Socioeconomic and fashion trends may have contributed to increased incidence of melanoma over the past century, according to a recent study.

Researchers from NYU Langone Medical Center and NYU School of Medicine found that a century's worth of cultural and historical forces have contributed to the rise in the incidence of melanoma, including changes in fashion and clothing design.

The authors surmised that early diagnosis and improved reporting practices do not fully account for the steady rise in cases of melanoma. They set out to explore extenuating factors that may also have contributed to the increase in reported cases in the United States.

For the study, researchers analyzed clothing styles, social norms, medical paradigms, perceptions of tanned skin, economic trends and travel patterns. For comparisons between periods, they estimated percentage of exposed areas of the body. For example, early in the 20th century people donned clothing that almost totally concealed the body from head to toe. "Porcelain" skin was favored over the "tanned" skin, which was associated with a lower class of people who worked outdoors.

Researchers said changes in medical practice also would pave the way for a shift.

"In the early 20th century, sunshine became widely accepted as treatment for rickets and tuberculosis, and was considered to be good for overall general health," Polsky said.

This "medical prescriptive" translated into a growing belief in the benefit of tanning. People also began to enjoy more leisure time and to favor swimwear and sportswear that progressively covered less skin. Voices that raised concern about the dangers of UV exposure were largely ignored.

The reversal in attitude about tanned skin is another contributing factor, researchers added. Tanned skin became a sign of the leisurely upper class quality of life and good health. Graphs tracking the incidence by year and percentage of estimated skin exposure show that these developments rose in parallel with the rise in melanoma cases in the United States.

The increased incidence of melanoma over the years has been a particular concern, especially with the average age of diagnosis and death from melanoma trending younger than for most of the other major cancers.

The findings were published in the Oct. 6, 2014 issue of the American Journal of Public Health.