Saturday, July 24, 2010

CANCER TREATMENT: Surgery

Oncologists select from a number of options when treating cancer, depending on the type and stage of the tumor involved. The major treatments currently available are surgery, radiation therapy, chemotherapy, hormone therapy, and immunotherapy. Often, targeting cancerous tumors requires the artful combination of more than one type of cancer therapy.

Surgery is the most effective and fastest treatment for tumors that are caught early and have not metastasized. It is the only option ensuring that the entire visible tumor is eliminated. However, there is no guarantee that all microscopic extensions of a tumor have been removed. For this reason, surgeons may also remove a large portion of healthy tissue that surrounds the tumor. This may not be possible if the tumor lies near or within a vital tissue, such as a major nerve or organ.

Often, cancer surgery requires general anesthesia, in which the patient loses consciousness, and a hospital stay of several days. For example, women with breast cancer may have a lumpectomy or mastectomy, surgical removal of part (or all) of the breast. Depending on the stage of the tumor, doctors may also remove the nearby lymph nodes and muscle tissue. As with any major surgery, mastectomies and other major surgical cancer treatments involve some risk, and doctors must consider the overall health of the patient, as well as the stage of the tumor.

Some cancers can be treated surgically with less-invasive techniques, such as laser surgery. Laser surgery uses a powerful beam of high-energy light to vaporize certain tumors of the cervix, larynx, and skin. Physicians perform laser surgery with an endoscope inserted through a small incision in the skin. Laser surgery and other less-invasive surgical procedures may require only local anesthesia, in which a patient loses feeling in one particular area of the body but never loses consciousness.

Sometimes oncologists recommend surgery to improve a patient’s quality of life, even if it is not likely to rid the body of cancer. Surgery of this type aims to correct a problem that is causing discomfort or disability. For example, some cancers may spread to the spine, pressing on the spinal cord or nearby nerves. This pressure may cause severe pain, and in some instances, paralysis. Surgical removal of all or part of the tumor near the spine may alleviate these symptoms.

Wednesday, July 21, 2010

DIAGNOSA CANCER BY STAGING


In previous writings I wrote an article Diagnosis of Cancer by Detection of Cancer, now I'll write a continuation of the article. When a tumor is detected, the physician takes a biopsy by removing a sample of the tissue. The biopsy sample is inspected under a microscope to determine if the tumor is benign or malignant. Cancerous cells usually appear abnormal in shape and no longer orient themselves in orderly configurations. If the tumor is cancerous, the physician assigns it a stage, indicating how far cancer has spread. The stage is a key factor in determining both the cancer’s treatment and prognosis.

Oncologists, physicians who specialize in the diagnosis and treatment of cancer, use several different staging systems. In one system, tumors are grouped into four stages denoted by Roman numerals I through IV. Stage I cancers are small localized cancers that are usually curable. Stage II and III tumors are usually locally advanced and may or may not have invaded nearby lymph nodes, and stage IV tumors have usually metastasized—that is, spread to distant tissues in the body.

The most widely used staging system is the Tumor, Lymph Node, and Metastasis system, commonly abbreviated TNM. This system uses numbers between zero and three to assess the size of the tumor (T), the extent that it has spread to nearby lymph nodes (N), and the extent that it has spread throughout the body (M). A cancer’s stage depends on a combination of these numbers. For example, a T-1, N-0, and M-0 tumor is a stage 1 tumor. This tumor is 2 cm (1 in) or less (T-1) and has not spread to nearby lymph nodes (accounting for N-0) or metastasized (M-0). The five-year survival rate for a patient with this stage tumor is accordingly excellent. A T-3, N-1, and M-0 tumor is a stage 3 tumor.

This tumor is greater than 5 cm (2 in) and has spread to nearby lymph nodes, but there is no evidence that the cancer has spread to distant tissues. The five-year survival rate for a patient with this tumor is not as high as the T-1, N-0, M-0 patient. Stage 4 tumors are distinguished by an M-1 number. This means they have progressed to the point where metastasis is widespread, and the prognosis is usually quite poor.

Monday, July 12, 2010

DIAGNOSIS OF CANCER BY DETECTION OF CANCER



Diagnosis of cancer often begins when a person notices an unusual health symptom and consults a doctor. Early warning signs of cancer include changes in bowel or bladder habits, a sore that does not heal, unusual bleeding or discharge, thickening or a lump in the breast or any other part of the body, indigestion or difficulty swallowing, change in appearance of a wart or mole, or a nagging cough or hoarseness.

People with early warning signs should consult their family doctor, who will evaluate symptoms and may refer the patient to a physician who specializes in cancer. A physician will first take the patient’s medical history to learn about current symptoms, past history of disease, and family members diagnosed with cancer. The procedures used in a physical exam depend on the patient’s clinical symptoms and may include a digital rectal examination, in which the physician uses a gloved finger to gently check the smoothness of the rectal lining. The physician may perform a breast exam on female patients, in which the breasts are gently probed to feel for lumps or unusual masses.

During the examination the physician may use a thin, lighted tube called an endoscope to look for tumors in internal body cavities. The endoscopy procedure used depends on the organ or body cavity examined. In gastric endoscopy, the doctor feeds a specialized endoscope down the throat to examine the lining of the esophagus, stomach, and first part of the small intestine. Fiberoptic sigmoidoscopy, in which a flexible instrument is inserted into the lower intestinal tract through the anus, enables a physician to visually examine the interior of the colon and rectum. Colonoscopy uses a much longer flexible instrument to view the entire length of the large intestine.

A number of laboratory tests help narrow the possible diagnoses. In a Pap smear, cells are removed from the cervical epithelium with a small plastic brush. These cells are examined under a microscope for cell changes that are a sign that cancer may be developing as well as signs of malignancy. If a patient’s clinical signs suggest colorectal cancer, the doctor may search for blood in the stool using a fecal occult blood test. A small sample of the patient’s stool is smeared on a card coated with a chemical called guaiac, which reacts with blood. The card is analyzed in a laboratory for occult (hidden) blood. Certain blood tests determine if levels of red and white blood cells are low, a possible indication of leukemia. Others test for the presence of tumor markers, chemicals that are present in higher levels when certain cancers are present. For example, a prostate-specific antigen (PSA) test measures levels of prostate-specific antigen in the blood. Prostate cancer cells overproduce this protein, causing an elevation of PSA levels in blood.

Medical imaging techniques help doctors locate and evaluate a tumor. These include computed tomography (CT) and magnetic resonance imaging (MRI) scans. CT and MRI scans use computers to form a three-dimensional image of the tumor and surrounding tissues. X-ray images of the breast called mammograms help physicians detect and evaluate breast cancer. Ultrasound scanning bounces high-frequency sound waves off a tumor and surrounding tissue to create an image of the tumor. The multimodality display technique combines the images from several imaging tools into one picture, providing a final three-dimensional image with much greater detail. Computer-aided diagnosis uses complex computer programming technology called artificial intelligence to scan mammograms and X rays to help look for signs of cancer and offer an automated second opinion.