Cancer Screening and Diagnosis
By Lisa Glickstein, Ph.D, Triplet Mom
Originally printed in January, 2006

My great-grandmother, my grandmother and grandfather, my father, my uncle, and 
my sister have all had cancer.  Their age at diagnosis ranged from under 30 to 
over 80-years old.  The majority survived their cancer, although in a few cases, 
the cancer had progressed and the treatments were disabling.  Early detection of 
cancer allows for less invasive or intense treatment, faster recovery and better 
prognosis.

What is the difference between screening and diagnostic testing?
In screening, individuals who are healthy are tested for signs of possible 
cancer.  Screening tests include breast exams and mammograms, the prostate 
surface antigen (PSA) blood test, digital rectal exam, fecal (stool) occult 
blood test (FOBT), sigmoidoscopy and colonoscopy, PAP test, and the human papilloma 
virus (HPV) DNA test.  The goal of screening is to detect cancer at an early stage, 
where it is small, localized, and more easily removed and treated.

In diagnostic testing, patients’ tissue that may be cancerous is tested to 
determine if cancerous cells are present.  These tests may include a breast, 
skin, or endometrial biopsy, the CA-125 blood test for ovarian cancer, blood 
counts and cell analysis for leukemia, sentinel node biopsy, or other tests.  
In these cases, the physician suspects that a lesion is cancerous, and is using 
the test to confirm or refute that suspicion.  The CA-125 blood test, in 
particular, is a good diagnostic test but gives too many false results to be 
useful as a screening test.  This type of testing will usually allow staging of 
the cancer, if a solid tumor is present.

Why is early detection important?
Cancer begins when a single cell starts to multiply out of control, forming a 
primary tumor.  Eventually, the cancer cells spread to the local lymph nodes 
by normal lymphatic circulation, and start growing in these and then in further 
(distal) nodes.  Finally, the cancer may enter the blood and spread to and grow 
in other tissues as secondary tumors (often in the liver, bones, or brain).  Stage 
I is small and localized, and stage IV involves a larger tumor with spread to other 
organs in the body.  Treatment is most effective and straightforward for a Stage 1 
tumor.  In many cases, the whole tumor can be snipped out during the biopsy procedure.  
A later follow-up surgery may be needed to take out a “margin” of tissue – an 
insurance policy that no tumor cells have been left in the body.  In many cases, 
no or only minimal radiation or chemotherapy is then needed.  In later stages, 
these types of treatment are needed to seek out and destroy the wandering cancer 
cells.  These treatments are not only toxic to normal tissues, but may not be able 
to destroy all cancer cells in the body.  When treatment ends, or following a period 
of dormancy (remission), the cancer begins to grow again.

What are the current screening recommendations?
For most otherwise healthy individuals, cancer screening will begin in earnest 
around age 40.  A lower age may be appropriate for a person with a lot of risk factors 
(such as smoking or a family history of cancer).  All of the tests above can be 
performed or ordered by your primary care physician.  The current guidelines from 
the American Cancer Society are available at www.cancer.org.  You can also consult 
your HMO or insurance provider guidelines in materials provided by your employer, 
or at the insurance company website.

Is screening enough?
No.  You should be aware of your body and watch for any signs or symptoms that may 
indicate cancer.  These may include lumps (particularly in a breast or testicle), 
abnormal bleeding (breakthrough bleeding, bleeding from a nipple or mole, blood in 
the stool), persistent abdominal pain or bloating, persistent or recurrent constipation 
or vomiting, persistent loss of appetite and weight loss (anorexia), skin changes 
(puckering, or a change in shape or color of a mole), changes in mental status, or 
changes in vision (blurring, double vision) or sense of smell.  Finally, although 
pain is rare in the early stages of cancer, unusual or severe pain (headache, vaginal 
burning, abdominal or rectal pain) may be the first sign of cancer for some people.

Any of these symptoms should be discussed rapidly with your primary care physician.  
See your doctor or visit an ER immediately for severe and disabling, sudden onset, 
headache or changes in mental status or vision.  Schedule an appointment in a day or 
two for bleeding, skin changes, or lumps, as you would if you were acutely ill, not 
as a regular office visit that may take months to schedule.  A good rule of thumb 
for persistent discomfort (bloating, constipation, itching, appetite and weight 
changes) is that for most of us, by the time we think, “I might need to call the 
doctor,” it is probably past time to make that call.  Your doctor will examine you 
and eval-uate your symptoms.  He or she may run some tests, or refer you for more 
extensive diagnostic testing.  It may take some time to coordinate, schedule, and 
evaluate your test results.  Stay on top of the process, with the help of your 
primary care doctor, so that testing and evaluation is completed in a reasonable 
amount of time.  One week to over a month may be required for a full diagnostic 
work-up; the longer time frame would be normal if biopsy surgery were performed.

Return to your doctor if the symptoms continue, even if the diagnostic work-up was 
negative.  We have all heard (or experienced) medical horror stories of missed 
diagnoses.  Be an advocate for yourself and your loved ones – because now, more 
than ever, cancer is not a death sentence, particularly if caught and treated 
in its earliest stages.