BREAST CANCER RADIATION,CHEMO AND HORMONAL THERAPY.

RADIATION.CHEMO AND HORMONAL THERAPY

RADIATION THERAPY OF BREAST CANCER.

Many women have treatment in addition to surgery, which may include radiation therapy, chemotherapy and hormonal therapy.
Radiation is a local treatment and therefore works only on the cancer cells that directly in its beam. Radiation therapy directs high energy rays at the breast area, under the arm, and/ or the collar bone area to destroy an invasive carcinoma cells that may be left behind surgery. This treatment also reduces the risk of recurrence [the cancer coming back].

The ways of giving radiation therapy as follows:
• External beam radiation: The treatments are directed to the entire breast after surgery to the area of skin, muscle and lymph nodes. Radiation therapy is usually given 5 days a week over 5 to 6 weeks. Each treatment takes only a few minutes.
• Internal partial-breast irradiation, also called brachy-therapy, is a form of treatment in which radioactive materials such as seeds or pellets are temporarily placed in or near the cancer was removed.
• External partial-breast irradiation is a method of external beam radiation that zeroes in the area around where the cancer was. This area is at risk of recurrence. Partial-breast radiation takes only 5 to 10 days for treatment versus 5 to 7 weeks for whole breast radiation.
Radiation therapy is painless and has relatively few side effects. However, it can irritate the skin or causes a burn similar to a bad sunburn in the area of radiation.

CHEMOTHERAPY OF BREAST CANCER.

Chemotherapy consists of the administration of medications that kill cancer cells or stop them from growing. There are 3 methods of chemotherapy:
• Adjuvant chemotherapy [CT] where the CT is given after surgery. It is given to reduce the possibility of recurrence [return of cancer]. Women with node-positive disease have a high risk of both local and systemic recurrence. Thus , lymph node status directly indicates the risk of occult [hidden] distant micro-metastasis.

Fig. 24: The log-kill hypothesis graph.

Patients with widespread cancer may have up to 10 power 12 tumor cells throughout the body at the time of diagnosis.

Relationship of tumor cell number to time of diagnosis, symptoms, treatment and survival.Three alternative approaches to drug treatment are shown for comparison with the course of tumor growth when no treatment is given [dashed line]

1. In the protocol diagrammed at top, treatment [indicated by the arrow] is given infrequently and the result is manifested as prolongation of survival but with recurrence of symptoms between courses of treatment and eventual death of the patient.

2. The combination chemotherapy treatment diagrammed in the middle section is begun earlier and is more intensive. Tumor cell kill exceeds regrowth, drug resistance does not develop, and "cure" results. In this example treatment has been continued long after all clinical evidence of Cancer has disappeared [1-3 years]. this approach has been established as effective in the treatment of childhood acute leukemia, testicular cancers, and Hodgkin's disease.

3. In the treatment diagrammed near the bottom of the graph, early surgery has been employed to remove the primary tumor and intensive adjuvant chemotherapy has been administered long enough [up to one year] to eradicate the remaining tumor cells that comprise the occult micrometastases.

In this situation, postoperative use of systemic adjuvant CT protocol”
Six cycle of cyclophosphamide, metrotrexate, and fluorouracil [CMF protocol] or
Fluorouracil, doxorubicin, and cyclophosphamide [FAC] has been shown to
significantly reduce relapse rate and prolong survival.
Each of these CT regimes has benefited women with stage 2 breast cancer with
one to three involved lymph nodes.
• Neo-adjuvant CT where CT may be given before surgery to shrink the cancer.
• Palliative CT. The approach to women with advanced breast cancer or stage 4 remains a major problem, as current treatment options are only palliative [to improve symptoms and help live longer, not cure the cancer]. Combination of CT and hormonal therapy has been found to reduce higher and more durable remissions of patients.

HORMONAL THERAPY OF BREAST CANCER.

If the cancer tested positive for hormone receptors, the patient’s doctor will recommend some form of hormone therapy. Hormonal therapy also called anti-estrogen therapy, works by lowering the amount of estrogen in the body or blocking the estrogen from signaling breast cancer to grow.
• The anti-estrogen Tamoxifen has proved to be useful for the treatment of both early stage and metastatic breast cancer. It is also approve as a chemotherapy agent in women at high risk for breast cancer. Tamoxifen usual adult dose is 20 mg/day orally. Tamoxifen is given orally and is rapidly and completely absorbed. Tamoxifen is well tolerated, and its side effects are generally mild
• Aromatase inhibitors. Aminoglutethymide is primary used in the treatment of metastatic breast cancer in women whose tumors express significant levels of estrogen or progesterone receptors. It also has activity in hormone dependent advanced prostate cancer.Aminoglutethimide is normally administered with hydrocortisone to prevent symptoms of adrenal insufficiency. Usual adult dosage: 250 mg orally twice daily and hydrocortisone 20 mg twice daily. Adverse effects are fatigue and mild nausea..

Anastrozole [Arimides] is a selective non-steroidal inhibitor of aromatase that has no inhibitory effect on adrenalglucocorticoid. It is presently approved for first line treatment of post-menopausal women with metastatic breast cancer, and as adjuvant therapy of postmenopausal women with hormone-positive, early stage breast cancer. Usual adult dosage:

1 mg orally daily. Adverse effects are mild nausea and headache.

HERZ-TARGETED THERAPY.

Herceptin [Trastuzumab] is a recombinant DNA-derived, humanized monoclonal antibody that binds to the extra cellular domain of the human epidermal growth factor receptor HER-2/neu. This antibody blocks the natural ligand from binding and down-regulate the receptor. Transtuzumab is approved for he treatment of metastasis breast cancer in patients whose tumors over-express HER-2/neu. Herceptin usual dosage: 440 mg powder; reconstitute for intravenous [IV] infusion.