, Arimidex and Femara) has been used in postmenopausal women instead of tamoxifen and found to be slightly more effective in preventing a recurrence of the cancer.
In premenopausal women with advanced breast cancer, removal of the ovaries can be carried out to decrease the oestrogen levels in the blood stream.
Targeted therapy is a new form of treatment where a special drug is developed against a specific target in the breast cancer. The first targeted drug in breast cancer was developed against the HER2 proto-oncogene, which is found to be over-expressed in 20-30% of breast cancers. This new drug, a monoclonal antibody against HER2 is called Herceptin. Herceptin when used for a year as adjuvant therapy in breast cancer was found to improve the cure rate significantly in women with breast cancers which over-express HER2. However this drug is very expensive. Another anti-HER2 drug which has been shown to be effective in HER2 over-expressing breast cancer is lapatinib which has been shown to have activity after failure of Herceptin.