You are taking care of your aging parents in their own home. They have a primary care provider, a cardiologist, a neurologist, and an oncologist. Frequently all of these providers do not talk with one another, and do not have a well coordinated plan of care.
So what do you do? One of the biggest things you can do to make things more seamless is to take a list of medications that your parents are taking and set up a visit with their primary care physician to make sure there medications are not producing unwanted results IE producing side effects. Often times medications can counteract each other, but with a well coordinated plan of care you can eliminate most if not all of those issues, because after all it is hard enough being a caregiver for your parents in the first place!