@elsie37
I have a math background and find the statistics for cancer hard to understand. (Which I'd never looked at, coming from a cancer-free family, until a bad news biopsy last year led to a lumpectomy.)

Here's one example that makes no sense. Two oncologists I saw said that the rule of thumb is that taking an aromatase inhibitor could [note: "could".] lower my risk of recurrence by approximately 45% in general. But that was before the OncotypeDX showed a risk of recurrence of approximately 5.5% if I didn't take them so I didn't have the 'industry accepted' higher risk that the 45% 'could' lower.

The rule of thumb of 45% risk reduction in favor of aromatase inhibitors for ER+, PR+, HER2- breast cancers is usually rounded up to 50% as it's easier to quote.

BUT, one article in the respected New England Journal of Medicine by an oncologist, a leader in his field, noted that the NNT number (aka 'number needed to treat' to prevent projected cancer) for aromatase inhibitors is 49. And his point was that it's a serious ethical question of whether 48 women should be told to take a 'toxic' (his word) drug that they may not even benefit from. And that patients should be fully informed of the side effects and statiscally-derived likely benefit so each can decide whether to take them. And that failing to adequately inform breast cancer patients is further fostering the environment of patient non-compliance or, worse, loss of confidence in physicians at a time when they most need to have it.

What bothers me is that 1 in 49 does not yield a statistic anywhere near the 45% risk reduction talked about. So how does 1 in 49, rounded to 2%, become that near-50%?

I have an M.B.A. in finance and am used to double-checking pro forma numbers and too-rosy projections so this caught my attention and I've not yet found the explanation unless there's some arcane stat to explain it, e.g., the drugs prevent 100% of recurrences for some kind of cancer that accounts for, say, 70+% of cancers to bring the mean (average) risk reduction up to 45-50%?

I'm sure there are benefits (and known downsides) to aromatase inhibitors. But getting clean data points to connect and base a decision on is oddly difficult.

I skipped the drugs. A friend asked if, if I suffer a recurrence, I'll think that not taking them caused it. And, upon thinking it over, my answer would be no. I'd have a 3% risk of recurrence if I'd done the trifecta of radiation, chemo and adjuvant anti-hormone therapy (and get osteoporosis from the latter, at a minimum). So I'd never know what 'caused' the recurrence except that something is very wrong when 1 in 8 women in this country is predicted to get breast cancer in her lifetime in the first place...