The impact of lymph node yield on Duke's B and C colorectal cancer survival.
OBJECTIVE
The number of positive lymph nodes retrieved following colorectal cancer (CRC) resection impacts on the staging and further treatment of the disease. We compared 5-year survival by lymph node yield for Duke's B and C patients to assess the impact on prognosis.


METHODS
A retrospective methodology was employed to review patients who underwent operative resection for Duke's B or C CRC between 1999 and 2003.


RESULTS
A total of 351 patients were included in our analyses. Lymph node yield, N-stage and extramural vascular invasion were independent predictors of overall 5-year survival. A significant difference in 5-year survival by lymph node yield was seen among Duke's B patients (< 9 nodes vs ≥ 9 nodes, 45.2%vs 68.4%; P = 0.0043) and Duke's C patients (< 10 nodes vs ≥ 10 nodes, 25.6%vs 48.8%; P = 0.0099). There was a significant reduction in the relative risk of 2.8% in mortality for each additional node sampled in Duke's B and C patients (RR 0.972, 95% confidence interval 0.949-0.994, P = 0.0102). Duke's B patients who had < 9 lymph node yield and no neoadjuvant/adjuvant treatment had a similar survival to all Duke's C patients (47.8%vs 41.7%, P = 0.5136).


CONCLUSIONS
Lymph node yield independently predicts for survival in patients with Duke's B and C CRC. Duke's B patients with < 9 lymph node yield have no better survival than patients with Duke's C disease. Therefore, prospective randomized studies are required to examine if inadequate lymph node yield could be one of the deciding factors in offering adjuvant therapy among Duke's B cancer patients.
Fretwell
V L
VL
Department of Colorectal Surgery, Royal Liverpool and Broadgreen University Hospital NHS Trust, Liverpool, UK.
Ang
C W
CW
Tweedle
E M
EM
Rooney
P S
PS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate