You are very close. When my brother was diagnosed with stage 4 pancreatic cancer I did some research. He was gone in less than 3 months. So many pancreatic cancers are not diagnosed until they’re already in stage 4.
And then there are people like RBG...
Outlook
Pancreatic cancer is the fourth most common cause of cancer death. The median survival rate for stage 4 pancreatic cancer is between two and six months. Though the disease cannot be cured at this stage, treatment may improve your quality of life.
Older people are as likely to respond well to treatment as younger ones, though life expectancy among older people with stage 4 pancreatic cancer is shorter. This is especially true if a person’s health is further complicated by other conditions like diabetes and high blood pressure.
Getting treatment for a late-stage cancer can be confusing and stressful. If you start to feel overwhelmed, ask your medical team, family, friends, and counselors for help and support.
https://www.healthline.com/health/pancreatic-cancer/stage-4#clinical-trials