Adjuvant radiotherapy for positive lymph nodes of oesophageal squamous cell carcinoma: Can it earn promising benefits at long-term follow-up?

PURPOSE

The value of adjuvant radiotherapy for patients with positive lymph nodes after curative resection of oesophageal squamous cell carcinoma is controversial. This study aims to investigate its long-term benefits in a specific cohort.

PATIENTS AND METHODS

The charts between 1990 and 2003 from patients with positive lymph nodes were retrospectively reviewed. Those subjects were divided into adjuvant radiotherapy and surgery alone groups, with two subgroups defined by radiation dose (cutoff value: 50Gy). Overall survival, disease-free survival and locoregional recurrence-free survival were compared between two groups, with predictive factors of overall survival analysed meanwhile.

RESULTS

In sum, 175 matched patients with 1:2 ratios for group balance were enrolled for final analysis. During the follow-up (median: 37.0 months), 143 (81.7%) deaths were recorded, with 70.6% of deaths from cancer progression. The median overall survival time (19.5, 4 to 172 months) was not significantly different between the two groups (18.9 vs. 20.0 months, P=0.179). However, the disease-free survival time was significantly shorter in the adjuvant radiotherapy group than that in the control group (median, 11.5 vs. 14.9 months; P=0.001), with the locoregional recurrence-free survival time impressively prolonged (median: 18.3 vs. 16.5 months; P=0.022). Age (P=0.030), number (P=0.005) and ratio (P=0.002) of positive lymph nodes were associated with overall survival, but radiation dose was not (P=0.204).

CONCLUSION

Adjuvant radiotherapy with low- or high-dose did not improve survival compared with surgery alone. However, radiotherapy was effective to control locoregional recurrence, and could be applied as salvage therapy when recurrence event occurred.