Introduction
Esophageal cancer is ranked seventh in the number of new cases and sixth for the number of deaths among all cancers worldwide [1]. There are two types of esophageal cancer including esophageal squamous cell carcinoma (ESCC) and adenocarcinoma. ESCC is classified into mucosal cancer, submucosal cancer, and advanced cancer. Mucosal cancer is classified into T1a-EP (epithelial), T1a-LPM (lamina propria mucosa) and T1a-MM (muscularis mucosa) based on the classification system from the Japan Esophageal Society (JES) [2]. According to the classification system from the JES, the growth and infiltrative patterns of these tumors are classified into three groups. An expansive growth pattern of tumor nests with a well-demarcated border from surrounding tissue is INF-a, infiltrative growth of tumor nests with an ill-defined border from surrounding tissue is INF-c, and an intermediate growth pattern between INF-a and INF-c is classified as INF-b. An infiltrative growth pattern such as INF-c correlates with worse outcomes for advanced ESCC and pT1-ESCC including submucosal invasion[3-6] . However, the clinical impact of the INF pattern was unclear in patients with pT1a-LPM ESCC.
Aims & Methods
This study was conducted to clarify clinicopathological features of tumor growth patterns in pT1a-LPM type ESCC and the relationship between tumor growth patterns and magnifying endoscopic findings.
One hundred ninety-four consecutive ESCC lesions treated by endoscopic submucosal dissection (ESD) at the Saku Central Hospital from February 2012 to October 2015 were reviewed. Eighty-four patients and 87 lesions pathologically diagnosed as pT1a-LPM ESCC were included. No patients underwent ESD for locally recurrent lesions or were treated with chemoradiotherapy. Clinicopathological findings including tumor growth pattern and narrow band imaging with magnifying endoscopy (NBI-ME) based on the JES classification of magnifying endoscopy for ESCC [7] in the LPM area were investigated.
Results
Vascular pattern of LPM area
(n=30)
| Tumor growth pattern, n
INF-a/ INF-b/ INF-c
| Lymphatic invasion, n (%)
|
B1 (n=23)
| 23/ 0/ 0
| 0 (0%)
|
B2 (n=7)
| 2/ 4/ 1
| 2 (29%)
|
p value
| < 0.05
| < 0.05
|
Eighty-seven lesions were classified as infiltrative growth pattern-a (INF-a): expansive growth (n=81), INF-b: intermediate growth (n=4) and INF-c: infiltrative growth pattern (n=2). Lymphatic invasion was shown in one INF-b and one INF-c lesion. NBI-ME and histopathological images were matched for 30 lesions. The microvascular pattern was classified into types B1 (n=23) and B2 (n=7) using the JES classification of magnifying endoscopy for ESCC[2] . All 23 type B1 lesions were classified as INF-a without lymphatic invasion. Type B2 lesions were classified as INF-a (n=2), INF-b (n=4) and INF-c (n=1), and lymphatic invasion was present in two lesions (INF-b and INF-c). The rate of lymphatic invasion was significantly higher in type B2 than type B1 (p=0.048).
Conclusion
The tumor growth pattern of pT1a-LPM ESCC was mostly INF-a in type B1 patterns. Type B2 patterns are rarely present in pT1a-LPM ESCC, however lymphatic invasion with INF-b or INF-c was frequently observed. Careful observation before endoscopic resection with NBI-ME is important to identify B2 patterns to predict histopathology.
References
- Sung H, Ferlay J, Siegel RL, et al. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin. 2021;71(3):209-49
- Japan Esophageal S. Japanese Classification of Esophageal Cancer, 11th Edition: part I. Esophagus : official journal of the Japan Esophageal Society. 2017;14:1-36.
- Ooki A, Yamashita K, Kobayashi N, et al. Lymph node metastasis density and growth pattern as independent prognostic factors in advanced esophageal squamous cell carcinoma. World J Surg. 2007;31(11):2184-91.
- Ito E, Ozawa S, Kijima H, et al. New invasive patterns as a prognostic factor for superficial esophageal cancer. J Gastroenterol. 2012;47(12):1279-89.
- Zhao Y, Xu E, Yang X, et al. Tumor infiltrative growth pattern correlates with the immune microenvironment and is an independent factor for lymph node metastasis and prognosis in stage T1 esophageal squamous cell carcinoma. Virchows Arch. 2020;477(3):401-8.
- Anciaux M, Demetter P, De Wind R, et al. Infiltrative tumour growth pattern correlates with poor outcome in oesophageal cancer. BMJ Open Gastroenterol. 2020;7(1).
- Oyama T, Inoue H, Arima M, et al. Prediction of the invasion depth of superficial squamous cell carcinoma based on microvessel morphology: magnifying endoscopic classification of the Japan Esophageal Society. Esophagus. 2017;14:105-12.
Disclosure
There are no conflict of interest regarding this study.
