Saldanha G, et al. - Via a cohort study of 1,239 patients with cutaneous melanoma presented to the Leicester and Nottingham National Health Service hospital trusts in the United Kingdom, researchers ascertained calculated tumor area (CTA) precision and prognostic value. After adjusting for Breslow thickness, age, gender, ulcer, mitotic rate, and microsatellites, CTA was an independent prognostic factor in Cox proportional hazards regression models in 918 patients in the Leicester cohort. In multivariable analysis only when CTA was not in the model, Breslow thickness was notable. The relative importance of CTA was demonstrated by its retention in all 100 bootstrap multivariable models with backward selection, whereas Breslow thickness was retained in only 53. Melanomas stratified by CTA exhibited wider separation of survival curves than those stratified by Breslow thickness using the American Joint Committee on Cancer Staging Manual , 8th Edition, and the model with CTA categories had a Bayesian information criterion difference of 13.9 in comparison with T category, suggesting substantially better fit. A Harrell C index of 83.7% was noted in this model, and bootstrap analysis exhibited little evidence of model optimism, with a corrected calibration slope of 0.99. Thus, a novel microscopic feature, CTA, with evidence of its independent prognostic value was given in this study. Moreover, CTA should be a priority for a prospective study.