I believe subset analysis of one breast-hypo fractionated trials showed worse hypofractionation outcomes with patients with the EIC (extensive intraductal component) subset. When I was in residency, my breast attending would conventionally fractionate those by hypo frac all others. In my current practice, my colleagues and I hypofrac just about everything except for pre-menopausal women who need RNI. In those cases we sometimes conventionally fractionate.
If I recall and read correctly in FAST-forward toward the end of the study they actually loaded up on ER- (and triple negative, and Her2+) to try and increase the power of the study to catch a difference because so few events were being seen.
I would have 0 hesitation to offer 5 fractions. It's literally current standard of care in the UK right now for any whole breast pt. fast forward had plenty of tumors with less than favorable features.
FWIW from ASTRO evidence-based guideline ...
Statement KQ1C. The decision to offer HF-WBI may be independent of hormone receptor status, HER2 receptor status, and margin status. Recommendation strength: Conditional Quality of evidence: Moderate Consensus: 100%*
Statement KQ1C. The decision to offer HF-WBI may be independent of hormone receptor status, HER2 receptor status, and margin status. Recommendation strength: Conditional Quality of evidence: Moderate Consensus: 100%*
Ah yes, EIC. While I also choose to hypofrac most every breast case, some of the older docs really grumble at me when they see patients with EIC getting hypofrac.
I have not seen convincing evidence about EIC and fractionation, but if anyone has a compelling argument otherwise, I would love to hear it.
(well, not really, because the amount of "I told you so" I would have to hear at the next chart rounds would be embarrassing)
This is for Moderate Hypofx (if referencing most recent WBI guidelines), not for 5Fx regimens.
Regardless, I would not not let ER negative patients get 5Fx WBI if I was doing that routinely in clinical practice. Currently, for me, I offer 26/5 in those who are also candidates for observation per CALGB/PRIME-II.
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deleted1111261
Yes, it's for "moderate hypofx", also called "modern fractionation" 🙂
Not routinely for ER-. What holds you back, though, for ER-? Is there data showing difference with regards to recurrence rates based on fractionation?
I would point out again that in FAST-forward over the 2011-14 recruitment period, patients from 2013 onward who were 65+yo, T1, Gr1/2, were EXCLUDED from the study if ER positive and could only be enrolled if ER-.
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deleted1111261
Florence study included ER- for 5fx PBI. I wonder why people use that as a reason to not use hypoFX or APBI. Where the tumor recurs within the breast or how sensitive it is to a dose hasn't been shown to correlate with receptor status (AFAIK).
Double negative in my previous post - I was trying to say that ER negative would not stop me from giving 5Fx.
In short, I would give ER negative 5Fx if I was otherwise considering 5Fx. Agreed that there is no data suggesting ER negative specifically cannot get 5Fx.
So a 65yo+ patient ER- could get offered 26/5.
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deleted1111261
"not not" - that was confusing! Got it.
