Using Genetic Biomarkers in Prostate Cancer Diagnoses- A Review.

 

Looking for something? Sandhill cranes in my yard. Photo: BJ Gabrielsen
Looking for something? Sandhill cranes in my yard. Photo: BJ Gabrielsen

New research has identified several ‘biomarkers’ or genetic fingerprints that report the underlying biology of a tumor. Combinations of these biomarkers can aid clinical management of prostate cancer by:  1) allowing accurate diagnoses;  2) establishing whether a patient’s cancer is aggressive or indolent;  3) deciding if repeat biopsies are needed;  4) aiding clinical decisions on therapeutic options (drug combinations for maximal patient benefit);  and,  5) evaluating whether a patient’s cancer is responding to therapy or not. For an excellent review article describing many of the diagnostic (including genetic) tests currently available or in the developmental pipeline, see the March 29th, 2013 Prostate Cancer Foundation (PCF) NewsPulse  and the articles contained therein.  Many of these biomarker-driven diagnostic / prognostic tests nearing clinical use are in the final stages of clinical validation and are listed in table form in the Newspulse article. The New York Times recently published a feature article  discussing many of these new tests. These latest prostate cancer tests evaluate blood, urine or prostate biopsy specimens for the presence of either an abnormal gene activity pattern, or specific chemicals that are released by cancer cells. For example, the GenProbe test currently evaluates urine samples for the expression of PCA3 (prostate cancer antigen) DNA. It is anticipated that the GenProbe test evaluating both PCA3 DNA and expression of the TMPRSS2-ERG gene fusion will soon be approved for use. The abnormal TMPRSS2-ERG gene fusion is present in 50 percent of all prostate tumors, and PCA3 is expressed at high levels in 95 percent of prostate cancer patients, therefore the combination of these two tests has a high probability of accurate diagnoses. Testing these biomarkers in urine samples holds potential due to the non-invasiveness of urinalysis, ease of collection, and the fact that prostate cells are directly released into the urethra through prostatic ducts after a digital rectal exam (DRE) or prostate massage.

Are You in a Time of Need?

I would like to share a small example which I believe illustrates God’s timetable and daily provision for circumstances in our lives. While this narrative might seem relatively insignificant, the principle it demonstrates is a major one.  Just as we rely on God’s help and provision for serious issues such as prostate cancer, He also makes His presence known in more routine ways of daily life. During the summer months, temperatures along the sun-drenched southwestern Florida Gulf of Mexico coast consistently range into the mid-90’s accompanied by intense humidity. But civilization functioned here long before the advent of climate-controlled air conditioning. A few days ago my wife and I experienced to a small but realistic degree what it would have been like to live here without such modern conveniences. It was a hot, rainy evening at midnight when our 20-year old air conditioning unit finally expired. It would take days to replace it. As we try to consistently do, we prayed that God would enable us to accept our  circumstances with His peace and tranquility. To our pleasant surprise, the next few days became mostly cloudy and rainy with temperatures only in the mid-80’s,  thereby negating Florida’s hot intense sunshine heating our home. It made our circumstances very bearable and made us appreciate all the more how people thrived without the modern conveniences of air conditioning. God did not alter the weather patterns to conform to our immediate need but we believe He arranged the timetable such that when our need arose, He made the circumstances quite bearable. Our earthly bodies are subject to illnesses and various less-desirable conditions, yet when we release them to the Lord, He carries us through often in ways we could never have anticipated and even guarantees it in His Word. Two examples follow. “Therefore, let us draw near with confidence to the throne of grace, so that we may receive mercy and find grace to help in time of need,” according to Hebrews 4:16. From the Old Testament, Lamentations 3:22-23 states “the Lord’s lovingkindnesses indeed never cease, for His compassions never fail. They are new every morning; great is Thy faithfulness.”