Background: The depth of tumor invasion (T) and regional lymph node status (N) are two factors that define the stage of an esophageal carcinoma. However, the arrangement of staging groups assumes that these factors are independent variables. A retrospective review of 359 consecutive patients undergoing esophageal resection was conducted to define the relationship between T and N and to determine whether T is a significant predictor of regional lymph node metastasis (N1).
Methods: Primary treatment was operation without preoperative therapy. There were 295 (82%) adenocarcinomas, 55 (15%) squamous cell carcinomas, and 9 (3%) adenosquamous carcinomas. T status was Tis in 29 (8%) patients, T1 in 65 (18%), T2 in 37 (10%), T3 in 219 (61%), and T4 in 9 (3%). N status was N0 in 161 (45%) patients and N1 in 198 (55%). M status was M0 in 327 (91%) patients and M1 in 32 (9%). Stage was 0 in 29 (8%) patients, I in 58 (16%), IIA in 70 (20%), IIB in 22 (6%), III in 148 (41%), and IV in 32 (9%).
Results: The likelihood of N1 disease occurring with increasing T was tested using the trend test. The percentage of patients with N1 disease is 0% for Tis, 11% for T1, 43% for T2, 77% for T3, and 67% for T4 (p < 0.001). This relationship existed for both adenocarcinoma and squamous cell carcinoma. Multivariable analysis identified increasing T, adenocarcinoma, and lack of well-differentiated histologic features as significant predictors of N1 disease. Compared with a T1 patient, a T2 patient is 6 times more likely to have N1 disease, a T3 patient 23 times, and a T4 patient 35 times.
Conclusions: We conclude that for patients with esophageal carcinoma, T is an important predictor of N and this association should be included with other established factors used in clinical staging and treatment decisions.