21.NOV.2019 6 MIN READ | 6 MIN READ

Prostate cancer may be the third most prevalent cancer amongst men in Singapore, but early detection and treatment can help save lives.

According to statistics from the Singapore Cancer Society, an average of 35 people are diagnosed with cancer every day.

Prostate cancer is the third most common cancer among Singaporean men, and it often strikes men from the age of 50 onwards.

What is Prostate Cancer?

The prostate is a walnut-sized gland situated below the urinary bladder. It’s the organ responsible for the production of semen and its development depends on the male sex hormone testosterone.

Prostate cancer develops when cells in the prostate gland grow and develop in an uncontrolled manner, become malignant and form a lump that invades surrounding tissue such as the seminal vesicles and bladder neck.

In most cases, prostate cancers develop without any visible symptoms. This makes detection difficult and the cancer may spread through the body’s lymphatic system and into other parts of the body such as the lungs. It can also spread to lymph nodes in the pelvis or to the bones.

Early detection of prostate cancer can reduce the risk of death. And the sooner treatment commences, the higher the chances of positive outcomes and recovery.

Symptoms of a Prostate Issue

Prostate cancer symptoms
Prostate cancer may lurk without visible symptoms, but do consider seeking advice from a doctor if you encounter the following symptoms:

  • Constantly feeling the need to urinate
  • Feeling a strong need to urinate, but having a very low stream of urine
  • Frequent urination at night
  • Dark, reddish coloured urine
  • Difficulty urinating
  • Weakness or swelling of the lower limbs
  • Back pain, especially at rest/at night

Detecting Prostate Cancer

However, as most early prostate cancers do not cause symptoms, men who are concerned about prostate cancer can speak to their doctors about testing for early prostate cancer. This can be considered when men reach 50 years of age, or earlier if they have a family member with prostate cancer.

Checking for prostate cancer involves an examination of the prostate with the doctor’s finger (Digital rectal exam) and a blood test (PSA).

During a Digital rectal exam, the doctor may detect abnormal hard areas of the prostate when his finger inside your rectum feels the back portion of the prostate.

Prostate specific antigen (PSA) is present in small quantities in the blood of men with healthy prostates, but is often elevated in the presence of prostate cancer or other prostate disorders.

An abnormal-feeling prostate, or abnormal PSA levels should be investigated by a urologist. A prostate biopsy will be ordered to check for cancer.

The standard prostate biopsy is a blind procedure. That is, although they are guided by ultrasound, urologists doing a biopsy really can’t see whether one area of the prostate looks any different from another – so they do the best they can by trying to sample tissue in a systematic way throughout the gland. The problem with this approach, is that significant prostate cancers can be missed. About 30% of men require a repeat biopsy because of concerns that cancer was hiding and was simply missed.

Prostate biopsies usually involve piercing a biopsy needle through the rectum to take samples from the prostate (Transrectal biopsy). This comes with a risk of serious infection requiring hospitalisation as bacteria in the faeces can be transferred into the blood stream when the biopsy needle passes through the rectum.

Advances in technology have led to improvements in prostate cancer diagnosis that address these issues.

More Accurate Prostate Diagnosis

PSA test
An abnormal PSA usually leads to a prostate biopsy. Unfortunately, the PSA is a non-specific marker for cancer, and there can be other reasons for a high PSA besides cancer, so prostate biopsies often turn out to be unnecessary. For example, 70 – 75% of biopsies done for PSA in the abnormal 4 – 10 range, turn out to be negative.

The Prostate Health Index (PHI) blood test is three times more accurate in predicting the presence of prostate cancer in men with a high PSA in the 4 – 10 range. Men with a high PSA but low PHI may now be able to avoid a prostate biopsy. A study validated its use in Singaporean men, and found that the PHI can help men avoid up to half of unnecessary biopsies.

