Head/neck skin cancer tied to chronic sun exposure

NEW YORK (Reuters Health) – People with melanomas in the
head and neck area have experienced a greater total amount of
sun exposure than those who develop the deadly skin cancers in
their trunk area, Australian researchers report.

The findings lend support to the theory that melanomas on
different parts of the body arise through different mechanisms,
the researchers note in the Journal of Clinical Oncology.

Dr. David C. Whiteman of the Queensland Institute of
Medical Research and colleagues tested their theory that people
with melanomas of the head and neck would have been exposed to
a greater cumulative amount of sun than people with melanomas
on the trunk.

They compared 154 patients with melanoma of the trunk, 76
with head and neck melanomas, and 76 with lentigo maligna or
lentigo maligna melanoma (LMM), the slowest-growing form of the
disease. LMM patients acted as a reference group to which the
other two groups were compared.

Head and neck melanoma patients were more than twice as
likely as trunk melanoma patients to have had high levels of
sun exposure, and were more than three times as likely to be
exposed to sun on the job. However, they were half as likely to
have high levels of recreational sun exposure.

“Melanomas of the head and neck are associated with chronic
patterns of sun exposure, whereas trunk melanomas are
associated with intermittent patterns of sun exposure,
supporting the hypothesis that melanomas may arise through
divergent causal pathways,” Whiteman and his colleagues
conclude.

SOURCE: Journal of Clinical Oncology, July 1, 2006.