Prostate Cancer Landscape in Singapore: In Conversation with Dr. Edmund Chiong

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Dr. Edmund Chiong

In July, Singapore played host to the 14th Urological Association of Asia Congress 2016, themed “Urological Advancement in Asia”. In this session, two key scientists namely Professor Kurt Miller from the Department of Urology, Charité Berlin, Berlin, Germany and Associate Professor Edmund Chiong, President of the Singapore Urological Association (SUA) and Senior Consultant Urologist at NUH provided insights about a recent clinical drug trial and the prostate cancer landscape in Singapore respectively.

In an interview with Biotechin.Asia, Dr. Edmund Chiong spoke in detail about the current landscape of prostate cancer in Singapore, the treatment modalities, treatment options available etc.

Can you provide us with some insights on the prostate cancer landscape in Singapore. How can these insights help shape the treatment of prostate cancer?

According to the Singapore Cancer Registry, prostate cancer is the third most common cancer among Singaporean men. It is also the sixth most common cancer that causes death amongst Singaporean men. There has been more awareness over the years on the detection of prostate cancer, which could partly explain why there has been an increasing incidence rate observed.

Despite the fact that we have seen a steep increase in prostate cancer being diagnosed at earlier stages, especially in the last 2 decades, nearly 30 per cent of all the prostate cancer cases among Singapore males were found to be in Stage IV or advanced prostate cancer1. Hence, having proper understanding of the disease will benefit men who are at risk.

Diagram_showing_prostate_cancer_pressing_on_the_urethra_CRUK_182.svg

A diagram of prostate cancer pressing on the urethra, which can cause symptoms Credit: Cancer Research UK, Wikimedia Commons

Which demographic or percentage of population are likely to be diagnosed with prostate cancer?

Prostate cancer is the third most common cancer found in Singaporean men with 3,705 new cases of prostate cancer being diagnosed from the period of 2010 – 20141. This cancer usually occurs after the age of 50 years and is seen more commonly in those over 70 years of age.

  • It is also the sixth most common cancer causing death amongst Singaporean men
  • The third most common cancer found in Chinese Singaporean men after lung and colo-rectal cancer
  • The fourth most common cancer found in Malay Singaporean men after lung and colo-rectal cancer and lymphoid neoplasms
  • The second most common cancer found in Indian Singaporean men after colo-rectal cancer

What were some of the key takeaways from the 14th Urological Association of Asia Congress 2016?

There are a number of advances in the field of prostate cancer management, including newer imaging modalities to better detect prostate cancer. Many modalities of treatment are now available as options for both localised & metastatic prostate cancer compared to 10 years ago, and many other therapies are in exciting stages of development. There is also an increasing emphasis and investigation on the use of personalised medicine in the management of prostate cancer patients.

On the sidelines of the urological conference, I also presented at a media briefing, local data on the prostate cancer landscape in Singapore. As a healthcare practitioner, we often receive questions on survival duration from patients with cancer. Whilst aiming to prolong survival time for patients with advanced cancer is important, management strategies that involve maintaining quality of life and delaying symptoms progression of the cancer also form integral parts of holistic cancer care.

What was the highlight of Prof Kurt Miller’s findings?

Professor Kurt Miller highlighted new data derived from a post-hoc analysis of the Phase 3 COU-AA-302 trial, on the use of abiraterone acetate plus prednisone in men with early and less aggressive advanced castration-resistant prostate cancer. Results showed that abiraterone acetate plus prednisone provided patients with greater survival benefit compared to an active control of placebo plus prednisone.

There were two patient groups under the COU-AA-302 trial, which were compared to an active control of placebo plus prednisone. Group 1 were patients diagnosed with earlier, less advanced and less symptomatic stage of advanced prostate cancer, while Group 2 were patients diagnosed with later, more advanced and more symptomatic stage of advanced prostate cancer

Data from the post-hoc analysis showed that abiraterone acetate plus prednisone demonstrated a significant 11.8 months median life extension (53.6 months vs 41.8 months) when treated in Group 1 patients with early and less aggressive disease. This is in comparison to 4.4 months shown in the final analysis of the COU-AA-302 trial (34.7 months abiraterone acetate plus prednisone vs 30.3 months placebo plus prednisone)

The new data also demonstrates that first and early use of abiraterone acetate plus prednisone may lead to an improvement in a patient’s overall quality of life and may delay the need for additional, more invasive treatment.

