The pandemic kept me away from personal contact with my doctors and testing. My wife has a serious chronic illness, and I am older with some other problems. Had we developed a COVID infection, it would not have ended well. I have told you my personal cancer story before and you know that I received abdominal radiation and aggressive chemotherapy in 1990. We both are now fully vaccinated. I made an in-person appointment with my doctor, and she ordered some lab work. It turns out I have iron deficiency anemia. Iron deficiency is almost always about blood loss. Women frequently have iron deficiency related to childbirth and periods. Men are different. If a man becomes iron deficient and there is no history of obvious bleeding, it is usually coming from the digestive system and those individuals should have their colon and stomach examined to look for bleeding sources.
My case has an added twist, however. I received extensive radiation to my abdomen which inevitably damages the bowel. My radiation occurred 31 years ago, and I have had recurrent partial bowel obstructions for most of that time. I am now learning that radiation bowel injury is progressive. The bowel gets thinner, more inflamed, scarred, and there is also inflammation of the small arteries. The arterial injury leads to poor blood flow. Because of these changes the bowel is thin, with local narrow areas, and it is easily damaged by mechanical factors. The tissue is delicate. It does not heal well. The vessels easily break and that can be a source of chronic blood loss. I think that is where I am. There are no easy answers. Situations like these expand physician’s vocabularies so they understand what a conundrum is.
The scarred narrowing in my bowel is two inches long. So, you might think, that’s easy, just cut that part out. The problem is the bowel is damaged. It does not heal well and surgery itself causes bowel blockages. The damage I described earlier means the bowel is sick, it may develop a leak, infection, and the newly joined sections may not heal together. As many as 22% die from this surgery. I have found that I must be careful about my eating. Raw vegetables and fruits like an apple cause trouble. Overeating causes a problem. In fact, as part of my CT scan prep, I drank three pints of water in an hour immediately before the exam. Even that was enough to set it off. On the scan, the bowel upstream was dilated and with the last pint of water I started having mild cramping abdominal pain that signals a partial blockage is coming. Since this was just water, it quickly went away, and I was fine.
So far, I have had these symptoms twice a year. Partial bowel obstruction is easy to recognize. It begins as a mild cramping pain and then it builds, and it can become very severe. Anything blocking a hollow organ causes that same kind of pain—gallstones, kidney stones, even delivery. The pain builds up and then it goes away. If I stop eating and drinking and take one or two pain pills as needed, eventually the blockage opens, and I am ok.
This is pretty common problem. One million Americans have had cancer treatments that involved bowel radiation. They all have some degree of radiation bowel damage and if they live long enough it is likely to cause difficultly. You don’t hear much about it and someone reading this is probably at risk. I hope this story helps you understand the problem so you can deal with it more effectively.
Lesson- It turns out this is a perfect example of the new chronic disease model I have been taking about. I have a chronic condition called abdominal radiation disease. Make no mistake, my cancer was cured 31 years ago. I have had years of gravy. I am thrilled to be here to grumble, but there is a price to pay. Focused beams of abdominal radiation coming from different directions ideally kill the rapidly growing tumor cells, but they always damage other cells and organs. In the bowel the injury is progressive. Radiation increases oxidative particle formation. This is also known as oxidative stress, reactive oxygen species (ROS), or oxidants. The lining cells of the bowel also grow rapidly and that makes them especially sensitive to radiation and ROS. Genes in the damaged intestinal stem cells that produce ROS are persistently switched on and these changes are transmitted to daughter cells and adjoining tissues. As seen in the diagram below, these changes persistently activate master metabolic switch mTOR and inactivate AMPK which leads to intestinal cell death, inflammation, poor absorption, and scar tissue formation. Chemotherapy makes the severity of radiation bowel damage worse. The net effect is the chronic metabolic changes in the cells become a vicious cycle.
Once again, if you examine the diagram above, you can easily see why statins (atorvastatin), and ACE inhibitors (lisinopril) reduce the injury. We have discussed repeatedly the central role of oxidative particles in chronic diseases and aging. Chronic intestinal radiation damage is a chronic disease and it is no exception to this rule. Prior segments discussed the critical role of oxidative particles in cardiovascular and related conditions. Rapamycin in heart artery stents gradually leaks out to reduce inflammation and scar formation to keep the stent open by inactivating mTOR. ACE inhibitors (lisinopril), ARBs (losartan), statins, metformin, spironolactone, aspirin, and SGLT2 inhibitors do the same thing directly or indirectly in the heart arteries and the bowel. Statins and ACE inhibitors reduce acute radiation injury to the bowel and this effect is preserved at one year. Metformin inhibits mTOR directly, just like rapamycin does. It has reduces intestinal injury in lab animals and enhances damage to the target malignancy. I just increased my metformin dose by a half tablet.
Radiation enteritis is the most direct current threat to my quality of life and life itself. I will continue to take losartan, atorvastatin, metformin, and eplerenone which are antioxidant that inactivate mTOR and activate AMPK. I will eat real food, fast intermittently, and exercise to the extent I am able. These efforts also inactivate mTOR. I will live each day as normally as I can. If I go down, just know that I went down swinging.
Addendum: This article shows how angiotensin II and aldosterone play a central role in scar tissue and other tissue damage from radiation. It explains how lisinopril, losartan, and eplerenone could slow the process.