The prostate gland, found only in men, is situated just beneath the bladder. It envelops the urethra which continues into the penis from the bladder.
The prostate gland, along with seminal vesicle develops from the urogenital sinus. The gland is divided into biologically distinct regions, vital among them is the peripheral (PZ) and transition zone (TZ).
When looked under the microscope, one can see that the glands are surrounded by muscular and fibrous tissue. These glands are the ones which secrete the prostatic fluid. This walnut-sized gland plays an important role in keeping the sperms alive in the acidic environment of the vagina.
The prostatic fluid is alkaline; this alkaline nature of the fluid neutralises the acidic environment of the vagina so that the sperms can live longer, hence improving the chances of fertilisation. This prostatic fluid gives a milky to white colour to the semen.
The growth function of the prostate is tightly controlled by the male sex hormone, testosterone, which is produced in the testes. The prostate is generally resistant to disease conditions.
Infections and inflammations are uncommon, and a common source of infection is recurrent urinary tract infection. These conditions are challenging to diagnose as the presenting symptoms are vague such as low back pain, burning micturition (urination) and pain on touch in the suprapubic region.
It is usually treated with antibiotics.
The most common condition involving the prostate, which is seen in almost all men if they live long enough, is benign prostatic hyperplasia.
In this condition, the prostate gland starts growing excessively in response to the androgen hormone. However, the exact cause is unknown.
This enlargement of the gland, notably the TZ, which is the area immediately surrounding the urethra, leads to the symptoms of difficulty in passing urine, difficulty in starting urine, frequent urination and increased incidence of urinary bladder infections.
Treatment, most of the time, is a surgical procedure to remove the extra-growth squeezing the urethra.
The other common condition after benign prostatic hyperplasia is prostate cancer, which is the fourth highest cancer among men in Malaysia. Awareness about this cancer helps us to detect it at an early stage so that it can be treated effectively.
It is generally seen in men above 50 years, and the incidence continues to rise with age.
Like benign enlargement of the prostate, if a man lives long enough, he is most likely to get prostate cancer.
The type of prostate cancer to strike men is usually adenocarcinoma, which is a malignant lesion involving the glands present in the prostate.
Benign prostatic hyperplasia likes to develop from the PZ of the prostate while prostatic cancer, most commonly arises from the TZ.
Prostatic cancer, fortunately, is a very slow-growing cancer. Post-mortem studies have shown that people having prostatic cancer usually die of causes other than prostatic cancer.
In recent years, there has been a significant drop in prostate cancer-related deaths while the quality of life has also improved among men who have prostate cancer.
This is partly due to effective screening programmes and an increase in awareness.
In North America, the month of September is observed as the “National Prostate Health Month”. Light blue ribbon is the symbol of prostate cancer.
The causes implicated in the development of prostatic cancer include androgens, heredity, environment and acquired somatic mutations. The clinical presentation is very nonspecific and delayed. This is because as the tumour arises from the PZ, the clinical features are delayed. When the gland is enlarged, it can be felt as hard nodules on per-rectal digital examination.
As the risk factors and clinical presentation are not clear, it becomes important to have a robust screening system.
The finding of prostate-specific antigen (PSA) as a marker for both prognosis and diagnosis has greatly helped in making an early diagnosis and getting prompt treatment.
PSA and digital rectal examination are used for screening. PSA is used for both detection, and assessment of treatment and prognosis. PSA is produced by the glands present in the prostate and is mixed with the semen. It helps in breaking down of the semen after ejaculation.
Generally, values less than 4ng/ml is taken as normal, values between 5-10ng/ml are seen in benign prostatic hyperplasia. Values higher than 10ng/ml in the presence of clinical presentations is indicative of malignancy.
These recommended cut-off levels of PSA have reliably helped in the diagnosis of prostatic conditions. The drawback of PSA is that it is elevated in any conditions affecting the prostate without being specific to cancer.
Though not routinely done, screening is recommended for men between the ages of 55-69 years. If one wants to get screened, they should consult their doctor.
Routine screening for PSA leads to the survival of one in every 1,000 men screened for prostatic cancer.
After 70 years, screening is not generally recommended because it is less likely to influence the quality of life.