[Clinical implications of the new TNM staging system for thoracic esophageal squamous cell carcinoma]

To evaluate THE clinical significance of the 2009 UICC staging system for thoracic esophageal squamous cell carcinoma.

Two hundred and nine patients with thoracic esophageal squamous cell carcinoma undergone selective cervico-thoraco-abdominal lymphadenectomy were reviewed retrospectively and restaged according to the new 2009 UICC staging system. The relationship between individual stages and survival were analyzed accordingly.

The five-year overall and cause-specific survivals were 35.0% and 38.8%, respectively. Depth of invasion (T, P = 0.004), number of metastatic lymph nodes (N, P < 0.001), distant lymph node metastasis (M, P = 0.003), complete resection (R, P = 0.005) were significantly related to postoperative survival. On the other hand, location of primary tumor (L, P = 0.743) and histological grade (G, P = 0.653) were not significantly related to long-term prognosis. Upon stratification, the 5-year survival for T4a (32.0%) was significantly better than that of T4b (0, P < 0.001), but was similar to that of T3 (28.4%, P = 0.288). Patients without nodal involvement (47.8%, P < 0.001) and those with single station nodal disease (37.5%, P < 0.001) had significantly better survival than patients having 2 or more stations of lymph node metastasis (11.3%). Also patients without nodal involvement and those with metastasis confined to a single field (34.2%) had significantly better survival than patients having nodal diseases in 2 fields (12.1%) and 3 fields (0, P < 0.001). The 5-year survival for cervical metastasis after complete resection was 20.0%. Upon multivariate analysis, depth of tumor invasion (P = 0.001, RR = 1.635), numbers of metastatic nodal stations (P = 0.043, RR = 1.540) and fields (P = 0.010, RR = 2.187) were revealed as independent risk factors for long-term survival.

The new UICC staging system effectively predicts long-term prognosis for thoracic esophageal squamous cell carcinoma. Depth of tumor invasion and extent of lymph node involvement are two most important prognostic factors. To improve surgical outcomes, much effort is needed to increase the accuracy of preoperative staging and to include effective induction therapies into a multidisciplinary setting.