Breast cancer is the most common form of cancer in women aside from non-melonoma skin cancer. It is the second leading cause of all cancer deaths in women today.   Approximately, 187,000 women and 1,800 men were diagnosed with breast cancer and 41,116 women and 375 men died of breast cancer in 2005.  
 
The lifetime risk of developing breast cancer for women is 1 in 9.  More than 66% of women who develop breast cancer will have no known risk factors.  Two major risk factors for developing breast cancer are gender (being a woman) and age; both which cannot be controlled.
 
Studies have shown that here are a number of other factors that may increase a women’s chance of developing breast cancer:

1)   Hormonal Factors: general rule -- uninterrupted menstrual cycle for a long period of time increases one’s risk
       a.    Menstrual history
              i.     Early menarche
              ii.     Late menopause
       b.    Reproductive history
              i.     Having no children can increase risk by 30%
              ii.     Risk may increase for women who have their
                     1st child after age 35.
       c.    Hormone replacement therapy
              i.      Use increases risk of developing breast cancer
                     1.    longer the duration , the higher the risk
 
2)   History of abnormal breast biopsy – Atypical hyperplasia
 
3)  Previous history of cancer
       a.  personal history of endometrial or ovarian cancer
       b.  history of DCIS or LCIS
       c.  breast cancer has been associated with melanoma, salivary
           gland tumors, and colon cancer
 
4)  Personal history of breast cancer
 
5)  Obesity
 
6)  History of Radiation for Hodgkin’s disease (mantle radiation)
 
7)  Family history of breast cancer
       a. can be from either mother or father side
 

Breast Anatomy

Understanding breast cancer, one needs to first understand the anatomy of the breast.  The breast is an organ that produces milk. It is made up of ducts and lobules.  The lobules are part of the breast that produces the milk and the ducts carry the milk from the lobules to the nipple.  The ducts and lobules are surrounded by fat and supportive tissue which holds the breast in place.  
 
Breast also has a branch of the lymphatic system within.  The lymphatic system filters the tissue’s fluid of bacteria, foreign particles and immune cells.  The reservoirs for the breast tissue are the lymph nodes underneath the arm and the lymph nodes underneath the breast bone.  
 
The breast goes through hormonal changes during the course of one’s lifetime.  During the menstrual cycle women may notice cyclical pain and swelling.  When pregnant, the lobules prepare to produce milk.  After menopause, the ability to produce milk is no longer needed secondary to the drop in hormone levels.   The breast tissue then becomes replaced with fatty tissue.
 
Breast Cancer/Type:
 
Invasive breast cancer is an abnormal growth of cells that invade the surround tissue.  
 
Lobular carcinoma in situ (LCIS):  is abnormal growth of cell that is localized in the lobules.  This is not cancer, this is consider a high risk lesion. Meaning, LCIS is a marker of an increased risk of developing breast cancer in either breast.  
 
Ductal carcinoma in situ (DCIS):  it is precancerous cells that have stayed with the milk ducts.  DCIS over time if left untreated can progress to invasive breast cancer
 
Invasive or infiltrating breast cancer:  The majority of the breast cancers are of ductal type.  Cancer cells within the ducts have invaded the surround tissue.  Some invasive cancer can be lobular.  Other types which are not as frequent include tubular, papillary, medullary and mucinous.  
 
Inflammatory Breast Cancer:  Inflammatory breast cancer is a rare cancer and can present itself like a breast infection. The skin of the breast appears red or discolored or may appear like “peau d’orange” (skin thickening with tiny dimples that resembles an orange peel).  
 
Staging:

Breast cancer staging is based on the TNM staging.  

T:  Tumor size
N:  Based on whether the disease has spread to the lymph nodes under the arm, and if so the number of lymph nodes involved.
M:  If the disease has spread to other parts of the body (metastasized)
More information about staging.

 
Treatment:

The treatment usually coarse of treatment for breast cancer is a combination of surgery, chemotherapy, radiation and/or hormonal therapy.  The treatment of breast cancer has evolved over a period of time. Treatment is usually based on the stage and the characteristics of the tumor and the personal preference of the patient as well.  
 
Surgery:
Surgery is often the first line of treatment.  The surgical options are a lumpectomy or a mastectomy with the evaluation of the lymph nodes underneath the arm.  Studies have shown that the survival and recurrence rate between a lumpectomy and a mastectomy are similar.  
 
