Your Doctor Suspects Cancer – First Steps

When your doctor discovers a “red flag” complaint, symptom, lab abnormality, or physical examination finding that might indicate cancer; further investigation needs to be done to help determine if a cancer is actually there or not.  This process of getting a “cancer test” is often very stressful and creates an atmosphere of uncertainty.  The purpose of this article is to help understand the process and what questions to ask that will be helpful through this anxiety provoking process.

Many studies and much practical clinical experience shows that much of discussions that occur in a doctor’s office are either not remembered or misinterpreted.  This is even truer when the discussion involves a sensitive or stressful topic such as cancer.  Often, after the word cancer is used the emotional reaction to the word takes over and significant barriers to communication exist.  It is very helpful to have a spouse, relative or close friend present to help take notes and to help remember what is discussed.

A test is usually indicated when a key sign, symptom, examination finding or laboratory abnormality is interpreted as possibly indicating the presence of a cancer.   It is vitally important to realize that many such tests are ordered so as not to miss a cancer when the actual suspicion or possibility of the cancer being present is quite low.  On the other hand, there are certain “red flag” symptoms that may strongly indicate the presence of a cancer.  The risk of a various sign or symptom being attributable to a cancer is modified based upon the relative risk that the person has cancer.  For example, a new breast lump in a young woman who has no relatives with breast cancer is not initially as suspicious as an older woman who has a breast lump who also happens to have several relatives with breast cancer.  Both women may or may not have breast cancer, but statistics say that the second woman is more concerning.

When a physician recommends further testing for the purpose of checking for cancer it is important to understand several things about this test:

  • The purpose of the test: Is the test a screening test based upon my age or is my risk increased based upon the symptoms I’m having, family history or something else.  Understanding that the test is simply a screening test that everyone who is 50 years of age should get may alleviate some anxiety about it.
  • The accuracy of the test: This is a very complicated question and you may get different answers depending upon which study or book is read, or which “expert” you ask.  The accuracy of a test can be expressed in many different ways.  The real question you want to know is how reliable the test is.  Most screening tests are basically good enough to exclude the disease but not very good at diagnosing the disease.  For example, the simple office test that might be done to check for trace amounts of blood in the stool is called fecal occult blood test.  If this test says there is no blood in the stool, this is about 75% accurate for excluding the presence of colon cancer.  If the test says there is blood in the stool, this means there is about a 5% chance of finding an invasive colon cancer.  If this test is “normal” meaning no blood found, usual screening can be resumed most of the time.  If this test shows the presence of blood, then an additional confirmatory test is usually recommended such as a colonoscopy.  An errant test result that reports everything is normal when there is a cancer present is known as a false negative.  Alternatively, a test result that declares there is a cancer present when there is not one really present is a false positive.  The accuracy, sensitivity, specificity, negative predictive value and positive predictive value vary for every medical tests performed.  Even more complicating, is that these percentages will change based upon the risk factors of a given population of people.  If the test is “calibrated” on a group of families that have many cancers within them, the test will come out looking far more accurate than it really is.
  • The risks associated with the test: Some tests have very little to no risks such as testing the stool for blood, or the testing of a blood level.  Other testing such as a CAT scan or a colonoscopy can have significant even very serious complications and should be discussed.  There is a small risk of puncturing a hole in the colon with colonoscopy and an even rare risk of bruising / rupturing the spleen.  CAT scan delivers a high dose of radiation that might increase risk for cancer in the future and also exposes the patient to risks of IV dye if used that can cause severe allergic reaction or harm the kidneys.
  • The possible outcomes of the test: At times getting too much information before a test may be counter-productive and create more anxiety.  However, understanding the implications of a test is important.
  • Possible reactions to these outcomes: As with the last comment, having a general understanding of the purpose of the test is helpful.
  • How long will it take for the results to be obtained: Very important to discuss, especially if the stress level is high about the test.
  • Will I receive the results over the phone, in person, in the mail, etc.: Your doctor should establish a line of communication to make this clear.
  • If I hear no results can I assume they were normal: This is sometimes practiced but not a good idea – the idea that “no news is good news” is not a very good policy for medical tests in general much less cancer tests.  There is the very real possibility that an important test result that you should be informed about is not communicated properly or worse forgotten and then the consequences might be worse.
  • How much concern is there for the presence of cancer: Open and honest communication should help answer this important question.
  • What preparation for the test is needed: Very important to establish before the test.  Some blood work requires fasting the night before.  Some tests such as CAT scan or colonoscopy may require a special preparation.


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  4. U.S. Preventive Services Task Force. Screening for prostate cancer: recommendation and rationale. Ann Intern Med 2002; 137:915.
  5. This article was originally published on September 3, 2012 and last revision and update was 9/4/2015.