Postoperative Recurrence Pattern of Clinical Stage I Esophageal Cancer After Esophagectomy with Two- or Three-Field Lymph Node Dissection: Supplementary Analysis from JCOG0502.

Background: Although recurrence after curative surgery for cT1bN0M0 clinical stage I (cStage I) esophageal squamous cell carcinoma (ESCC) is not rare, reports of recurrence analyses are sparse. Detailed data on optimal postoperative follow-up evaluation of cStage I ESCC are lacking. This study aimed to evaluate the frequency, characteristics, and predictors of postoperative recurrence in patients with cT1bN0M0 cStage I ESCC.

Methods: The study analyzed 210 patients who underwent surgery for cT1bN0M0 cStage I ESCC and a follow-up computed tomography (CT) examination in the prospective multicenter study, JCOG0502. The study categorized the characteristics of postoperative recurrences such as the recurrence sites and whether regional/non-regional lymph nodes (LNs) and single/multiple organs were involved. Backward elimination was applied (p < 0.2) to identify postoperative recurrence predictors and obtained hazard ratios (HRs) based on Fine and Gray's model.

Results: Postoperative recurrence was experienced by 31 patients (14.8%) at one or more of the following sites: regional LNs (n = 18), non-regional LNs (n = 10), lung (n = 2); bone (n = 2), and liver, local recurrence, skin, pleura, pericardium, and other (n = 1 each). In four patients, the first recurrence developed in multiple organs. The median interval between trial registration and the first recurrence was 18.6 months. In multivariable analyses, pathologic nodal metastasis (hazard ratio [HR], 3.29; p = 0.003), tumor location in the upper-thoracic esophagus versus lower-thoracic esophagus (HR, 6.71; p = 0.013), and two-field lymphadenectomy (HR, 4.31; p = 0.001) were independently associated with the development of postoperative recurrence.

Conclusion: The main postoperative recurrence sites of cT1bN0M0 ESCC are the LNs, but recurrence in non-regional LNs or distant organs is also quite common, indicating the importance of post-surgery systemic follow-up evaluation.