1. Lymph nodes in colon cancer – national data.
Tarik Sammour
Ryash Vather
Arman Kahokehr
Andrew B. Connolly
Andrew G. Hill

2. Introduction Majority of colon cancer patients are
potentially curable at diagnosis
Surgery is offered on this basis
Single most important prognostic factor is
lymph node status. 2

3. Dukes B How many nodes are required for
accurate differentiation of Dukes B cancers?
Controversial
“Ideal” number of nodes varies: 6 – 17.
12 nodes generally accepted
as optimum by consensus.

4. Recent Middlemore study
216 patients with Dukes B colon cancer
Jan Dec 2001
5 year follow-up

5. <16 nodes gives recurrence rates similar to that expected in Dukes B cases (25-30%).
Drop from to is significant (p=0.0368)
Drop <16 to >16 is significant (p=0.0001)
p=0.0001

6. Conclusion
Dukes B patients with > 16 nodes in the sample had a significant reduction in recurrence.

7. Need to verify this finding in a larger subset of patients.

8. Methods NZ Cancer Registry data
All patients who underwent resection for colon cancer Jan 1995 – July 2003.
Looked at Dukes B and C patients
Exclusions:
Dukes A
Distant mets preop
No TNM / Dukes stage recorded

9. Results 4,309 patients included in analysis
Mean age 70 years (16 – 100)
Euro %
Maori 2.8%
PI %
Other 2.9%
R sided (including transverse) 57.3%
L sided %

10. Who had more nodes? Factors associated with higher node retrieval
Younger age p <
Females vs 13.4 Males, p 0.001
R sided cancer vs 12.4 L sided, p <
Pacific islander 17.8 vs 14.0 for rest, p 0.016

11. VS
More nodes
Fewer nodes

12. Dukes B

13. Dukes B 5 year mortality 31% Mean number of nodes 13.7 (range 1 – 99)
Death
Survival
Mean number of nodes examined
11.9
14.5
P <

15. Dukes B
Seemingly linear increase in survival with more lymph nodes in the specimen.
What if you factor in confounders such as
age, sex, site, and ethnicity?
=> COX regression analysis

16. No reduction in survival past 16 nodes

17. Dukes C

18. Dukes C 5 year mortality 60.4%
Mean number of nodes 13.8 (range 1 – 99)
Death
Survival
Mean number of nodes examined
13.1
14.8
P <

19. No reduction in survival past 16 nodes

20. Conclusions
Number of sampled lymph nodes predicts mortality in Dukes B and C colon cancer.
Survival increases up to 16 lymph nodes, after which survival benefit is negligible.
This finding is consistent with our local data.
Should inform patient counselling and decision making regarding chemotherapy referral.