What are some preventative measures one can take to prevent prostate cancer?

There are currently no proven prevention strategies. In general, living a healthy lifestyle, eating a well-balanced diet with less animal fat consumption, maintaining a healthy body weight and regular exercise might help mitigate the risk. However, again, there are no conclusive studies to prove that prostate cancer can be prevented.

Some studies have also suggested that diet rich in lycopenes (eg. tomatoes) and isoflavonoids (eg. soy products) may reduce the risk of prostate cancer, but researchers are yet to be certain that these compounds can really affect prostate cancer development. If you notice symptoms, consult a doctor at the earliest opportunity.

Symptoms may include frequent urination, painful urination, increased urination at night, blood in the urine, and difficulty starting and maintaining a steady flow of urine, but these symptoms are not specific to prostate cancer.

What is a reliable platform to turn to if one requires further information on prostate cancer? Who will be the best person to approach?

Possible avenues of further information on prostate cancer could include the Singapore Cancer Society or the Singapore Urological Association.

Has there been a cure for metastatic prostate cancer at this point in time?

There has been no known cure for metastatic prostate cancer at this point in time but there have been advancements made in the way this disease is treated. Novel therapies for metastatic castration-resistant prostate cancer (mCRPC) have emerged in the last few years, including immunotherapy, hormonal therapies, chemotherapeutics, radio-pharmaceutics etc., many of which have shown survival benefit in phase 3 studies. These have provided physicians with more options to develop treatment pathways for this group of patients.

What is the most suitable treatment available at present for someone who has been diagnosed with prostate cancer?

Current options available for treating early stage clinically localized prostate cancer include expectant management (such as active surveillance and watchful waiting), radical prostatectomy, radiation therapy and energy ablative therapy. Surgery’s (Radical prostatectomy) long term efficacy as a therapeutic modality is well established. Radiation therapy is also another commonly used modality.

Each modality has its own benefits and risks of side effects, and there is no high level evidence showing superiority of one modality over the other. Active surveillance is now becoming more accepted as an option to manage low risk early disease. Energy ablative therapies (such as cryotherapy and high intensity focused ultrasound) are relatively newer and yet to be fully established as standard treatment. The latter 2 modalities may offer better quality of life and possibly fewer side effects.

However, as there is no single ‘best’ option for all men with localized prostate cancer, management should be individualized. Some considerations before treatment recommendations can be made include patient’s life expectancy, overall health, risk-benefit ratio of treatment, disease risks, quality of life issues and patients’ expectations.

For advanced metastatic disease, Androgen Deprivation Therapy (ADT) or hormonal therapy to reduce blood levels of testosterone to castrate level, is the mainstay of treatment. Newer reports suggest that the addition of chemotherapy to ADT early in the diagnosis of metastatic disease, may improve survival in select men with high volume cancers.

There has also been an increase in the number of treatment options for men with advanced prostate cancer who progress while on treatment with ADT (metastatic castrate resistant prostate cancer), in recent years.

The options include chemotherapy, immunotherapy, abiraterone Acetate, Enzalutamide and Radium-223, all of which have been shown to improve survival in phase 3 studies. The selection of these agents for treatment should also be individualized between the treating physician and the patient.

Any message for our readers on prostate cancer awareness?

There are currently many effective modalities of treatment for both localised and advanced prostate cancer, and the selection of these treatment options should be individualized between the treating physician and patient.

[1] National Registry of Diseases Office (NRDO). Singapore Cancer Registry. Annual Registry Report. Trends in Cancer Incidence in Singapore 2010 – 2014.

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