Breast Cancer

Breast : is a glandular, reproductive and skin organ

• By birth there are 15-20 glands in each breast
• Gland ends into ducts (milk ducts in females)
• Each duct ends at the nipple area
• Breasts change throughout the womans lifetime increasing the likelihood of developing cancer with each change
• 1st menarche (first period)
• pregnancy
• menopause
• with an increase in age there is an increase in the likelihood of developing cancer
• areolar – is the area around the nipple
• amuplea – end of the ducts
• the tissue of the breast is made up of adipose tissue (12-15 lobes around each gland)
• breast lies on the chestwall from the 2nd to 6th rib and is continous with the pectoralis major
• blood supply is the intramammary veins and arteries

Lymphatic Supply (3 sets of nodes): (every female doesn’t have the same number of nodes to begin with)

• axillary nodes : are dissected all of the time.  There are 3 levels of axillary nodes. I, II, and III.
• Nodal mets will follow the chain Axillary Nodes I, II, III, Supraclavicular Nodes and the Internal Mammary Nodes
• Axillary nodes are dissected to stage the patient (only a few nodes are removed because if they all are removed this will cause lymphedema into the arm)
• If more than 3 nodes in the axillary chain are positive then we must treat the supraclav (we will treat a 4 field 2 tangents, supraclav and PAB if the patient is thick)
• If more than 3 nodes are positive then the prognosis is poorer
• Inernal Mammary Nodes (IMN): only involved with inner quadrant tumors
• Supraclavicular Nodes

The way we treat breast depends on the number of nodes involved**

Prognosis is dependent on the number of nodes involved**

There is a strong bilateral incidence in breast and they are 2 separate primaries not mets!

Pattern of Spread:

• Spread is by direct invasion
• Lymphatic spread
• Bloodborne metastases (bone mets spread by the blood)
• May spread to the pectoralis major in which case a radical mastectomy would be needed
• first station of spread would be to the lymphatics (lymphatics are not part of the breast)

Incidence

 increases with:

• Age
• Familial incidence : (mother, sister, aunt) not as common as you would thing only represents 5% of breast cancers (BRCA gene)
• The average woman needs to start having mammograms done at 35 and if there is a family history of breast cancer then at 25
• Ovulation problems
• Nulliparous : patient never had a child
• Never breast fed
• Early menarche or late menopause (dependent on the number of ovulations!!)
• Had a late 1st birth
• High socioeconiomic jewish woman
• Increase in weight (fatty content is greater)
• 1/100 breast cancer occur in men
• early radiation exposure such as with treatment for hodgskins
• some woman will have a prophylactic mastectomy

Histology:

Adenocarcinoma is the most common histolgy

• infiltrating ductal adenocarcinomas : (most common) represents advanced disease
• intraductal adenocarcinomas DCIS : 2nd most common and on the rise due to better detection exams.  Represents and earlier stage disease that hasn’t broken through the ducts yet.
• Lobular Cancer of the Breast : not ductal, is cancer of the lobes
• Pagets Disease of the Breast : cancer of the nipple region which presents with discharge of fluid (treatment is removal of the ductal system)
• Inflammatory Breast Cancer : represents Stage IV breast cancer
• Breast is inflamed, red, hot
• Peaudorange – orange skin appearance
• NO SURGERY (will cause problems) , treated with Radiation and Chemo Palliatively

Most common route of spread for all breast cancers is to the axillary nodes**