Recently approved by Singapore’s Health Sciences Authority (HSA), Zytiga is the first oral medication designed for advanced stage castration-resistant prostate cancer patients whose treatment does not respond well to chemotherapy. It is to be consumed once a day, without food.

Developed by Janssen, a subsidiary of Johnson & Johnson, the drug has proven itself in global clinical trials, extending participants by from four to five months on average for end stage, castration-resistant prostate cancer patients and whose treatment does not improve with chemotherapy.

34% reduction of mortality risk

Its novel mechanism of action is to halt the androgen-making process by inhibiting a key step in androgen production at three sources: the testes, the adrenal glands, and the tumour itself.

The study involved 1,195 men spanning 13 countries. Those who are on the drug also received steroid therapy along with the new pill survived for an average of 14.8 months, compared with 10.9 months for those treated with a placebo coupled with steroids. This translated into a 34% reduction in risk of dying.

Hope amidst high efficacy showings

In fact, the medication was considered so effective that those who were assigned a placebo were allowed to consume the actual medication before the conclusion of the clinical trial.

"These results, now published in a major peer-reviewed medical journal, highlight the value of earlier use of Zytiga in treating metastatic castration-resistant prostate cancer and advance our understanding of the role of its mechanism of action," said Charles J. Ryan, the study’s principal investigator and associate professor of clinical medicine at the UCSF Helen Diller Family Comprehensive Cancer Center.

In addition to a longer life expectancy, it was proven to improve patient’s quality of life in patients whose cancer has metastasised beyond the prostate gland. Not only that, patients also saw better responses in levels of prostate-specific antigen (PSA), a known marker for prostate cancer, coupled with improvements in disease-related symptoms and a slowing of the cancer’s progression.

Third most common cancer in Singaporean men

Prostate cancer is the third most common cancer and the sixth leading cause of death among Singaporean men. In prior research, it is found that Singaporean men has a 2.7% chance of developing prostate cancer during their lifetimes, and annually, 500 men in Singapore are diagnosed.

Most commonly found in aging men aged above 60, it is projected that by 2030, the risk factor would increase to a startling 20% for men older than 65 years of age.

Expressing concern for delayed treatment and its associated ill effects, Dr Sim Hong Gee, director of urologic oncology at the Singapore General Hospital said "Unfortunately, they are only coming to us at the advanced stages of prostate cancer.”

Diagnosed early, prostate cancer is often confined to the prostate gland and has a better outlook; delayed treatment would result in the metastasis of the cancer to the bones, lungs, and liver, and is often fatal.

No connection between vasectomies and prostate cancer

A review of existing research, accounting for 7,000 deaths by prostate cancer, by American Cancer Society’s epidemiologists, has found no connection between the only proven long-term birth control method for males and prostate cancer. A total of 364,000 men aged 40 and above were analysed in this survey.

As study author Eric Jacobs states, "Vasectomy is an effective and inexpensive long-term method of birth control. This new, large study provides some reassurance that vasectomy is unlikely to meaningfully increase risk of prostate cancer."

Although there are no current methods to reduce the risk of prostate cancer, the study authors emphasised the importance of early detection in mitigating the side effects of prostate cancer, and reiterated that early detection is widely associated with a better prognosis.


Read more:
Prostate cancer patients can avoid treatment, a 10-year study shows
Dr Daniel Tan: Introducing a new cure for prostate cancer to Singapore
SBRT touted as superior treatment for prostate cancer

Sources:
http://health.asiaone.com/health/health-news/new-pill-advanced-prostate-cancer-patients
http://www.investor.jnj.com/releasedetail.cfm?releaseid=726643
http://www.nejm.org/doi/full/10.1056/NEJMoa1209096
http://medicalxpress.com/news/2016-09-vasectomy-prostate-cancer.html
https://www.zytiga.com/about-zytiga/how-zytiga-works