Is there an age cutoff you use to determine when you will offer standard vs hypofractionated breast radiation in early stage breast cancer?

About 20% of patients in both START A and START B were under the age of 50, and these were huge trials. As such, I don't see a compelling reason not to treat younger women with hypofractionation.

To put it another way, I don't think we have good reason to believe that schedules that are designed to be isoeffective to 50 Gy/25F would not act isoeffectively across different age groups. This is not to say that age doesn't affect recurrence risk (it probably does), but rather that choice of fractionation shouldn't affect risk within those groups.

I agree. Not only was there no significant difference in locoregional control between regimens in START B (the HR for LRR was actually 0.77 for the 40 Gy regimen compared to the 50Gy regimen, p=0.21), but the reduction in late normal tissue effects including breast shrinkage, induration, edema, and telangiectasia in long term follow-up is quite striking. Based on this compelling data I offer hypofractionation to my young patients now so they have the opportunity to potentially also benefit from the reduction in late toxicity, not to mention the convenience of a 3-4 week regimen in their busy lives.

The new ASTRO guideline on Radiation therapy for the whole breast has just been published on line in Practical Radiation Oncology (PRO). With a 93% consensus, the panel indicated that hypo-fractionated radiation may be used regardless of age. The discussion notes that followup data on hypo-fractionation of 10-15 years is not as long as standard fractionation, and although there is no reason to believe that the impact of fractionation will change after 10-15 years, that the physician engage the patient in individualized decision making, particularly for very young women considering their treatment options, given the evidence based followup for standard fractionation exceeds 20-25 years. As with the previous comments and as part of the task f...

There isn't a good reason to use age as a cut off, especially based on the evidence.

25% of the patients on the Canadian trial were under 50, and they did just as well as the older patients. In fact, their hazard ratio for local recurrence was lower (0.77 vs 1.02), so they may actually do better than older patients with hypofractionation, but this was not statistically significant, but still interesting. The START A and B trials had about 20% of their patients under the age of 50, and they also did well with hypofractionation. When they added those 2 studies together (in a subsequent report), there was a trend in favor of hypofractionation offering better local control in the younger patients, but again, this was not statistically significan...

I have used 50 as the general cutoff, but I will make exceptions for younger women if they need to be finished sooner.

I think the major issue with younger women, is that they often require chemo, and I do not like the hypofractionated schedule in that situation.