Microsatellite instability did not predict individual survival of unselected patients with colorectal cancer

Abstract

No clear influence of MSI status on overall survival and response to 5-FU chemotherapy was found.

Microsatellite instability and DNA ploidy in colorectal cancer

“…Although a previously performed meta-analysis on all studies published up to 2003 stated that there was an overall weak yet significant survival benefit from having MSI, 13 our study was in line with more recently obtained results reporting no significant differences in DSS for patients who had the MSI genotype compared with patients without MSI. 14,15,[17][18][19][28][29][30] It is noteworthy that, in recent years, laboratory molecular diagnostics and standardization of MSI testing have improved; however, the determination and interpretation of MSI remains an ongoing clinical challenge. 16,31 Also, the discrepancies in the reported survival results also reflect the heterogeneity of the populations studied; eg, unselected or institutional series of sporadic CRC, 14,32 hereditary cancer (hereditary nonpolyposis CRC) screening, 19 analysis of adjuvant chemotherapy trials, 15,17 site-and/or stage-specific analyses (ie, only colonic cancers, only stage II and/or III cancers), as well as in age-related, geographic, and ethnical differences.…”

“…14,15,[17][18][19][28][29][30] It is noteworthy that, in recent years, laboratory molecular diagnostics and standardization of MSI testing have improved; however, the determination and interpretation of MSI remains an ongoing clinical challenge. 16,31 Also, the discrepancies in the reported survival results also reflect the heterogeneity of the populations studied; eg, unselected or institutional series of sporadic CRC, 14,32 hereditary cancer (hereditary nonpolyposis CRC) screening, 19 analysis of adjuvant chemotherapy trials, 15,17 site-and/or stage-specific analyses (ie, only colonic cancers, only stage II and/or III cancers), as well as in age-related, geographic, and ethnical differences. 20,33 It is also is worth noting that, in the current study, the majority of older patients (aged >75 years) were excluded from the systematic surveillance program and, as such, were not included in the current survival analysis.…”

“…33 MSI also has demonstrated prognostic value in very young CRC patient populations 34 and, in several heterogeneous (stage-dependent) analyses, included patients of all ages derived from trials on adjuvant chemotherapy or selected cohorts of patients. 14,15,17,18,28,32,35,36 In the current population-based study on surveillance after surgery, the exclusion of elderly patients may have masked an overall survival benefit with regard to MSI. However, the current results are in line with several other studies, which reported no statistically significant difference in DSS for patients who had MSI tumors, although the results demonstrated nonsignificant trends or only stage-dependent improved overall survival for patients who had MSI tumors.…”

“…11,12 Most previous studies on MSI status in patients with CRC have focused on survival and response to chemotherapy, for which recent data continue to produce equivocal results. [14][15][16][17][18][19] Conversely, few, if any, studies have investigated the effect of MSI status in CRC on recurrence patterns and survival among patients who were included in a strict surveillance program. Thus, in this study, we investigated the role of MSI and CIN on the influence on recurrence (locoregional or distant) and disease-specific survival (DSS) in a defined patient cohort that underwent systematic surveillance after curative resection of CRC.…”

Large proportion of low frequency microsatellite-instability and loss of heterozygosity in pheochromocytoma and endocrine tumors detected with an extended marker panel

“…In colorectal cancer (CRC), high-frequency MSI is independently predictive for an improved prognosis and reduces the feasibility of metastasis (Gryfe et al 2000). However, several studies contradict an improved survival for MSI-positive CRC patients (Lamberti et al 2007;Storojeva et al 2005). Based on these controversial reports, MSI routine screening for CRC patients is not recommended at present.…”