Obesity, alcohol and ancestry play a role

Prostate cancer is the most common cancer in Bahamian men. Present statistics show that one in six men will develop prostate cancer in their lifetime.

The prostate gland is a walnut-sized organ located underneath the bladder and its primary role is related to male fertility and aiding the sperm to fertilize the ovum.

Many Bahamian men are at a greater risk of developing prostate cancer due to their racial profile, genetics, overall high obesity rate and high alcohol intake.

Studies have shown that men who drank at least seven drinks per week between ages 15 to 49 years had a more than three-fold greater likelihood for developing high-grade prostate cancer than men who did not drink.

Bahamian men who are obese or overweight put themselves at a greater risk of developing a more aggressive form of prostate cancer. A study from Norway, that followed 950,000 men for an average of 21 years, found that a body mass index (BMI) of greater than 30 kg/m 2 increased the risk of prostate cancer by nine percent. However, obese men aged 50 to 59 years at study completion had a 58 percent increased risk of prostate cancer; no other age group had such a statistically significant increased risk.

African ancestry is in itself a high risk factor for developing prostate cancer.

African American men are two to three times as likely to develop prostate cancer than their Caucasian counterparts, and more than twice as likely to die from prostate cancer and more likely to develop prostate cancer at an earlier age than their other racial counterparts. Men of Indian, Hispanic and Asian ancestries also have a lower risk profile for prostate cancer than men of African ancestry.

There is insufficient evidence to determine whether men of mixed race with a single African descended parent have the same risk profile of men with two parents of African ancestry.

But multiple British and French studies have shown that men of Afro-Caribbean and African Ancestries have a higher incidence of prostate cancer, a higher likelihood of an aggressive variant of prostate cancer, and a worse prognosis when diagnosed with both early and advanced prostate cancer than other men of other racial backgrounds.

The exact reason behind African descended men having all these greater risks related to prostate cancer is currently being extensively scientifically studied, but it is likely due to multiple contributing causes and not just one. Economic, social, environmental and cultural factors certainly play some role, but it is strongly believed that the disparity in prostate cancer amongst African male descendants is related to genetics.

Many Bahamian men are at a greater risk of developing prostate cancer due to their racial profile, genetics, overall high obesity rate and high alcohol intake.

There is a known strong link between the BRCA 1 gene mutation and more aggressive forms of prostate cancer. This BRCA 1 gene mutation is disproportionately prevalent in the Bahamian population, leading to a higher incidence of breast cancer and a more aggressive form of breast cancer in Bahamian women and, though to a much less extent, in Bahamian men.

Germline mutations in BRCA 1/2 and HOXB13 gene’s have been shown to have an increased associated risk in developing prostate cancer.

The disparity of prostate cancer in African ancestry men compared to other racial ancestry men is nothing new but previously prostate cancer research has been based on men of European ancestry.

The University of Southern California Keck School of Medicine researchers are leading the charge into investigating the variables between men of African ancestry and prostate cancer. This research group has a $26.5 million grant to extensively study prostate cancer in Black men. The study is actively recruiting ten thousand African American men who have recently been diagnosed with prostate cancer.

The Keck School of Medicine researchers aim to gain insight into the genetic nature of aggressive prostate cancer and how genetic variants might interact with environmental and social factors in African American men who develop prostate cancer.

Men of African and Afro-Caribbean ancestry who are diagnosed based on prostate biopsies as having the earliest pathological stage of prostate cancer have a worse prognosis than their Caucasian male counterparts who are diagnosed with the exact same pathological prostate cancer stage.

African ancestry men have a one in three chance of being understaged with prostate biopsies, therefore a low pathological prostate cancer score is actually higher in about 33 percent of such cases. One of the reasons for this understaging of prostate cancer is the anatomical location of the prostate cancer. Prostate cancer often does not have a uniform distribution within the prostate gland in terms of the pathological stage so that a low pathological stage might be biopsied but a higher pathological stage of prostate cancer can be missed elsewhere in the prostate.

Many men of African descent have prostate cancer in the apical area of the prostate and this area is more difficult to biopsy, particularly in men with very large prostates. This apical area of the prostate often harbours a more advanced prostate cancer and therefore can be under evaluated in routine prostate biopsies.

This understaging of prostate cancer during biopsies can be limited by the use of magnetic resonance imaging (MRI) of the prostate gland with special computer software that allows an urologist to fuse the MRI prostate images with the ultrasound and in real time do prostate biopsies that are directed at any suspicious lesions determined on the MRI.

The risk of understaging prostate cancer or missing prostate cancer lesions on ultrasound guided 12 core prostate biopsies, is significantly reduced with the use of this MRI/Ultrasound fused technology.

Early prostate cancer, most commonly, has no symptoms. The cause of most middle aged men having urinary symptoms is more likely due to noncancerous benign prostate hyperplasia (BPH) than prostate cancer. Many men who have prostate cancer, have no symptoms until the prostate cancer is advanced and beyond the scope of cure.

Early diagnosis of prostate cancer has a 98 percent five year survival rate, even in men of African ancestry.

Therefore men of African ancestry older than 40 years old should definitely have an annual prostate specific antigen [PSA] blood test. Further PSA blood tests can be requested if necessary such as the PSA free to total ratio and the PSA density or PSA velocity may be calculated. The PSA blood test result can be elevated for reasons other than prostate cancer, such as an infection of the prostate, prostatitis or a very large benign prostate, and incomplete emptying of the bladder.

It must be emphasised that a large number of Bahamian men unfortunately have a very high risk for prostate cancer and they also have increased risk of developing a more aggressive form of prostate cancer and at an earlier age than their other racial counterparts.

Fortunately, early detection of prostate cancer has an excellent cure rate. Confirmed low-volume, low-grade prostate cancer can be actively surveilled if all the criteria are met. Active surveillance involves monitoring a patient until the prostate cancer upstages in volume or stage, then curative treatment can be employed.

Prostate cancer curative management does not always necessitate surgery. Surgery is an option, as is brachytherapy. Brachytherapy involves placement of radioactive seeds into the prostate minimally invasively, whereby the prostate cancer cells are killed but the normal prostate cells and gland are left intact. Brachytherapy has the same or greater cure rate for low risk prostate cancer, when compared to radical prostate cancer surgery.

External beam radiation is another curvature management option for prostate cancer. High intensity focused ultrasound (HIFU) is also a prostate cancer curative option.

Advanced prostate cancer could potentially lead to a prolonged painful death that may result in kidney failure, painful spread of prostate cancer to bones, paraplegia from spinal cord compression, secondary to prostate cancer metastasis and many other devastating complications.

The emotional, physical and financial toll of advanced prostate cancer can be profound. Patients and their families suffer together.

The key to a cure: early detection.

Seek the confidential and compassionate consult of an urologist and start annual routine PSA blood tests at the age of 40 years old.

Written by Dr. Greggory Pinto
Urology Care Bahamas
Published in The Tribune: August 20, 2019