Breast cancer is the most common cancer in females and second to lung cancer in cancer deaths. The surgical treatment has evolved quite a ways from the days of Halsted radical mastectomy, nearly a century ago. Radical mastectomy is rarely performed today, unless the chest muscles are involved. The majority of T1 tumors, 2 cm or smaller can be treated with breast conservation (lumpectomy, segmentectomy, quadrantectomy). With the advent of radiation and effective chemotherapy, larger breast cancers, T2 and T3, can be treated with breast conservation, after shrinkage with chemotherapy prior to surgery (neo-adjuvant chemotherapy). Patients with tumor stage, T4 and some T3, multicentric tumors or BRCA gene positive individuals may still require mastectomy. Selected T4 and T3 tumors with good chemotherapy responses may also be candidates for breast conservation. Patient's choice may dictate a mastectomy. Here is where the surgeon can reassure the patient regarding their right choices of the surgical treatment.
The axillary lymph nodes can be spared a node dissection in majority of women, by undergoing a sentinel lymph node mapping and biopsy. The sentinel mapping, using an injected dye or radioactive colloid particles, is accurate in determining the first few nodes that drain the breast cancer, and when examined by pathology and verified to be free of cancer cells, additional node dissection can be avoided.
Today, the majority of surgical treatment of breast cancer can be accomplished as an outpatient procedure. The patient achieves recovery sooner and has fewer delays for the post-operative chemotherapy and radiotherapy.
DIAGNOSIS - LUMP OR ABNORMAL MAMMOGRAM / BREAST STUDY
Most breast lumps are non-malignant, diagnosed as cysts or fibronodular areas in the breast. The imaging tests, that can better define a lump in the breast, are improving with current technologies. The "gold standard" is the mammogram. Women 40 years or older should obtain yearly screening mammograms. Breast exams should also be performed yearly, even if the mammograms are normal. About 15% of breast cancers present with "normal" mammograms. Mammograms abnormalities can be tiny calcifications, densities and shadows consistent with a mass or cyst. Further tests such as magnification views, ultrasound or MRI can determine the likehood of being a growth needing a biopsy or follow-up mammograms only. Today, the diagnosis can be made with a needle biopsy and only seldomly an open biopsy is done for diagnostic purposes. Occasionally, the appearance on imaging studies and exam are so compelling that a lumpectomy can be done for diagnosis and treatment at the same procedure. Frozen section tissue pathology exam, which can yield a result in approximately 20-30 minutes, can provide proof whether the lesion is cancerous or not, at the time of surgery. With this information, decisions by the surgeon can effect a definitive treatment at time of diagnosis such as assuring clear margins of resection and whether sentinel lymph node biopsy should be done.
MINIMALLY INVASIVE LUMPECTOMY
Small cancers are ideal for lumpectomy or segmentectomy procedure. Usually additional sites of tumors are located along the ductal system of the primary tumors, consequently a segmentectomy can encompass these additional multifocal tumors. Cosmesis can be achieved without compromising the extent of lumpectomy or segementectomy to obtain optimal curative results. The incision and access to the lumpectomy cavity can be limited to a 3-4 cm length on the skin and likewise in the subcutaneous and breast tissue using a cylinder retractor designed by Dr Chu (US patent # 5,882,316 ). The cavity of the lumpectomy or segmentectomy can be much larger depending on the tumor characteristics. The cavity after closure of the breast, heals by first filling up with tissue fluid then conversion or laying down of scar tissue. Usually the volume and conformity of the breast is preserved unless the fluid is drained out due to infection, for example, or collapse of breast tissue with scar tissue contracture.
Clearly, the primary goal of the procedure is to remove the malignancy with clear margins, including any occult multifocal sites. Here is where the experience of the surgeon enhances the chances of detecting nearby multifocal tumors missed by pre-operative imaging studies. Studies examining multifocality of breast cancer indicate a rate of 15%, mostly in the same segmental ductal system. Segmentectomy and quadrantectomy are superior to lumpectomy in terms of lower local recurrence rates.
