The only way to cure prostate cancer, if detected early, is to undergo an operation called radical prostatectomy. Before the advent of robotic surgery with the Da Vinci Robotic System, the operation was performed through a sizeable incision in the abdomen. With the availability of robotic surgery, the same operation can be achieved through smaller incisions leading to shorter hospital stay, quicker recovery and less incidence of erectile dysfunction. According to urologists, it is not too difficult to become proficient at the technique of robotic surgery as the robot makes the surgery ’easier’ to perform as compared to an open prostatectomy. Does this equate to similar recurrence rate (or cancer control) as achieved with open prostatectomy?

Researchers from Memorial Sloan-Kettering Cancer Center reported their analysis of 7765 open radical prostatectomy cases carried out in 4 major US academic medical centres (J Natl Cancer Inst 2007; 99: 1171 – 1177). The study showed that the learning curve for prostate cancer recurrence after open radical prostatectomy was steep. The predicted probabilities of cancer recurrence at 5 years were 17.9% for patients treated by surgeons with 10 prior operations and 10.7% if performed by surgeons with 250 prior operations.

The same researchers just published their analysis of 4702 patients with prostate cancer treated laparoscopically (robotic surgery) at 7 centres in Europe and North America between January 1998 and June 2007 (Lancet Oncol epub; 2009 March 31). The 5 years risk for recurrence in patients treated by surgeons who had performed 10 laparoscopic prostatectomies was 17%. The rate became 16% when the surgeon had performed 250 laparoscopic prostatectomies. By the time the surgeon had performed 750 laparoscopic prostatectomies, the 5 years risk for recurrence had reached 9%. In other words, surgeons had to perform approximately 750 laparoscopic prostatectomies before they achieved the same low level of disease recurrence (10.7%) as surgeons who had performed 250 open prostatectomies. The study shows that the learning curve was even longer for those who perform laparoscopic radical prostatectomy. Interestingly, the study also found that surgeons with previous experience of open radical prostatectomy had significantly poorer results than those whose first operation was laparoscopic.

If medicine were pure science, then once a doctor has learnt the science of how to perform robotic surgery, his or her results should be consistent. To me, medicine is indeed not just science, it is a mixture of science and art. Hence the term - the art of medicine.

Does your face go red after a glass of wine or beer? If the answer is yes, then you have the so-called alcohol flushing response, also known as ‘Asian glow’ or ‘Asian flush’. This characteristic physiological response to drinking alcohol includes facial flushing, nausea and tachycardia and is seen in approximately 36% of East Asians (Japanese, Koreans and Chinese).  The response is due to an inherited deficiency in the enzyme aldehyde dehydrogenase 2 (ALDH2). Although most if not all of the East Asian public is aware of this alcohol flushing response, few realise that ALDH2-deficient individuals are at much higher risk of developing oesophageal cancer from alcohol consumption when compared to individuals with fully active ALDH2. It is estimated that there are at least 540 million ALDH2-deficient individuals worldwide and this represents about 8% of the world population.

Ethanol is first metabolised by alcohol dehydrogenase (ADH) into acetaldehyde, which is a mutagen and animal carcinogen. It causes DNA damage and has other cancer promoting effects. Acetaldehyde is then metabolized to acetate mainly by ALDH2. There are 2 main variants of ALDH2 in the East Asian population – the normal one (ALDH2 Glu/Glu ) with full activity and the abnormal one (ALDH2 Lys/Lys) with no activity at all. If you are a heterozygote, then you have a mixture of the two (ALDH2 Glu/Lys) and you have some ALDH2 activity.

In individuals with no ALDH2 activity, the accumulated acetaldehyde will cause intense facial flushing, nausea, tachycardia and histamine release which is so unpleasant that the individual is unable to consume any significant amount of alcohol. Thus, the individual is protected from the increased risk of oesophageal cancer from alcohol consumption. Heterozygotes have a low level of ALDH2 activity and so develop tolerance to acetaldehyde and the flushing response, thus, becoming regular heavy drinkers with the associated increased risk of developing oesophageal cancer. Studies in Taiwan and Japan have shown that alcohol consumption in ALDH2 heterozygotes increased their risk of oesophageal cancer by 3.7 to 18.1 times.

A simple but accurate way to determine if you are ALDH2 deficient is to answer yes or no to the following 2 questions: (1) Do you have a tendency to develop facial flushing immediately after drinking a glass (about 180 cc) of beer? (2) Did you have a tendency to develop facial flushing immediately after drinking a glass of beer in the first one or two years after you started drinking? If you answer yes to either question then you are considered ALDH2 deficient. ALDH2-deficient individuals should be warned about their increased risk of developing oesophageal cancer with alcohol consumption.

What would be the impact on oesophageal cancer risk if you, an ALDH2 heterozygote, went from a heavy (≥ 18 units / week) or moderate (9 – 17.9 units / week) drinker to a light (1 – 8.9 units / week) drinker? It has been calculated that 53% of oesophageal squamous cell carcinoma might be prevented in the Japanese male population if moderate or heavy drinking heterozygotes became light drinkers!

(If you wish to read about Asian glow in more detail, please go to www.plosmedicine.org/article/info%3Adoi%2F10.1371%2Fjournal.pmed.1000050)