The global financial crisis may have caused an additional 500,000 cancer deaths from 2008 to 2010, according to a new study, with patients locked out of treatment because of unemployment and healthcare cuts.

The figures were extrapolated from an observed rise in cancer deaths for every percentage increase in unemployment, and every drop in public healthcare spending.

"From our analysis we estimate that the economic crisis was associated with over 260,000 excess cancer deaths in the OECD (34-member Organisation for Economic Cooperation and Development) alone, between 2008-2010," said Mahiben Maruthappu of Imperial College London.

"This suggests that there could have been well over 500,000 excess cancer deaths worldwide during this time."