Secondary goal is to achieve an acceptable cosmetic result in the conserved breast. Breast size is usually not a factor in post-operative cosmesis. Interestingly, neither is the size of the resection, since even after a quadrantectomy, acceptable breast contouring is obtainable. One of the prerequisites is to make sure that the nipple-areolar complex remain projected anteriorly. Areolarplasty may be done at the time of closure, after the cancer resection, by bringing surrounding breast tissue and subcutaneous tissue to fill the space immediately posterior to the nipple. A well placed purse string suture will also help the nipple itself from inversion. The remainder of the breast cavity will initially be filled with fluid and with healing, will be replaced with fibrous tissue. The cosmetic repair of the "tissue collapse" at the resected site is controversial. Local prosthetic placement and collagen injection are partially successful and only recommended long after the adjuvant cancer treatment is completed.
SENTINEL NODE MAPPING
The lymphatic drainage of the breast is predominantly to the axillary nodes. Central and medial cancers can drain to the nodes along the breast bone, the sternum, called the internal mammary nodes, and the majority will at the same time drain into the axillary nodes. Nodes just above the clavicle can also be involved although a rarity without axillary node involvement. In addition, the sentinel node(s) is found mainly in the central group of axillary nodes, see illustration below. A 2-3 cm transverse incision is made in the low axilla and once the deep subcutaneous scarpa's facia is entered, the blue dye or radioactivity can be detected visually or by using the gamma probe. In addition, often the sentinel lymph node can be palpable, making the identification easier, by using the surgeon's finger. The palpable sentinel node has been called the dominant node. The hypertrophy of the sentinel node can be due to reaction to the tumor or reaction to previous biopsy without having metastatic cells. The American College of Surgeons Oncology Group and the National Surgical Breast and Bowel Project have studies which will shed more light on the need of added node dissection for micrometastases, involved nodes, etc. We should be reminded that if the lymph nodes are clinically positive, node dissection should be carried out.
CHEMOTHERAPY PRIOR TO SURGERY?
Node positive and large breast cancers benefit from post-operative adjuvant with resulting improved disease free interval and patient survival. Pre-operative chemotherapy, also known as neo-adjuvant treatment, can be given with advantages in some situations: 1. Large T2 tumors resulting in shrinkage and allowing breast conservation surgery, 2. T4 and T3 tumors (inflammatory cancers, ulceration, satellites and greater than 5 cm in size) where shrinkage allow a greater chance of margin negative resection. 3. Significant nodal involvement, any N1-3. Sentinel lymph node mapping can be performed in this setting for patients with initial clinical N0 disease. Patients with initial clinical N positive disease should undergo a level I node dissection even if complete response is achieved with neo-adjuvant chemotherapy.
PREVENTION AND SCREENING
The overall rate of breast cancer in the general population can be summarized as 12% life-time risk for women in the U.S. These rates can be altered or modulated by genetic make-up, diet, exposure to radiation and other environmental factors. Prevention of breast cancer can be based on screening for early disease, avoidance of known carcinogens, healthy life-styles and chemoprevention. For example, radiation to the breast area around menarche for the treatment of Hodgkin's disease, is associated with increased rates of breast cancer in adulthood. Mantle radiation for lymphoma can thus be modified to avoid this risk in young women. Diet and physical activity can be modified to reduce risks. SERMS (selective estrogen receptor modulators) have shown to reduce estrogen receptor positive breast cancers. Aspirin and other anti-inflammatory agents have some effects in reducing risks although the benefits may be outweighed by the risks of stomach irritation and bleeding. Several trials under way will clarify the future recommendations in this area.
Screening with yearly mammograms starting at age 40 can reduce breast cancer mortality. It is a concern that in some women, screening mammograms will lead to an excessive rate of biopsies to verify the nature of study detected abnormalities. Fortunately, follow-up studies for abnormal mammograms (with ultrasound, MRI, or 6 month follow-up mammograms) and biopsy techniques are improving, which will reduce invasive tests for abnormal findings. Personalized approach in prevention will take into account the risks of the individual, potential benefits of changing daily diet and activity routines, consideration of chemopreventive agents and ultimately prophylactic mastectomy and reconstruction for life-time risks exceeding 50%, in individuals with strong family history or known gene involvement with BRCA1 or BRACA2.