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New Immunotherapy May Benefit Black Men With Prostate Cancer

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Dr Greggory Pinto

By Dr Greggory Pinto

The prostate is a walnut-sized gland that lies underneath the bladder in men and it plays an important role in providing nutrients for sperm and optimising the environment for sperm trying to reach and fertilize the female's ovum. The only role that the prostate gland has is in male fertility.

The main risks factors for getting prostate cancer are advancing age, obesity, genetic changes, first degree relatives being previously diagnosed with prostate cancer and being of African ancestry.

African ancestry men are at high risk for prostate cancer

Men of African ancestry unfortunately collectively face a higher risk of developing a more aggressive form of prostate cancer than men of other racial backgrounds. They also have a much higher incidence of prostate cancer.

In the United Kingdom, one in four black men will develop prostate cancer in their lifetime. One in eight Caucasian men in the UK will get prostate cancer.

One in five African American men will be afflicted with prostate cancer.

Black men also tend to get prostate cancer three to six years earlier than other racial counterparts.

Immunotherapy for prostate cancer

Genetics play a role in prostate cancer; particularly in the case of black men.

Recent groundbreaking new research at Northwestern University has determined that black men may have an improved outcome when facing prostate cancer when immunotherapy treatments are used in conjunction with other management modalities.

Immunotherapy involves stimulating the natural immune system to fight prostate cancer.

The Northwestern University study was published on February 10, 2020 in the scientific journal Nature Communications.

The study involved analysing the genomics of 1,300 prostate cancer tumor specimens from prostate cancer patients who self identified their racial background.

The US-based study found that African American men have a higher proportion of plasma immune cells on their prostate cancer tumours than Caucasian men.

Many Black men have a type of cell on their prostate cancer cells that can be targeted by immunotherapy, which could significantly improve their survival from prostate cancer.

The plasma cells are protective in nature and can be directed by immunotherapy to attack prostate cancer tumours. Increasing the number of plasma cells was shown to increase the survival rate in black men following prostate cancer curative surgery.

The larger the number of plasma cells that a man has on his prostate cancer tumour, the better his survival rate from prostate cancer.

Immunotherapy can also be used to fight prostate cancer that has become resistant to other forms of treatment.

Immunotherapy treatment for prostate cancer involves taking blood from a prostate cancer patient and through a process called plasmapheresis, the patient's white blood cells are isolated. These white cells are exposed to and trained to fight prostate cancer then, these prostate cancer-fighting white cells are placed back into the patient. The available US Food and Drug Administration approved immunotherapy drug is Provenge, sipuleucel-T.

The very promising studies showing immunotherapy having prostate cancer specific survival benefits particularly in black men is a wonderful positive finding. Black men have been plagued with higher incidences of prostate cancer and more aggressive forms of prostate cancer than any other race. Black men are twice as likely to be diagnosed with prostate cancer than Caucasian, Asian and Hispanic men. Black men generally have worse survival outcomes when diagnosed with prostate cancer. Socioeconomic factors and a possible distrust or fear of the medical system could all play a role in worse prognosis for many black men diagnosed with prostate cancer.

BRCA gene mutations and prostate cancer

What does prostate cancer have in common with breast cancer?

The answer is the BRCA 1 and 2 gene mutations. The BRCA 1 and 2 genes were first discovered in 1994.

BRCA stands for breast cancer associated gene. Women with the inherited BRCA 1 or BRCA 2 gene mutations are at higher risk of developing breast cancer, ovarian cancer, colon/rectal cancer and pancreatic cancer in their lifetimes.

This BRCA 1 and 2 gene mutations or faults aren’t just an increased cancer risk for women.

Men can also inherit BRCA gene mutations, which puts them at risk for not just breast cancer, colon/rectal cancer, melanomas and pancreatic cancer, but also prostate cancer.

Every human, men and women have BRCA 1 and BRCA 2 genes. BRCA genes do not cause breast cancer or prostate cancer or any other cancers.

In fact, BRCA genes play a role in preventing breast cancer and BRCA 2 gene has an important role in preventing prostate cancer. These genes help repair DNA breaks that could potentially lead to cancer formation; they are tumor suppressor genes.

In certain individuals, these BRCA tumor suppressor genes have mutations and do not function properly in their important role in suppressing or preventing cancer formation.

When a BRCA 2 gene is mutated, it is not effective at repairing broken DNA, in helping to prevent prostate cancer, breast cancer and certain other cancers.

Every cell in our body contains DNA and this DNA is continually damaged by various factors.

The cells in our body undergo a daily cycle of DNA damage and repair. The repair mechanisms are controlled by genes such as the BRCA 1 and 2 genes.

BRCA 2 genes play a far more important role in preventing prostate cancer in men than the BRCA 1 genes. The BRCA 2 gene mutation is associated with 8.6-fold increased risk of developing prostate cancer in a lifetime and the BRCA 1 gene mutation related 3.9 fold increased risk of developing prostate cancer.

Men with the BRCA 2 gene mutation are also 8 times more likely to develop breast cancer before the age of 80 than men without this gene mutation.

It is estimated that one in eight women will develop breast cancer in their lifetime. Approximately 55 percent to 65 percent of women with the BRCA 1 gene mutation will develop breast cancer by the age of 70 years old.

BRCA 1 gene mutations can also lead to a more aggressive form of breast cancer.

An estimated one in 300 Caucasian American men have the BRCA 2 gene mutation. Some studies have determined that the incidence of BRCA 2 mutations in African American men is approximately one in one hundred.

Persons of Ashkenazi Jewish ancestry have a one in 40 incidence of BRCA 2 gene mutations.

Men with the BRCA 2 gene mutation are eight times more likely to be diagnosed with prostate cancer and at a younger age, 61 years old age versus an average age of 64 years old for men without the BRCA 2 gene mutation. The BRCA 2 gene mutation can also double the risk of developing a more aggressive form of prostate cancer.

In the Bahamian population, there is a disproportionately high number of BRCA 1 and BRCA 2 gene mutations in both men and women and unfortunately this results in large numbers of women being diagnosed in the Bahamas with an aggressive form of breast cancer at an earlier age and Bahamian men being diagnosed with aggressive forms of prostate cancer at earlier ages than men without the BRCA 2 gene mutation.

Obesity and prostate cancer

There is compelling evidence that obesity in men is linked to a higher incidence of a more aggressive form of prostate cancer. There is also a strong correlation between obesity and the spread of prostate cancer.

Obesity doesn't necessarily cause prostate cancer but it can make survival from prostate cancer more difficult.

The key to cure for prostate cancer is early diagnosis. Prostate cancer often has no symptoms when at an early stage.

Men in the Bahamas are at a high risk for prostate cancer and they should have at a minimum, an annual prostate specific antigen (PSA) blood tests every single year starting at the age of 40 years old.

• Dr Greggory Pinto is a board-certified Bahamian urologist and laparoscopic surgeon. He can be contacted at OakTree Medical Center, #2 Fifth Terrace & Mount Royal Avenue, Nassau, or by calling (242) 322-1145-7.

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