Newswise — Vacationing at the shore led to a 5 percent increase in nevi (more commonly called "moles" ) among 7-year-old children, according to a paper published in Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research.

Number of nevi is the major risk factor for malignant melanoma, the most dangerous form of skin cancer. Melanoma rates have been rising dramatically over recent decades. More than 62,000 Americans are diagnosed with melanoma each year and more than 8,000 die.

The study was conducted among children who lived in Colorado, but lead author Lori Crane, Ph.D., M.P.H., chair of the Department of Community and Behavioral Health at the Colorado School of Public Health, said the findings are applicable worldwide.

"Parents of young children need to be cautious about taking their kids on vacations that are going to be sun-intensive at waterside locations, where people are outside for whole days at a time in skin-exposing swimsuits," said Crane.

Crane said parents often mistakenly believe that sunscreen is a cure-all. Although it does offer some protection, the likelihood is that children stay out in the sun longer, thus increasing their risk.

"We recommend that, for young children, parents keep the kids involved in indoor activities from 10:00 a.m. to 4:00 p.m. to decrease risk, or if they are to be outside, that they wear shirts with sleeves," said Crane.

Crane and colleagues examined 681 white children born in 1998 who were lifetime residents of Colorado. Vacation histories were assessed by interview and skin exams were used to evaluate the development of nevi.

Researchers observed that each waterside vacation one or more years prior to the exam at age 7 was linked to a 5 percent increase in nevi, or skin moles, less than two mm. "Daily sun exposure at home did not seem to be related to the number of moles, while waterside vacations were. Vacations may impart some unique risk for melanoma," said Crane.

Crane and colleagues also found that young boys had a 19 percent higher risk than young girls for nevi development. "This may be due to an increased likelihood among boys to want to stay outdoors," said Crane.

Finally, higher incomes were associated with greater risk, as those with higher incomes were more likely to take waterside vacations.

The mission of the American Association for Cancer Research is to prevent and cure cancer. Founded in 1907, AACR is the world's oldest and largest professional organization dedicated to advancing cancer research. The membership includes more than 28,000 basic, translational and clinical researchers; health care professionals; and cancer survivors and advocates in the United States and 80 other countries. The AACR marshals the full spectrum of expertise from the cancer community to accelerate progress in the prevention, diagnosis and treatment of cancer through high-quality scientific and educational programs. It funds innovative, meritorious research grants. The AACR Annual Meeting attracts more than 17,000 participants who share the latest discoveries and developments in the field. Special conferences throughout the year present novel data across a wide variety of topics in cancer research, treatment and patient care. The AACR publishes five major peer-reviewed journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; and Cancer Epidemiology, Biomarkers & Prevention. The AACR's most recent publication and its sixth major journal, Cancer Prevention Research, is dedicated exclusively to cancer prevention, from preclinical research to clinical trials. The AACR also publishes CR, a magazine for cancer survivors and their families, patient advocates, physicians and scientists. CR provides a forum for sharing essential, evidence-based information and perspectives on progress in cancer research, survivorship and advocacy.