(Disclaimer: This article is only used for scientific purposes. To protect the privacy of patients, the relevant information in the following content has been processed) Abstract: The patient presented in this article is an elderly duodenal adenocarcinoma patient, who came to the clinic with symptoms of abdominal pain and coughing, and was diagnosed with adenocarcinoma of the duodenum after a comprehensive examination. As metastasis had already appeared at the time of diagnosis, the opportunity of surgery was lost, so chemotherapy was recommended. After standardized chemotherapy, the patient’s condition was temporarily stabilized, and the symptoms of abdominal pain and vomiting were relieved. Basic information] Male, 85 years old [Disease type] Duodenal adenocarcinoma [Hospital] The First Affiliated Hospital of Kunming Medical University [Date of consultation] January 2022 [Treatment plan] Chemotherapy (oxaliplatin injection, tiglio capsule) [Treatment cycle] 15 days of hospitalization, long-term outpatient chemotherapy [Effect of treatment] Temporary stabilization of the condition, abdominal pain, vomiting symptoms have been relieved I. Initial consultation The patient is 85 years old and has been experiencing vague pain in the upper abdomen for the past 2 years. Recently, the pain has worsened and symptoms of coughing and frequent vomiting have appeared. 1 week ago, the patient underwent a relevant examination in the local hospital, which suggested that there was a high probability of malignant tumor in the horizontal segment of the duodenum, accompanied by nodules in the left lung, and so she came to the clinic on the advice of her doctor to receive further examination. Detailed questioning of the patient and his family members revealed that the patient had a history of hypertension for 5 years and prostate hyperplasia for 10 years, and no obvious abnormal positive signs were found in his physical examination. Combining the patient’s medical history, symptoms, and the results of the out-of-hospital examination, he was initially diagnosed with a malignant tumor of the duodenum, and it was recommended that the patient be admitted to the hospital for further examination and treatment. After the patient was admitted to the hospital, the routine admission examination was completed, and PET-CT, tumor markers, gastroscopy and other related examination items were arranged at the same time. Tumor markers showed elevated carcinoembryonic antigen, PET-CT showed lesions in the descending, ascending and horizontal part of the duodenum, diagnosed as malignant tumor of duodenum, lesions invaded the head and neck of the adjacent pancreas, multiple nodules in the left lung, and polyps in the gallbladder, and gastroscopy showed stenosis of the descending part of the duodenum and chronic gastritis, and the pathological examination suggested adenocarcinoma of the duodenum, which was ultimately diagnosed as adenocarcinoma of the duodenum, and there was already infiltration of the pancreas, Pancreatic infiltration and lung metastasis were also present. Considering the patient’s age, the chance of radical surgery had been lost, so after detailed communication with the patient’s family, palliative treatment was given to improve the quality of life and prolong the survival period. After continuing to improve the relevant auxiliary examinations, exclude the patient’s contraindications to chemotherapy, given oxaliplatin injection combined with tiglio capsules for chemotherapy, the process went smoothly, no obvious side effects, 2 weeks after stopping the drug, the family asked to go home for treatment, and then agreed to leave the hospital. The patient was discharged after 15 days of hospitalization. The epigastric pain and frequent vomiting symptoms at the time of admission had been relieved, and the patient’s body tolerated the treatment to a better degree without obvious side effects of chemotherapy, and was arranged to be discharged from the hospital. The patient insisted on chemotherapy in the later stage, adjusting the chemotherapy regimen according to the relevant review indexes and symptomatic treatment each time. At present, 5 times of chemotherapy have been carried out, and the situation is still stable, relative to the median survival period of 4-7 months for patients with advanced duodenal adenocarcinoma, the patient has been surviving for 5 months, and his condition is still stable, with an improvement in the quality of life. After treatment, the patient’s discomfort symptoms such as abdominal pain and vomiting were reduced, and his condition was temporarily controlled and stabilized, which as the attending doctor was still relatively gratified. However, since the patient has missed the best treatment period and is now mainly on palliative care, she should strictly follow the doctor’s instructions to take the medication after discharge from the hospital, in addition, the patient should also actively control hypertension. Patients may gradually develop metastatic cancer pain, so the care and concern of their loved ones in daily life is very important. After being discharged from the hospital, patients should pay attention to daily diet, eat more high-protein nutrients and vitamin-rich fruits and vegetables, which can improve the degree of chemotherapy tolerance, and avoid eating too greasy and spicy stimulating food. If duodenal adenocarcinoma is found in early stage and treated in time, patients may have longer survival period and higher quality of life. However, as early symptoms of duodenal adenocarcinoma are atypical, mainly manifested as pain and digestive symptoms, so many patients will ignore it. It is recommended that people over 40 years old should have gastroscopy every year, especially those who have symptoms such as upper abdominal discomfort or dull pain.