Treatment (Continued)

Radiation treatment is also used to help destroy cancer cells that may linger after surgery. Radiation can reduce the risk of recurrence by 50-66% (1/2 - 2/3rds reduction of risk) when delivered in the correct dose.

Prognosis

A prognosis is the medical team's "best guess" in how cancer will affect a patient. There are many prognostic factors associated with breast cancer: staging, tumour size and location, grade, whether disease is systemic
(has metastasized, or traveled to other parts of the body), recurrence of the disease, and age of patient.

Stage is the most important, as it takes into consideration size, local involvement, lymph node status and whether metastatic disease is present. The higher the stage at diagnosis, the worse the prognosis. The stage is raised by the invasiveness of disease to lymph nodes, chest wall, skin or beyond, and the aggressiveness of the cancer cells. The stage is lowered by the presence of cancer-free zones and close-to-normal cell behaviour (grading). Size is not a factor in staging unless the cancer invasive. Ductal Carcinoma in situ throughout the entire breast is stage zero.

Grading is based on how biopsied, cultured cells behave. The closer to normal cancer cells are, the slower their growth and the better the prognosis. If cells are not well differentiated, they will appear immature, will divide more rapidly, and will tend to spread. Well differentiated is given a grade of 1, moderate is grade 2, while poor or undifferentiated is given a higher grade of 3 or 4 (depending upon the scale used).

Younger women tend to have a poorer prognosis than post-menopausal women due to several factors. Their breasts are active with their cycles, they may be nursing infants, and may be unaware of changes in their breasts. Therefore, younger women are usually at a more advanced stage when diagnosed.

The presence of estrogen and progesterone receptors in the cancer cell, while not prognostic, is important in guiding treatment. Those who do not test positive for these specific receptors will not respond to hormone therapy.