Purpose: To stratify stage IIB (pT4a PN0) colorectal cancer in terms of histopathologic findings.
Methods: We reviewed the medical records of 80 patients who underwent surgery for stage IIB colorectal cancer. The disease-free survival (DFS) and overall survival (OS) rates were evaluated and correlated with the presence or absence of "Tumor Necrosis", "Crohn's-like lymphoid reaction", and "Perineural Invasion".
Results: Patients with "Tumor Necrosis" had significantly lower DFS rates (p < 0.0001), those with "Crohn's-like lymphoid reaction" had significantly higher DFS rates (p = 0.037), and those with "Perineural Invasion" had significantly lower DFS rates (p < 0.0001). Patients with "Tumor Necrosis" had significantly lower OS rates (p = 0.016), those with "Crohn's-like lymphoid reaction" had significantly higher OS rates (p = 0.022), and those with "Perineural Invasion" had significantly lower OS rates (p = 0.003).
Conclusions: Since stage IIB colorectal cancers accompanied by the pathological findings of "Tumor Necrosis" and "Perineural Invasion", but with the absence of "Crohn's-like lymphoid reaction" carried a poor prognosis, the efficacy of adjuvant chemoradiation must be considered for these patients.
Keywords: Crohn’s-like lymphoid reaction; Perineural invasion; Tumor necrosis.