prostatic specific antigen – watercress words by Dr Aletha

This post has been updated June 11, 2021

Both doctors and patients have mixed emotions about diagnostic tests done to screen for disease. We physicians want to help patients stay healthy, prevent disease, and treat problems early and effectively.But the time spent counselling, ordering, performing, and reviewing these tests means less time available to manage patients’existing medical problems.

I agree with Dr. William Zinn, family physician in Boston, who wrote

“Keeping track of the ever-increasing health maintenance requirements and cancer screening sometimes make it hard to remember why the patient came to the office in the first place.”
JAMA, January 7, 2020

For patients the issues are similar. While they want to stay healthy, prevent disease, and get treated promptly, they don’t like the inconvenience, time away from work, cost, and sometimes discomfort the tests require.

What are screening tests?

A screening medical test is done to uncover a disease or disorder in a person who may or may not be a risk for it and who otherwise feels well and has a normal exam. Suppose we are considering screening a group of people for disease X. Let’s start by dividing them into 3 groups.

Those with no symptoms, feel fine, at average risk of health condition X.
Those with no symptoms, feel fine, at increased or high risk of condition X.
Those who have symptoms suggestive of condition X, or have had other testing that suggests they might have it

Screening for X in groups 1 and 2 might be appropriate, based on medical guidelines, physician judgement, and patient preference. For group 3, with symptoms of condition X, testing would be considered diagnostic; a doctor would test for X, and possibly other conditions that the symptoms suggest.

Diagnostic vs Screening

That might seem like a picky difference, but there are several implications for both doctors and patients.

Documentation- The medical record needs to reflect accurately why a test is being ordered and done. This is necessary for billing because inaccurate coding can make doctors and clinics liable for fraud. Also, the government and other payers are starting to judge doctors’ quality of care based on medical record audits of care given or not given, and why.

Interpretation and Follow up-A test is rarely interpreted in isolation. The history and exam together with the test lead to a diagnosis.

Reimbursement– Most if not all insurances, including Medicare, reimburse differently based on whether a test is diagnostic or screening. And this usually determines how much the patient pays for each. Screening tests are usually covered 100% while diagnostic testing may require a deductible or copay .

A Country Doctor Writes blog explains this dilemma in detail –

But because in the inscrutable wisdom of the Obama Affordable Care Act, it was decided that screening colonoscopies done on people with no symptoms whatsoever are a freebie, whereas colonoscopies done when patients have symptoms of colon cancer are subject to severe financial penalties.
read more at this link

This link at FamilyDoctor.org helps explain

Health Insurance: Understanding What It Covers

Cervical cancer screening frequency also now takes into account a woman’s HPV, human papilloma virus, status. Go here to learn

When should a woman begin cervical cancer screening, and how often should she be screened?

a microscope image of a cell infected with HPV

A koilocyte is a squamous epithelial cell that has undergone structural changes as a result of infection by human papillomavirus (HPV). This image of a koilocyte shows human ectocervical cells (HEC) expressing HPV-16 E5 oncoprotein, and immortalized with HPV-16 E6 and E7 oncoproteins. Formation of koilocytes requires cooperation between HPV E5 and E6 oncoproteins. The cell culture is stained with hematoxylin and eosin (H&E).National Cancer Institute \ Georgetown Lombardi Comprehensive Cancer Center, Ewa Krawczyk, public domain

Does disease screening make a difference?

Screening tests don’t prevent disease although they may be helpful for health maintenance or improvement. They may prevent progression or complications of a disease, but don’t prevent it’s onset. They may not even prevent death from the disease, although we like to believe they do. Screening may diagnose the disease before symptoms develop, so the patient lives longer with the disease, but not affect the eventual outcome.

Doctors can now offer patients another option that is more accurate than the stool blood test and less invasive than colonoscopy.

Stool DNA testing looks for certain DNA or gene changes in cells that can get into the stool from polyps (pre-cancerous growths) or cancer cells. It may also check for blood in the stool. For this test, people use a take-home kit to collect a stool sample and mail it to a lab. Cologuard^® is the name of the stool DNA test that is currently FDA-approved. This stool test needs to be done every 3 years.

So when should we offer screening tests?

If there is a clear benefit to patients from an effective treatment available to make a difference in the disease course or

If knowledge of the condition helps the patient and family make choices about managing the condition’s likely course or the need for family members to be screened

If the test is reliable enough to identify most people with the disease without falsely identifying people who don’t have it. The scientific terms for this are sensitivity and specificity.

When the benefits clearly outweigh the risks and costs.

a mammogram image — a mammogram revealing a breast cancer image source- National Library of Medicine, Open-i

How to decide for yourself

These are just some of the factors involved in deciding when to undergo screening tests. To make an intelligent decision about your own screening, you need a physician who reviews your past and current medical history, your family history, and your health goals. Then the doctor can make recommendations based on your needs and desires with the help of expert guidelines published by medical organizations who carefully review the medical literature.

Review the graphics in this post for recent guidelines from professional organizations and discuss with your physician. Help your doctor help you by scheduling a health maintenance visit rather than bringing it up when you are there sick or for chronic care. These discussions deserve your physician’s full attention.

further information from the National Institutes of Health.

To Screen or Not to Screen

¿Hacer o no hacer pruebas de detección?

exploring the HEART of health maintenance

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(this post has been updated 11/17/2015)

Prostate cancer is to men what breast cancer is to women in the United States-

The number 1 diagnosed cancer in men
The number 2 cause of cancer-related death in men

So, naturally we would like to be able to diagnose it at a stage where the chance for a cure is greatest.

A screening test is a test that is done on a healthy person to detect a disease that is not causing symptoms.

For breast cancer, that is a mammogram. For prostate cancer, it is a fairly simple blood test to measure a chemical called Prostate-specific antigen, or PSA

The blood level of PSA may be high or normal in the presence of cancer. If high, it will decline with treatment.

PSA is a protein produced only by the prostate gland; levels in the blood can be elevated by any disease of the prostate, not just cancer. And, in some cases, it can be normal, even in the presence of cancer.

anatomy of the prostate gland — The prostate gland sits just under the bladder in the pelvic area.

Despite the bleak sounding statistics, we know that most prostate cancers grow so slowly that they will never cause death. And, for cases that are discovered and treated, sometimes the treatment can cause complications worse than would have occurred from the cancer.

So, multiple organizations including the American Cancer Society, and the American Urological Association, have issued guidelines for screening. To simplify, I am listing a composite of the recommendations from them and others, since they are all quite similar.

Men under 50 years old- screening not recommended (unless high risk, see below)
Men from age 50 to 70 years old should discuss the benefit versus risk with their physician, and make a decision together
Black men are at higher risk so should discuss screening with their physician at age 45 years.
Men whose father or brother had prostate cancer prior to age 65 years, should begin discussions at age 45 years.
Men age 70 and older do not need screening, because they will unlikely die from prostate cancer.
Finally, any man whose health status suggests a life expectancy of less than 10-15 years does benefit from screening.

The goal for cancer screening, other than merely finding a cancer, is to

increase a person’s chance for cure and survival.
minimize complications of the screening and treatment

In the case of prostate cancer, screening does not seem to accomplish this. But these, like other screening guidelines, are based on current evidence, so must be reviewed regularly and changed based on new information.

Here are the guidelines as published for patients in the Journal of the AMA with a link to a podcast discussion.

This Guide to Surviving Prostate Cancer

by Dr. Patrick Walsh

“covers every aspect of prostate cancer, from potential causes including diet to tests for diagnosis, curative treatment, and innovative means of controlling advanced stages of cancer.”