NF-kappa B/p65 expression before and after treatment in rectal cancer patients undergoing neoadjuvant (chemo)radiotherapy and surgery: prognostic marker for disease progression and survival
Abstract
The aim of the present study was to determine expression of NF-kappa B/p65 in tumor specimens before and after treatment of rectal cancer patients and to evaluate possible relationship between expression of NF-kappa B/p65 before and after (chemo)radiotherapy, other tumor characteristics and the clinical outcome. Furthermore, NF-kappa B/p65 was studied in relationship to pathologic response to preoperative (chemo)radiotherapy.
Fifty patients with rectal cancer undergoing neoadjuvant (chemo)radiotherapy and surgery were included in the study. Pre-treatment rectal cancer specimens were obtained from diagnostic colonoscopy.
Post-treatment rectal cancer specimens were obtained from surgically removed part of the rectum with the tumor. NF-kappa B/p65 expression was determined by immunohistochemistry and analysis was performed both in biopsies and in post-treatment tumor samples.
Cytoplasmic positivity in tumor cells and nuclear positivity in lymphocytes were detected. High NF-kappa B/p65 positivity in pre-treatment tumor samples was significantly associated with shortened overall survival (OS).
Disease-free survival (DFS) tends to be shortened as well. In post-treatment tumor samples, high NF-kappa B/p65 positivity was neither associated with shortened OS nor with shortened DFS.
In post-treatment samples residual tumor cells deeply infiltrating the wall of the rectum with high NF-kappa B/p65 expression were found. The cells were linked to significantly worse clinical outcome in terms of shortened OS and DFS.
NF-kappa B/p65 positivity did not correlate with pathologic response to preoperative (chemo) radiotherapy. In conclusion, our data suggest that high level of NF-kappa B/p65 subunit may be associated with more aggressive features of the tumor, higher metastatic potential, and shortened overall survival, but it does not correlate with resistance to (chemo)radiotherapy.