Expert: Claes-Gustaf Nordquist, M.D. - 5/29/2004

Question
Hello,
I am 16 years old and am concerned about the increasing rate of breast cancer diagnosis in Australia (where I live). I am concerned about a few things regarding cancer. In the past I have received forwards that have claimed certain "everyday" items could be possible causes of cancer in general, and breast cancer.
1) The first item claimed that antiperspirants caused breast cancer due to their application in the armpit area and was particularly a risk to those who shaved their armpits (due to possible "nicks" that you can get as a result of shaving). Mind you, I have never shaved and only waxed my armpits. Is there truth in the antiperspirant claims and, if so, am I at risk?
2) A separate email claimed that numerous products can cause cancer in general. These include (i)Satays (which is claimed to contain carsinogens), (ii) taking Vitamin C after eating Prawns (which is claimed to result in death), (iii) A chemical in shampoos and toothpaste called Sodium Laureth Sulfate (claimed to cause cancer), and (iv) Instant noodles. I'd like to know if there's any truth in these claims either.
3) Finally, I was wondering what else could possibly cause breast cancer? I have a 12C bra size and was wondering if breast size is a factor in the increased risk of developing breast cancer? I had heard that the pop singer Anastacia recently overcame the disease and I was wondering if ANY young person is at risk whatsoever? I have never been sexually active and don't intend to be until after I am married and I was wondering if this was also a possible factor in getting breast cancer?
Thank you for your time.

Answer
This was a lot of questions masked as one! But ok. From the beginning: 1.  There is NO scientific or clinical evidence that shaving or waxing your armpits or the use of anti perspirants deodorants can cause breast cancer!
2. There is NO scientific or clinical proof of this either!
3. The risk of breast cancer increases with age. While young age is no guarantee against breast cancer it is in reality practically unheard of at your age (the youngest patient I have seen with it was 23 and she was a rare case indeed). So a main reason for the increased breast cancer rate is the simple fact that more women now live to an old age. Sex activity in itself does not matter at all either way! But the younger you are when you have your first menstruation does matter, it increases your risk. The older you are when you stop menstuating also matters, it also increases your risk. The taller you are and the heavier you are increase your risk too somewhat. The more children you have, the less risk. The earlier you have your first pregnancy the less risk (I do NOT suggest that you should get pregnant fast because of this!). The more nursing you do with your babies the less risk. BUT none of these things gives you a guarantee against breast cancer! However since women nowadays tend to have fewer children and have them later in life you have here a couple of other main reasons why breast cancer has become more common. Others are the facts that due to better nutrition women become taller and have bigger mass than before and also start menstruating earlier. Breast size in itself does not matter. Most of these factors are hormonal. Hormonal medication MAY to some extent influence the situation too. As you can understand from the facts above, nuns, who are never sexually active, run a higher breast cancer risk due to the fact that they never get pregnant. I hope this has answered your questions! Instead of getting worried by unsubstantiated rumours on the internet and elsewhere, read up on the subject! I recommend that you look up breast cancer (and any other medical topic you may be interested in) on "The Merck Manual On The Web"! It is very good, it is free and any search engine will find it. Good luck!