Tumor budding and tumor-infiltrating lymphocytes can predict prognosis in pT1b esophageal squamous cell carcinoma

Background: Tumor budding (TB) and tumor-infiltrating lymphocyte (TIL) are significant predictive indicators of lymph node metastasis (LNM) and unfavorable prognosis in various tumors. Currently, there is no gold standard for TB and TIL evaluation in esophageal squamous cell carcinoma (ESCC). This study aimed to identify the standard of TB and TIL evaluations and build a predictive model for prognosis among patients with pT1b ESCC.

Methods: We retrospectively analyzed the prognostic values of TB and TIL in 150 pT1b ESCC cases. Hematoxylin and eosin (H&E) and immunohistochemistry (IHC) of anti-pan cytokeratin (AE1/AE3) were used to analyze the threshold of TB, and intratumoral TIL and peritumoral TIL (pTIL) were evaluated using the receiver operating characteristic curves (ROC).

Results: We found that TB in a three-tiered grading system (low-TB: 0-4; middle-TB: 5-15; high-TB: ≥16) displayed an excellent prognosis prediction for LNM and survival based on IHC staining using a 20× objective lens. Low pTIL level (≤20%) was a significant indicator of LNM and unfavorable prognosis (p < 0.05). Moreover, lower tumor location and lymphovascular invasion (LVI) were correlated with an unfavorable prognosis (p < 0.05). A nomogram developed based on TB, pTIL, LVI, and tumor location showed good discrimination, as shown by the area under the ROC and calibration curves.

Conclusion: We therefore recommend identifying TB using a 20× objective lens under IHC staining and TIL adjacent to the tumor. Additionally, a nomogram was built for facilitating individualized prediction of survival for patients with pT1b ESCC.