Lymph node harvest after proctectomy for invasive rectal adenocarcinoma following neoadjuvant therapy: does the same standard apply?
OBJECTIVE
Recent reports indicate that neoadjuvant therapy significantly reduces the lymph node harvest of rectal cancer. The aim of this study was to interpret the lymph node harvest in this setting based on the primary tumor response.


METHODS
All patients undergoing proctectomy were included. Three variables were used as indicators of primary tumor response: ypT stage, tumor size, and tumor regression grade.


RESULTS
From 1998 to 2007, 237 patients were identified: 157 in the neoadjuvant therapy group and 80 in the nonneoadjuvant therapy group. Neoadjuvant therapy significantly reduced the number of lymph nodes harvested (P = 0.011). Compared with the nonneoadjuvant group, there were significantly fewer lymph nodes in the neoadjuvant early T stage group (P = 0.001), small tumor size group (P = 0.003), and low tumor regression grade group (P < 0.001). However, there was no significant difference between the nonneoadjuvant group and the neoadjuvant advanced T stage (P = 0.664), large tumor (P = 0.815), and high tumor regression grade groups (P = 0.566).


CONCLUSIONS
The current standard of lymph node harvest should be applied to patients with poorly responding primary tumors after neoadjuvant therapy. However, a new standard may be necessary to define the adequate number of lymph nodes for tumors that respond well to neoadjuvant therapy.
Wang
Hao
H
Department of Colon and Rectal Surgery, Cleveland Clinic Florida, Weston, Florida 33331, USA.
Safar
Bashar
B
Wexner
Steven
S
Zhao
Ronghua
R
Cruz-Correa
Marcia
M
Berho
Mariana
M
D000230:Adenocarcinoma / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D013048:Specimen Handling
D000964:Antimetabolites, Antineoplastic; D005472:Fluorouracil