Prostate cancer and how it develops:
Based on an article published by The Straits Times in 2017, the incidence of prostate cancer in Singapore has gone up fivefold – from 6 to 30 per 100 000 men in the past 4 years. This article however concludes by factoring in the ageing population of Singapore and dismissed the climb in numbers as something that was “generally not significant” as it is natural for older people to be at higher risk of cancer. While this is true, it does spark interest as to why the prostate is one of the organs that faced such an increment in cancer cases.
The growth of the prostate gland is controlled by male sex hormones – androgens. Not only are androgens in charge of initiating the formation of the external male genitalia such as the penis, testes and scrotum in the fetus, it also aids in the subsequent development and maturation of secondary sexual organs such as the seminal vesicles and the prostate gland in a male as well.
Cancer develops when the rates of cell division and cell death are no longer equivalent to each other. When this occurs, there will be uncontrolled tumour growth. This can happen when either the rates of cell division are too high or the mechanism responsible for mutant cell surveillance and subsequent apoptosis do not work well. When cells divide too rapidly, there is a decreased ability of the monitoring system in the body to effectively filter and ensure that only good quality cells are produced. This in turn increases the risk of accumulation of mutations. On the other hand, if these mutant cells fail to be killed off or have their DNA repaired by another monitoring system, the mutated cells will survive and this can lead to the eventual development of cancer.
At this juncture, a link can be postulated. In the event where there is an elevation in the amount of androgens in the males, there will likewise be an increase in growth of the prostate gland. Should the rate of growth surpass the rate of cell death in the prostate gland, there is then an increased risk of the development of cancer.
Apart from a postulated increase risk of the development of prostate cancer, an increase in levels of androgens is also tied closely with the development of acne!
Our hormones and acne:
It is common knowledge that acne is affected by our hormones. In fact, for both genders, acne tends to be triggered by the increase in levels of androgens. Androgens are a reproductive hormone found in our body. Its level increases especially at the onset of puberty or in the case of females, during their menstrual cycle as well. While androgens are male sex hormones, they are present in both females and males, just that they are present in greater proportion in the latter. They have the effect of stimulating our sebaceous glands to produce more sebum – an oily substance – that aids in the lubrication of our skin. However, with a surge in the level of androgens, excessive sebum is produced and this aggravates the development of acne. To simplify the process behind this phenomenon, it will be easy to understand the formation of pimples as an inflammatory process that occurs when the pilosebaceous units of our skin get clogged by dirt, dead skin cells and Propionibacterium acnes (P. acnes) bacteria. The possibility of this happening is increased with an increase in sebum production.
Acne, risk of prostate cancer and androgens:
If we put two and two together, we notice that there is a possible increased risk of prostate cancer in an individual with acne because of the underlying cause of the two diseases – raised levels of androgens.
In fact, a study carried out amongst men serving the army in Sweden unveiled that there was a risk for prostate cancer in men with acne in general but a significant sixfold increase in those with severe acne. There has also been a notable association between acne and the advanced stage of prostate cancer. Research carried out subsequently suggests that P.acnes bacteria which is main perpetrator behind the development of acne may play a role in the development of prostate cancer. Not only is P.acnes found as part of the normal flora of the skin, but other organs as well. In the prostate, P.acnes may lead to prostate tissue inflammation and subsequently, the development of prostate cancer.
Treatments for prostate cancer:
The management of prostate cancer typically involves risk stratification of the individual firstly. After which, depending on severity, different modalities of treatment options are available for them. Some of the more common and conventional ones include radiation therapy and radical prostatectomy – either partial or full.
Apart from these treatment modalities, other forms of therapy have arose over the recent years as well.
In light of the possible relationship between androgenic stimulation and prostate cancer, the Prostate Cancer Prevention Trial and REDUCE Trial have been conducted. The two studies made use of the drugs finasteride and dustasteride respectively to block the effects of 5-alpha reductase and hence reduce the conversion of testosterone to dihydrotestosterone (DHT). Both testosterone and DHT are two types of androgens but DHT is more potent as compared to testosterone. Through limiting the amount of DHT in the body by cutting down on its conversion from testosterone, the intended effect of finasteride and dustasteride is to lower the impact thatthe androgens have on the prostate gland growth and possibly, can even play a role in preventing prostate cancer development. The US Food and Drug Association however had not approved of these agents due to potential concerns about risks and long-term safety. Examples of some side effects of these drugs include gynecomastia, decreased libido, erectile dysfunction and decreased ejaculate volume. Furthermore, these agents only serve to decrease the risk of prostate cancer but have no concrete evidence of being able to eliminate the risk altogether. Additionally, no research nor literature is available to justify that finasteride and dustasteride can reduce the number of deaths from prostate cancer or improve overall survival. Hence, in view of this, both drugs do not have a favourable risk-benefit profile and are not recommended as preventive medications for patients.
Due to the limitations of radical prostatectomy such as inaccuracy of clinical staging, a rough estimate of 50% of patients are diagnosed to have early stage prostate cancer when in actual fact, have extension of the cancer beyond the prostate capsule. As a result, radical prostatectomy is limited in its effectiveness. In response to this, neoadjuvant androgen deprivation therapy (NADT) has surfaced. It is meant to aid in the killing off of malignant androgen-dependent prostate cancer cells in hope that this will result in tumour regression and thus allow for complete resection of the remaining cancer. Apart from helping to shrink the tumour before surgery, NADT has been theorised to treat micro-metastasis of prostate cancer and this has the ultimate goal of improving long term disease free survival of the patient post-surgery. With the availability of safe and reversible forms of androgen depriving drugs such as lutenising hormone-releasing hormone (LHRH) analogues, NADT is slowly becoming a popular therapeutic option for “high risk patients”. There is however no one definition of “high risk patients” and owing to the multiple definitions available, trial-to-trial comparisons are difficult. To add on, even with NADT, there is no complete guarantee that the tumour can be completely removed and the cost of therapy is another concern for this treatment.
Conclusion:
This article has brought up several interesting research findings that are seemingly pointing towards an association between acne and prostate cancer. It has certainly spurred on more interest into this area but more research and studies still have to be conducted in order for a definite link to be drawn. For now, males with severe acne can perhaps just take this possible risk of them developing prostate cancer with a pinch of salt till more literature is available.
