Surgery for Breast Cancer
The surgeon removes the cancer with a rim of healthy breast tissue in order to ensure that there are no cancerous cells left in the adjacent breast tissue. The universal recommendation is that a 1cm margin of healthy breast tissue be removed along with the cancer. This may be combined with an operation to remove some (axillary sampling, sentinel node biopsy) or all of the lymph nodes( axillary clearance when the lymph nodes are known to be positive) in the armpit.
The lessons learnt from cosmetic surgery of the breast are now used in the reshaping of the breasts after lumpectomy. These plastic surgery skills allow the breast surgeon to remove large cancers without having to resort to a mastectomy where there is sufficient breast tissue. These operations are often called therapeutic mammoplasties. However, oncoplastic surgery is a more appropriate term as the word ‘onco’ implies it is a cancer operation. Sometimes, chemotherapy is given prior to surgery to shrink the tumour down and then make oncoplastic surgery feasible.
Oncoplastic surgery should be considered wherever possible. It relies on sufficient breast tissue being available to reshape the breast and make up for the defect created by the lumpectomy. Breast surgeons need to have focused training in this field and not all breast surgeons are able to offer oncoplastic surgery.
Mastectomy is the removal of all breast tissue. When the nipple is preserved it is called Subcutaneous Mastectomy. When all the breast tissue is removed along with a large portion of the skin including the nipple it is called a Simple Mastectomy.
In Radical Mastectomy, along with the breast tissue and the overlying skin and nipple, the pecs (pectoral muscles) are also removed as are all the lymph nodes in the armpit. This is rarely done these days as the cosmetic appearance is awful.This operation is largely responsible for the fearful reputation of mastectomy. Nowadays, a form of modified radical mastectomy is performed where the major pectoral muscle is spared.
What happens to the tissue that is removed?
The pathologist will examine the breast tissue removed and report on:
- the size of the cancer
- the grade of the cancer (grade 1,2 or 3- grade 1 being slow growing and grade 3 being the more faster growing)
- whether the cancer is of the invasive type or non-invasive
- the type of breast cancer ( ductal or lobular or of a special type)
- the distance of the margins from the cancer and the nearest margin
- many cancer cells were seen in the blood vessels within the tissue removed ('lymphovascular invasion')
- whether the cancer is hormone sensitive [Oestrogen Receptor (ER) positive, Progesterone Receptor (PR) positive]
- whether the cancer is HER-2 receptor positive
Based on a combination of these features one can determine the outlook or prognosis and recommend additional treatment. This additional treatment may be further surgery such as a mastectomy &/or radiotherapy, chemotherapy, Herceptin , Tamoxifen/other anti-hormone therapies.
The lymph nodes (also known as lymph glands) are little islands of tissue placed strategically at various sites in the body. Their role could be compared to those of sentries or guards. The fluid that bathes the body tissues is carried by small channels called ' lymphatics' to the lymph nodes. The lymph nodes act as sieves or filters. Here the impurities within the fluid are entrapped and disposed off by some of the body's cells. The lymph nodes are organised in a network in each region of the body like the the links in a chain. They interconnect and eventually drain into the body's circulation at the root of the neck. This theoretically forms one pathway for cancer cells to disperse ('metastasize' or secondary spread) to other organs or sites in the body. Removing these glands or nodes enables the specialist to determine the probability of cancer cells spreading beyond the breast and this in turn suggests additional treatments such as chemotherapy are necessary to overcome these cells.
The muscles commonly known as 'pecs' consist of the Pectoralis major and Pectoralis minor. The latter is the smaller muscle and lies behind the major muscle. The minor muscle divides the lymph nodes of the breast into 3 levels as shown in the diagram above. Cancer is believed to spread in a stepwise fashion from level 1 to level 2 and then to level 3 and thereafter into the circulation.
Why do the lymph nodes (also known as lymph glands) have to be removed?
It is important to know whether there are cancer cells in the lymph nodes. This can only be determined by having the glands examined by the pathologist after removing them. The first opportunity to determine this is by ultrasound scan and needle biopsy at the same time as the cancer is detected and biopsied. If the lymph node is negative for cancer cells, then it is necessary to identify the sentinel lymph node (first node in the chain of lymph nodes) and remove it for proper assessment by a technique called Sentinel node biopsy. This is the universally accepted gold standard (of staging the axilla) for determining the need for removing all the lymph nodes (axillary clearance). Additional methods of staging the axilla include axillary sampling.
In 60 - 70% of women with breast cancer the glands or nodes do not contain cancer cells. In these women, it is unnecessary to remove all the lymph glands.
If there are cancer cells within the lymph nodes then the addition of chemotherapy in women who still have periods increases the chances of success in treating the cancer by 30%. Also where there are cancer cells in the lymph nodes and all the lymph nodes have not been removed, the remaining nodes will need to be surgically removed or treated with radiotherapy.
Sentinel Node Biopsy
Extensive studies have shown that when cancer cells spread from the breast to the lymph nodes they usually follow a predicted path to one or more lymph nodes first before spreading to the other lymph nodes. These one or more lymph nodes (usually one or two) are called sentinel lymph nodes. If these are removed and found to be clear of any cancer cells, then it is assumed ( accurate to 97%) that the remaining lymph nodes are also clear. If the sentinel nodes contain cancer cells, then the remaining lymph nodes need to be removed as there is a chance (40%) that the remaining nodes will have cancer cells in them. Leaving such lymph nodes behind will result in the cancerous lymph nodes getting larger and involving the blood vessels, muscles and nerves in the neighbourhood. This can result in lymphoedema and nerve pain and paralysis of the arm (rare , 1%). This is then extremely difficult to treat. Hence, removing the remaining lymph nodes is necessary.
The accepted gold standard technique for Sentinel Node Biopsy based on its high detection and prediction rates is a combined technique involving injection of radioactive tracer into the skin around the nipple between 3-24hours before the surgery and also a blue dye into the same area at the time of the surgery. The radioactivity is traced with a scanner much like a metal detector which helps find metal in the ground. This is like a compass which tells you the location of the the sentinel node. The blue dye travels along the lymph channels which are coloured blue and act like a SatNav in guiding the surgeon to the precise location of the lymph node.
With the use of a molecular analyzer (OSNA), it can be determined during the surgery whether the sentinel lymph nodes contain malignant cells or not. If they do, the remaining lymph nodes are removed at the same time under the same anaesthetic. Where this facility is available, patients are saved readmission for a second operation on their lymph nodes because the results normally take 1-2 weeks. It also ensures that any risk reducing treatments like chemotherapy can be started approximately 4-6 weeks earlier. The patients also know the result immediately after recovering from the anaesthetic.
When radioactive tracing is not possible, removing four nodes following the injection of blue dye is considered an acceptable alternative.
Axillary Lymph Node Sampling
Axillary node sampling involves removing a few glands to determine if there has been any spread to them ( the absolute minimum recommended is 4. The criticism of this technique is that it is random and may result in the involved lymph nodes being missed
For detailed information on all aspects of Breast Reconstruction please visit our Breast Reconstruction page