Winson Jianhong Tan1, Julie Liana Hamzah2, Sanchalika Acharyya3, Fung Joon Foo2, Kiat Hon Lim4, Iain Bee Huat Tan5, Choong Leong Tang2, Min Hoe Chew2. 1. Department of Colorectal Surgery, Singapore General Hospital, 20 College Road, Academia, Singapore, 169856, Singapore. winson.tan.j.h@singhealth.com.sg. 2. Department of Colorectal Surgery, Singapore General Hospital, 20 College Road, Academia, Singapore, 169856, Singapore. 3. Centre for Qualitative Medicine, DUKE NUS Graduate Medical School, Singapore, Singapore. 4. Department of Pathology, Singapore General Hospital, Singapore, Singapore. 5. Division of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore.
Abstract
PURPOSE: Microsatellite instability in colorectal cancer (CRC) and its long-term outcomes remains poorly studied in Asians. We investigate the prognostic significance of microsatellite instability in an Asian population and assess its clinical impact in patients who undergo adjuvant chemotherapy. METHODS: Six hundred fifty-four consecutive CRC patients who underwent surgical resection between January 2010 and December 2012 were recruited. Survival was estimated using the Kaplan-Meier approach. Univariate Cox proportional hazard models were used to estimate the hazard ratios for variables associated with survival. A subgroup analyses was performed for stage III patients who underwent chemotherapy to evaluate the prognostic significance of microsatellite instability in this group. RESULTS: Five hundred ninety-one (90.4%) patients were microsatellite stable (MSS) while 63 (9.6%) were microsatellite instable (MSI). Three years recurrence-free survival (RFS) and disease-specific survival (DSS) were 83.7 versus 73.7% (p = 0.295) and 87.1 versus 91.2% (p = 0.307) in MSS and MSI tumors, respectively. Among stage III patients who received adjuvant therapy, MSI status was found to be an adverse prognostic factor for RFS (HR 2.74 (95% CI 1.43-5.26), p = 0.002). This remained significant on multivariate analysis (HR 2.38 (95% CI 1.15-4.93), p = 0.018). Adjuvant chemotherapy was associated with survival benefit for patients with MSS tumors (HR 0.35, 95% CI 0.17-0.69, p = 0.002) but not MSI tumors (HR 0.67, 95% CI 0.08-8.15, p = 0.750). CONCLUSIONS: MSI status is not a prognostic indicator in the general CRC population but appears to be an adverse prognostic indicator for RFS in stage III CRC patients who received adjuvant chemotherapy.
PURPOSE: Microsatellite instability in colorectal cancer (CRC) and its long-term outcomes remains poorly studied in Asians. We investigate the prognostic significance of microsatellite instability in an Asian population and assess its clinical impact in patients who undergo adjuvant chemotherapy. METHODS: Six hundred fifty-four consecutive CRC patients who underwent surgical resection between January 2010 and December 2012 were recruited. Survival was estimated using the Kaplan-Meier approach. Univariate Cox proportional hazard models were used to estimate the hazard ratios for variables associated with survival. A subgroup analyses was performed for stage III patients who underwent chemotherapy to evaluate the prognostic significance of microsatellite instability in this group. RESULTS: Five hundred ninety-one (90.4%) patients were microsatellite stable (MSS) while 63 (9.6%) were microsatellite instable (MSI). Three years recurrence-free survival (RFS) and disease-specific survival (DSS) were 83.7 versus 73.7% (p = 0.295) and 87.1 versus 91.2% (p = 0.307) in MSS and MSI tumors, respectively. Among stage III patients who received adjuvant therapy, MSI status was found to be an adverse prognostic factor for RFS (HR 2.74 (95% CI 1.43-5.26), p = 0.002). This remained significant on multivariate analysis (HR 2.38 (95% CI 1.15-4.93), p = 0.018). Adjuvant chemotherapy was associated with survival benefit for patients with MSS tumors (HR 0.35, 95% CI 0.17-0.69, p = 0.002) but not MSI tumors (HR 0.67, 95% CI 0.08-8.15, p = 0.750). CONCLUSIONS: MSI status is not a prognostic indicator in the general CRC population but appears to be an adverse prognostic indicator for RFS in stage III CRC patients who received adjuvant chemotherapy.
Authors: Christine M Ribic; Daniel J Sargent; Malcolm J Moore; Stephen N Thibodeau; Amy J French; Richard M Goldberg; Stanley R Hamilton; Pierre Laurent-Puig; Robert Gryfe; Lois E Shepherd; Dongsheng Tu; Mark Redston; Steven Gallinger Journal: N Engl J Med Date: 2003-07-17 Impact factor: 91.245