Background: Transcriptional factor nuclear factor-kappaB (NF-kappaB) seems to be associated with aggressive clinical biology (chemoradiation resistance and metastatic progression) of esophageal cancer. We hypothesized that activated NF-kappaB would define clinical biology irrespective of the type of chemotherapy or sequence administered.
Methods: Pretherapy and/or posttherapy cancer specimens were examined for activated NF-kappaB and correlated with pathologic response to chemoradiation, metastatic potential, overall survival, disease-free survival, and type of chemotherapy or sequence used.
Findings: Eighty patients undergoing chemotherapy and concurrent radiation were studied. Activated NF-kappaB prior to any therapy was associated with the lack of complete pathologic response (pathCR, P = 0.006). Forty-five (78%) of 58 patients achieving <pathCR had activated NF-kappaB in pretherapy and/or posttherapy cancer specimens versus 2 (9%) of 22 patients with pathCR (P = 0.001). Twenty-four (51%) of 47 patients with activated NF-kappaB in cancer developed metastases versus 7 (21%) of 22 patients with negative NF-kappaB in cancer (P = 0.01). At a median follow-up of 32 months, 25 (53%) of 47 patients with activated NF-kappaB cancer had died versus 3 (9%) of 33 patients with negative NF-kappaB cancer. NF-kappaB activation was the only independent predictor of disease-free survival (P = 0.01) and overall survival (P = 0.007) in a multivariate model. The class of chemotherapy or its sequence had no effect on NF-kappaB expression or patient outcome.
Conclusions: Our data are the first to show that pretreatment-activated NF-kappaB significantly correlates with clinical biology of esophageal cancer, and most importantly, with pathCR. To therapeutically exploit NF-kappaB-regulated genes and their pathways, further research is warranted.