Recent Advances in the Management of Breast Cancer
Recent Advances and the Present Status of Breast cancer Management
If you suffer from this ‘dreaded disease’ what are your options? Do you need to live in fear? What follows are the current methods used in the management of breast cancer -
Breast conservation surgery (BCS)
The whole of the breast need not be removed if the patient has an early stage of the cancer. In Breast conservation surgery (BCS) it is the cancer that is removed, breast is saved to the maximum possible extent. Breast conservation surgery includes:
Lumpectomy: Here the lump (the tumour) and a small amount of nearby normal tissue are removed.
Partial mastectomy: This is also called segmental mastectomy; the part of the breast that has cancer is removed along with a small amount of normal tissue.
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Along with BCS, sometimes lymph node dissection will be required. It is a procedure where some lymph nodes are removed for biopsy. Lymph nodes are aggregates of tissue that take part in filtration of lymph and storage of lymphocytes (white blood cells).
BCS followed by radiation therapy has replaced mastectomy as the preferred surgery in the treatment of early-stage breast cancer.
In the past Mastectomy was the only surgical option. In mastectomy the breast (as much tissue as possible) is removed, Only about 75% of women diagnosed with breast cancer survived 5 years. Little was known about the genes associated with breast cancer. Trials with chemotherapy using multiple drugs, hormonal therapy were all in their infancy.
Combination chemotherapy using multiple drugs is now standard in the adjuvant treatment of early-stage breast cancer. The aim of this modality is to kill cancer cells that may have spread beyond the breast. An adjuvant therapy may be defined as the treatment given to patients after surgical removal of their primary tumour.
In cases where the size of the tumour is very large Neoadjuvant chemotherapy is tried. Here drugs are given prior to a surgery so as to reduce the size of the tumour. Smaller the tumour higher is the chance for a successful breast conservation surgery.
The role of hormones was suggested in the 1880s. It was only in 1966 that the ‘Oestrogen receptor’ was identified, and thus the hormonal connection with breast cancer established beyond doubts. The identification of this receptor was a major breakthrough. Breast cancers began to be classified as oestrogen receptor positive and oestrogen receptor negative ones.
When the hormone oestrogen (a hormone is one that serves as a chemical messenger) binds to the above mentioned receptor, the cancer cells grow. Drugs that inhibit this interaction would hence prevent the growth of cancer cells. Such drugs are now available- SERMS. The acronym ‘SERMS’ stands for Selective Oestrogen Receptor Modulators. A typical example is Tamoxifen.
Tamoxifen and another SERM called Raloxifene may also prevent an invasive breast cancer from developing. Invasive or infiltrating breast cancer is one that invades adjacent normal tissue.
Another category of drugs useful in managing oestrogen receptor positive cancers are Aromatase Inhibitors. These inhibit oestrogen production by the body. Available ones include Anastrozole and Letrozole.
Molecular targeted therapy
Molecular targeted therapy took birth in the 1990s. It was found that about 20% of breast cancers overproduce a protein called human epidermal growth factor receptor 2 or HER2. Such cancers are more aggressive and have greater chances for recurrence. This protein is selectively acted upon by Trastuzumab (Herceptin) which is a monoclonal antibody. Monoclonal antibodies are made in laboratories from a single type of immune cell. Trastuzumab when combined with chemotherapy is highly effective.
In addition there are Tyrosin kinase inhibitor drugs that block signals required for tumour cells to grow. Drugs of this class like Lapatinib come to aid when treatment with trastuzumab has failed.
High-dose chemotherapy with stem cell transplant
High doses of chemotherapy followed by replacement of blood-forming cells (these cells may die during the cancer treatment) are in clinical trials.
The role of genes
Breast cancer runs in families. It was in 1994 that the BRCA1 gene was isolated. This, along with BRCA2 gene may undergo mutation and account for up to 90% of hereditary breast cancers. Women with these mutations have a 10 times higher lifetime risk to develop breast cancer than the general population.
Today about 90%of women diagnosed with breast cancer survive their disease at least 5 years.