Exploring the Prognostic Role of Microsatellite Instability in Patients With Stage II Colorectal Cancer: A Systematic Review and Meta-Analysis.
Many studies have disclosed the prognostic effect of microsatellite instability (MSI) and/or loss of mismatch repair proteins in colorectal cancer. Nevertheless, little evidence supports their role in the decision-making of adjuvant therapy for patients with stage II disease.



The aim of this systematic review was to evaluate the prognostic and/or predictive role of MSI status in patients with stage II colorectal cancer on disease-free survival and overall survival. MEDLINE, EMBASE, and Cochrane libraries were searched to identify eligible studies.



Only 2 of 389 articles identified fulfilled the eligibility criteria. In both treated and untreated patients, high-level MSI improved disease-free survival compared with low-level MSI, suggesting a prognostic role but not supporting the hypothesis of a predictive effect of MSI.



Further studies are needed to explore the predictive role of MSI/mismatch repair proteins, because available data do not allow definitive conclusions.
Clinical and Molecular Medicine Department, Sapienza University, Rome, Italy.
Adriana
A
Romiti
Laboratory of Clinical Research, Department of Oncology, IRCCS - Istituto di Ricerche Farmacologiche 'Mario Negri', Milan, Italy. Electronic address: eliana.rulli@marionegri.it.
Eliana
E
Rulli
Clinical and Molecular Medicine Department, Sapienza University, Rome, Italy.
Emanuela
E
Pilozzi
Laboratory of Clinical Research, Department of Oncology, IRCCS - Istituto di Ricerche Farmacologiche 'Mario Negri', Milan, Italy.
Chiara
C
Gerardi
Clinical and Molecular Medicine Department, Sapienza University, Rome, Italy.
Michela
M
Roberto
Laboratory of Clinical Research, Department of Oncology, IRCCS - Istituto di Ricerche Farmacologiche 'Mario Negri', Milan, Italy.
Lorenzo
L
Legramandi
Clinical and Molecular Medicine Department, Sapienza University, Rome, Italy.
Rosa
R
Falcone
Laboratory of Clinical Research, Department of Oncology, IRCCS - Istituto di Ricerche Farmacologiche 'Mario Negri', Milan, Italy.
Ilaria
I
Pacchetti
Clinical and Molecular Medicine Department, Sapienza University, Rome, Italy.
Paolo
P
Marchetti
Laboratory of Clinical Research, Department of Oncology, IRCCS - Istituto di Ricerche Farmacologiche 'Mario Negri', Milan, Italy.
Irene
I
Floriani
D000970:Antineoplastic Agents / Q000008:administration & dosage*; D017024:Chemotherapy, Adjuvant; D000066491:Clinical Decision-Making; D015179:Colorectal Neoplasms / Q000235:genetics / Q000473:pathology*; D053843:DNA Mismatch Repair / Q000235:genetics; D018572:Disease-Free Survival; D006801:Humans; D053842:Microsatellite Instability; D009367:Neoplasm Staging; D011379:Prognosis; D015996:Survival Rate
D000970:Antineoplastic Agents
Adjuvant therapy; Colorectal cancer; Mismatch repair proteins; Predictive factor; Prognostic factor