Prostate MRIs can now detect suspicious areas of the prostate that may harbour cancer. Integrating this information with the real-time ultrasound images of the prostate (MRI-US fusion biopsy) allows the urologist to accurately target these abnormal areas. This improves the detection of significant prostate cancer. As such, urologists can be more confident of the accuracy of their biopsies, and repeat biopsies are less required.

On the other hand, if the Prostate MRI is normal, a prostate biopsy may not be required.

In Transperineal (TP) prostate biopsy, the biopsy needle goes through the skin of the perineum, which is the area between the scrotum and anus, instead of the standard route through the rectum.

This technique eliminates contact with the bacteria in the rectum, thus lowering the risk of serious infections to near zero. As the skin of the perineum can be sterilised, there is no need for routine use of antibiotics to prevent infection (as in the case of transrectal biopsies), thus minimising the risk of developing antibiotic resistance.

TP biopsies can be done in an outpatient setting under local anaesthesia.

TP biopsies can also be combined with information from an MRI to do targeted biopsies, combining accuracy with safety.

Treatment Options for Localised Prostate Cancer

Prostate cancer that is found early have a high chance of being cured with treatment to the prostate, either with surgery, radiotherapy or surveillance.

Surgical removal of the prostate is called Radical Prostatectomy. This is most commonly done in Singapore with the assistance of the Da Vinci surgical robot. This tool gives the surgeon magnified vision, with small wristed instruments that replicate the dexterity of the surgeon’s own hand, allowing the surgeon to precisely remove the prostate through small incisions (1cm or less). The advantage of robotic assisted radical prostatectomy over open surgery is less pain from smaller wounds, less blood loss and shorter hospital stays (usually 2 nights).

The alternative to surgery is radiotherapy. This involves the use of high-energy x-ray beams targeted at the prostate from outside the body. These x-ray beams damage the cancer cells and stop them from growing and spreading to other parts of the body. Radiotherapy permanently damages and kills the cancer cells, but healthy cells can repair themselves and recover more easily.

Not all prostate cancers need to be treated immediately. Some early cancers have a very low potential to cause death and can be observed with repeated PSA testing, MRI scans and biopsies. This is called active surveillance, and aims to detect the small group of low risk cancers that progress, while avoiding overtreatment of those men with cancers that are destined not to harm them. In appropriately selected men, active surveillance has a very high 10 year survival rate of 99.7%.

Overcoming Prostate Cancer

Overcoming prostate cancer
If prostate cancer is found early, treatment with either surgery or radiotherapy can yield 5 year survival rates are almost 100%, and 10 year survival rates of more than 90%.

On the other hand, the 5 year survival for men diagnosed with advanced prostate cancer that has already spread beyond the prostate is around 30%. While the prognosis with men with advanced cancer has steadily improved with advancements in drug therapy, this is still an incurable disease.

Conclusion

Improvements in technology have reduced many of the problems of prostate diagnosis.

While there have been many technological advancements in prostate cancer treatment, this cannot overcome the bad biology of late advanced cancer. The key to a good outcome is early diagnosis.

 

Article contributed by Dr Lincoln Tan, urologist at Gleneagles Hospital

References

Prostate Cancer. (n.d.) Singapore Cancer Society. Retrieved from https://www.singaporecancersociety.org.sg/learn-about-cancer/types-of-cancer/prostate-cancer.html#treatment

Tan, L., Tan, Y., Tai, B., Tan, K., Gauhar, V., Tiong, H., … Chiong, E. (2017). Prospective validation of %p2PSA and the Prostate Health Index, in prostate cancer detection in initial prostate biopsies of Asian men, with total PSA 4-10 ng ml-1. Asian Journal of Andrology, 19(3), 286–290. doi: 10.4103/1008-682x.168687

21.NOV.2019
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Tan Guan Lim Lincoln
Urologist
Gleneagles Hospital

Dr Lincoln Tan is a urologist practising at Gleneagles Hospital. He is also an accredited robotic surgeon at Mount Elizabeth Hospital.