Welcome back to the journal review. This is our December twenty twenty-five run through the Journal of the American Academy of Dermatology, and we've got four pieces worth your time this month — a new field cancerization scoring tool, a randomized trial on sequential AK therapy in transplant patients, a county-level look at climate and melanoma incidence, and a practical piece on when confocal microscopy actually earns its keep after digital dermoscopic follow-up. Let's get into it.

First up is a brief report proposing a new clinical scoring system called FAST — the Field cancerization Actinic keratosis Severity Tool, essentially a three-tier global assessment for photodamage and AK burden. This is a retrospective cohort study, and the gap it's addressing is one you already feel in clinic: raw AK counts and tools like the Actinic Keratosis Area and Severity Index have poor interrater reliability or are just too cumbersome for routine visits. So a group of authors across several academic centers in the US and UK developed a dead-simple three-stage scale — FAST one is photodamage without discrete AKs, FAST two is discrete non-confluent AKs, and FAST three is confluent AK or field SCC-in-situ so extensive you can't count discrete lesions anymore. The idea is that a clinician can eyeball this in seconds during a regular skin exam.

Methodologically, they enrolled 338 patients, almost entirely Fitzpatrick one through three and almost entirely White, across six sites, excluded anyone with field therapy in the prior three years so treatment wouldn't muddy the picture, staged them with FAST, then went back through the chart to see who'd had a keratinocyte carcinoma in the preceding two years. That's a sensible retrospective design here — you're validating whether a snapshot score correlates with a real clinical outcome, and looking backward lets you capture that two-year cancer history efficiently without waiting years for events to accrue prospectively. They used Fisher's exact test for the associations and logistic regression to generate adjusted odds ratios controlling for age, sex, and immunosuppression status.

The results are the real story here. As FAST stage climbed, so did the proportion of patients with facial keratinocyte carcinoma and specifically facial squamous cell carcinoma — facial SCC went from about one in a hundred at FAST one, up to roughly one in seven at FAST two, up to about one in three at FAST three. After adjusting for age, sex, and immunosuppression, FAST two carried roughly a sixteen-fold increased odds of facial SCC, and FAST three carried a striking forty-some-fold increased odds, both clearly statistically significant. Scalp SCC showed a similar gradient, with FAST three again driving a significant roughly seven and a half-fold increase in odds. Basal cell carcinoma, notably, showed no such relationship with FAST stage at all — this tool tracks specifically with the squamous pathway, which makes biologic sense given it's measuring field actinic damage.

The authors are appropriately modest in their conclusions — this is a single retrospective cross-sectional look, it's not prospectively validated, and the cohort is overwhelmingly light-skinned, so generalizability to skin of color is unknown. They frame FAST three patients as a group who may warrant more aggressive field therapy and closer follow-up, and they call for prospective work to see whether treating down a FAST stage actually reduces subsequent SCC risk — that causal link isn't established yet.

For your practice, I'd call this interesting and plausible but not yet practice-changing in the sense of mandating a new documentation habit — the odds ratios are large enough that the signal feels real, and the tool is genuinely fast to apply, so there's little downside to starting to note FAST stage in your own field-damage patients, especially anyone drifting toward stage three on the face. Just don't treat it yet as a validated risk-stratification instrument the way you would, say, AJCC staging.

Second article is a randomized clinical trial, and this one has more direct actionability: sequential cryotherapy followed by topical tirbanibulin versus cryotherapy alone for actinic keratoses in solid organ transplant recipients. The clinical problem is familiar — transplant patients have essentially no spontaneous AK regression, a thirty-two-fold increased risk of progression to SCC, and shockingly little trial data on tirbanibulin specifically in this immunosuppressed population, since the pivotal phase three trials were done in immunocompetent patients.

This was a single-center, intra-individual, observer-blinded trial — each of the forty enrolled transplant recipients got cryotherapy on two matched twenty-five square centimeter areas of face or scalp, then one side was randomized to receive tirbanibulin a month later while the other got nothing further. The intra-patient split design is a smart choice here methodologically — by using each patient as their own control, you eliminate between-patient variability in field cancerization severity, immunosuppression regimen, and sun exposure history, which lets a modest sample size still detect a real treatment effect. Efficacy was read by a blinded dermatologist using standard AK mapping and grading, and the primary endpoint was percent change in AK count at four months.

Thirty-seven patients completed the trial. The sequential arm saw AK counts drop by about eighty-two percent on average, versus about fifty-three percent with cryotherapy alone — a highly significant and clinically meaningful gap. Complete clearance was achieved in about half the sequential-treatment patients versus roughly one in ten with cryotherapy alone, again significant. And critically for a field-cancerization strategy, new lesion development between month one and month four was cut roughly in half with the addition of tirbanibulin, while the cryotherapy-alone side actually saw a rise in total AK count over that same window — lesions kept appearing and persisting. Tolerability was reassuring: local skin reactions were essentially universal but mostly mild, no grade four reactions, pain was minimal, and quality-of-life scores didn't differ meaningfully between the two treatment areas by the end of the study.

The authors are upfront about the limits — four months is a short follow-up for a disease process that plays out over years, and since most of the tirbanibulin applications after the first were self- or family-administered at home, adherence can't be fully verified. It's also a single center with an industry funding source from the manufacturer.

