Published online Dec 15, 2026. doi: 10.4251/wjgo.124919
Revised: July 24, 2026
Accepted: August 17, 2026
Published online: December 15, 2026
Processing time: 136 Days and 21.7 Hours
Colorectal metastasis from gastric adenocarcinoma is a rare manifestation of advanced disease that frequently mimics primary colorectal adenocarcinoma, creating substantial diagnostic challenges and potentially leading to inappropriate management. Existing evidence is limited to isolated case reports and small institutional series, resulting in an incomplete understanding of its clinicopathologic characteristics, diagnostic approach, treatment patterns, and clinical outcomes. We hypothesized that comprehensive clinicopathologic evaluation of a retrospective cohort could improve recognition of this uncommon metastatic pattern and facilitate accurate diagnosis and appropriate clinical management.
To characterize the clinicopathologic features, diagnostic challenges, treatment patterns, and clinical outcomes of colorectal metastases from gastric adenocarcinoma.
We retrospectively reviewed patients with histologically confirmed colorectal metastases from gastric adenocarcinoma treated at a tertiary referral center from January 2011 to January 2025. Cases were identified through institutional electronic medical records and pathology databases using predefined eligibility criteria. Diagnosis was established by integrating clinical history, histomorphology, immunohistochemistry, and clinicoradiologic findings. Clinicopathologic characteristics, treatment strategies, and survival outcomes were analyzed using descriptive statistics.
Among 1485 patients diagnosed with gastric adenocarcinoma, six (0.4%) developed histologically confirmed colorectal metastases. The median age at colorectal metastasis diagnosis was 66 years (range, 39-78 years). Five patients (83.3%) had metachronous metastases with a median disease-free interval of 32 months (range, 20-131 months). Poorly cohesive carcinoma, including signet-ring cell carcinoma, was the predominant histological subtype. Immunohistochemistry demonstrated frequent cytokeratin 7 positivity with variable cytokeratin 20 and caudal-type homeobox transcription factor 2 expression, emphasizing the importance of integrated clinicopathologic correlation rather than individual markers for determining tumor origin. Surgery was primarily performed for symptom relief or diagnostic confirmation, while systemic therapy remained the principal treatment. Median overall survival after colorectal metastasis diagnosis was 9 months.
Colorectal metastasis from gastric adenocarcinoma remains diagnostically challenging. Accurate clinicopathologic correlation facilitates appropriate management, although prognosis remains poor despite multidisciplinary treat
Core Tip: Colorectal metastasis from gastric cancer is an exceptionally rare entity that frequently mimics primary colorectal carcinoma, creating substantial diagnostic challenges. In this retrospective study of six patients, we characterized the clinicopathologic features, immunohistochemical profiles, treatment strategies, and survival outcomes of this uncommon metastatic pattern. Our findings demonstrate considerable heterogeneity in cytokeratin 7, cytokeratin 20, and caudal-type homeobox 2 expression, emphasizing that immunohistochemistry should always be interpreted together with morphologic features and clinical history. Despite multimodal treatment, prognosis remained poor, although very late metastasis can occur more than 10 years after initial gastric cancer diagnosis.