TY - JOUR A1 - Emons, Georg A1 - Auslander, Noam A1 - Jo, Peter A1 - Kitz, Julia A1 - Azizian, Azadeh A1 - Hu, Yue A1 - Hess, Clemens F. A1 - Rödel, Claus A1 - Sax, Ulrich A1 - Salinas-Riester, Gabriela A1 - Ströbel, Philipp A1 - Kramer, Frank A1 - Beissbarth, Tim A1 - Ghadimi, Michael A1 - Ruppin, Eytan A1 - Ried, Thomas A1 - Gaedcke, Jochen Werner Christian A1 - Grade, Marian T1 - Gene-expression profiles of pretreatment biopsies predict complete response of rectal cancer patients to preoperative chemoradiotherapy T2 - British journal of cancer N2 - Purpose: Preoperative (neoadjuvant) chemoradiotherapy (CRT) and total mesorectal excision is the standard treatment for rectal cancer patients (UICC stage II/III). Up to one-third of patients treated with CRT achieve a pathological complete response (pCR). These patients could be spared from surgery and its associated morbidity and mortality, and assigned to a “watch and wait” strategy. However, reliably identifying pCR based on clinical or imaging parameters remains challenging. Experimental design: We generated gene-expression profiles of 175 patients with locally advanced rectal cancer enrolled in the CAO/ARO/AIO-94 and -04 trials. One hundred and sixty-one samples were used for building, training and validating a predictor of pCR using a machine learning algorithm. The performance of the classifier was validated in three independent cohorts, comprising 76 patients from (i) the CAO/ARO/AIO-94 and -04 trials (n = 14), (ii) a publicly available dataset (n = 38) and (iii) in 24 prospectively collected samples from the TransValid A trial. Results: A 21-transcript signature yielded the best classification of pCR in 161 patients (Sensitivity: 0.31; AUC: 0.81), when not allowing misclassification of non-complete-responders (False-positive rate = 0). The classifier remained robust when applied to three independent datasets (n = 76). Conclusion: The classifier can identify >1/3 of rectal cancer patients with a pCR while never classifying patients with an incomplete response as having pCR. Importantly, we could validate this finding in three independent datasets, including a prospectively collected cohort. Therefore, this classifier could help select rectal cancer patients for a “watch and wait” strategy. Translational relevance: Forgoing surgery with its associated side effects could be an option for rectal cancer patients if the prediction of a pathological complete response (pCR) after preoperative chemoradiotherapy would be possible. Based on gene-expression profiles of 161 patients a classifier was developed and validated in three independent datasets (n = 76), identifying over 1/3 of patients with pCR, while never misclassifying a non-complete-responder. Therefore, the classifier can identify patients suited for “watch and wait”. KW - Genetics research KW - Predictive markers KW - Radiotherapy KW - Surgical oncology Y1 - 2022 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/63259 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-632598 SN - 1532-1827 N1 - Gene-expression data were deposited to Gene Expression Omnibus (GSE87211). N1 - This work was supported by the Deutsche Forschungsgemeinschaft (Klinische Forschergruppe 179) and the Intramural Research Program of the National Institutes of Health, National Cancer Institute. Open Access funding enabled and organized by Projekt DEAL. VL - 127 IS - 4 SP - 766 EP - 775 PB - Nature Publ. Group CY - Edinburgh ER -