Practically, I'd call this close to practice-changing for your transplant population specifically. The effect size is large, the biologic rationale is sound, and it directly targets the subclinical field that lesion-directed cryotherapy alone can't touch — which matters enormously in a population where AKs essentially never regress on their own. I'd feel comfortable incorporating sequential cryo-then-tirbanibulin into your transplant AK management now, while still watching this population closely given that two SCCs, one in situ and one invasive, still emerged during follow-up on treated skin.

Third is a brief report using a purely ecological, population-level design — an analysis of climate and UV variables against melanoma incidence across more than two thousand US counties. The question being asked is whether the well-established temporal relationship between rising UV exposure and rising melanoma incidence over time also holds up geographically — do sunnier, hotter counties simply have more melanoma than colder ones.

The methodology here is straightforward correlation and linear regression, pulling melanoma incidence from SEER and the National Program of Cancer Registries and matching it to CDC environmental tracking data on temperature and UV irradiance, covering over eighty percent of the US population. This is inherently an ecological design, which the authors themselves flag as a limitation — you're correlating county-level averages, not individual behavior, so you can't attribute risk to any given person's actual sun exposure.

The temporal finding replicates prior literature cleanly — average daily UV dose and melanoma incidence rose together year over year, a strong and significant correlation. But the geographic finding is the twist, and it's counterintuitive: counties with lower year-round temperatures and, in the overall population, lower average UV actually had higher melanoma incidence, a significant inverse correlation. When they broke it out by race, the relationship for non-Hispanic White populations specifically was a positive, though quite small, correlation with UV — statistically significant but not a large effect. Counties with larger Black populations had significantly lower melanoma incidence, and counties with older populations had significantly higher incidence, both expected findings that don't tell us anything new mechanistically.

The authors' interpretation is that this apparent paradox — more melanoma in colder, lower-UV counties — likely reflects modifiable behavioral factors rather than true protective effects of cold climates: intermittent high-intensity UV bursts from winter travel to warmer destinations, outdoor recreational and occupational exposure patterns in places like Maine or Montana, and possibly the dangerous misconception that cloudy or cold climates are inherently lower risk, leading to laxer sun protection. That's a reasonable interpretation but it remains speculative, since the ecological design simply can't test individual behavior directly.

This one is genuinely interesting but not remotely practice-changing at the level of individual patient care — it doesn't change how you counsel any given patient in front of you. Where it is useful is as ammunition for public health messaging: it's a nice data point to cite when a patient in a northern, cooler climate assumes they're at lower risk and could use a reminder that intermittent intense exposure and outdoor recreation patterns matter more than ambient regional climate.

Fourth and last is a retrospective single-center study asking a very practically-minded question: among high-risk melanoma patients on total body photography and sequential digital dermoscopic follow-up, which lesions can skip reflectance confocal microscopy and go straight to excision, and which genuinely benefit from that extra confocal step.

They retrospectively reviewed one hundred four suspicious melanocytic lesions identified through digital dermoscopic follow-up, split into those sent directly to surgery and those that went through RCM first, with three expert dermoscopists reviewing baseline and follow-up images for specific static and dynamic dermoscopic features. The rationale for this design is implicit but clear — RCM adds real time and cost to a high-risk surveillance program, so if certain dermoscopic changes are reliable enough on their own to warrant excision, you can triage more efficiently without a formal prospective trial; a retrospective comparison of the two decision pathways as they actually happened in real practice is a pragmatic way to interrogate that.

Of the sixty-eight lesions that went through RCM, forty were ultimately excised, nineteen of which were melanoma, while twenty-eight were spared unnecessary surgery entirely — which is RCM doing exactly its intended job. The thirty-six lesions sent straight to excision without RCM yielded fifteen melanomas. When they compared the dermoscopic profiles of the two groups, the directly-excised lesions were significantly more likely to show focal structural change, regression, atypical blotches, and streaks — all several-fold more common in the direct-excision group, and all statistically significant. Within the RCM-assessed group specifically, asymmetrical growth over time was seen in about half the lesions that turned out to need excision versus only a quarter of the benign ones, also significant, whereas symmetrical growth pattern leaned benign in both groups. And importantly, when they compared the dermoscopic profile of melanomas caught after RCM against those excised directly without it, there was no meaningful difference between them — which is the crux of the argument for skipping the confocal step in certain cases.

The authors are careful to note this reflects real-world selective RCM use rather than the protocol-driven universal RCM-then-excise-everything design of earlier foundational studies, which they argue is both a strength for generalizability and a reason their findings differ somewhat from that prior literature. Limitations are the retrospective single-center design and the absence of histology for lesions that were never excised, though they did require a minimum two-year clinical follow-up as a safety net for those spared lesions.

The practical takeaway: if you're running a total body photography and sequential dermoscopy surveillance program, lesions showing asymmetrical growth over time, new focal structural change, regression, atypical blotches, or streaks are reasonable candidates to send straight to excision rather than routing through RCM first — that's a genuinely actionable triage heuristic. I'd call it practice-refining rather than fully practice-changing, since it's one retrospective single-center dataset, but it aligns with and extends prior work, and the logic holds up: RCM's real value is in the equivocal middle ground, not in lesions already showing high-confidence dermoscopic red flags.

That wraps our four articles this month — a promising new field-severity staging tool that tracks tightly with SCC risk, solid randomized evidence for adding tirbanibulin after cryotherapy in your transplant patients, a reminder that geographic climate correlations with melanoma are messier and more behavior-driven than they first appear, and a useful dermoscopic checklist for deciding when confocal imaging is actually earning its place in your surveillance workflow. Thanks for listening, and we'll see you next month.