Metastatic pattern of stage IV colorectal cancer with high-frequency microsatellite instability as a prognostic factor

K Fujiyoshi, G Yamamoto, T Takenoya… - Anticancer …, 2017 - ar.iiarjournals.org
K Fujiyoshi, G Yamamoto, T Takenoya, A Takahashi, Y Arai, M Yamada, M Kakuta…
Anticancer research, 2017ar.iiarjournals.org
Background: A recent clinical trial on the immune check-point inhibitor pembrolizumab
demonstrated that microsatellite instability (MSI) is a good biomarker for response to this
inhibitor. However, clinicopathological features of advanced colorectal cancer (CRC) with
high-frequency MSI (MSI-H) are unclear. Patients and Methods: A total of 2,439 surgically
resected CRC tissues were analyzed for MSI status, and mutational status of V-Ki-Ras2
Kirsten rat sarcoma 2 viral oncogene homolog (KRAS), neuroblastoma RAS viral oncogene …
Background
A recent clinical trial on the immune check-point inhibitor pembrolizumab demonstrated that microsatellite instability (MSI) is a good biomarker for response to this inhibitor. However, clinicopathological features of advanced colorectal cancer (CRC) with high-frequency MSI (MSI-H) are unclear.
Patients and Methods
A total of 2,439 surgically resected CRC tissues were analyzed for MSI status, and mutational status of V-Ki-Ras2 Kirsten rat sarcoma 2 viral oncogene homolog (KRAS), neuroblastoma RAS viral oncogene homolog (NRAS) and v-Raf murine sarcoma viral oncogene homolog B (BRAF). Stage IV cases were selected, and clinical and molecular features were evaluated.
Results
There was no significant survival difference observed between MSI-H CRC and microsatellite-stable (MSS) CRC in patients with stage IV disease (3.92 vs. 2.50 years; p=0.766). However, hematogenous and lymphogenous metastasis-dominant CRC with MSI-H demonstrated poor prognosis, whereas peritoneal metastasis-dominant CRC with MSI-H demonstrated good prognosis, (1.33 vs. 5.2 years; p=0.006).
Conclusion
Prognosis of stage IV CRC with MSI-H depended on the metastatic pattern. These findings provide useful information for the adaptation of CRC immunotherapy.
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