Skewed numbers?

Gracie, do you recall the source of that data?

The only numbers factoid I remember in the US is that roughly 160,000 women are diagnosed with BC each year (any stage), and roughly a quarter of that number die from the disease every year. The 40,000 who die were almost always diagnosed earlier, of course. 

Prevalence rates of any disease are hard to come by. The government usually tracks diagnosis rates and death rates for illnesses but tends to worry about prevalence more for transmissible diseases because those are the ones that can be controlled through public health measures.

....probably much more information than you needed.

Off to see what I can find on prevalence rate of MBC.... 

Actually the number makes sense.  230K women are diagnosed every year; ~ 22.5% will eventually develop mets.  Approx. 50k develop mets every year (generally these are women who were diagnosed years earlier).  The average number of years of survival once diagnosed with mets is 3 years.  

Statistics for Metastatic Breast Cancer 

http://www.cancer.org/acs/groups/content/@epidemiologysurveilance/documents/document/acspc-031941.pdf 

http://seer.cancer.gov/csr/1975_2008/browse_csr.php?section=4&page=sect_04_table.18.html 

Don't know the numbers, but at the time of my first cancer diagnosis I was told 1 in 9 women get breast cancer.

I believe it is 1 in 8 now. And more younger women get it these days.

I was 46 in 1982 and that was considered young for breast cancer at that time.

Now as we know, women in their 20s get it.  Wish we knew why---

230K diagnosed every year.

50k diagnosed with mets every year.

Average number of years that someone has mets:  3

3 * 50K = 150K

It makes sense.

Of course in reality, some women who develop mets pass within a short time while others live for many many years. 3 years is the average. So it's not really 3 * 50k; it's more likely something like this:

• 1k who were diagnosed over 15 years ago 
• 5k who were diagnosed over 10 years ago
• 10K who were diagnosed between 5 and 10 years ago
• 20K who were diagnosed between 3 years and 5 years ago 
• 25k who were diagnosed three years ago 
• 40k who were diagnosed two years ago 
• 49k who were diagnosed within the last year 

Gracie, I can only speculate, as there is no info on how the estimate was arrived at, but this is the most likely scenario:

There may be 160,000 individuals with MBC at any given moment - but that group probably changes its members quickly, as some die and others "join" the group because they get dx'd. So, for example, the total number of individuals who had MBC on, say, Oct. 1, 2011 is a much smaller number than the total number of individuals who, on any day in 2011, were alive and had a dx' of MBC. Does that make sense?

Sadly, what we see here on BCO is a microcosm of that trend. The stage IV forum has a lot of arrivals and departures.

You could probably construct a dataset with SEER data and get the number for some years - probably nothing more recent than 2009, though. You can do lots of things with SEER data - I found it useful while making treatment decisions, although to do anything too complex you'd have to be a statistician. But it would be interesting if someone could come up with the total number of people dx'd with MBC in, say, all of 2008. It might call attention to just how deadly BC is. I have no idea what that number would be, but I agree with you, Gracie. I think it would be much higher.

Gracie, judging from the pink ribbon kitsch and Komen propaganda we have to put up with, I bet people are working on the smaller number. Too many people think that:"breast cancer" is "something you don't die of anymore."