A Multi-cohort Study of the Prognostic Significance of Microsatellite Instability or Mismatch Repair Status after Recurrence of Resectable Gastric Cancer

• Published in: Cancer research and treatment Vol. 52; no. 4; pp. 1153 - 1161
• Main Authors: An, Ji Yeong, Choi, Yoon Young, Lee, Jeeyun, Hyung, Woo Jin, Kim, Kyoung-Mee, Noh, Sung Hoon, Choi, Min-Gew, Cheong, Jae-Ho
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Cancer Association 01-10-2020; 대한암학회
• Subjects: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols - administration & dosage; Antineoplastic Combined Chemotherapy Protocols - adverse effects; Chemotherapy, Adjuvant - adverse effects; Chemotherapy, Adjuvant - methods; Clinical Decision-Making; DNA Mismatch Repair; Female; Gastrectomy; Humans; Kaplan-Meier Estimate; Male; Microsatellite Instability; Middle Aged; Neoplasm Recurrence, Local - diagnosis; Neoplasm Recurrence, Local - genetics; Neoplasm Recurrence, Local - mortality; Neoplasm Recurrence, Local - therapy; Neoplasm Staging; Original; Prognosis; Retrospective Studies; Risk Assessment - methods; Risk Factors; Stomach - pathology; Stomach - surgery; Stomach Neoplasms - diagnosis; Stomach Neoplasms - genetics; Stomach Neoplasms - mortality; Stomach Neoplasms - therapy; Survival Analysis; Time Factors; Treatment Outcome; 의학일반; Recurrence; Biomarker; Prognosis; Microsatellite instability; Stomach neoplasms
• ISSN: 1598-2998; 2005-9256
• DOI: 10.4143/crt.2020.173

High microsatellite instability (MSI) is related to good prognosis in gastric cancer. We aimed to identify the prognostic factors of patients with recurrent gastric cancer and investigate the role of MSI as a prognostic and predictive biomarker of survival after tumor recurrence.
This retrospective cohort study enrolled patients treated for stage II/III gastric cancer who developed tumor recurrence and in whom the MSI status or mismatch repair (MMR) status of the tumor was known. MSI status and the expression of MMR proteins were evaluated using polymerase chain reaction and immunohistochemical analysis, respectively.
Of the 790 patients included, 64 (8.1%) had high MSI status or MMR deficiency. The tumor-node-metastasis stage, type of recurrence, Lauren classification, chemotherapy after recurrence, and interval to recurrence were independently associated with survival after tumor recurrence. The MSI/MMR status and receiving adjuvant chemotherapy were not associated with survival after recurrence. In a subgroup analysis of patients with high MSI or MMR-deficient gastric cancer, those who did not receive adjuvant chemotherapy had better treatment response to chemotherapy after recurrence than those who received adjuvant chemotherapy.
Patients with high MSI/MMR-deficient gastric cancer should be spared from adjuvant chemotherapy after surgery, but aggressive chemotherapy after recurrence should be considered. Higher tumor-node-metastasis stage, Lauren classification, interval to recurrence, and type of recurrence are associated with survival after tumor recurrence and should thus be considered when establishing a treatment plan and designing clinical trials targeting recurrent gastric cancer.