Simplify the following text for a Grade 10 native English-speaking person.
Original: Patients diagnosed with pancreatic cancer typically have a poor prognosis , partly because the cancer usually causes no symptoms early on , leading to locally advanced or metastatic disease at time of diagnosis .
Simplified: Pancreatic cancer is cancer affecting the pancreas . It has a poor prognosis , with less than 5 % of patients surviving beyond five years after the cancer has been diagnosed .