Prostate cancer is now the most frequently diagnosed cancer among men over the age of 50, in both developed and developing countries. After lung cancer, it is the second most common cause of cancer-related deaths in men. It has been estimated that about 30 percent (1 in 3) of the men in the West are at the risk of developing microscopic prostate cancer. However, since it is a slow growing cancer just about 10 percent (1 in 10) will develop clinical disease; “a stage in the history of a pathologic condition that begins with anatomic or physiologic changes that are sufficient to produce recognisable signs and symptoms of a disease.” The lifetime risk of dying from prostate cancer is about 3 percent.
The worldwide diagnosis of clinically significant prostate cancer has been increasing for the last few decades, but, of late, it has reached a plateau. As it is mainly a disease affecting men above and around the age of 50 and with an increasing ageing population, it is expected that the number of deaths related to prostate cancer will rise significantly.
Despite a high prevalence of prostate cancer, unfortunately, very little is known about its causes and risk factors. There are, however, a few established factors among which the topmost is the patient’s ‘age’.
Clinical disease is relatively rare below the age of 50 years and the risk rises significantly above 60 years of age. Microscopic foci of prostate cancer are present in 30 percent of the men in their 50s, but increases to almost 70 percent around 80 years of age.
‘Race’ is another etiological factor for prostate cancer. There are marked ethnic and geographical variations in the incidence of prostate cancer. This disease has its incidence in North America and Western Europe. The lowest incidence is in the Far East. Its prevalence among the African American is the highest and lowest in the Chinese and Japanese races. Ethnic races from the Indo-Pak subcontinent show an intermediate risk.
Latent disease, however, reveals the same incidence among all races. It is noted among migration studies that the incidence of prostate cancer among men migrating from low to high risk areas increases to that of the local population within two generations. There is a definite hereditary link to the prostate cancer, with a two to three fold increase in its risk in men with first degree relatives (father or brother) diagnosed with prostate cancer.
Moreover, this risk increases further if more than one first degree relatives have the disease. Around 9 percent of prostate cancer is thought to have a genetic link. A couple of genes associated with prostate cancer have now been identified and more are under investigation. There is a strong linkage of the male hormone testosterone and its active metabolite dihydrotestosterone with prostate development, and also is implicated in both benign prostate disease and prostate cancer. Then there is a correlation between prostate cancer and unsaturated fats and red meat consumption.
On the other hand, Vitamin E, selenium and tomatoes seem to have a protective effect. Various environmental factors related to the industrial chemicals have been identified as potential promoters of prostate cancer. It is suggested that men working in the nuclear power industry and those exposed to cadmium have an increased risk of prostate cancer. Lastly, it is also thought that men exposed to low levels of ultraviolet light may be prone to develop it.
The presentation of prostate cancer can vary significantly and can range from mainly asymptomatic to symptoms of outflow obstruction or severe effects of metastatic and widespread disease. As men age, the risk of prostatic symptoms increases from around one in seven for men in their 40s to around one in two for men in their 70s. It is impossible to differentiate between symptoms secondary to benign disease from prostate cancer. The main reason for this is that in both cases, the prostate increases in size leading to symptoms. These symptoms mainly present themselves as increased urinary frequency during the day as well as the night.
On micturition (the process of discharging waste matter), significant straining may be required and there is a delay in getting started. Thereafter, the stream may be weak with terminal dribbling. The urinary stream may also stop and start. Many patients feel that they are not emptying their bladders and feel the desire to go back to the toilet soon after passing urine.
A significant proportion of men with prostate symptoms complain of urgency (strong desire to pass urine), which on occasions may be associated with urinary incontinence. When prostate cancer spreads outside the prostate but remains local, then, in addition to the above symptoms, a few other complaints can arise. These can be haematuria (blood in the urine), burning on micturition, lower abdominal pain or discomfort, urinary incontinence or even impotence.
When the disease spreads a bit further away from the prostate, then it can cause obstruction to the drainage of urine from the kidneys, leading to loin pain and symptoms of renal failure. In addition, it can present with blood within the semen. On distant spread of disease, serious events like bone fractures, loss of weight, low haemoglobin and spinal cord compression leading to severe neurological symptoms can occur.
Prostate cancer can be investigated with fairly simple tests. A blood test named PSA (prostate specific antigen) can raise the suspicion of disease, which then can be confirmed by further investigations like prostate biopsies. Once the disease has been diagnosed, it needs to be assessed further by radiological scans like MRI (magnetic resonance imaging), CT (computerised tomography) and radio-isotope bone scans.
Prostate cancer is a disease that can be cured completely if caught in its early stages when it is confined to the prostate leading to an almost normal lifespan. There are, both, surgical and non-surgical treatment options available. It is treatable even when it has spread distant from the prostate, but cannot be cured. It is generally thought the survival of prostate cancer once spread is limited to around three years.
Around the world, millions of dollars are being spent in research related to the diagnosis and treatment of prostate cancer. It has now been recommended both by the American Urological Association (AUA) and the European Organisation for Research and Treatment of Cancer (EORTC) for men around and above the age of 50 years to have an annual PSA check. This blood test should be performed even earlier when there is a family history of prostate cancer, especially among first degree relatives.
The PSA test needs to be assessed and evaluated very carefully to minimise the risk of false suspicion of prostate cancer. Given the lack of specific symptoms of this disease, it is important to seek advice from a properly-trained urologist at an early stage so that the disease can be diagnosed and cured without any significant complications and have annual PSA check for men around 50 years of age and above.
The writer is FRCS(Ed), M.Med.Sci(Gl), FRCS in UROLOGY(UK), and fellow of the European Board of Urology. Email: firstname.lastname@example.org