Statistics

[valpal]

I was diagnosed with bc in May 2003.  With the info that my doctors have I have been staged IIA breast cancer.  I have read through some of the other Q&A's that many women want to know statistics for survival.  All answers say the same thing....the statistics are old.  Why are the stats not updated monthly, quarterly, etc? Who accumulates the stats?  Are these stats based on women who are or are not receiving chemotherapy. What is the age range for these stats. These are so important to breast cancer survivors.

[CCF-RN,MSN-rf]

Dear valpal:  The best way to explain why statistics are old is to give an example.  For the sake of argument, lets use a low number like 100.  Most research is done on much higher numbers of women.  Lets say that of these 100 women all are stage 2 but we must stratify by 2A or 2B.  So lets say there are 50 women with 2A and 50 women with 2B.  Now realize that treatment types, age, and hormone status must all be recorded as variables.  Now comes the fun part - we must wait for years to see what happens to these women.  Given that women with stage 2 breast cancer do very well - we may be waiting 20+ years until we can begin to analyze the data (in other words we must track women when they recur or die - otherwise there is no statistic at all).  In that 20 years time, things change.  Take for example the discovery of HER2-neu.  This has happened in the last 10 years.  But - we cannot deprive the women who are in this study of this latest treatment.  So some of them will benefit and some may not have had the opportunity.  In most cases, survival statistics are based on women who receive the recommended standard therapy - since most women choose this.  Women who decide to do nothing are so few that it is meaningless to measure.  So, we finally reach the end point of the trial.  Now the data must be analyzed and published - this process may take another year or more.  So, our statistics are old, merely because of the process required to obtain them.  Obviously, survival statistics are an imperfect science.  So, if you are diagnosed today, the best statistics we have are by definition old - but it is the best we have.  Furthermore, statistics describe groups - not individuals.  This is why, in many cases, we recommend against comparing statistics.  With treatments improving rapidly, a person might falsely deflate their survival potential.  This is of no help to anyone.  And, really, no one knows how long ANY individual will live.  Dr. Susan Love includes good information describing relative risk and ways to make good decisions regarding therapy.  You might consider checking her book out from the library.

[heidiho]

Dear Valpal:
  Go to (www.mhs.mayo.edu/mhs/live/adjuvant) for tools to help you calculate your 10-year survival prognosis based on:  age, tumor size, lymph node status & hormone receptor status; also, it'll calculate your estimated prognosis based on if you are or are not having additional treatment in addition to surgery (chemo and/or hormone therapy will up these odds).
  Survival statistics are based on population, on large numbers of people with similar clinical presentations as yours.  The reason stats are not up-to-date is that, in order to get a 5 or 10-year survival statistic, they would have had to start the study at least that long ago.  The good news is that, any survival stat you see is probably already outdated by several years for the above reason, and figures most certainly have risen due to advances made since the study began.   Best Wishes.