Lumpectomy (also referred to as partial mastectomy, wide excision, segmentectomy) is removed of the cancer cells with a rim of normal tissue.  The decision to undergo a lumpectomy is based on a joint decision between the patient and the breast surgeon.  Patients that opt for a lumpectomy, radiation therapy is usually advised after the surgery has been complete.  
 
Mastectomy is removal of the entire breast including the nipple areolar complex.  Patient can elect to undergo breast reconstruction at the time of surgery or no reconstruction at that time.  If reconstruction is done, a skin sparing mastectomy is usually performed.  An envelope of skin a left behind while the breast tissue is separated from the skin and underlying fat and the chest wall muscle.  This envelope allows the plastic surgeon to use your own skin for reconstruction.  A new nipple areolar complex is the reconstructed at a later date.  The new nipple is usually made from skin so there is be no sensation after it is complete.   More information about breast reconstruction
 
Sentinel Lymph Node Biopsy has now become the preferred mode to determining whether there is disease in the axillary lymph nodes, if there is no evidence of disease on clinical evaluation.  Sentinel lymph node is the primary group of lymph nodes in the axilla to drain the breast. The number of nodes removed usually range from 1 to 3.  The way the lymph nodes are identified can be done by using a radioisotope and/or a blue dye, depending on surgeon’s preference.  The lymph nodes are then tested for metastatic disease. If there is no disease present, no more axillary surgery is required.  If the node is positive, an axillary lymph node dissection is recommended.   Multiple studies have confirmed the accuracy of the SLN biopsy to be >95%.  
 
Axillary lymph node dissection is removal of the lymph nodes in the underarm.  This is done when there is disease present in the lymph nodes.  This is a more extensive procedure and has a higher risk of developing lymphedema (swelling of the arm) as compared to sentinel node biopsy.  
 
Systematic Therapy:

Chemotherapy is usually given after surgery has been complete.  The reason for giving chemotherapy is to kill any microscopic cancer cells that may have been left behind and to prevent the cancer from recurring.  There are a few occasions where chemotherapy is given before surgery, (neoadjuvant therapy). The main reason for giving chemotherapy prior to surgery is to possibly decrease the size of the tumor which may give the patient more surgical options.  
 
Chemotherapy is not given to every breast cancer patient.  The decision to give chemotherapy is based on a number of factors.  The ultimate decision for chemotherapy is determined by the medical oncology once the final pathology has been complete.  
 
Hormonal Therapy:
 
There are some tumors that depend on estrogen and progesterone to grow.  If the tumor has positive receptors for estrogen and/or progesterone it is recommended that the patient be started on hormonal therapy.  Hormonal therapy, such as tamoxifen or an aromastse inhibitor prevents estrogen and progesterone, which are produced in the body, from interacting with the breast tissue. Like chemotherapy, hormonal therapy is used to prevent cancer from coming back in the breasts and well as throughout the body.    Treatment is typically, one pill a day for five years.  The major side effects that women experience are hot flashes and muscle aches.
 
Radiation therapy:

Radiation is a treatment using high energy xray beams to destroy cancer cells.  It is a local treatment to prevent recurrence in the affected breast.  Typically, it is after a lumpectomy as been performed.  There are a few cases where radiation is need after a mastectomy that is if the tumor is of a larger size and if there is a specific amount of positive axillary lymph nodes.
 
Whole breast radiation can typically last for about 6-7 weeks.  Treatment is given Monday through Friday.  Treatment sessions usually last between 15 to 20 minutes.   The main side effects is skin changes, typically a sunburn effect and fatigue. Radiation does not make a patient nausea or cause them to loss one’s hair.  
 
Partial breast radiation is another alternative to whole breast radiation.  Radiation treatment usually lasts about 5 days with treatment twice a day.  Typically, a catheter is placed in the lumpectomy cavity at the time of surgery. Once the final pathology has been complete and there is no residual disease and the lymph nodes are negative then treatment can begin.  Not every patient is a candidate for partial breast radiation.  The decision to offer partial breast radiation is made by a radiation oncologist and the breast surgeon.  
 
What to expect once treatment is done:

Once treatment is complete, a patient is closely followed for the first 5 years.  Typically, a patient is seen by a physician every 3 mos for a physical and a clinical breast exam for the first year and then every 6 mos for the next 4 years.  Mammograms and additional imaging if warranted will be obtain as well.