Tag: UV

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High Melanoma Rates Reported in Sunny US State

On By ModernMedia

A study reports that melanoma mortality among people in Utah, a sunny, high-altitude state, outpaced that of the rest of the country over 1975 to 2013.

This runs counter to the falling melanoma death rates in recent years in both Utah and the United States, a trend likely due to improved treatments such as immunotherapy. It is still the deadliest skin cancer type, with melanoma diagnosis rate in Utah the highest in the US.

Motivation for the research was recent evidence showing that for most of the 1990s and 2000s, even as melanoma mortality in the United States remained constant, incidence increased six-fold. This increasing incidence without accompanying mortality rise indicates overdiagnosis, ie false cancer diagnoses. 

In the case of melanoma, overdiagnosis may result from increased scrutiny, where increasing numbers of biopsies may find a benign lesion that would have gone undetected.

Since Utah has the highest melanoma incidence, a team from Huntsman Cancer Institute (HCI) at the University of Utah set out to evaluate the state’s melanoma diagnosis and death rate data. Biostatistician Kim Herget analysed data from the Utah Cancer Registry, a National Cancer Institute Survival, Epidemiology, and End Results (SEER) database, and the researchers found that in contrast to the rest of the country, melanoma mortality in Utah rose 0.8% per year from 1975 to 2013. Even though Utah’s melanoma death rates have been falling in recent years, they are still higher than the rest of the country.

“Although we agree that overdiagnosis of melanoma is a growing problem, the sustained increase in melanoma mortality in Utah suggests that at least some fraction of the increasing incidence is real and cannot be attributed solely to overdiagnosis,” said Doug Grossman, MD, PhD, who co-leads the HCI melanoma and skin cancer centre at HCI and serves as professor of dermatology at the University of Utah. “Our research underscores an increased risk for Utahns, and so we must remain vigilant about melanoma. For doctors, this means regular conversations with patients about their skin health and family history. For patients, this means practicing sun-safe behaviors like diligent sunscreen use, wearing sun-protective clothing, and monitoring their skin at home on a monthly basis to reduce risk of skin cancer and optimize early detection.”

Future studies should determine whether this trend in people living in Utah results from increased ultraviolet exposure in a mostly fair-skinned population living in a sunny, high-altitude climate or if it is associated with other factors such as environment or genetics. Melanomas are also found at higher rates in immune compromised patients.

Source: Medical Xpress

Journal information: Doug Grossman et al, The Rapid Rise in Cutaneous Melanoma Diagnoses N Engl J Med 2021; 384:e54 DOI: 10.1056/NEJMc2101980

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UV Key to Seasonality of Airborne Respiratory Diseases

On By ModernMedia

It has long been observed that flu seasons in the northern hemisphere tend to last over autumn and winter, while in regions closer to the equator, they tend to have a year-round prevalence.

A group of Italian researchers believe that the sun – specifically its UV rays, which are known to inactivate various pathogens – holds the key. This periodic change in UV radiation over the seasons resonates with another cyclical event – the loss of resistance in the host over half a year of antigenic drift. The researchers incorporated these effects into a series of models, which reflect the seasonality of airborne respiratory diseases.

“From an epidemiologic point of view, these models clarify an important and long-standing mystery: why do influenza epidemics disappear every year when the number of susceptible individuals is still very far from that needed to trigger the herd immunity mechanism?” said Mario Clerici, Immunologist at the University of Milan and the Don Gnocchi Foundation.
“The Italian data of the SARS-CoV-2 pandemics can also be described accurately by our model,” said Fabrizio Nicastro, INAF researcher and PI of the work, “but the predictive power of the model depends critically (other than on the implementation of new restriction measures) on the exact UV-B/A lethal doses for the COVID-19 virus, which our collaboration is about to measure.”

Source: Medical Xpress