Pro IQRA News Updates.
Finger-up-down screening for prostate cancer has been called into question. An international panel of experts recently suggested that so-called “active surveillance” digital rectal exams should be replaced by MRI scans.
This news may be celebrated as an intrusive medical examination bypass by the march of high technology, but what exactly is a digital rectal exam (DRE) and what are the implications of replacing it?
DRE involves a doctor examining a patient’s rectal wall by inserting a finger into the lower part. This gives doctors access to the prostate gland, which helps them find signs of cancer. Before the introduction of the prostate-specific antigen (PSA) test (from blood drawn) in 1986, the DRE was the only way to screen men for prostate cancer.
The DRE can also be used to screen for other types of cancer, such as rectal cancer and anal cancer. It can be used to check for impacted stools in people with constipation and, under certain circumstances that will not be discussed in further detail, foreign bodies.
It is also used in women to screen for cancer, including spread of ovarian cancer.
Done correctly, it shouldn’t be too uncomfortable. And privacy and good communication can go a long way to overcoming awkwardness.
All medical students are taught to do this and have been told for generations that when examining patients: “If you don’t put your finger in it, you can put your foot in it.”
The walnut-sized prostate gland is located in the pelvis, surrounding the urethra where it leaves the bladder. Instead, it is located next to the rectum and can be easily felt with the examining finger.
If it is inflamed, as in cases of prostatitis, it will be soft. And in the case of benign prostatic hyperplasia, which occurs in middle age and causes a slow urethra, the prostate gland feels enlarged.
In cases of prostate cancer, the surface may be irregular and firm to the touch. However, it is very common for prostate cancer to be missed in the early stages of the disease.
In the UK medical school system, a lot of emphasis is placed on learning good clinical skills. Overreliance on technology is seen as a potential waste of scarce resources, and patients seem to like to think of their doctors as skilled diagnosticians. But there are times when technology is more accurate at detecting disease — especially in its early stages.
Magnetic resonance imaging (MRI) provides detailed pictures of the body’s structures. Unlike X-rays and CT scans, it does not rely on ionizing radiation (which is linked to an increased risk of cancer) and is believed to be safe. It is good at catching prostate cancer early and “surveillance” (monitoring the disease).
But MRI scans are expensive, the machines are bulky, are off power, and are usually confined to hospitals. This limits their use.
There is a blood test, the previously mentioned PSA test, that is used as a marker for prostate disease, but it is not specific for cancer. When used with DRE, it helps detect cases. But PSA levels become elevated after the DRE which makes the timing of the test awkward. This means that blood must be drawn at a separate visit.
So what is the role of the DRE in diagnosing prostate cancer? I think it still has a place. Prostate cancer easily spreads to the bones, and it is not uncommon for undiagnosed prostate cancer to present as back pain when it spreads to the vertebrae. If suspected, positive rectal examination results may lead to timely diagnosis and reduce delays in obtaining correct treatment.
The glove again?
DRE works best for rectal cancer. If the tumor is in a site accessible to the examiner’s finger, up to 76% can be detected.
For constipation, finding stool impacted in the rectum can save the expense and radiation exposure of modern investigations, which have done away with X-rays of the abdomen in favor of radio-dense CT scans.
Was the rectal examination his day? I do not think so. It is a cheap check that yields useful information when used and interpreted correctly.