Modified Radical Mastectomy Health Article

Definition

A surgical procedure that removes the breast, surrounding tissue, and nearby lymph nodes that are affected by cancer.

Purpose

The purpose for modified radical mastectomy is the removal of breast cancer (abnormal cells in the breast that grow rapidly and replace normal healthy tissue). Modified radical mastectomy is the most widely used surgical procedure to treat operable breast cancer. This procedure leaves a chest muscle called the pectoralis major intact. Leaving this muscle in place will provide a soft tissue covering over the chest wall and a normal-appearing junction of the shoulder with the anterior (front) chest wall. This sparing of the pectoralis major muscle will avoid a disfiguring hollow defect below the clavicle. Additionally, the purpose of modified radical mastectomy is to allow for the option of breast reconstruction, a procedure that is possible, if desired, due to intact muscles around the shoulder of the affected side. The modified radical mastectomy procedure involves removal of large multiple tumor growths located underneath the nipple and cancer cells on the breast margins.

Demographics

The highest rates of breast cancer occur in Western countries (more than 100 cases per 100,000 women) and the lowest among Asian countries (10–15 cases per 100,000 women). Men can also have breast cancer, but the incidence is much less when compared to women. There is a strong genetic correlation since breast cancer is more prevalent in females who had a close relative (mother, sister, maternal aunt, or maternal grandmother) with previous breast cancer. Increased susceptibility for development of breast cancer can occur in females who never breastfed a baby, had a child after age 30, started menstrual periods very early, or experienced menopause very late.

In the United States, there were approximately 175,000 cases of breast cancer in 1999 with more than 43,000 deaths. Breast cancer accounts for 30% of all cancer diagnosed in American women and for 16% of all cancer deaths. Breast cancer is a worldwide public health problem since there are approximately one million new cases diagnosed annually. A woman's lifetime risk of developing breast cancer is one in eight. The incidence rose 21% from 1973 to 1990, but in recent years there has been a decline.

Description

The surgeon's goal during this procedure is to minimize any chance of local/regional recurrence; avoid any loss of function; and maximize options for breast reconstruction. Incisions are made to avoid visibility in a low neckline dress or bathing suit. An incision in the shape of an ellipse is made. The surgeon removes the minimum amount of skin and tissue so that remaining healthy tissue can be used for possible reconstruction. Skin flaps are made carefully and as thinly as possible to maximize removal of diseased breast tissues. The skin over a neighboring muscle (pectoralis major fascia) is removed, after which the surgeon focuses in the armpit (axilla, axillary) region. In this region, the surgeon carefully identifies vital anatomical structures such as blood vessels (veins, arteries) and nerves. Accidental injury to specific nerves like the medial pectoral neurovascular bundle will result in destruction of the muscles that this surgery attempts to preserve, such as the pectoralis major muscle. In the armpit region, the surgeon carefully protects the vital structures while removing cancerous tissues. After axillary surgery, breast reconstruction can be performed, if desired by the patient.

Diagnosis/Preparation

Modified radical mastectomy is a surgical procedure to treat breast cancer. In order for this procedure to be an operable option, a definitive diagnosis of breast cancer must be established. The first clinical sign for approximately 80% of women with breast cancer is a mass (lump) located in the breast. A lump can be discovered by monthly self-examination or by a health professional who can find 10–25% of breast cancers that are missed by yearly mammograms (a low radiation x ray of the breasts). A biopsy can be performed to examine the cells from a lump that is suspicious for cancer. The diagnosis of the extent of cancer and spread to regional lymph nodes determines the treatment course (i.e., whether surgery, chemotherapy, or radiation therapy, either singly or in combinations). Staging the cancer can estimate the amount of tumor, which is important not only for diagnosis but for prognosis (statistical outcome of the disease process). Patients with a type of breast cancer called ductal carcinoma in situ (DCIS), which is a stage 0 cancer, have the best outcome (nearly all these patients are cured of breast cancer). Persons who have cancerous spread to other distant places within the body (metastases) have stage IV cancer and the worst prognosis (potential for survival). Persons affected with stage IV breast cancer have essentially no chance for cure.

Persons affected with breast cancer must undergo the staging of the cancer to determine the extent of cancerous growth and possible spread (metastasis) to distant organs. Patients with stage 0 disease have noninvasive cancer with a very good outcome. Stages I and II are early breast cancer, without lymph node involvement (stage I) and with node positive results (stage II). Persons with stage III disease have locally advanced disease and about a 50% chance for five-year survival. Stage IV disease is the most severe since the breast cancer cells have spread through lymph nodes to distant areas and/or other organs in the body. It is very unlikely that persons with stage IV metastatic breast cancer survive 10 years after diagnosis.

It is also imperative to assess the degree of cancerous spread to lymph nodes within the armpit region. Of primary importance to stage determination and regional lymph node involvement is identification and analysis of the sentinel lymph node. The sentinel lymph node is the first lymph node to which any cancer would spread. The procedure for sentinel node biopsy involves injecting a radioactively labeled tracer (technetium 99) or a blue dye (isosulphan blue) into the tumor site. The tracer or dye will spread through the lymphatic system to the sentinel node, which should be surgically removed and examined for the presence of cancer cells. If the sentinel node and one or two other neighboring lymph nodes are negative, it is very likely that the remaining lymph nodes will not contain cancerous cells, and further surgery may not be necessary.

Once a breast lump (mass) has been identified by mammography or physical examination, the patient should undergo further evaluation to histologically (studying the cells) identify or rule out the presence of cancer cells. A procedure called fine-needle aspiration allows the clinician to extract cells directly from the lump for further evaluation. If a diagnosis cannot be established by fine-needle biopsy, the surgeon should perform an open biopsy (surgical removal of the suspicious mass). Preparation for surgery is imperative. The patient should plan for both direct care and recovery time after modified radical mastectomy. Preparation immediately prior to surgery should include no food or drink after midnight before the procedure. Post-surgical preparation should include caregivers to help with daily tasks for several days.