Prostate Cancer

The prostate is a walnut-shaped gland within the male reproductive system that is involved in the production of semen. Prostate cancer develops when abnormal cells in the prostate gland grow uncontrollably and become malignant.¹ The early stages of prostate cancer refers to cancer cells that have not spread beyond the prostate.

For the majority of men, prostate cancer develops slowly and may not cause any problems for many years.

Prostate cancer is the third most common cancer among men in Singapore. ¹

5 –10% of all prostate cancer cases are thought to be hereditary (passed on from one family member to another).² Gene mutations that can influence the development of prostate cancer include:

• HOXB13 – this gene is involved in the development of the prostate gland, however mutations are uncommon. ²
• BRCA 1 and BRCA 2 – mutations in these genes have been implicated in breast, ovarian and prostate cancers, especially BRCA 2 gene mutations.²
• MSH2 and MLH1 – these genes help repair mismatched DNA, mutations can result in a condition called Lynch Syndrome which increases the risk of prostate, colorectal and other cancers.²
• RNASEL (also known as HPC1) – this gene helps to get rid of cells that begin to function abnormally, mutations mean these abnormal cells are no longer destroyed which can lead to an increased risk of prostate cancer. ²

The majority of prostate cancer cases are thought to be due to cell mutations that occur during a man’s lifetime, rather than mutations being passed down from his ancestors.²

Prostate cancer is typically classified into stages from 0 – IV based on: ⁴

• tumour size (T)
• if the cancer has involved any lymph nodes (N)
• whether the cancer has metastasised (spread) to other parts of the body (M).³

The stages of prostate cancer are: ¹¹

• Stage I – the tumour is in half or less than half of the prostate, and has not spread
• Stage IIA – the tumour may be in more than half of the prostate, and has not spread
• Stage IIB – the tumour has not spread outside of the prostate
• Stage III – the tumour has spread beyond the outer layer of the prostate, but not to lymph nodes
• Stage IV – the tumour has spread to nearby tissues, lymph nodes or other organs of the body