MRI-identified multidimensional nodal features predict survival and concurrent chemotherapy benefit for stage II nasopharyngeal carcinoma

BACKGROUND

Reliable predictors are urgently needed to identify stage II nasopharyngeal carcinoma (NPC) patients who could benefit from concurrent chemoradiotherapy (CCRT). We aimed to develop a nomogram integrating MRI-identified multidimensional features of lymph nodes to predict survival and assist the decision-making of CCRT for stage II NPC.

PATIENTS AND METHODS

This retrospective study enrolled 242 stage II NPC patients treated from January 2007 to December 2017. Overall survival (OS) was the primary endpoint. Performance of nomogram was evaluated using calibration curves, Harrell Concordance Index (C-index), area under the curve (AUC) and decision curves analysis (DCA) and was compared with TNM staging. According to the individualized nomogram score, patients were classified into two risk cohorts and therapeutic efficacy of CCRT were evaluated in each cohort.

RESULTS

Three independent prognostic factors for OS: age, number and location of positive lymph nodes were included into the final nomogram. T stage was also incorporated due to its importance in clinical decision-making. Calibration plots demonstrated a good match between the predicted and our observed OS rates. C-index for nomogram was 0.726 compared with 0.537 for TNM staging (p < 0.001). DCAs confirmed the superior clinical utility of nomograms compared with TNM staging. CCRT compared to intensity-modulated radiotherapy (IMRT) delivered OS benefit to patients in the high-risk group (5-year: 89.9% vs. 72.1%; 10-year: 72.5% vs. 34.2%, p = 0.011), but not in the low-risk group.

CONCLUSIONS

This lymph node features-based nomogram demonstrated excellent discrimination and predictive accuracy for stage II patients and could identify patients who can benefit from CCRT.

The Value of Cervical Node Features in Predicting Long-Term Survival of Nasopharyngeal Carcinoma in the Intensity-Modulated Radiotherapy Era

Objective

To investigate the prognostic value of cervical node features in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT) and build a prognostic nomogram to predict the long-term survival.

Methods

In this study, 1752 patients after IMRT from 2008 to 2011 were recruited. The clinical and laboratory characteristics and the nodal features including the nodal number, maximum dimension diameter, extranodal extension (ENE), and cervical node necrosis (CNN) were retrospective analyzed. Univariate Cox and multivariate proportional hazard regression models were used to test the prognostic value of nodal features. Prognostic nomograms were established to predict survival.

Results

The 10-year distant metastases-free survival (DMFS) and disease-specific survival (DSS) rates were 86.5% and 80.8%, respectively. Multivariate analysis showed that age, sex, lactate dehydrogenase (LDH), CNN, ENE, T stage, and N stage were independent factors for DSS. Two nomograms-nomogram A (without nodal features) and nomogram B (with nodal features)-were built. The calibration curve for the probability of DSS showed good agreement between prediction by nomogram and the actual observation. The C-index of nomogram B was higher than that for nomogram A in predicting DSS (0.708 vs 0.676, P<0.01).

Conclusion

The nodal features including ENE and CNN were negative prognostic factors for NPC, and the prognostic nomogram incorporating the nodal features was more accurate in predicting survival than the nomogram without nodal features.

A Nomogram for Predicting Distant Metastasis Using Nodal-Related Features Among Patients With Nasopharyngeal Carcinoma

Distant metastasis is among the main reasons for treatment failure in nasopharyngeal carcinoma (NPC) patients. To identify patients with a high risk of distant metastasis is important to guide posttreatment surveillance, appropriate time treatments, and prolonging their long-term survival. In this study, we systematically examined the associations between a series of nodal-related characteristics and distant metastasis-free survival (DMFS) by detailed MRI reading and established a nomogram for DMFS in NPC patients. T-stage, age group, Epstein-Barr virus (EBV) level, central nodal necrosis, and nodal number were identified as independent risk factors for distant metastasis and were included into the final nomogram. The calibration plot showed a high agreement between the prediction by the nomogram and actual observations. Our established nomogram achieved a high C-index in predicting distant metastasis in both of the training cohort (0.737) and the validation cohort (0.718). This nomogram incorporated several readily available nodal features from the MR images, and it might be useful for guiding clinical decision and NPC patients' posttreatment surveillance. It also provides cues for how to redefine N-stage. Additional research is needed to confirm our conclusions.