Background: Lymph node yield (LNY) and lymph node ratio (LNR) are recognized as independent prognostic factors in colorectal cancer (CRC).
Objectives: To examine the relationship between LNY and other clinico-pathological variables, and the prognostic value of LNY and LNR on patient survival in CRC.
Methods: The clinico-pathological and survival data for patients diagnosed from January 2000 to July 2012 were retrieved from the New Zealand Cancer Registry. Multiple linear regression was used to identify clinico-pathological factors influencing LNY, and Cox regression was used to determine the association between LNY and LNR and patient survival.
Results: 14,646 patients were included in the study (mean age 70.3 years, 50.1% male). Mean LNY was 17.4. Younger age, right-sided disease, higher T stage, female sex and no neoadjuvant radiotherapy (rectal cancer) were all associated with higher LNY (P ≤ 0.001). Overall survival in Stage I-III disease increased with higher LNY (for LNY ≥ 12, HR = 0.67, 95% CI 0.64-0.72; P < 0.001). Survival in Stage III-IV disease was inversely related to LNR (HR = 0.56, 95% CI 0.51-0.62; P < 0.001).
Conclusion: LNY is influenced by patient age, site of disease and T stage. LNY (Stage I-II) and LNR (Stage III-IV) have independent prognostic value in CRC.
Keywords: colon cancer; prognosis; rectal cancer.
© 2015 Wiley Periodicals, Inc.