Neoadjuvant therapy for rectal cancer decreases the number of lymph nodes harvested in operative specimens

BackgroundWe evaluated the effect of neoadjuvant therapy (NAT) on lymph node harvest in rectal cancer patients undergoing anatomic resection with curative intent.MethodsA prospectively maintained database was retrospectively queried for rectal cancer cases from 1990 to 2010. Demographic data, NAT, and lymph node yield were analyzed. Nonanatomic resections were excluded.ResultsFive hundred two cases were identified; the mean age was 68 years (range 34–89), and 56% were men. One hundred fifty-one (30%) patients received NAT. Overall, the lymph node yield was diminished in proctectomy specimens after NAT (mean = 9, median = 7) compared with specimens without therapy (mean = 13, median = 10, P = .001). Age was not a significant factor in the lymph node yield (P = .213 and .329). Among patients treated with NAT, younger patients had a significantly lower lymph node yield (P < .0001).ConclusionsA decreased lymph node yield in proctectomy specimens from patients treated with NAT is consistent with prior studies. Younger patients had a greater reduction in lymph node harvest after NAT compared with senior patients.