title: Impact of age and mismatch repair status on survival in colorectal cancer.
abstract: Previous studies have suggested that deficiencies in mismatch repair genes (dMMR) often occur in patients with colorectal cancer (CRC) and contribute to disease etiology. Here, we looked for a correlation of MMR status to disease outcomes from a large number of Chinese CRC patients stratified by the age of onset of disease. A total of 2233 CRC patients were analyzed and tissue biopsies of surgically removed tumors scored for MMR gene status. The patient distribution after classification consisted of 188 younger aged patients (20-39 years of age), 1024 middle aged patients (40-59 years of age), and 1020 older aged patients (60-85 years of age). In this analysis, the expression of four MMR genes was assessed by immunohistochemistry (IHC). We found that the young group of CRC patients with dMMR had higher overall survival (OS) than the young group of patients with proficient MMR (pMMR) (77% vs. 56%, P = 0.03). Middle-aged patients with dMMR also had higher OS than middle-aged group patients with pMMR (78% vs. 68%, P = 0.012). However, we found no statistical difference in OS between dMMR and pMMR status in the older group of patients (75% vs. 71%, P = 0.224). Finally, the middle- and older-aged group set of patients had higher OS than the young group of patients (69% vs. 71% vs. 59%, P = 0.008). These data demonstrated that the age of disease onset can be an important factor to help evaluate the prognosis of CRC when combined with the analysis of MMR status within tumor biopsied tissue.
authors.affiliation: Department of hematology and oncology, Medizinische Klinik und Poliklinik IV, Ludwig Maximilians University, Munich, Germany.
authors.forename: Pan
authors.initials: P
authors.lastname: Li
authors.affiliation: Department of Colorectal Surgery, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.
authors.forename: Zhi-Tao
authors.initials: ZT
authors.lastname: Xiao
authors.affiliation: Department of hematology and oncology, Medizinische Klinik und Poliklinik IV, Ludwig Maximilians University, Munich, Germany.
authors.forename: Todd A
authors.initials: TA
authors.lastname: Braciak
authors.affiliation: Department of Colorectal Surgery, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.
authors.forename: Qing-Jian
authors.initials: QJ
authors.lastname: Ou
authors.affiliation: Department of Colorectal Surgery, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.
authors.forename: Gong
authors.initials: G
authors.lastname: Chen
authors.affiliation: Department of hematology and oncology, Medizinische Klinik und Poliklinik IV, Ludwig Maximilians University, Munich, Germany.
authors.forename: Fuat S
authors.initials: FS
authors.lastname: Oduncu
mesh_terms: D000328:Adult; D017677:Age Distribution; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D002681:China; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D045643:DNA Repair Enzymes / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000070976:Mismatch Repair Endonuclease PMS2 / Q000378:metabolism*; D000070957:MutL Protein Homolog 1 / Q000378:metabolism*; D051718:MutS Homolog 2 Protein / Q000378:metabolism*; D009367:Neoplasm Staging; D011379:Prognosis; D016019:Survival Analysis; D055815:Young Adult
chemical_list: D004268:DNA-Binding Proteins; C094443:G-T mismatch-binding protein; C501486:MLH1 protein, human; C094934:PMS2 protein, human; C497172:MSH2 protein, human; D000070976:Mismatch Repair Endonuclease PMS2; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein; D045643:DNA Repair Enzymes
keywords: Age; MMR status; biomarker; colorectal cancer; prognosis