William Chan, 75, had been in good health, though he did have a few episodes of prostatitis, a condition where the prostate swells.
The annual physical that Chan (name changed for patient confidentiality reasons) had in 2007 showed his prostate-specific antigen (PSA) levels had risen to 5.2 nanograms per millilitre of blood, from an initial value of 3.1 nanograms per millilitre.
PSA is produced by the cells of the prostate - a walnut-sized gland located directly below the bladder in men - and can be used as a biological marker for disease detection. According to the US National Cancer Institute, the higher a man's PSA level, the likelier it is that cancer is present, but there are other possible reasons for an elevated PSA level. Benign conditions, such as prostatitis, can also raise it.
In the past, most doctors considered a PSA level below four nanograms per millilitre normal, but recent studies have concluded that there is no specific normal or abnormal PSA level. Consequently, one abnormal PSA test result does not necessarily indicate the need for a prostate biopsy. However, if the PSA level continues to rise over time, other tests may be needed.
Unfortunately for Chan, biopsies taken from both lobes of his prostate tested positive for malignancy. He was diagnosed with stage T2a cancer.
His Gleason score - which grades prostate cancer on a scale of two to 10 - was five. High-grade tumours generally grow more quickly and are likelier to spread. Chan's relatively low score suggested a low-grade cancer that would grow slowly.
Based on these results, his urologist outlined several treatment options - radiation therapy, radical prostatectomy (removal of prostate and some of its surrounding tissue) or expectant management (watchful waiting).
Chan researched the various options extensively and concluded that the side effects and negative impacts on his social functioning and quality of life far outweighed the benefits of active treatment. So he decided to wait and watch.
Dr Yiu Ming-kwong, consultant and chief of urology at the department of surgery, Queen Mary Hospital, says: 'Prostate cancer differs from most other cancers in the body, because some small areas of cancer within the prostate are common in elderly males, and some may remain unchanged for some time before they get really malignant and begin to grow.
'In a group of low-risk cancer cases, these cancers could grow very slowly, and so may not cause an immediate problem, particularly in elderly men. As such, active surveillance is a viable treatment option for selected cases of low-risk prostate cancer among patients, say, over the age of 70 to 75.'
For the next five years, Chan had regular PSA tests every three months and digital rectal examinations every six months. However, during this period, Chan and his family constantly worried about his health, and any pain, ache or malaise would be scrutinised for fear of cancer.
Earlier this year Chan's PSA level rose to 9.2 nanograms per millilitre. Chan had an emotional discussion with his family and reviewed the options again with his urologist. He decided to go for permanent internal radiotherapy called brachytherapy.
Yiu says: 'Low-dose-rate brachytherapy involves placing radioactive seeds in the prostate gland permanently, where they slowly release radiation. The idea is to place the seeds close to the cancer cells, where the radiation can kill the cancer cells without causing too much damage to healthy tissue. However, it still carries side effects of impotence, painful urination, urinary frequency, rectal pain and problems of bowel motions due to an inflamed rectum.'
Before the procedure, Chan was asked to follow a clear liquid diet the day before and fast from midnight onwards. For the procedure, Chan was given a general anaesthetic. During the brachytherapy process, a fluoroscope and an ultrasound procedure were used to visualise his prostate and guide the long needles containing the radioactive seeds, the size of rice grains, into his prostate.
A CT scan was performed later that day to check the positioning of the radioactive seeds before Chan was allowed to go home. Although Chan was assured that the low levels of radiation in the seeds weren't harmful to his family, as a precaution he was told to avoid close contact with his grandchildren for a couple of weeks.
After the procedure, Chan reported expected side effects including mild pain, painful urination, and increased urinary frequency. His urologist recommended Chan maintained a high fluid intake and prescribed a week's course of antibiotics.
Ten months after treatment, Chan is now continent and able to sustain erectile function. His latest follow-up PSA level was two nanograms per millilitre. Looking back, he says he has no regrets about delaying treatment.