Abstract
Prostate cancer diseases are rising in men especially African- American, although, it has not yet known whether, similar high risk rates occur among blacks living in Africa. The diagnosis of prostate cancer includes prostate specific antigen (PSA) total, PSA free, percentage PSA free, and digital rectal examination (DRE). The patients with intermediate values of PSA of 4.0ng/ml to 10.0ng/ml (30% of them could have cancer), are the groups where doctors should examine meticulously, with the objective of detecting those with prostate cancer so that we could cure them. Prostate cancer could be classified into stage and grade. Stage means the growth and spread of the cancer while, grade means aggressiveness of the disease. Early detection is the key to curative therapeutic options available for the patient. Due to improved economic and western life styles in Africa, the incidence of prostate cancer will likely increase, hence, the need for more high quality training of pathologists, and clinical laboratory scientists, entrusted with the laboratory testing and clinical evaluation of these patients is mandatory.
Key words: Prostate cancer, Silent, Killer, Man
Introduction
Prostate is a part of the male reproductive system which comprises of the penis, prostate and testicles. As man ages, the prostate tends to increase in size. The three most common prostate problems are prostatitis, enlarged prostate and prostate cancer. Prostate cancer is one of the absolutely most common cancers in the whole world, and this cancer affects men. The symptoms of prostate cancer includes; trouble in urinating, frequency to pass urine, pain or burning sensation when passing urine, hematuria (blood in the urine), painful ejaculation and constant pains in the back or hips. Although, most of the prostate cancer cases, at the early stage have no sign at all, that is the reason why it is also branded a silent killer.
Epidemiology
Currently, the American cancer society reported that in every 19 minutes an American dies from prostate cancer, this is a little more than 75 deaths per day. The United States cancer statistics working group reported 177,487 new cases of prostate cancer in 2012 with 27,244 deaths from the disease. In 2015, the case projected dramatically, with 220,800 new prostate cancer cases with 27,540 deaths been recorded so far. About 2.8million Americans are currently living with prostate cancer. However, the overall mortality rate is 49% for the African- American black descendants. The American cancer society further stated that 56% of prostate cancer cases are diagnosed in men of about 65 years old, whereas, 97% of all cases are pointed to men below 50 years and older.
In Nigeria, the most populous black race in history, the research bearing scientists revealed that prostate cancer was 13.3% among men with intermediate PSA values of 4.0ng/ml to 10.0ng/ml detected by prostate biopsy. A similar research work reported an incidence of 127 prostate cancer cases in every 100,000 men. Other recent workers believed that it is the commonest cancer among Nigerian men. In a recent genetic survey of African-American blacks in the USA, half of the blacks tested were traced genetically to Nigerian and Jamaican descendants respectively. Still in Nigeria, the controversies over benefit from early intervention rages on, some experts are holding the Federal ministry of health responsible for lack of an organized structure for screening program for prostate cancer. The management of this disease, in Nigeria, is unfortunately very challenging as most cases are at the advanced stage, and the prognosis is poor. Nigerian men, however, continue to have high propensity for prostate cancer, so there is an urgent need on the part of the federal government to put an organized system to evaluate how prevalent the disease is, and solution for better laboratory and medical intervention.
Diagnosis
The diagnosis starts by visiting your doctor for clinical evaluation, and then to the medical laboratory scientist to have your PSA blood test performed by the scientist on duty. A medical doctor with a specialty in urology, called urologist is preferable in evaluating prostate cancer disease. Prostate cancer is measured mostly by PSA, and, PSA is an enzyme that leaks out from the prostate in both prostate cancer disease and in normal prostate. The United States Food and drug administration (FDA) has approved the use of PSA test along with digital rectal examination (DRE) to help in early diagnosis and monitoring of prostate cancer. DRE is a very simple test done by your doctor, preferably, Urologist, by inserting a gloved lubricated finger into the rectum to estimate the size of the prostate and check for firmness, hardness, lumps or growth, spreading beyond the prostate and or any pain caused by touching or gently pressing the prostate. The test lasts for few seconds.
