Affiliation:
1. Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University
2. Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya, Central South University
Abstract
Abstract
Individual prognosis assessment is of paramount importance for treatment decision-making and active surveillance in cancer patients. We aimed to propose a radiomic model based on pre- and post-therapy MRI features for predicting disease-free survival (DFS) in locally advanced rectal cancer (LARC) following neoadjuvant chemoradiotherapy (nCRT) and subsequent surgical resection. This retrospective study included a total of 126 LARC patients, which were randomly assigned to a training set (n=84) and a validation set (n=42). All patients underwent pre- and post-nCRT MRI scans. Radiomic features were extracted from higher resolution T2 -weighted images. Pearson correlation analysis and ANOVA or Relief were utilized for identifying radiomic features associated with DFS. Pre-treatment, post-treatment, and delta radscores were constructed by machine learning algorithms. An individualized nomogram was developed based on significant radscores and clinical variables using multivariate Cox regression analysis. Predictive performance was evaluated by the C-index, calibration curve, and decision curve analysis. The results demonstrated that in the validation set, the clinical model including pre-surgery Carcinoembryonic Antigen (CEA), chemotherapy after radiotherapy, and pathological stage yielded a C-index of 0.755 (95% confidence interval [CI]: 0.630-0.880). While the optimal pre-, post-, and delta-radscores achieved C-indices of 0.724 (95%CI: 0.585-0.863), 0.701 (95%CI: 0.544-0.858), and 0.625 (95%CI: 0.439-0.811), respectively. The nomogram integrating pre-surgery CEA, pathological stage, alongside pre- and post-nCRT radscore, obtained the highest C-index of 0.833 (95%CI: 0.694-0.972). The calibration curve and decision curves exhibited good calibration and clinical usefulness of the nomogram. Furthermore, the nomogram categorized patients into high- and low-risk groups exhibiting distinct DFS (both P<0.0001). In summary, the nomogram incorporating pre- and post-therapy radscores and clinical factors could predict DFS in patients with LARC, which warrants further external validations.
Publisher
Research Square Platform LLC
Reference32 articles.
1. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries;Sung H;CA Cancer J Clin,2021
2. Colorectal cancer statistics, 2017;Siegel RL;CA A Cancer Journal for Clinicians,2017
3. A, V.V., C.A. B, B.G. E, et al. Multidisciplinary Rectal Cancer Management: 2nd European Rectal Cancer Consensus Conference (EURECA-CC2). Radiotherapy and Oncology 2009; 92(2): p. 148–163.
4. Preoperative chemoradiotherapy and postoperative chemotherapy with fluorouracil and oxaliplatin versus fluorouracil alone in locally advanced rectal cancer: initial results of the German CAO/ARO/AIO-04 randomised phase 3 trial;Rödel C;Lancet Oncol,2012
5. Preoperative radiotherapy combined with total mesorectal excision for resectable rectal cancer: 12-year follow- up of the multicentre, randomised controlled TME trial;Gijn W;Lancet Oncol,2011