David, my husband, was diagnosed in July of 2018 with Bile Duct Cancer, Stage 1. He had a successful Whipple Surgery at Oregon Health Sciences University Hospital in Portland, Oregon (no metastasis and clean margins) and his recovery was better than expected. Following surgery, his Radiation Oncologist declared him "cancer free", but his oncologist recommended follow-up chemo therapy. He started a course of Capecitabine, and on day 7 began to have adverse reactions (vomiting, diarrhea). By day 11 he was in ER with a full body rash, mouth blisters and mucosa. He was released the next day with a fistful of RXs for each of these symptoms. Three days later I bought him back to the ER and he was admitted to the hospital for worsening symptoms, including Neutropenia, On day 17, he was finally seen by an oncologist making hospital rounds (and not seen prior to that by his own oncologist!!), and a DPD enzyme deficiency was immediately suspected. The antidote, Vistogard, was ordered but not delivered until 4 days later, and 7 days after that he died an excruciating and painful death in the ICU. The DPD enzyme deficiency generally results in death, as the chemo is not able to be metabolized. We were not verbally warned about this potential lethal outcome (yes, it is unexpected but no longer considered "rare"). We were not given the list of symptoms to watch for as well. His oncologist did not monitor his continuing deterioration, despite our many phone calls and ER visits. He did receive a blood test after the window of reversal had passed, and tested positive for the DPYD *2A variant. The antidote would have saved his life had his oncology team been alert to his symptoms and administered it within 96 hours of his last chemo dose. IN SUMMARY, I want to call attention to the issue of DPD enzyme deficiency when taking Capecitabine, Xeloda or 5-FU drugs. You must insist on testing -- either a blood or genetic test -- prior to taking this chemo. About 1000 people die a year in the US for the DPD enzyme deficiency when on this chemo. The doctors are playing Russian Roulette with your life if they do not make you aware of this potentially fatal reaction. My life's mission now is to spread the word about testing and monitoring in order to prevent one more excruciating death. It is totally preventable and the FDA refuses to mandate pre-testing. Testing is now required by law in France, and other European countries are beginning to follow. Please spread the word!