PSA is a very good test and the best test we have in clinical laboratories up to date for prostate cancer diagnosis. PSA is a gamma-seminoprotein analyzed by the radioimmuno assay, immunoradiometric assay and immunoenzymatic determination, a field that is haven for medical laboratory scientist with clinical chemistry specialty. Interpreting PSA results in a clinical setting, could be a puzzle for inexperienced doctor or health professional. PSA values of 0 to 2.5ng/ml is considered safe, also, PSA level of 2.6ng/ml to 4.0ng/ml is considered safe but, all medical laboratory results must be evaluated by the doctor. PSA values of 4.0ng/ml to 10.0ng/ml are suspicious, and medical doctors must critically examine the patients with an objective of true diagnosis and treatment. PSA levels of 10.0ng/ml and above is dangerous. What is the scientific postulation here? This indicates that in a patient of PSA values of 3.0ng/ml and 10.0ng/ml, 30% have prostate cancer, while 70% do not have prostate cancer at all. Well, what do these 70% have? They have an enlargement of the prostate called benign prostate hyperplasia or hypertrophy. A large prostate produces more PSA than small one. Other conditions where PSA levels are slightly increased are urinary tract infection (UTI), inflammation, and PSA slightly increases with age of the patient. When PSA is slightly increased, a doctor must be consulted to rule out other possible causes of this result. Medical Laboratory scientist could make the sensitivity and specificity of the test better in patients having slight increase in PSA. How? The scientist could group his PSA tests to include; PSA total, PSA free, and free PSA percentage.
The percentage free PSA is the level of enzyme PSA that travels around in the blood stream in the body not bound to any protein. The normal limit of percent free PSA is around 18%, so, above 18% is good. Medical laboratory scientist could also correlate his PSA findings to the size of the prostate and this is referred to as PSA density. The prostate, then has to be measured using ultrasonography. The scientist could also correlate the increase of PSA Level in time. This is referred to as PSA velocity. For instance, If PSA doubles in a year, oh, it is really alarming, but if PSA doubles in 10 years, that is really calming down. So, it is important to do PSA tests on a yearly basis for men as from 40 years and older. The PSA results could be interpreted in this way; If both total PSA and free PSA are higher than normal value, that is high percentage free PSA, this suggests Benign Prostate hypertrophy (BPH) rather than Cancer. If total PSA is high, but free PSA is not, that is low percentage of free PSA, cancer is more likely. Biopsy could be done by the pathologist or experienced medical laboratory scientist with histopathology specialty. A positive biopsy means that prostate cancer is definitively present, after extensive examination of Hematoxylin and Eosin (H&E) smear, and other histopathological stains. However, once a definitive diagnosis is made, all prostate cancer patients are classified according to the stage and grade of the cancer. Stage means the growth of the cancer, and spread of the cancer (metastasis of the cancer). Grade means aggressiveness of the cancer. Patients having a slight increase in PSA and a prostate cancer usually have T1 cancer. This means that the cancer is in the prostate, but you cannot feel it, cannot see it, and cannot palpate it. It is only seen by PSA test and biopsy. The patient that has PSA levels of 10.0ng/ml to 20.0ng/ml has T2 cancer. At this stage you can palpate it, but only within the prostate.
The patients with PSA levels above 20.0ng/ml, the cancer is a little more extensive, it has grown through the capsules, and it is palpable on the surface of the prostate. This is called T3 prostate cancer. Patients with PSA values over 50.0ng/ml usually have T4 prostate cancer. This means that, there is a cancer of the prostate but, it has grown over on other organs especially the rectum. It is very difficult to cure a patient with T3 and T4 prostate cancer than T1 and T2 prostate cancer. The risk of metastasis in patients with PSA levels between 3.0ng/ml and 10.0ng/ml is almost zero. Patients having between 10.0ng/ml and 20.0ng/ml usually do not have prostate cancer metastasis but, some really do. Patients having PSA level of 20.0ng/ml, and above have prostate cancer metastasis to a degree that urologist really have to look critically for it, in order to cure such patients. Patients with PSA levels 50.0ng/ml and above often have metastasis and cannot be absolutely cured.
The aggressiveness of the cancer is measured using Gleason score method, it is scored from 1 to 10, and in order to find out the aggressiveness, the higher the number, the worse aggressive the cancer becomes. So, the grades can be anywhere from slightly aggressive to very aggressive malignancies in all the different PSA levels.
Treatment
Prostate cancer can be treated if detected early with great efficacy. There is curative and palliative therapy among other methods, available to your doctor (urologist) to treat prostate cancer efficiently and effectively. Urologists can both operate and perform surgical radical prostatectomy. Radical prostatectomy is the total removal of the prostate, and this could be done with either open technique or laparoscopic technique. The laparoscopic technique can either be done with traditional method or with robotic assisted laparoscopic prostatectomy. Well, if surgery is not decided, then radical radiotherapy can also cure a patient with prostate cancer. Radical radiotherapy to the cancer, is given either through external radiotherapy from the outside of the body to the inside or through brachy technique. This is local radiotherapy inside the prostate directly on the cancer itself. Patients who opted, or cannot be cured may adopt palliative treatment where the size of the cancer may be reduced, and cancer activity may shrink away in the process, while patients live a normal life style.
