TY - JOUR
T1 - Decreased Tumoral Expression of Colon-Specific Water Channel Aquaporin 8 Is Associated with Reduced Overall Survival in Colon Adenocarcinoma
AU - O'Brien, Stephen J.
AU - Kalbfleisch, Theodore
AU - Srivastava, Sudhir
AU - Pan, Jianmin
AU - Rai, Shesh
AU - Petras, Robert E.
AU - Ronquillo, Nemencio
AU - Polk, Hiram C.
AU - Galandiuk, Susan
N1 - Publisher Copyright:
© Copyright The American Society of Colon & Rectal Surgeons, Inc.
PY - 2021/9/1
Y1 - 2021/9/1
N2 - BACKGROUND: Colon cancer survival is dependent on metastatic potential and treatment. Large RNA-sequencing data sets may assist in identifying colon cancer-specific biomarkers to improve patient outcomes. OBJECTIVE: This study aimed to identify a highly specific biomarker for overall survival in colon adenocarcinoma by using an RNA-sequencing data set. DESIGN: Raw RNA-sequencing and clinical data for patients with colon adenocarcinoma (n = 271) were downloaded from The Cancer Genome Atlas. A binomial regression model was used to calculate differential RNA expression between paired colon cancer and normal epithelium samples (n = 40). Highly differentially expressed RNAs were examined. SETTINGS: This study was conducted at the University of Louisville using data acquired by The Cancer Genome Atlas. PATIENTS: Patients from US accredited cancer centers between 1998 and 2013 were analyzed. MAIN OUTCOME MEASURES: The primary outcome measures were recurrence-free and overall survival. RESULTS: The median age was 66 years (147/271 men, 180/271 White patients). Thirty RNAs were differentially expressed in colon adenocarcinoma compared with paired normal epithelium, using a log-fold change cutoff of ±6. Using median expression as a cutoff, 4 RNAs were associated with worse overall survival: decreased ZG16 (log-rank = 0.023), aquaporin 8 (log-rank = 0.023), and SLC26A3 (log-rank = 0.098), and increased COL1A1 (log-rank = 0.105). On multivariable analysis, low aquaporin 8 expression (HR, 1.748; 95% CI, 1.016-3.008; p = 0.044) was a risk factor for worse overall survival. Our final aquaporin 8 model had an area under the curve of 0.85 for overall survival. On subgroup analysis, low aquaporin 8 was associated with worse overall survival in patients with high microsatellite instability and in patients with stage II disease. Low aquaporin 8 expression was associated with KRAS and BRAF mutations. Aquaporin 8 immunohistochemistry was optimized for clinical application. LIMITATIONS: This was a retrospective study. CONCLUSION: Aquaporin 8 is a water channel selectively expressed in normal colon tissue. Low aquaporin 8 expression is a risk factor for worse overall survival in patients who have colon cancer. Aquaporin 8 measurement may have a role as a colon-specific prognostic biomarker and help in patient risk stratification for increased surveillance. See Video Abstract at http://links.lww.com/DCR/B603.
AB - BACKGROUND: Colon cancer survival is dependent on metastatic potential and treatment. Large RNA-sequencing data sets may assist in identifying colon cancer-specific biomarkers to improve patient outcomes. OBJECTIVE: This study aimed to identify a highly specific biomarker for overall survival in colon adenocarcinoma by using an RNA-sequencing data set. DESIGN: Raw RNA-sequencing and clinical data for patients with colon adenocarcinoma (n = 271) were downloaded from The Cancer Genome Atlas. A binomial regression model was used to calculate differential RNA expression between paired colon cancer and normal epithelium samples (n = 40). Highly differentially expressed RNAs were examined. SETTINGS: This study was conducted at the University of Louisville using data acquired by The Cancer Genome Atlas. PATIENTS: Patients from US accredited cancer centers between 1998 and 2013 were analyzed. MAIN OUTCOME MEASURES: The primary outcome measures were recurrence-free and overall survival. RESULTS: The median age was 66 years (147/271 men, 180/271 White patients). Thirty RNAs were differentially expressed in colon adenocarcinoma compared with paired normal epithelium, using a log-fold change cutoff of ±6. Using median expression as a cutoff, 4 RNAs were associated with worse overall survival: decreased ZG16 (log-rank = 0.023), aquaporin 8 (log-rank = 0.023), and SLC26A3 (log-rank = 0.098), and increased COL1A1 (log-rank = 0.105). On multivariable analysis, low aquaporin 8 expression (HR, 1.748; 95% CI, 1.016-3.008; p = 0.044) was a risk factor for worse overall survival. Our final aquaporin 8 model had an area under the curve of 0.85 for overall survival. On subgroup analysis, low aquaporin 8 was associated with worse overall survival in patients with high microsatellite instability and in patients with stage II disease. Low aquaporin 8 expression was associated with KRAS and BRAF mutations. Aquaporin 8 immunohistochemistry was optimized for clinical application. LIMITATIONS: This was a retrospective study. CONCLUSION: Aquaporin 8 is a water channel selectively expressed in normal colon tissue. Low aquaporin 8 expression is a risk factor for worse overall survival in patients who have colon cancer. Aquaporin 8 measurement may have a role as a colon-specific prognostic biomarker and help in patient risk stratification for increased surveillance. See Video Abstract at http://links.lww.com/DCR/B603.
KW - Aquaporin 8
KW - Colon cancer
KW - Overall survival
KW - RNA-sequencing
UR - http://www.scopus.com/inward/record.url?scp=85112358839&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85112358839&partnerID=8YFLogxK
U2 - 10.1097/DCR.0000000000002071
DO - 10.1097/DCR.0000000000002071
M3 - Article
C2 - 33990498
AN - SCOPUS:85112358839
SN - 0012-3706
VL - 64
SP - 1083
EP - 1095
JO - Diseases of the Colon and Rectum
JF - Diseases of the Colon and Rectum
IS - 9
ER -