Impact of chemotherapy on eosinophilia-associated advanced rectal cancer: A case report and review of the literature.

The present study reports a case of eosinophilia-associated rectal cancer that was successfully stabilized using chemotherapy, and reviews the mechanisms of eosinophilia and the importance of chemotherapy. A 65-year-old man, who had previously been diagnosed with suspected rectal cancer, presented with the chief complaint of melena. Eosinophilia, abnormal blood coagulation, and elevated carcinoembryonic antigen and carbohydrate antigen 19-9 tumor marker levels were observed, and the patient was subsequently diagnosed with advanced rectal cancer accompanied by multiple lymph node metastases that extended from the para-aortic lymph nodes to the left axillary lymph nodes. The complication of deep vein thrombosis was also observed. Tumor hemorrhage was exacerbated, and thus, Hartmann's procedure was performed. Pathological findings included poorly- to moderately-differentiated adenocarcinoma; however, no eosinophil infiltration was observed within the tumor. Following surgery, the eosinophilia and lymph node metastasis were exacerbated, and an oxaliplatin plus capecitabine chemotherapy regimen was initiated. The patient's eosinophil count and tumor marker levels normalized, and the lymph nodes decreased in size; however, re-enlargement of the lymph nodes was observed 6 months after surgery. The patient was then administered a chemotherapeutic regimen of irinotecan/fluorouracil/folinic acid + bevacizumab, and stable disease was maintained until pleural and peritoneal dissemination were observed at 22 months post-surgery. Following a rapid deterioration in condition, the patient succumbed to the disease at 23 months post-surgery. The present case indicates that although eosinophilia-associated colon cancer exhibits a poor prognosis, early chemotherapeutic intervention may improve this.