Cancer appears to be inversely associated with both Alzheimer's and
Parkinson's disease. The relationship between
cancer and sporadic
motor neuron disease (
SMND), however, remains uncertain. Most previous
cancer-
SMND studies have been undertaken in northern hemisphere populations. We therefore undertook a case-control study to see if a link between
cancer and
SMND exists in an Australian population. A questionnaire was used to compare past
cancer diagnoses in 739
SMND patients and 622 controls, recruited across Australia. Odds ratios with 95% confidence intervals were calculated to look for associations between
cancer and
SMND. A history of
cancer was not associated either positively or negatively with a risk of subsequent
SMND. This result remained when age, gender, smoking status, and the four
SMND diagnostic subgroups were taken into account. No association was observed between
SMND and specific tumours, including
melanoma, a common
malignancy in Australia. In conclusion, this Australian case-control study does not support an association between a past history of
cancer and the development of
SMND. This suggests that some pathogenetic mechanisms, such as apoptosis, are less relevant in
SMND than in other
neurodegenerative diseases where negative associations with
cancer have been found.