DEAR DR. ROACH: Recently I was diagnosed with exocrine pancreatic insufficiency after symptoms of unexpected and sustained diarrhea for three months. I was also diagnosed with NAFLD (nonalcoholic fatty liver disease) last November. A year ago, I first noticed slight weight loss (5 pounds) and decreased energy. I am 69 years old, 6 foot, 2 inches tall and currently weigh 173. I underwent a colonoscopy (unremarkable) and a stool exam that showed below normal elastase (189 vs. 200 being the low end of normal). I will begin a drug therapy next week, using pancreatic enzymes, but I worry about pancreatic cancer. Recently I had two friends die of pancreatic cancer. I just can’t seem to get past the worry that I may have it. What do you suggest? – D.C.

ANSWER: The pancreas has two main jobs: to make insulin and other hormones (this is the endocrine function, from the Greek roots meaning “secretion within”), and to make digestive enzymes (exocrine, meaning “secretion outside”). The pancreatic digestive enzymes are critical for proper absorption of food, especially the fats we eat. Without pancreatic enzymes, food cannot be digested, and people will notice diarrhea, often with visible fat; abdominal discomfort; and weight loss. It takes near-complete insufficiency of the pancreas to develop severe symptoms.

There are several conditions that can cause exocrine pancreatic insufficiency. In my career, virtually all of the cases I have seen were due to recurrent episodes of pancreatitis, from alcohol or stones. However, cystic fibrosis and surgical removal of part of the pancreas, stomach or intestines can also lead to EPI, along with a few other rarer conditions.

Pancreatic cancer is one cause of EPI, because a tumor can block the duct that releases the enzymes. Because you haven’t identified any other cause of EPI and have had some weight loss, I would think a scan (CT or MRI) to look for pancreatic cancer or other structural pancreas problems would be prudent.

DEAR DR. ROACH: Is there an age limit where it is no longer necessary to have a mammogram or a colonoscopy? I’m 87 and having a debate with my daughters. – M.A.G.

ANSWER: Screening tests, like mammograms and colonoscopies, are performed on people with no symptoms in order to prevent problems later in life. There is always a cost of performing these tests. I don’t mean just the dollar costs, although these can sometimes be significant, but rather the potential for harm that can come from the test itself as well as from the follow-up testing and procedures that may be required.

For example, a colonoscopy requires a preparation (mildly unpleasant and time-consuming), sedation (which can have side effects) and the procedure itself, which may have unexpected bad outcomes (such as a perforation). None of these things is likely, but they become more likely as people get older. Moreover, if something abnormal is seen, it may require biopsy or even surgery, which have a much higher risk of an adverse outcome.

Balancing against these risks is the possibility of benefit. A premalignant polyp might be found and removed years before ever becoming a cancer. An early cancer might be identified and more easily cured. But there is always the trade-off between risk of harm now against possibility of benefit later. As people become older, the benefits “later” become less and the harms “now” tend to increase.

There is no defined or accepted age cutoff for these procedures, but for most people, the benefits and harms start to become about equal around age 75. Really healthy people with exceptional longevity might continue them until age 80 or more, but no experts recommend these screening tests beyond age 85.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or send mail to 628 Virginia Dr., Orlando, FL 32803.