Your odds of surviving pancreatic cancer are 25:1. If you get it, you will probably die.
That's because pancreatic cancer research is shockingly underfunded and under-publicised.
People are already gambling with their lives, so let's make it a bit more obvious. For one race only, we rename a horse with 25:1 odds as 'Pancreatic Cancer', and give the demographic most likely to fall foul of the disease the chance to test their odds.
They'll almost definitely lose. That's OK - we'll match all bets and donate the money to Pancreatic Cancer Action, so they might not lose their life next time.