J Cancer 2017; 8(17):3498-3505. doi:10.7150/jca.19879

Research Paper

Development and Validation of a Nomogram to Predict the Benefit of Adjuvant Radiotherapy for Patients with Resected Gastric Cancer

Shu-Qiang Yuan1*, Wen-Jing Wu2, 3*, Miao-Zhen Qiu4, 5*, Zi-Xian Wang4*, Lu-Ping Yang4, Ying Jin4, Jing-Ping Yun6, Yuan-Hong Gao7, Yu-Hong Li4, Zhi-Wei Zhou1, Feng Wang4✉, Rui-Hua Xu4✉

1. Department of Gastric Surgery, Sun Yat-sen University Cancer Center; State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China;
2. Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-sen University Memorial Hospital, Guangzhou, 510120, China;
3. Department of Breast Oncology, Sun Yat-sen University Memorial Hospital, Guangzhou, 510120, China;
4. Department of Medical Oncology, Sun Yat-sen University Cancer Center; State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China;
5. Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA;
6. Department of Pathology, Sun Yat-sen University Cancer Center; State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China;
7. Department of Radiotherapy, Sun Yat-sen University Cancer Center; State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China.
*These authors contributed equally to this study.

Abstract

Background: The US guidelines for gastric cancer (GC) recommend adjuvant radiotherapy (ART) combined with 5-fluorouracil as a standard treatment for patients with resected locally advanced GC. However, patient selection criteria for optimizing the use of adjuvant therapies are lacking. In this study, we developed and validated a nomogram to predict the individualized overall survival (OS) benefit of ART among patients with resected ≥stage IB GC.

Patients and Methods: The 2002-2006 Surveillance, Epidemiology, and End Results (SEER) data of 5,206 patients with resected GC were used as a training set for the development of a nomogram. The 2007-2008 SEER data of 1,986 patients with resected GC were used as validation data.

Results: In the multivariate analysis weighted by inverse propensity score, the efficacy of ART varied by the ratio of positive to examined nodes (Pinteraction<0.01). The magnitude of this difference was included in the nomogram with associated prognosticators to predict the 3- and 5-year OS with and without ART. The nomogram showed significant prognostic superiority to the 8th TNM staging in the training set (Concordance index, 0.68 versus 0.65; P<0.01) and the validation set (Concordance index, 0.68 versus 0.64; P<0.01). Moreover, the calibration was accurate, and the actual efficacy of ART was positively correlated with the nomogram-estimated survival benefit from ART (Pinteraction<0.01 and Pinteraction=0.02 in the training set and the validation set, respectively).

Conclusion: The nomogram can aid individualized clinical decision making by estimating the 3- and 5-year OS and potential benefits of ART among patients with resected GC.

Keywords: gastric cancer, adjuvant radiotherapy, survival, nomogram, Surveillance, Epidemiology, and End Results (SEER).

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How to cite this article:
Yuan SQ, Wu WJ, Qiu MZ, Wang ZX, Yang LP, Jin Y, Yun JP, Gao YH, Li YH, Zhou ZW, Wang F, Xu RH. Development and Validation of a Nomogram to Predict the Benefit of Adjuvant Radiotherapy for Patients with Resected Gastric Cancer. J Cancer 2017; 8(17):3498-3505. doi:10.7150/jca.19879. Available from http://www.jcancer.org/v08p3498.htm