Diagnostic Tests for Cancer
Diagnostic Test list for Cancer: The list of diagnostic tests mentioned in various sources as used in the diagnosis of Cancer includes:
- Tests depend on the specific type of cancer but some types of tests are common
- Physical exam
- Imaging - used to see the tumor or its related damage.
- Pathology tests - this is the analysis of biopsy tissue.
- Other tests depend on the specific type of cancer
Tests and diagnosis discussion for Cancer: A biopsy is the only sure way to know whether a medical problem is cancer. In a biopsy, the doctor removes a sample of tissue. The tissue is examined under a microscope to check for cancer cells. 1
In routine physical exams, the doctor looks for anything unusual and feels for any lumps or growths. Specific screening tests, such as lab tests, x-rays, or other procedures, are used routinely for only a few types of cancer.
Breast. A screening mammogram is the best tool available to find breast cancer before symptoms appear. A mammogram is a special kind of x-ray image of the breasts. Breast cancer screening has been shown to reduce the risk of dying from this disease. The National Cancer Institute recommends that women in their forties and older have mammograms on a regular basis, every 1 to 2 years.
Cervix. Doctors use the Pap test, or Pap smear, to screen for cancer of the cervix. For this test, cells are collected from the cervix. The cells are examined under a microscope to detect cancer or changes that may lead to cancer.
Colon and rectum. A number of screening tests are used to find colon and rectal (colorectal) cancer. If a person is over the age of 50 years, has a family medical history of colorectal cancer, or has any other risk factors for colorectal cancer, a doctor may suggest one or more of these tests.
Sometimes tumors in the colon or rectum can bleed. The fecal occult blood test checks for small amounts of blood in the stool.
The doctor sometimes uses a thin, lighted tube called a sigmoidoscope to examine the rectum and lower colon. Or, to examine the entire colon and rectum, a lighted instrument called a colonoscope is used. If abnormal areas are seen, tissue can be removed and examined under a microscope.
A barium enema is a series of x-rays of the colon and rectum. The patient is given an enema with a solution that contains barium, which outlines the colon and rectum on the x-rays.
A digital rectal exam is an exam in which the doctor inserts a lubricated, gloved finger into the rectum to feel for abnormal areas.
Although it is not certain that screening for other cancers actually saves lives, doctors also may suggest screening for cancers of the skin, lung, and oral cavity. And doctors may offer to screen men for prostate or testicular cancer, and women for ovarian cancer.
Doctors consider many factors before recommending a screening test. They weigh factors related to the individual, the test, and the cancer that the test is intended to detect. For example, doctors take into account the person's age, medical history and general health, family history, and lifestyle. The doctor pays special attention to a person's risk for developing specific types of cancer. In addition, the doctor will assess the accuracy and the risks of the screening test and any followup tests that may be necessary. Doctors also consider the effectiveness and side effects of the treatment that will be needed if cancer is found.
People may want to discuss any concerns or questions they have about screening with their doctors, so they can weigh the pros and cons and make informed decisions about having screening tests.2
If symptoms are present, the doctor asks about the person's medical history and performs a physical exam. In addition to checking general signs of health, the doctor may order various tests and exams. These may include laboratory tests and imaging procedures. A biopsy is usually necessary to determine whether cancer is present.
Blood and urine tests can give the doctor important information about a person's health. In some cases, special tests are used to measure the amount of certain substances, called tumor markers, in the blood, urine, or certain tissues. Tumor marker levels may be abnormal if certain types of cancer are present. However, lab tests alone cannot be used to diagnose cancer.
Images (pictures) of areas inside the body help the doctor see whether a tumor is present. These pictures can be made in several ways.
X-rays are the most common way to view organs and bones inside the body. A computed tomography (CT or CAT) scan is a special kind of imaging that uses a computer linked to an x-ray machine to make a series of pictures.
In radionuclide scanning, the patient swallows or receives an injection of a radioactive substance. A machine (scanner) measures radioactivity levels in certain organs and prints a picture on paper or film. The doctor can detect abnormal areas by looking at the amount of radioactivity in the organs. The radioactive substance is quickly eliminated by the patient's body after the test is done.
Ultrasonography is another procedure for viewing areas inside the body. High-frequency sound waves that cannot be heard by humans enter the body and bounce back. Their echoes produce a picture called a sonogram. These pictures are shown on a monitor like a TV screen and can be printed on paper.
