5 years or 5 days.

We’ve got the rant you’ve been looking for this holiday season. This editorial sums up what we’ve all been questioning for years: Why, again, are we omitting radiation in favor of years of hormone deprivation for low-risk ER+ breast cancers in older women? “Today, after more than two decades and significant advances in radiation, we still apply CALGB-9343 and PRIME-II results.” These trials were designed in the early 90s when radiation was delivered with 2D techniques without image guidance, much less breath hold or conformal partial breast techniques and with full courses delivered over many weeks. Nonetheless, the idea that the clearly effective radiation be omitted from adjuvant treatment rather than the arguably less tolerable and less consistent endocrine therapy remains the driver of trials accruing even today (think DEBRA, IDEA, and LUMINA). Good news is there is EUROPA, a large trial pioneering the comparison of aromatase inhibitors alone versus partial breast irradiation alone for women over age 70; bad news is it's unlikely to report until the 2030s. | Naoum, J Clin Oncol 2022