Oncotype not as effective on young women?

Perhaps it was my post?  In any case, it was my oncologist who says the Oncotype is not well tested in young women.  Very little is, in fact.  Many of the risk factors and outcomes are quite the opposite for young, premenopausal women.

I was 39 at diagnosis.  I had a different situation than you:  I was grade 3, and many hospitals still go by NCI guidelines and recommend chemo on that basis regardless of Oncotype.  The combination of that with my age, as well as LVI present on initial biopsy, none at final path (haunted me, didn't bother my onc, interestingly enough) made me convinced chemo was right for me, despite my score of 12.

I think the best thing you can do is get as many opinions from as many hospitals as possible.  Check the hospital designations.  Oncotype is most certainly not the only deciding factors at NCI and research hospitals. I got "yes", "no", and "maybe" from my three opinions, one from University of Chicago which is one of the leading research hospitals for BC in the country...that should give you some idea of how much work is needed to really get it right with us youngin's. 

I was so glad to see this discussion! I am 38 years old, stage 1 IDC, 2cm, grade 3, 0/2 nodes, unclear margins after surgery, ER/PR +, HER2-. I just received my oncotype dx number today and it is 22. The surgeon told me the oncologist will be suggesting no chemo which is completely opposite of what I was told at our initial meeting where she said the oncotype dx would have no factor in her decision--she was suggesting chemo. Although I am not jumping for joy to do chemo I do not want a recurrance in 10 or even 20 years. I feel it would be best to hit it hard now while I am young and in good health.  What are thoughts and feelings on people deciding to have chemo even if the doctor is suggesting it may not be necessary?

Mel_miller, if possible, please go get another opinion.  I'm not a doctor, but with your stats, two of my three opinions (both top-ranked hospitals in the country) would have said "yes" to chemo.

My solution to this: anyone diagnosed pre-menopausally should get three, not two opinions if possible.  Research the hospitals where you are getting the opinion.  Directives are different at teaching, research, NCI-ranked, etc. hospitals.

It's a complicated decision, but I think it's urgently important young women understand the standard of care may not apply in all our cases.  Grade can be predictive of Oncotype score, however, not always.  ALL the women in my chemo group (three of us) had unpredictable oncotype scores.  Two of the three had sky-high Oncotypes with grade 1.  I had a grade 3, and was a 12.

It's so very hard.  Chemo comes with risks.  So does not doing it. The medical field is a long way off from accurately assessing risk, but there are lots of studies to go on.  Some suggest that chemo is more effective in young women.  They really don't quite understand why.  Cessation of menses in ER/PR+ cancers is thought to be part of it, hence the studies on ovarian suppression + AI in lieu of chemo.  However, triple negatives seem to get more bang for the chemo buck in young women, too.  Other studies suggest cancer moves faster and more aggressively in young women.

Research and question as much as you can.  You have a fantastic window of opportunity to seek answers, but it comes and goes so fast, and that's why I recommend as many opinions as you can get.

Esmerelda... Once again, I will clarify the answer to your question regarding whether or not the Oncotype DX test is as effective for "younger" women as it is for "older women. When the folks who made the Oncotype DX test were looking for a sample of women who got breast cancer, they based THAT sample on the population of women who got breast cancer. In the population, a MAJORITY of women who get breast cancer are POSTMENOPAUSAL and are considered "older.". Those women who are PREMENOPAUSAL, are grouped as "younger" and they represent less than 40% of the population of all women who get breast cancer. So, the Oncotype DX test was validated based across the population despite the fact that FEWER premenopausal tumor samples were included.





Likewise, when the Oncotype DX test was developed, the folks also included a handful of rare histology breast cancers like mine, mucinous, in the sample based on the population. While mucinous BC only represents 2% of diagnosed breast cancers, the average Oncotype DX score for mucinous breast cancer has held pretty constant since the test became public. So, one might conclude that the test is significantly quantitative and quite predictive even with a MINORITY sample.

LtotheK.... The question regarding validation of the Oncotype DX test for various cohorts comes up often in various threads. I am EXTREMELY interested in the topic because I had been concerned that the test wasn't as strongly validated for my type of breast cancer and the fact that I was premenopausal at diagnosis. I follow the post trial data and I am very encouraged by the numbers that continue to be reported for mucinous breast cancer. The median score seems to be holding steady and it makes no difference whether someone is PRE or POST menopausal. The only question that needs answering in my book is the one that can only be answered by the TailorX trial, and that is at what Intermediate score does the benefits of chemo outweigh the risks. Unfortunately we won't have that answer for several more years.



I also think that until we know with certainty, the Oncotype DX test might not hold as much weight especially for younger women in the intermediate score range. However, I am encouraged by the fact that for most women whether PRE or POST menopausal who have low scores are mostly being recommended to not under go chemo. This is a really important finding because before the test was marketed, oncologists knew they were OVER treating many ER positive women and now many are being spared chemo.





If anyone is interested, they can google search how EXACTLY the test was designed. Fascinating! Furthermore, the design of the TailorX trial is interesting reading as well...

LtotheK....I hear the frustration in your postings. Hopefully, in the not too distant future, population based studies will be a thing of the past and individualized treatment based on each of our unique genomics will guide our treatments...  Maybe it's a little too late for us...but it's NEVER too late....

OncoType has not been used in Canada to determine treatment plans to the same degree that it's relied upon in the States.  I'm not sure what the reasoning is behind that.  I don't know if the government has rejected the test as unreliable or if the oncology community doesn't trust it, or whatever.  I do know that a few women have had it, recently, and have used the results to determine their treatment plans.  But it's still very much the exception here.

Selena...I think Ontario is permitting the use of the Oncotype DX test. Also interesting is the data regarding post marketing that reports that many women who would have been encouraged to have chemo based on St. Gallen and NCCN guidelines, have chosen instead endocrine therapy without chemo based on their low Oncotype DX score.This data suggests that the role of the Oncotype DX test is becoming more generally accepted.

Bevin, good point. A way to limit treatment.