OBJECTIVETo evaluate the patterns of recurrence and the related factors in patients with pT3N0M0 thoracic esophageal squamous cell carcinoma (ESCC) after two-field esophagectomy.

METHODSFrom Jan 2008 to Dec 2009, 208 patients with stage pT3N0M0(2002, UICC) thoracic ESCC were treated with two-field esophagectomy in our hospital. There were 138 males and 70 females, and the median age was 60 years old (range 33-78). There were 33 patients in the upper-, 134 in the middle-, and 41 in the lower-thoracic esophagus, with a median length of lesion of 5 cm. There were 32 patients with no-, 78 with mild- and 98 patients with severe adhesions at surgery. The median number of dissected lymph nodes was 9 (range 1-27). 98 patients were treated with surgery alone and 110 with postoperative adjuvant chemotherapy. The statistical analysis was conducted using SPSS 13.0 software.

RESULTSThe follow-up was ended on July 2013. In the total group of 208 patients, the total recurrence rate was 41.8% (87/208). Among them, 52 patients had locoregional recurrence (LR), 15 had distant metastasis (DM) and 20 patients had both local recurrence and distant metastasis. 40.2% (35/87) of all recurrences were found within one year after operation, 67.8% (59/87) within 2 years, 86.2% (75/87) within 3 years, and 100% (87/87) within 4 years. The 1-, 3-, and 5-year progression-free survival (PFS) rate was 83.0%, 62.8% and 56.3%, respectively. The overall locoregional recurrence rate was 34.6% (72/208), among them, 9 cases had recurrence in the cervix (all were supraclavicular lymph node metastasis), 66 cases in the mediastinum and 4 cases had para-aortic lymph node metastasis. 83.3% (60/72) of the locoregional recurrence was located in the carinal region or upper area. The 1-, 3-, 5-year locoregional recurrence rate was 15.6%, 32.2%, and 36.8%, respectively, and the median time of recurrence was 15.5 months. The overall distant metastasis (DM) rate was 16.8% (35/208). The 1-, 3-, and 5-year DM rate was 4.4%, 15.3%, and 20.1%, respectively, and the median time of DM was 24 months. The most common site of DM was the lung and bone. The univariate analysis showed that age and tumor site were associated with PFS, tumor site and small lymph node in the mediastinum (diamter <1 cm) before surgery were related with LR (P<0.05 for all), and tumor site, histological differentiation and LR were related with distant metastasis after surgery (P<0.05). Multivariate analysis showed that the tumor site was an independent prognostic factor affecting the progression-free survival and locoregional recurrence (P<0.05), and histological differentiation and LR were independent factors associated with distant metastasis (P<0.05 for all).

CONCLUSIONSThe recurrence rate is very high in patients with pT3N0M0 thoracic ESCC after surgery, and most of them occur within 3 years after operation. Locoregional recurrence occurs more frequently and shortly than distant metastasis, and most of LR is located in the carinal region or upper-mediastinum. LR rate in upper-thoracic ESCC is very high, therefore, postoperative radiotherapy (PORT) is strongly suggested. LR rate in middle thoracic ESCC is also rather high and PORT is suggested. LR occur much less in the lower-thoracic ESCC, thus, PORT is not suggested routinely. Patients with poorly differentiated ESCC and LR have a high rate of distant metastasis.