Post-operative radiation therapy for patients with stage I or II breast cancer

Definition: The percentage of patients diagnosed with stage I or II breast cancer who received post-operative radiation therapy following breast-conserving surgery (BCS)

Numerator: Stage I and II breast cancer cases (female) starting radiation therapy within 270 days following breast-conserving surgery

Denominator: Stage I and II breast cancer cases (female) receiving breast-conserving surgery within one year of diagnosis

Data source: Provincial cancer agencies

Measurement timeframe: 2009, 2010, 2011 and 2012 diagnosis years

Stratification variables: Province, age group

Provinces submitting data: AB, SK, MB, ON, NB, NS, PE, NL

Province specific notes:

• AB: For 2009, segmental resections were included as lumpectomy. For 2010/2011/2012, treatment information is based on initially planned treatment to the primary site (ACR data). The CCI codes are not used by the ACR Data, as such Breast conserving surgery has been identified by a registry surgical modality variable with values ‘lumpectomy' or ‘segmental resection'. If more than one surgical procedure is performed as a part of the initial treatment, the most definitive procedure is documented. The definition of definitive is the surgical procedure with the intent to cure. Cases with radiation therapy before surgery were excluded.
• SK: Date of surgery was not available for cases diagnosed in 2009.
• ON: Radiation therapy was not limited to primary tumor site.
• MB: For 2011 and 2012, treatment intent filter was not applied. Radiation therapy was not limited to primary tumor site.
• PE: Treatment intent filter applied for 2009, but not applied for 2010 as it was only entered part way through the year so data is missing for half of the applicable cases. For 2010, radiation therapy is limited to primary tumor site. For 2011 and 2012, malignant phylodes tumor is included.
• NL: For 2009/2010/ 2011/2012, treatment intent filter applied and radiation therapy is limited to primary tumor site.

Notes:

1. Breast cases identified as ICDO3 codes: C50.0 to C50.9, AJCC group stage at Diagnosis = I or II.
2. Exclude male and lymphoma codes M-95 to M-98. For 2010 /2011/2012, also excluded sarcoma codes (see Appendix 1), neuroendocrine carcinoma and squamous cell carcinoma.
3. Cases for patients under 18 years of age (at diagnosis) were excluded.
4. Breast-conserving surgery cases are identified using CCI codes: 1YM87 or 1YM88.
5. Cases with a subsequent mastectomy within one year of breast conserving surgery were excluded, using CCI codes 1YM89 to 1YM92 in the specified time period.
6. Resected cases included regardless of margin status (due to data limitations).
7. Included cases which last resection date (if multiple) – diagnosis date <= 365 days, radiation start date – last resection date (if multiple) <=270 days.