Management of clinically node‐negative glottic squamous cell carcinoma patients according to risk‐scoring model for occult lymph node metastases

Abstract

Background Glottic squamous cell carcinoma (GSCC) is the most prevalent type of laryngeal carcinoma. The value of prophylactic lymph node dissection (LND) in resected GSCC remains controversial. This study aims to quantitatively assess the probability of occult lymph node metastasis (LNM) for GSCC patients and devise individualized postoperative radiotherapy strategies. Methods A total of 1319 patients with GSCC were retrospectively analyzed. Results GSCC patients with T1‐T2 stages showed significantly lower LNM rate than those with T3‐T4 stages. For patients with T3‐T4 GSCC, multivariate logistic analyses indicated that three factors—maximum tumor diameter (MTD) of more than 2.0 cm, relatively low differentiation, and tumor invasive depth of no less than 1.0 cm—were independent risk factors for the existence of LNM. A predictive nomogram was established based on these factors. The accuracy and validity of our model were verified by 0.716 and remained at 0.717 after 1000 bootstrapping. The calibration curve was also plotted and showed a favorable agreement. The patients were stratified into two groups based on their individual LNM risk points. Possible LNM rates for low‐risk and high‐risk subgroups were 4.7% and 25.2%, respectively. Conclusions A new post‐operative strategy selection flow chart was established based on our newly created nomogram which can effectively predict the individualized possibility of occult LNM for GSCC patients. For clinical T3‐4N0 patients in the high‐risk subgroup, prophylactic dose post‐operative radiation therapy is recommended. However, for all those clinically diagnosed as T1‐2N0 stage, regular follow‐up is sufficient in view of the low occult LNM rate. Level of Evidence: 2a

Application of an Interpretable Machine Learning Model to Predict Lymph Node Metastasis in Patients with Laryngeal Carcinoma

“…The accuracy, precision, recall rate, F1-score, AUC value, specificity, and calibration plots were performed to evaluate and compare the ML model performances, and we found that XGBoost was better than the other models with respect to the AUC value, Brier score, F1-score, recall rate, and accuracy, whether it was in the training set or in the test set ( Table 4 , Figures 4(a) , 4(b) , 5(a), and 5(b)). In addition, the AUC value of XGBoost was also higher than that of the model constructed in previous studies [ 8 , 34 , 37 ]. Therefore, we believe that XGBoost was the best predictive model to predict the LNM in LC patients.…”

“…However, due to the complexity and large size of the various factors in the data and the differences among the calculation methods of the models, the prediction performance was also significantly different. Heng et al [ 37 ] developed a nomogram to predict the occult lymph node metastases of glottic squamous cells with an AUC value of 0.716. Chen et al [ 34 ] used a nomogram to predict cervical LNM in laryngeal squamous cell carcinoma with an AUC value of 0.809.…”

Impact of lymph node ratio and number of lymph node metastases on survival and recurrence in laryngeal squamous cell carcinoma

“…The laryngeal subsites (supraglottis, glottis, and subglottis) show marked differences in terms of the risk of lymph node metastasis 6,7 . Malignant tumors of supraglottic origin have a greater tendency for locoregional involvement; the percentage of lymph node metastases identified in exclusively glottic or subglottic carcinomas is less pronounced 8,9 . The subsite of origin of the tumor is one of the factors that determine the behavior of laryngeal neoplasia.…”

“…Several studies 13,14 have defined the preferential patterns of lymph node metastasis. Laryngeal squamous cell carcinomas tend to affect levels I and V at very low percentages, and in almost all cases, there is simultaneous involvement of levels II–IV 9 . Tumors arising in the median supraglottic region and advanced‐stage tumors of the glottic region (T3‐T4) preferentially metastasize to levels II–III and IV, frequently bilaterally.…”

“…Tumors arising in the median supraglottic region and advanced‐stage tumors of the glottic region (T3‐T4) preferentially metastasize to levels II–III and IV, frequently bilaterally. Early‐stage glottic lesions (T1) rarely metastasize to regional lymph nodes 9 . Lateral supraglottic lesions and T2 glottic tumors preferentially metastasize to levels II–III and IV on the same side.…”