Sun may help battle skin cancer, studies find

Some exposure to the sun is necessary for health - it is excessive exposure leading to burning of the skin that does the damage. Photo / Doug Sherring

Sunbathing is known to cause skin cancer - but it may also help people survive when they get it, scientists are reporting.

Two studies published yesterday showed that vitamin D produced by the action of the sun on the skin may help improve survival for patients with skin and bowel cancer.

The bizarre finding suggests that health warnings to avoid the sun have been too simplistic. Some exposure to the sun is necessary for health - it is excessive exposure leading to burning of the skin that does the damage.

A research team from the University of Leeds working with the US National Institutes of Health found a high level of vitamin D - suggestive of high sun exposure - protected patients with malignant melanoma, the deadliest form of skin cancer.

Those with the lowest levels of vitamin D in their blood at diagnosis were 30 per cent more likely to suffer a recurrence of the disease after treatment than those who had the highest levels.

Patients with the highest levels of the vitamin also had the thinnest tumours at diagnosis. Results of the study, funded by Cancer Research UK and the National Institutes of Health, are published in the Journal of the National Cancer Institute.

The findings add to the growing body of evidence that boosting levels of vitamin D could protect against a wide range of diseases, or extend survival with them. The gloomy weather and long winter in countries north of 30 degrees latitude, such as the UK, means that a large part of the earth's population is deficient in the vitamin between October and March. The weight of evidence has grown so dramatically that governments around the world are reviewing their minimum recommended limits.

In the second study, researchers led by Professor Kimmie Ng, from the Dana-Farber Cancer Institute in Boston, US, who followed more than 1000 bowel cancer patients for nine years, found those with the highest level of vitamin D were half as likely to die from the disease compared with those with the lowest levels. The results are published in the British Journal of Cancer.

Sara Hiom, director of health information at Cancer Research UK, which funded the melanoma study, said: "The key is to get the right balance between the amount of time spent in the sun and the levels of vitamin D needed for good health."

- INDEPENDENT