Sadly, I am not very good at math and even worse at statistics.

If:

"During the average six years of follow-up, 3.1 percent of women developed a recurrence of DCIS or an invasive tumor in the same breast. For women who received radiation within eight weeks, the rate of recurrence was 2.5 percent. After adjusting for age, race, pathological factors, surgical margin status and hormone therapy, the risk of breast cancer recurrence was 26 percent higher for women who had delayed radiation therapy and 35 percent higher for women who did not initially receive radiation."

The difference between 3.1 and 2.5 doesn't seem that big to me. And how on earth do you "adjust" for age, race, pathological factors etc? It seems like educated guessing to me.

I see these studies and others and despair of being able to understand and evaluate them myself.

This is not a complaint for posting them - my thanks to cp418 and to dlb823. I just get frustrated that I can't trust what I am reading at face value.

Bounce, I agree, the difference does not sound like much, only .6%. I think it would have been more helpful if they had specified the recurrence rates for each of the three groups rather than use percentages. 26% and 35% sounds like a lot, but when you are dealing with low numbers, it may not be much.

3.1% was the average of everyone: those who got timely radiation, those who got delayed radiation, and those who got none. So, 26% higher is a 3.9% rate of recurrence for those getting delayed radiation, and 35% higher is 4.18% recurrence rate for those getting none. (If I did my math right, and there's a 50-50 chance of that....)

Another thing I think they should have said was what kind of recurrences the patients had. Was it DCIS again, or IDC, or some of both? Was there any difference in the type of recurrence based on having radiation? And were they all local or were there any distant recurrences?