Removal and examination of 12 or more lymph nodes in colon resections

Definition: The percentage of colon resections with 12 or more lymph nodes removed and examined within 12 months of diagnosis

Rationale for measurement: 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. Most clinical guidelines recommend that a minimum of 12 lymph nodes be removed and examined by a pathologist to more definitively establish a cancer’s nodal status.

Measurement timeframe: Diagnosis years 2011 to 2014

Denominator: All invasive colon cancer cases resected within 12 months of diagnosis in the timeframe, which meet the criteria in “Variable details” box

Numerator: Invasive colon cancer cases that were resected with 12 or more lymph nodes removed and examined within 12 months of diagnosis in the timeframe

Exclusion criteria: 

1. Cases with age ≤ 17
2. Cases with unknown number of lymph nodes removed and examined were excluded

Data availability:

• 2011-2014: AB, SK, MB, NB, NS, PE, NL
• 2011-2013: BC
• 2013-2014: ON

Stratification: 

1. By year
2. By province

Data source: Provincial cancer agencies and programs

Data retrieval date: October 2017

Variables details: 

Cancer definition:

1. Colon cancer was defined as C18 in ICD-O3 with behavior code 3 (invasive)
   C18.1 (Appendix) was excluded
   For the cancer cases with lymphoma Codes M-95 to M-98, sarcoma codes neuroendocrine carcinoma, and squamous cell carcinoma were excluded (see Appendix A).

Resection identification:

2. Colon resections were identified using CCI codes: 1NM87 or 1NM89 or 1NM91. CCI code 1NM87BA was excluded
3. All resections were included regardless of margin status.

Treatment criteria:

4. All colon resections were within 12 months of diagnosis. If there were multiple resections, counted the last resection: last resection date (if multiple) – diagnosis date ≤ 365 days

Notes from jurisdictions:

• BC: We do not have surgery data past 2014 and since the indicator includes surgery up to 1 year following diagnosis, we cannot provide data for diagnosis year 2014.
• ON: Synoptic reporting in Ontario completed in 2012. 2011, and part of 2012 are incomplete down to level of lymph node examined counts.
• PE: Out of province treatment is included if known about.

Methodology notes:

1. The cancer incidence sites/types were classified by World Health Organization, International Classification of Diseases for Oncology, Third Edition (ICD- O-3).
2. The Canadian Classification of Health Interventions (CCI) codes were used to identify surgery types, except AB.

Changes to definition compared to previous years: Not applicable