NEW YORK, Sept 18 (Reuters) -- Sun exposure is known to increase the risk of skin cancer, but it may also cause cancers such as leukemia and lymphoma, according to a report issued this week in Britain.
The largest epidemiologic investigation to date in the U.K of the incidence of lymphoma, leukemia, and other hematologic malignancies shows a marked increase in the incidence of non-Hodgkin's lymphoma among Caucasians, officials with The Leukaemia Research Fund reported Tuesday.
Between 1984 and 1993, the number of cases of non-Hodgkin's lymphoma in England and Wales increased from 3,300 to 4,620 a year, an increase of 40%, according to the new findings. The data confirm patterns seen in Europe, North America and in Australia. The prevalence of non-Hodgkin's lymphoma is greatest in Scandinavia.
Dr. Ray Cartwright, director of The Leukaemia Research Fund clinical epidemiology unit at Leeds University says that there's increasing evidence that exposure to ultraviolet light may be a factor in the development of these cancers. "The really startling thing is that non-Hodgkin's lymphoma is increasing, year on year, in real terms by roughly 5%. If it continues, by early next century (it) will become the fourth commonest cancer, possibly the third," said Cartwright in an interview with The Daily Telegraph.
"Part of the increase may be due to better diagnosis and part to the aging population, but this is by no means the whole story," said Cartwright, who cited three theories about the root of the non-Hodgkin's lymphoma epidemic. One is that increasing pollution from sources such as the internal combustion engine is a causative factor. Another is that increasing use of antibiotics over the last 50 years has led to weakening of the immune system.
"The third theory, and my favorite, is that it is due to increased exposure to sunlight," Cartwright said. "We know that the population has been more exposed to the sun because of the increase in skin cancer. We know people who get skin cancer also get more lymphomas, and people whose occupations expose them to the sun, like farmers, get more lymphomas."
Other factors which support the theory are that there are more reported cases of non-Hodgkin's lymphoma in the south and southwest of Britain, where sun exposure is greater, and where the more affluent population tends to take more holidays to sun spots, according to the Telegraph report.
Researchers speculate that ultraviolet light from the sun affects blood cells as they travel through blood vessels in the skin.
The study examined 27,000 cases of leukemia, lymphoma, and other related diseases in a population of 11 million people.
SOURCE: The Daily Telegraph (September 17, 1997)