In MRI, a powerful magnet linked to a computer is used to make detailed pictures of areas in the body. These pictures are viewed on a monitor and can also be printed.
A biopsy is almost always necessary to help the doctor make a diagnosis of cancer. In a biopsy, tissue is removed for examination under a microscope by a pathologist. Tissue may be removed in three ways: endoscopy, needle biopsy, or surgical biopsy.
During an endoscopy, the doctor can look at areas inside the body through a thin, lighted tube. Endoscopy allows the doctor to see what's going on inside the body, take pictures, and remove tissue or cells for examination, if necessary.
In a needle biopsy, the doctor takes a small tissue sample by inserting a needle into the abnormal (suspicious) area.
A surgical biopsy may be excisional or incisional. In an excisional biopsy, the surgeon removes the entire tumor, often with some surrounding normal tissue. In an incisional biopsy, the doctor removes just a portion of the tumor. If cancer is present, the entire tumor may be removed immediately or during another operation.
Patients sometimes worry that having a biopsy (or any other type of surgery for cancer) will spread the disease. This is a very rare occurrence. Surgeons use special techniques and take many precautions to prevent cancer from spreading during surgery. For example, if tissue samples must be removed from more than one site, they use different instruments for each one. Also, a margin of normal tissue is often removed along with the tumor. Such efforts reduce the chance that cancer cells will spread into healthy tissue.
Some people may be concerned that exposing cancer to air during surgery will cause the disease to spread. This is not true. Exposure to air does not cause the cancer to spread.
Patients should discuss their concerns about the biopsy or other surgery with their doctor.
When cancer is diagnosed, the doctor will want to learn the stage, or extent, of the disease. Staging is a careful attempt to find out whether the cancer has spread and, if so, to which parts of the body. Treatment decisions depend on the results of staging. The doctor may order more laboratory tests and imaging studies or additional biopsies to find out whether the cancer has spread. An operation called a laparotomy can help the doctor find out whether cancer has spread within the abdomen. During this operation, a surgeon makes an incision into the abdomen and removes samples of tissue.2
Diagnosis of Cancer: medical news summaries: The following medical news items are relevant to diagnosis of Cancer:
- 60% of at risk Americans over 50 haven’t been screened for colorectal cancer.
- Adenocarcinoma incidence is increasing dramatically
- Annual mammogram and doctor visits are sufficient follow-ups for breast cancer survivors
- Anxious people more likely to notice symptoms of rectal cancer
- Australia’s cancer death rate is low but incidence of new cancers is relatively high
- Cancer deaths take over deaths caused by heart disease
- Cervical cancer may be detected through urine test
- Cervical cancer screening recommendations detailed
- Ductal lavage is an inaccurate breast cancer detection method
- Fecal DNA test more effective than standard test for detecting colorectal cancer
- Genetic biomarkers has potential to diagnose psychiatric disorders
- Genetic profile test determines if breast cancer victims need chemotherapy
- Good patient-doctor communication and awareness of colon cancer ensures greater participation in colon cancer screening programs
- Increasing awareness of cancer symptoms by doctors and patients may improve diagnosis
- Male breast cancer undiagnosed
- Need for unnecessary prostate cancer may be reduced with new risk assessment technique
- New bowel cancer screening anticipates greater participation
- New pancreatic cancer drug trial provides hope for improved survival rates
- Overweight men risk having their prostate cancer misdiagnosed
- Pancreatic cancer surgery less common in black men
- Passive smoking during childhood increases risk of adult lung cancer
- Poor women are undereducated about cancer screening
- Prostate cancer incidence increasing in Nigerian men
- Prostate cancer prognosis may be predicted by measuring levels of beta-catenin
- Prostate cancer risk reduced in diabetics
- PSA tests are not as “useless” as the inventor claims
- Skin cancer rate increasing in Australia
- Smoking increases the risk of development of hereditary pancreatic cancer
- Software allows accurate visual diagnosis
- Symptoms of ovarian cancer should not be ignored
- Two cancer patients suspected of spreading TB to 19 other people
- Uterine cancers can be symptomatic or asymptomatic
- Vegetable compound to be tested for its effect on cervical cancer
- Women too are at risk of lung cancer
1. excerpt from Cancer: NWHIC
2. excerpt from What You Need To Know About Cancer - An Overview: NCI
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