title: Nomograms to predict survival after colorectal cancer resection without preoperative therapy.
abstract: The predictive accuracy of the American Joint Committee on Cancer (AJCC) stages of colorectal cancer (CRC) is mediocre. This study aimed to develop postoperative nomograms to predict cancer-specific survival (CSS) and overall survival (OS) after CRC resection without preoperative therapy.
  
  
  
  Eligible patients with stage I to IV CRC (n = 56072) diagnosed from 2004 to 2010 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. The patients were allocated into training (n = 27,700), contemporary (n = 3158), and prospective (n = 25,214) validation cohorts. Clinically important variables were incorporated and selected using the Akaike information criterion in multivariate Cox regressions to derive nomograms with the training cohort. The performance of the nomograms was assessed and externally testified using the concordance index (c-index), bootstrap validation, calibration, time-dependent receiver-operating characteristic curves, Kaplan-Meier curves, mosaic plots, and decision curve analysis (DCA). Performance of the conventional AJCC stages was also compared with the nomograms using similar statistics.
  
  
  
  The nomograms for CSS and OS shared common predictors: sex, age, race, marital status, preoperative carcinoembryonic antigen status, surgical extent, tumor size, location, histology, differentiation, infiltration depth, lymph node count, lymph node ratio, and metastasis. The c-indexes of the nomograms for CSS and OS were 0.816 (95 % CI 0.810-0.822) and 0.777 (95 % CI 0.772-0.782), respectively. Performance evaluations showed that the nomograms achieved considerable predictive accuracy, appreciable reliability, and significant clinical validity with wide practical threshold probabilities, while the results remained reproducible when applied to the validation cohorts. Additionally, model comparisons and DCA proved that the nomograms excelled in stratifying each AJCC stage into three significant prognostic subgroups, allowing for more robust risk classification with an improved net benefit.
  
  
  
  We propose two prognostic nomograms that exhibit improved predictive accuracy and net benefit for patients who have undergone CRC resection. The established nomograms are intended for risk assessment and selection of suitable patients who may benefit from adjuvant therapy and intensified follow-up after surgery. Independent external validations may still be required.
authors.affiliation: Department of Gastrointestinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, Pudong New District, No. 150, Jimo Road, Shanghai, 200120, China.
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: Zhang
authors.affiliation: Department of Gastrointestinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, Pudong New District, No. 150, Jimo Road, Shanghai, 200120, China.
authors.forename: Qi-Feng
authors.initials: QF
authors.lastname: Luo
authors.affiliation: Department of General Surgery, Qingpu Branch of Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Yin
authors.affiliation: Department of Gastrointestinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, Pudong New District, No. 150, Jimo Road, Shanghai, 200120, China.
authors.forename: Zhen-Ling
authors.initials: ZL
authors.lastname: Dai
authors.affiliation: Department of Gastrointestinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, Pudong New District, No. 150, Jimo Road, Shanghai, 200120, China.
authors.forename: Shiva
authors.initials: S
authors.lastname: Basnet
authors.affiliation: Department of Gastrointestinal Surgery, Shanghai East Hospital, Tongji University School of Medicine, Pudong New District, No. 150, Jimo Road, Shanghai, 200120, China. gesurgery@163.com.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Ge
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002272:Carcinoembryonic Antigen / Q000097:blood; D015179:Colorectal Neoplasms / Q000097:blood / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049451:Nomograms; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D018426:SEER Program; D016019:Survival Analysis; D055815:Young Adult
chemical_list: D002272:Carcinoembryonic Antigen
keywords: Cancer-specific survival; Colorectal cancer; Decision curve analysis; Nomogram; Overall survival