Cancer Screening Tests
Screening Options for Cancer
Most cancers, when detected early are relatively easier to treat than in the advanced stages. The cancer screening tests aim to detect a cancer early before any symptoms occur, making the treatment’s success rate as positive as it could be.
While some screening tests might have associated risks as well, you should be well aware of the success rates of a screening test from your doctor. If successful, a screening test would pose more benefits like early detection which can increase the cancer’s cure probability.
An effective screening test should be
- Accurate – elimination of false positives, and precisely determining the presence of a disease
- Acceptable – Safe and convenient
- Easily available and affordable
Types and tests
Screening tests vary according to the cancer type. While types like cancers of the breast, bowel (colon and rectum), and cervix have screening tests that can help detect the cancer early, some still do not have effective screening tests. Screening for such types are among the actively researched in the discipline of oncology.
Here are the types of cancer and their associated screening tests –
Mammography – As one of the most effective methods to screen for breast cancer, this is shown to reduce the death rates among women in the age group of 40 – 74, especially above 50. A mammogram is simply an X-ray, specifically designed to show tumours and irregularities of the breast. The images of these mammograms are then evaluated among the radiologists and suitable treatment option is advised by an oncologist.
Breast Magnetic Resonance Imaging (Breast MRI) – This uses strong magnetic field and radio waves to create detailed images of the breast. The method is not regularly used in the screening of breast cancer among women with average risks as the MRI may detect abnormalities even when there is no cancer. The imaging test is often used among women with a high risk, potentially carrying a harmful mutation in their BRCA1 or BRCA2 genes. . Breast MRI is usually conducted along with mammography.
Clinical examination – A doctor examines the breasts to detect lumps or other changes in the shape or size.
Self-examination – It is better to be familiar with any changes in the size and shape of the breasts. If there is a lump or such abnormality felt, a consultation with your oncologist is highly recommended.
Low-Dose Helical Computed Tomography (LDCT) – A CT scan of the chest is taken with a low-dose radiation (for detailed images) from different angles and a computer processes it into a cross sectional image . This image helps the examiner to detect any abnormalities or tumour in the lungs.
Early screening however is limited to the fact that not all cancers can be detected by the LDCT scans. For higher risk people, researches have shown that LDCT scans are more efficient than the chest x-rays. Annual LDCT scans are recommended before symptoms develop to lower the risk of dying from lung cancer.
Colonoscopy and sigmoidoscopy – An endoscope (a lighted, long, thin and flexible instrument) is inserted into the rectum through the anus where the examiner can check for polyps (abnormal growth of the colon) or tumour. As colorectal cancer mostly develops from precancerous polyp formation, the test is highly effective.
Fecal Occult Blood Test (FOBT) – This test detects blood in the feces or stools, which may be a sign of an abnormal growth of the colon (polyps) or cancer. There are two types – guaiac-based, where the stool sample is coated in a plant based substance called guaiac and changes in its color determine the blood in stool, and immunochemical which uses a special protein called antibody that attaches to the hemoglobin.
Stool DNA tests – This is done to help a doctor analyse if a colonoscopy is needed where they find any changes in the DNA of a person’s stool sample.
Double contrast X-ray (barium enema) – This is usually done in people who cannot have a colonoscopy. In the process, the patient is given an enema with a barium solution and a series of x-ray images of the entire colon and rectum is taken. Here, the barium makes the colon and rectum stand out in the image, helping the examiners look for abnormalities.
Learn all about colorectal cancer screening
Human Papillomavirus (HPV) Testing – Cells from the cervix are taken to test a specific strain of Human Papillomavirus. When such strains are at high concentrations, it may be indicative of cervical cancer.
Pap test – Sample cells from the cervix are taken and sent to a pathologist who determines if there are any cancerous or precancerous cells by examining with a microscope. It is one of the frequently used tests in determining the cancer at its early stages.
Learn all about cervical cancer screening
Prostate-specific antigen (PSA) test – PSA is a protein produced by both non-malignant as well as malignant cells in the prostate. When its levels are more than 4 nanograms-per-milliliter of blood, it may be indicative of prostate cancer. However, factors like aging may also be responsible for higher PSA levels.
Digital Rectal Examination (DRE) test – The doctor examines for abnormalities or irregularities in the rectum by inserting a gloved lubricant inside the prostate.
Learn all about prostate cancer screening
Head and Neck Cancer
Routine health examinations – Routine health examinations can be undergone where a doctor feels or looks for any lumps or abnormalities in the nose, mouth or throat. For people who consume or have a history of consuming alcohol and tobacco products, a screening is recommended.
Learn all about head and neck cancer screening
Risks of Screening
Cancer screening tests are helpful in detecting the cancer, but there are few associated risks as well:
Overdiagnosis – Screening options in few cases may find slow growing tumours, which are potentially not harmful throughout the lifetime. This can lead to treatments that are not actually needed.
Misdiagnosis – Sometimes, the screening tests show indicative of cancer even when they do not, and vice-versa.
Frequent and increased screening – Misdiagnosis may result in increased screening where tests will be performed even one doesn’t need it.
We recommend to have the following questions in mind when you are looking out for a screening test:
- Which type of cancer is the screening done for?
- What are the available screening tests for the respective type of cancer?
- What should I do if my screening tests look positive? Should I go for further screening options as well?
- How frequently should I get screened? Do factors like age and health conditions matter?
Discuss these with your oncologists to get a detailed clarity of further actions. They may recommend you with appropriate treatment options for the type and complexity of your cancer.
Our approach to screening cancer
The risks associated with the screening tests may be higher if the condition is not properly assessed. At Onco.com, our panel of care managers and expert oncologists assess all your reports, associated health conditions with close analysis and advise viable and safer screening options.