Nomogram model and risk score predicting overall survival and guiding clinical decision in patients with Hodgkin's lymphoma: an observational study using SEER population-based data

Abstract

Introduction: This study developed a prognostic nomogram of Hodgkin lymphoma (HL) for purpose of discussing independent risk factors for HL patients with Surveillance, Epidemiology and End Results (SEER) database.

Methods: We collected data of HL patients from 2010 to 2015 from the SEER database and divided it into two cohorts: the training and the verification cohort. Then the univariate and the multivariate Cox regression analyses were conducted in the training, the verification as well as the total cohort, after which the intersection of variables with statistical significance was taken as independent risk factors to establish the nomogram. The predictive ability of the nomogram was validated by the Concordance Index. Additionally, the calibration curve and receiver operating characteristic curve were implemented to evaluate the accuracy and discrimination. Finally, we obtained 1-year, 3-year and 5-year survival rates of HL patients.

Results: 10 912 patients were eligible for the study. We discovered that Derived American Joint Committee on Cancer (AJCC) Stage Group, lymphoma subtype, radiotherapy and chemotherapy were four independent risk factors affecting the prognosis of HL patients. The 1-year, 3-year and 5-year survival rates for high-risk patients were 85.4%, 79.9% and 76.0%, respectively. It was confirmed that patients with stage I or II had a better prognosis. Radiotherapy and chemotherapy had a positive impact on HL outcomes. However, patients with lymphocyte-depleted HL were of poor prognosis.

Conclusions: The nomogram we constructed could better predict the prognosis of patients with HL. Patients with HL had good long-term outcomes but novel therapies are still in need for fewer complications.

Keywords: Epidemiology; Lymphoma.

Figure 1

The flow chart of patient selection and statistical analysis. The patients pathologically diagnosed with Hodgkin lymphoma (HL) were extracted from the SEER database. The exclusion criteria were as follows: (1) Hodgkin lymphoma was not the first tumour. (2) Incomplete information on all the variables (blanks, unknown, NA). After patient selection, the remaining part of patients was divided into two cohorts randomly. We conducted the univariate and the multivariate Cox regression analyses in the training cohort, the verification cohort and the total cohort, respectively. The independent risk factors were the intersection of statistically significant variables of three cohorts and a nomogram based on these factors was established to predict the prognosis for Hodgkin lymphoma patients. We validated the new model and compared it with the AJCC-based one. The survival curves were drawn by Kaplan-Meier method. AJCC, American Joint Committee on Cancer; AUC, area under the curve; ROC, receiver operating characteristic; SEER, Surveillance, Epidemiology and End Results.

Figure 2

Nomogram for prediction of 1-year, 3-year, 5-year overall survival based on independent risk factors for HL patients. In the nomogram, each level of each variable means a score on the ‘points’ scale. Add up each score and draw a straight line down to the ‘1-year survival’, ‘3-year survival’, ‘5-year survival’ scale to get corresponding overall survival. cHL-NOS, classical Hodgkin lymphoma not otherwise specified; HL, Hodgkin lymphoma; LR, lymphocyte-rich; LD, lymphocyte-depleted; MC, mixed cellularity; NLPHL, nodular lymphocyte predominant Hodgkin lymphoma; NS, nodular sclerosis.

Figure 3

Calibration curves and ROC curves of the total cohort. (A–C) Calibration curves for prediction of 1-year (A), 3-year (B) and 5-year (C) overall survival. The grey dotted line is the standard line and the blue solid line is the calibration line. (D–F) ROC curves of the nomogram and the AJCC staging model for 1-year (D), 3-year (E) and 5-year (F) overall survival. AUC, area under the curve; ROC, receiver operating characteristic curve.

Figure 4

Kaplan-Meier survival curves of the independent risk factors of HL in the total cohort. (A) The survival curve concerning lymphoma subtype and their 1-year, 3-year, 5-year survival rates. (B) The survival curve associated with Derived AJCC Stage Group and their 1-year, 3-year, 5-year survival rates. (C) The radiotherapy-related survival curve and their 1-year, 3-year, 5-year survival rates. (D) The survival curve in relationship with chemotherapy and their 1-year, 3-year, 5-year survival rates. HL, Hodgkin lymphoma; NOS, not otherwise specified.

Figure 5

Kaplan-Meier survival curves of risk score of the total cohort. The survival curve of the risk score of the total cohort. The 1-year, 3-year, 5-year survival rates of high risk are respectively 86.3%, 81.0%, 77.3% and the low-risk survival rates are 97.9%, 95.6%, 93.3%, respectively.