Removal and Examination of 12 or More Lymph Nodes in Colon Resections

Key message

There have been steady improvements in the percentage of colon resections with 12 or more lymph nodes removed and examined from 2009 to 2012—this suggests greater adherence to evidence-based guidelines.

Indicator definition

The percentage of colon resections with 12 or more lymph nodes removed and examined for cases diagnosed from 2009 to 2012. Results are presented by province, age group and sex.

Target

90%, established in 2014 by the Partnership’s System Performance Targets and Benchmarks Working Group.

Measured since

The 2010 Cancer System Performance Report.

Why measure this?

The removal and examination of 12 or more lymph nodes is important for proper staging and subsequent treatment planning and has been associated with improved survival.^1-3 Most clinical guidelines recommend that a minimum of 12 lymph nodes be removed and then examined by a pathologist to more definitively establish a cancer’s nodal status—an indication of the extent of cancer spread to the lymph nodes.^{4, 5}

The recommendation is based on the fact that the chance of false negative nodal staging (i.e., the test fails to demonstrate that the cancer has in fact spread) is reduced to acceptable levels when a minimum of 12 lymph nodes are examined. Measuring provincial treatment patterns relative to this guideline can help identify variations and inform opportunities for quality improvement at the provincial level.

What are the key findings?

• In the 2012 diagnosis year, the percentage of colon resections with 12 or more lymph nodes removed and examined ranged from 70.7% in Prince Edward Island to 83.0% in Alberta; none of the reporting provinces achieved the target of 90% of colon resections with a minimum of 12 lymph nodes examined (Figure 4.1).
• Ontario achieved the target in 2011, but did not provide data for 2012 (Figure 4.1).
• The percentage of colon resections with a minimum of 12 lymph nodes examined was slightly higher for women aged 18–69 than for men in the same age group (83.1% vs. 78.9%), and also slightly higher for women aged 70 or older than for men in the same age group (81.3% vs. 76.6%) (data not shown).
• The percentage of colon resections with 12 or more lymph nodes examined increased in all reporting provinces from 2009 to 2012 (Figure 4.1).

Why do these findings matter?

There have been steady improvements across all provinces with respect to the percentage of colon resections with 12 or more lymph nodes removed and examined as per evidence-based guidelines. This pattern has positive implications for patients, such as better cancer staging and subsequent treatment planning, which has been associated with improved survival.^1-3

Several factors may have influenced the increasing trend, such as published evidence-based guidelines, public reporting and the implementation of quality improvement initiatives. One pan-Canadian quality improvement initiative is the Electronic Synoptic Pathology Reporting Initiative, which has participation from British Columbia, Manitoba, Ontario, New Brunswick, Nova Scotia and Prince Edward Island. The initiative will facilitate the implementation of electronic synoptic pathology reporting for several cancers, including colorectal cancer, to improve the quality of reporting. High-quality pathology reporting has the potential to lead to improved alignment with evidence-based guidelines (e.g., removal and examination of at least 12 lymph nodes), better care planning and improved patient outcomes.

References

1. Le Voyer TE, Sigurdson ER, Hanlon AL, Mayer RJ, Macdonald JS, Catalano PJ, et al. Colon cancer survival is associated with increasing number of lymph nodes analyzed: a secondary survey of intergroup trial INT-0089. J Clin Oncol. 2003 Aug 1;21(15):2912-9.
2. Bilimoria KY, Palis B, Stewart AK, Bentrem DJ, Freel AC, Sigurdson ER, et al. Impact of tumor location on nodal evaluation for colon cancer. Dis Colon Rectum. 2008 Feb;51(2):154-61.
3. Lykke J, Roikjaer O, Jess P. The relation between lymph node status and survival in Stage I-III colon cancer: results from a prospective nationwide cohort study. Colorectal Dis. 2013 May;15(5):559-65.
4. National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Colon Cancer Version 2.2016. 2015.
5. Smith AJ, Driman DK, Spithoff K, McLeod R, Hunter A, Rumble RB, et al. Optimization of Surgical and Pathological Quality Performance in Radical Surgery for Colon and Rectal Cancer: Margins and Lymph Nodes. Toronto (ON): 2008. 66 p.