Background: The presence/absence of extracapsular invasion in metastatic lymph nodes has been reported as being significantly correlated with the prognosis in a wide variety of cancers. However, the influence of extracapsular invasion in the metastatic lymph nodes on the prognosis in patients with stage III rectal cancer has not yet been investigated.
Objective: We investigated the presence/absence of extracapsular invasion in the metastatic nodes of the relevant main/lateral lymph node group in patients with rectal cancer to determine the usefulness of this parameter for stratifying the prognosis of patients with stage III rectal cancer.
Design: This was a single-institution study.
Settings: This study was conducted at a single institution.
Patients: We enrolled 101 consecutive patients with stage III rectal cancer who had undergone curative surgery with extended lymph node dissection and investigated the presence/absence of extracapsular invasion in the regional metastatic lymph nodes to determine the usefulness of such stratification for a more precise prediction of the patient prognosis.
Main outcome measures: The main outcomes measured were the disease-free and overall survival rates.
Results: Univariate analysis revealed a significantly poorer prognosis, in terms of both the disease-free survival rate (p = 0.003) and overall survival rate (p = 0.008), of the pN3-extracapsular invasion-positive cases in comparison with the pN3-extracapsular invasion-negative cases. Multivariate analysis revealed the presence/absence of extracapsular invasion in the metastatic lymph nodes as the only variable that was statistically significantly associated with the disease-free survival rate (p = 0.011).
Limitations: This was a retrospective study in a small number of patients from a single institution. There were no comparator groups.
Conclusions: Detailed stratification of pN3 cases based on the presence/absence of extracapsular invasion in metastatic lymph nodes has the potential to contribute significantly to more available prediction of the prognosis of patients with stage III colorectal cancer.