Nomogram for predicting pathologic complete response to neoadjuvant chemoradiotherapy in patients with esophageal squamous cell carcinoma

Abstract

Purpose: A pathologic complete response (pCR) to neoadjuvant chemoradiotherapy (nCRT) is seen in up to 40% of the patients with esophageal squamous cell carcinoma (ESCC). No nomogram has been constructed for the prediction of pCR for patients whose primary chemotherapy was a taxane-based regimen. The aim is to identify characteristics associated with a pCR through analyzing multiple pre- and post-nCRT variables and to develop a nomogram for the prediction of pCR for these patients by integrating clinicopathological characteristics and hematological biomarkers.

Materials and methods: We analyzed 293 patients with ESCC who underwent nCRT followed by esophagectomy. Clinicopathological factors, hematological parameters before nCRT, and hematotoxicity during nCRT were collected. Univariate and multivariate logistic regression analyses were performed to identify predictive factors for pCR. A nomogram model was built and evaluated for both discrimination and calibration.

Results: After surgery, 37.88% of the study patients achieved pCR. Six variables were included in the nomogram: sex, cN stage, chemotherapy regimen, duration of nCRT, pre-nCRT neutrophil-to-lymphocyte ratio (NLR), and pre-nCRT platelet-to-lymphocyte ratio (PLR). The nomogram indicated good accuracy and consistency in predicting pCR, with a C-index of 0.743 (95% confidence interval: 0.686, 0.800) and a p value of 0.600 (>0.05) in the Hosmer-Lemeshow goodness-of-fit test.

Conclusions: Female, earlier cN stage, duration of nCRT (< 62 days), chemotherapy regimen of taxane plus platinum, pre-nCRT NLR (≥2.199), and pre-nCRT PLR (≥99.302) were significantly associated with a higher pCR in ESCC patients whose primary chemotherapy was a taxane-based regimen for nCRT. A nomogram was developed and internally validated, showing good accuracy and consistency.

Keywords: esophageal squamous cell carcinoma; neoadjuvant chemoradiotherapy; nomogram; pathologic complete response.

FIGURE 1

Flowchart of included patients. ESCC, esophageal squamous cell carcinoma; nCRT, neoadjuvant chemoradiotherapy; pCR, pathologic complete response.

FIGURE 2

Nomogram for prediction of pCR after nCRT in patients with ESCC. For each patient, seven variables are assigned points on a nomogram, represented by seven lines moving upward. The sum of these points is then located on the “Total Points” axis. A line is drawn downward from this point to predict the probability of achieving pCR. ESCC, esophageal squamous cell carcinoma; pCR, pathologic complete response; PLR, platelet to lymphocyte ratio; nCRT, neoadjuvant chemoradiotherapy; NLR, neutrophil to lymphocyte ratio; TP, taxane and platinum agents.

FIGURE 3

Evaluation of the performance of the nomogram by discrimination and calibration. (A) ROC curve of the nomogram. (B) Calibration plots of the nomograms.