What happened, in summary

A 61-year-old man presented in October 2020 with difficulty swallowing, anemia and weight loss. Endoscopy found a large antral stomach mass, and biopsy showed poorly differentiated adenocarcinoma with signet-cell foci. He received neoadjuvant chemotherapy from December 2020 through March 2021.

In April 2021, he underwent a D2 total gastrectomy. The tumor had responded poorly to preoperative treatment and involved multiple lymph nodes, although the resection margins were clear. He recovered and received adjuvant chemotherapy.

Seven months after surgery, abdominal pain and urinary complications led to further evaluation. Rectal examination and MRI showed diffuse thickening involving the rectum and anal canal. Biopsy demonstrated metastatic poorly differentiated adenocarcinoma consistent with spread from the gastric primary rather than a new colorectal cancer.

He was referred for palliative chemotherapy, but his condition deteriorated. Hospice-led end-of-life care was provided, and he died two months after the rectal metastasis was diagnosed.