A JAAD Letter Asks Whether "Faster Treatment" Was Ever Really Measured

A letter published June 8, 2026 in the Journal of the American Academy of Dermatology carries a title that reads like a verdict: "Time as a Substantial Confounder in Evaluating Integrated Multidisciplinary Care for Advanced Cutaneous Squamous Cell Carcinoma." It is worth being precise about what kind of document this is. It is not a new study. It is a commentary from Tengfei Wang, Yunke Li, and Mengru Pang of the Department of Burns and Plastic Surgery at the Affiliated Hospital of Guizhou Medical University in China, and its evidentiary weight is that of a critique, not a trial.

The paper it critiques is a retrospective cohort study led by Neal Ran and colleagues at Brigham and Women's Hospital and Dana-Farber Cancer Institute in Boston, spanning dermatology, radiation oncology, medical oncology, head and neck surgery, and radiology. That study, also in JAAD, concluded that an integrated multidisciplinary care model shortened time to treatment for patients with advanced cutaneous squamous cell carcinoma. The authors were, in effect, measuring the clinic model they themselves had built.

Wang and colleagues' objection centers on a design problem with a specific name in epidemiology: immortal time bias. When researchers classify patients as having received "multidisciplinary care" only after they have already survived long enough, post-diagnosis, to be routed into that pathway, the group can look like it fares better on time-to-treatment or survival simply because time had to pass before anyone could earn that label. Patients who died or dropped out early never get the chance to be counted as multidisciplinary-care recipients at all, which can flatter the intervention regardless of whether it did anything.

This is not a novel critique invented for cutaneous squamous cell carcinoma. The same bias has been debated for years in cardiosurgery outcomes research, most recently laid out in the European Heart Journal's explainer on immortal time bias as a hidden confounder in assessing cardiosurgical treatment effects, and in statin and oncology treatment-timing literature going back further still. The Wang letter is best read as an application of an established statistical caution to a fresh clinical claim, not a discovery in itself.

The chain did not stop there. A second commentary, published separately in JAAD, raised a different objection to the original Ran et al. study: that integrated multidisciplinary tumor boards are concentrated at major academic centers like Dana-Farber and Brigham, and that the paper's framing said little about whether patients in underserved or rural populations could access this kind of coordinated care at all. And in a reply dated the same month as Wang's letter, Ran and coauthors responded directly to the immortal-time-bias critique, though the specific statistical defense they offer, whether a time-dependent Cox model, a landmark analysis, or a revised definition of time zero, is not laid out in the summary record and would require pulling the reply itself from JAAD to confirm.

What the original retrospective cohort study can support, on its own terms, is narrower than the headline claim that integrated care "reduces time to treatment." A separate patient-reported-outcomes paper on multidisciplinary care for high-risk head and neck cutaneous squamous cell carcinoma, drawn from an overlapping patient population, found the intervention had minimal effect on health-related quality of life even as patient satisfaction stayed high, with roughly a third of patients still wanting more information or decision support. Time-to-treatment, quality of life, and decisional conflict are three different outcomes, and a single retrospective cohort was never built to settle all three at once.

Four papers now sit in this JAAD chain: the original cohort study, the equity-focused response, Wang's confounder critique, and Ran's reply. Read together, they show less that the integrated-care model failed and more that a single retrospective design, published in March 2026, could not carry the weight the field wanted to put on it, an editorial back-and-forth playing out in real time over three months as a claim about a Boston tumor board's performance got tested against exactly the kind of scrutiny that retrospective coordinated-care studies have failed to survive before.