Seven low-mass ions in pretreatment serum as potential predictive markers of the chemoradiotherapy response of rectal cancer.
Preoperative chemoradiotherapy (CRT) is generally performed for locally advanced rectal cancer (LARC, cStage 2 or 3) to improve local disease control and patient survival. The pathological tumor response to CRT is a surrogate marker that is associated with oncological outcome. Thus, markers that predict the response to CRT would be valuable for individualizing treatment for LARC patients. The current study used metabolomics-based approaches to identify molecular markers that predict the response to CRT. Seventy-six patients with LARC who received pelvic radiotherapy and concurrent chemotherapy using tegafur-uracil and leucovorin were enrolled. Radical surgery was performed 6-8 weeks after the completion of CRT. The postsurgical pathological CRT response was evaluated using the ypStage or tumor regression grade. Profiling patterns of low-mass ions (LMIs) in the pretreatment sera were obtained from all patients using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Our previously developed two-step algorithms, which showed a powerful diagnostic capability during colorectal cancer screening, were then used to screen for meaningful LMIs with discriminatory power. One combination consisting of seven LMIs was identified, whose discriminatory score separated a good CRT response (ypStage 0-1) from a poor CRT response (ypStage 3-4) successfully. However, each individual LMI alone showed insignificant discriminatory power. This finding suggests that analysis of the LMIs in pretreatment serum could serve as a predictive marker of the CRT response in patients with LARC.
aDepartment of Genetic Engineering, Sungkyunkwan University, Suwon bColorectal Cancer Branch cOmics core Laboratory, Research Institute, National Cancer Center, Goyang dDepartment of Radiation Oncology, Soonchunhyang University College of Medicine, Cheonan eDepartment of Radiology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea.
Kangsan
K
Roh
Seung-Gu
SG
Yeo
Byong Chul
BC
Yoo
Kyung-Hee
KH
Kim
Sun Young
SY
Kim
Min-Jeong
MJ
Kim
D000230:Adenocarcinoma / Q000188:drug therapy* / Q000532:radiotherapy* / Q000601:surgery; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D059248:Chemoradiotherapy / Q000009:adverse effects; D005260:Female; D006801:Humans; D007477:Ions / Q000097:blood*; D008297:Male; D008875:Middle Aged; D025341:Principal Component Analysis; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy* / Q000601:surgery; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D016896:Treatment Outcome
D014408:Biomarkers, Tumor; D007477:Ions