onc brain

The longer read

The value of this trial is not its effect size but its position in the argument. HERO established that relugolix carried fewer major adverse cardiovascular events than leuprolide, and that finding has been awkward ever since, because the two drugs suppress testosterone to a comparable degree and should therefore produce comparable hypogonadal metabolic and dyslipidemic effects. A difference in outcomes with no difference in the presumed causal pathway invites the suspicion that the HERO signal was an artifact of trial conduct, differential discontinuation, or imbalance in baseline risk rather than pharmacology. REVELUTION was built to test whether there is a mechanism at all, and it reports one: an adjusted 68.9 mm³ greater increase in total coronary plaque volume under leuprolide at twelve months, concentrated in the non-calcified compartment.

That compartment matters more than the total. Calcified plaque is the stable, healed end of the spectrum; non-calcified and low-attenuation plaque are the phenotypes cardiology associates with rupture and with events. A total-volume difference driven by calcification would have been reassuring and largely uninterpretable. One driven by non-calcified plaque is at least the right shape for the proposed biology, GnRH receptor engagement on circulating immune effector cells acting at the coronary endothelium. It is worth being clear that the trial tests the imaging correlate of that hypothesis, not the hypothesis itself; no immune readout is reported in this source.

The methodological features that should move confidence run in both directions. Blinded reads, a validated automated quantification tool rather than human calipers, prespecified adjustment for age, statin use and baseline plaque volume, and stratified randomization on a cardiology-standard ten-year risk score are all the right choices for a surrogate-endpoint study, and they address the confounders most likely to manufacture a spurious difference. Against that: single institution, open label, and ninety-four men divided across a randomized comparison plus a separate non-randomized radiotherapy-alone cohort. Neither the per-arm counts nor the confidence intervals appear in this source, which makes the precision of the 68.9 mm³ estimate impossible to judge here, and adjusted mean differences in small samples are exactly where fragile results live.

The radiotherapy-alone cohort is the most interesting design element and the least resolved. Every man in the trial received prostate radiotherapy with or without pelvic nodal coverage, so radiotherapy is a constant across the randomized comparison and cannot confound it. But the parallel cohort was enrolled, not randomized, and lower risk by construction, so it can suggest what plaque does without hormonal therapy while remaining unable to separate the contribution of the radiotherapy itself. For a radiation oncologist that is the question left open: whether pelvic irradiation contributes anything measurable to coronary plaque trajectory, on top of the ADT effect this trial does resolve.

What would have to be true for the result to be wrong is a small number of imbalanced high-plaque-burden patients in one arm, which adjustment for baseline volume mitigates but does not eliminate at this sample size. Replication in a multi-institution cohort with reported precision would settle it. In the meantime, the honest read is that HERO's outcome difference now has a plausible and measurable mechanism behind it, which raises the prior on that difference being real without independently demonstrating that switching agents prevents events.