- Anal sex increases your chances to have anal cancer up to 17 , 31 times.
- Smoking cigarettes increases your chances to have lung cancer 23 times.
Yet, though you probably want to drop smoking, homosexual men should not worry too much about anal sex. Women, on the other hand…
So yeah, Merry Christmas and have a nice day… But wait a minute, before you rethink your lifestyle and become a monk or a nun to avoid a premature death, let’s see how dangerous danger is.
The relative risks listed above does not tell us how risky things are, for example, buying 20 tickets of a lottery will give you 20 times more chances to win the lottery than someone buying just one ticket, yet, the most likely scenario is none of you will be millionaires… there are no reasons to feel 20 times happier with twenty tickets because the probability for any of those tickets to be the winner is very low, and so might happen with the relative risks listed above, but let’s make sure; in particular we want to know
That is, the probability of Something Bad happening if a Risk Behavior is ongoing. Usually many statistics of this kind are given in a relative risk (RR) fashion as I did above, that is:
Yet, we can calculate the probabilities that interest us if we have the Something Bad total occurrence. Let’s consider these relationships:
And with these results we can calculate:
So let’s do now apply these formulas to anal sex and smoking…
Anal Sex
Considering in 2012 there were in the US about 6,230 new cases of anal cancer (3,980 in women and 2,250 in men), and of Dec 12, 2012 the population in the US is around 314,927,141 citizens, (the total number of men and women it’s been calculated with the ratio male/female = 0.97 for the US in 2011) we can estimate using the calculations above that the odds for a man who does not have anal sex in the US to be diagnosed anal cancer any particular year will be around of 1 / 1,240,000 (2,200,000 for RR = 31) whereas for a man engaging in anal sex the odds increase to one 1 / 73,000 (71,000 for RR = 31). For a woman not engaging in anal sex practices the odds are around 1 / 723,000 (1,285,000 for RR = 31) and for a woman engaging in anal sex practices the odds increase to 1 / 42,500 (41,500 for RR=31).

Given those odds does not look like if anyone should change his/her lifestyle based on them. The worst scenario would be for women having anal sex, and the roughly one out of forty thousand chances per year for it to happen does not sound very scary to me but, of course, I am a man so it is up to women to decide whether it is worth the risk, after all is men getting the pleasure (for the most part) and women getting the cancer.
Smoking
In the year 2012 a total of 226,160 new cases of lung cancer were diagnosed in the US. We can estimate again that the odds for a non smoker person in the US to be diagnosed with lung cancer any particular year will be around 1 / 33,000 whereas for a smoker person the odds increase to 1 / 1,400.
First thing to mention is that the around 1 / 33,000 odds for any of us non smokers to get lung cancer are noticeably worse than the around 1 / 40,000 odds for women engaging in anal sex to get anal cancer. Therefore, if you being a non smoker you’re not too scared of having lung cancer then you have even fewer reasons to be scared of having anal cancer by engaging in anal sex practices.
Secondly, the 1 / 1,400 odds for smokers to get lung cancer any particular year begins to sound pretty scary to me yet, truth to be told, with those odds it is still unlikely for a random smoker to be diagnosed with lung cancer throughout his/her life. Nonetheless, smoking is the cause of a long list of diseases and when you place the whole thing together smoking cigarettes is anything but a good idea.

Related articles
- Smokers Die About A Decade Earlier On Average (newyork.cbslocal.com)
- Anal Sex: Science’s Last Taboo (smutforsmarties.com)