The effect of neoadjuvant chemoradiation therapy on the prognostic value of lymph nodes after rectal cancer surgery

Background: Neoadjuvant therapy may affect the prognostic impact of total lymph node harvests and lymph node positivity after surgery for rectal cancer. Methods: We performed a retrospective review of 390 consecutive patients with histologically confirmed rectal cancer. Postoperative follow-up evaluation and survival were confirmed via medical record review. The impacts of lymph node positivity and total lymph node harvest on survival and recurrence are reflected as proportional hazard ratios (HRs). Results: A total of 221 patients underwent neoadjuvant therapy, of whom 75 had positive nodes. Node-positive patients showed a significantly shorter survival time (HR, 2.89; P = .002) and time to local recurrence (HR, 6.36; P = .031) compared with patients without positive nodes. Survival and recurrence were not significantly different between patients with a total harvest of fewer than 12 nodes and patients with a higher lymph node harvest. Conclusions: After neoadjuvant treatment and total mesorectal excision, lymph node positivity is associated with significantly shorter survival and time to local recurrence in rectal cancer patients, whereas absolute total lymph node harvests likely have little impact on prognosis.