Monday, April 15, 2013

OC STATISTICS. And an announcement


Linda at one.
cute as a bug's ear

I post this picture to announce that I will be a great grandfather, twice over, by Thanksgiving.  And that’s all I’m going to tell you. 
There has not been a boy born into the Beck family since 1933.  What are the odds?
I am at Fred Hutch today, reading.  One thing I have read is a study of ovarian cancer incidence and mortality, world-wide, using data from various sources covering the interval 1988 to 1998.  Unlike most of the research papers I attempt to read, this one is blessedly free of undefined acronyms (although there are a few), and terms that only a Ph.D. oncological geneticist could appreciate.  You can read it yourself by using Google Scholar and searching for the following pub: Lowe, et al¸ 2013, An international assessment of ovarian cancer incidence and mortality, Gynecologic Oncology, as yet unpublished, I guess, so I can’t give you the volume and page numbers.  But don’t bother: I will fill you in:
Things are getting better, but very slowly.  There are fractionally (small fractionally) fewer cases of ovarian cancer diagnosed each year**, and comparably fewer deaths.  World-wide it is estimated that 225,500 women were diagnosed with ovarian cancer in 2008, and 140,000 died.  The lifetime risk of developing ovarian cancer is <2% for the general population.  However, if there is one family member with OC, the risk is 4-5%, rising to `7% for women with two family member with the disease.  Notably, the lifetime risk for women who carry the BRCA1 or BRCA2 mutations, the risk is a whopping 30%.  To me, the moral here is: If you can afford it, get tested.
I want to emphasize that, although things are getting better, the statistics are still dismal.  We need to keep plugging away.
Curiously, there are significant differences between races and regions – and, for once, white people living in Europe and North America don’t make out so well.  Having an advanced economy also doesn’t seem to help, either.  For instance, within the Americas, the five-year incidence of ovarian cancer is twice as high in the United States and Canada as it is in Brazil and Mexico.  Asian countries (except, curiously, Japan) have rates only a third as high as the United States.  Our rates are comparable to all European countries, except Portugal, which is very low.  (Is it all the octopi they eat?). 
As for race, Caucasians have significantly higher rates than do all other races, both worldwide and within the U.S. 
So, what does this mean?  It may represent something genetic, and (I would guess) to some extent it does.  Is it an artifact of the medical system - that is, are women in Europe, Canada and the U.S. more likely to get a timely,  correct diagnosis*?  Or is it that Caucasian women in rich countries subject themselves or are subjected to more of the things known to be associated with risk of ovarian cancer, which I will list below?  Damned if I know. 
The list:
                Obesity
                Hormonal exposure
                High number of ovulatory years
                Exposure to radiation
                Smoking, caffeine consumption, alcohol consumption
                A diet high in lactose
                Frequent hair dying
                Use of antidepressants
                Asbestos exposure
                Use of talc in genital area
                Endometriosis or pelvic inflammatory disease
               
Note that the authors of this paper appear ambivalent about the connection between all of these and ovarian cancer.  My take on it is that you can’t avoid everything potentially unhealthy.   Just try to avoid the ones that aren’t fun.

*To test this it might have been relevant to include statistics from Cuba.

** This is in percent of all women.  Naturally, as population increases there are more cases of ovarian cancer diagnosed - but a smaller percent of the total.



4 comments:

  1. No sooner had I “published” this thing that I thought of something else. Cause and effect can be a little hard to tease out here. The facts are these: (1) Caucasian women tend to get more OC than women of other races; (2) Women in rich countries tend to get more OC than women in poor countries; (3) There is a correlation between the “risk factors” listed above and OC. So, which is cause and which is effect? Do the symptoms listed correlate with elevated risk of OC because OC is more prevalent in rich, white countries than otherwise – and only rich, white women can afford to overeat, over drink, use talc, etc? Maybe the correlation (risk factors with OC incidence) results because there is a genetic tendency for white women to get the disease, and by and large only white women can afford to indulge in several of the risk factors? Or are the risk factors driving the process, and preferentially white women tend to indulge in them? That is why the Japanese statistic is important: Asians get less OC, but the rich Japanese get it almost three times as often as do people from other Asian countries (the relative rich South Koreans are a partial exception.) Again: too bad there are no statistics from Cuba. But, heck, I’m beginning to confuse myself! Sorry.

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    1. It does seem very hard to tease out. If your list above is actually a list of causes, one thing that I can think of that we probably have much more of here in America is sugar. This is linked to obesity, but even many of us who are not obese probably eat way too much sugar. I wonder if there is a link.

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    2. Good question. I would think that someone has studied that question, but I don't know. I will ask at the Hutch.

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  2. Here is a primer/review article on breast/ovarian cancer risk. From a dental magazine, no less. Most of you will already know this stuff. The “risk assessment tool"l is useful.

    http://www.dentistryiq.com/articles/2015/11/familial-cancer-risk-assessment-breast-and-ovarian-cancer.html


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