Blood Drug Testing

will a blood test detect cancer?

Is it possible for a blood test to detect cancer?

Public Comments

1. Quite possible, but the correct test must be specified. cancers have specific markers in the blood which will indicate the type and seriousness of the condition. your dr will order the tests.
2. Virtually each type of cancer has some type of marker that shows up in the blood, but by the time markers can be detected, many types of cancer would already be advanced enough to cause obvious symptoms. Most cancer markers that show up in the blood are chemicals that normally occur in the blood, but they are either higher or lower than normal when someone has cancer. The problem is that normal levels of various blood constituents vary from person to person, so a cancer-free person with a normally-high level of a marker cannot be distinguished from a person with cancer who has an identical level of the marker, but would normally have a lower level of that marker if they didn't have cancer. If you know what type of cancer to look for, blood tests are sometimes useful for screening - which the docs use to determine if people need more testing. An example is the PSA test for prostate cancer. in the PSA test, increased levels of an antigen produced by the prostate gland are a warning that a person might have cancer. This test does not diagnose cancer, it is used to make a decision about performing a biopsy that would confirm or rule out cancer.
3. If you know the specific type of cancer that you are looking for, then the answer is maybe. As there really isn't any single test to detect all cancers and general blood tests cannot usually identify cancer unless a request was made to check for specific markers that could be associated with a particular type of cancer. Usually an analysis of other symptoms along with a range of blood tests may confirm that there is something not quite right, as was the situation with myself, which resulted in having further detailed tests and evaluations. This may include X-Rays, CT, MRI or PET scans. A general blood test such as a Complete Blood Count can however provide a lot of information, which in conjunction with other symptoms may establish the need for more specific tests that could identify the particular ailment more precisely. CBC measures include; - the amount of haemoglobin in the blood; - the number of red blood cells (red cell count); - the percentage of blood cells as a proportion of the total blood volume (haematocrit or packed cell volume); - the volume of red blood cells (mean cell volume); - the average amount of haemoglobin in the red blood cells (known as mean cell haemoglobin); - the number of white blood cells (white cell count); - the percentages of the different types of white blood cells (leucocyte differential count); and - the number of platelets.
4. Yes the CA-125 test can detect antigens to Ovarian and other gynecological carcinomas, but a tissue study (biopsy) is necessary for definitive diagnosis.