Another method is by hormonal manipulation. Prostate cancer loves testosterone- a hormone in man responsible for libido and sexual activity. Testosterone is just like food for the prostate cancer itself, and if we remove testosterone completely, the prostate cancer stops its active growth. The easiest way possible is to remove the testicles. This is called ablatio testis or bilateral orchidectomy. It will look as if a man is castrated and his manhood is no more, so his sexual life style is gone, this cannot be taken lightly by normal sexual active men. It is due to issues pertaining to manhood that made scientists to discover other means of hormonal application to prostate cancer treatment. Now, the action of testosterone could be blocked directly or inside cancer cells by the use of anti-androgen. Anti-androgens are common today and the block receptors so that patients still have testosterone moving around in the body, making the man feel a little more like a man than if the testosterone is totally gone. So, anti-androgen is a good option.
Conclusion
Early detection is necessary for the cure of prostate cancer.
Men as from 40 years and older, are advised to visit the urologist and Medical Laboratory Scientist, at least once in a year for check up tests of PSA.
The laboratory test of PSA must include; Total PSA, Free PSA and percentage free PSA.
Patients with suspicious PSA values must be referred to the qualified Urologist without delay.
The combination of PSA levels, digital rectal examination, necessary biopsy studies, stage and grade, Gleason score, age and general health condition of the patient in an early diagnosis, a total cure of the prostate cancer is possible.
References
Abbyesiku F M et al (2000): Prostate specific antigen in Nigerian- African. Afr Med Sci 29 (2): 97- 100.
American cancer Society (2015): Prostate cancer. 250 williams str. Nw Atlanta, Georgia, 30303.
Balk S P, Koy J & Bubley G J (2003): Biology of prostate specific antigen. J clin Oncol 21 (2): 383-391.
Catalona W J et al (1994): Comparison of digital rectal examination and serum PSA in early detection of prostate cancer: results of a multicenter clinical trial of 6,630 men. J Urol 151:1283-1290.
Center for Disease Control (CDC) and prevention 2013: Prostate cancer. 1600 Clifton Rd Atlanta, USA
Chu W. Lisa et al (2011): Prostate cancer incidence rates in African. Prostate cancer. Vol 2011 (947870):6
Cooner W H et al (1990): Prostate cancer detection in a clinical urological practice by ultrasonography, digital rectal examination and prostate specific antigen. J Urol 143: 1146-1148.
Eke N & Sappira M K (2002): Prostate cancer in Port Harcourt, Nigeria: Features and outcome. Nig J Surg Res. 4:34-44.
Ezenwa E, Tijani K, Jeje A, Ogunjimi A, Ojewola R (2012): Prevalence of prostate cancer among Nigerians with intermediate total prostate specific antigen level (4.0ng/ml to 10.0ng/ml): Experience at Lagos University teaching Hospital, Nigeria. The internet Journal of Urology Vol 9 (3)
Ezenwa E. V. et al (2012): The values of percentage free PSA in detection of prostate cancer among patients with intermediate levels of PSA in Nigeria. Arab Journal of Urology vol 10 (4):394-400.
Lehmann Craig (1998): Measuring PSA and clinical implications. Saunders manual of clinical laboratory science. WB Saunders Company: 81-280.
National cancer institute (2015): Prostate cancer. USA. Gov
Ogunbiyi J O & Shittu O B (1999): Increased incidence of prostate cancer in Nigerians. J Natl Med Assoc. 91: 159-164.
Parkin D M et al (1999): Estimates of the worldwide incidence of 25 major cancers. Int J Cancer 80: 827.
Philips D Mayne et al (1998): Prostate carcinoma. Clinical chemistry in diagnosis and treatment 6th edn ELST with Arnold: 347-424.
Prostate cancer in Nigeria (1997): Facts and non- facts. J Urolo 157(4):1340-1343.
Ukoli F, Osime U, Akereyeni F et al (2003): Prevalence of elevated serum prostate specific antigen in rural Nigeria. Intern J Urol 10:315-322.
United States of America cancer statistics working group (2015): United States cancer statistics: 1999- 2012. Incidence and mortality web based report, Atlanta. Dept. of Health and Human Services.
ZERO (2015): The end of prostate cancer. 515 king str, suite 420, Alexandria, VA 22314.
Autor:
Dr. Peter Ubah Okeke,
Ph.D, AMLSCN (Nig)
Laboratory & Health scientist
Ministry of Health, Cape Verde.