When we look for cancer prior to an individual having any symptoms at all, it is termed as screening. With the help of screening one can detect and diagnose an early stage cancer, as a timely diagnosis of cancer improves the prognosis. As usually when a cancer has physically visible symptoms or even the symptoms are starting to appear it implies that he cancer has spread
With advancement in science, we have information with medical professionals to recommend and identify individuals who are at higher risk of developing cancer and thus should be screened for cancer, what screening tests to be used and the frequency of the screening tests. Screening tests are not necessarily advised to people suspected to have cancer and it does not mean that an individual has cancer if the doctor advices cancer screening. On abnormal screening test results, further confirmatory test are performed called the diagnostic tests.
The screening tests can be of different types subjective to the requirement as assessed by the doctor. The basic and most common breast cancer screening tool is physical exam and history. This includes general body check up with a focus on the physical examination of the breast to look for any lumps or skin changes of the breasts. To assess susceptibility a clinical history with the lifestyle pattern of the patient is also taken. The medical history may include any past ailments and medications. Laboratory tests are also part of the screening tests, in which the blood, urine, tissue from the body is sampled and a histological and pathological examination of the same is performed. Other bodily fluids or substances from body may also be analyzed for detecting presence of cancerous cells. Imaging procedures make a vital part of the screening process, it provides with images of body parts and areas inside the body. Bone scans, CT, MRI, ultrasound, mammography, etc make a part of imaging tests. Also genetic tests are done which evaluate gene mutations causing cancer in the body.
There are certain risks associated with screening tests and as such it is not certified that all of them are helpful. Exposure to radiation for example in imaging tests can be an issue with certain patients. The importance and accurate diagnosis probability figures must be known to prevent risks.
It has been known that certain screening tests can lead to or result in serious conditions creating problems. Some tests may cause bleeding or harm the body like the colon cancer screening with sigmoidoscopy or colonscopy can result in tears in the colon lining.
Also screening tests can lead to stress and anxiety by giving false-positive test results. In these tests even the normal tissue or reading may come out to be abnormal and the patient may be subjected to further tests increasing his anxiety. These additional diagnostic tests may not be required and also cause extra risk to the patient.
There is also a possibility of false-negative test results in which an abnormilty may be mistaken for normalcy. This may delay the treatment intervention and worsen the prognosis from the condition.
Screening test will detect the cancer but it does not guarantee removal or cancer or an assurance against related mortality. In absence of symptoms, if cancer is diagnosed at the last stage with the help of screening tests, there is no surety of knowing if the treatment is going to help in removing the cancer. The treatments of cancer do have their own side effects.
A screening test is not a diagnostic test and it is not meant to diagnose cancer. In case of abnormal results extra additional tests are prescribed to obtain conclusive results. A screening test will only detect a symptom like a lump in the breast, but if the lump is benign or malignant is diagnosed by a diagnostic test. Test like biopsy would be best to determine cancerous growth, in it a sample breasts tissue is examined by a pathologist under a microscope. With the array of screening test available, it is best to discuss the available options with the treating doctor.