Published online Jun 10, 2016. doi: 10.5306/wjco.v7.i3.302
Peer-review started: January 30, 2016
First decision: March 24, 2016
Revised: April 16, 2016
Accepted: May 7, 2016
Article in press: May 9, 2016
Published online: June 10, 2016
AIM: To examine trends of contralateral prophylactic mastectomy (CPM) rates at a Canadian academic breast cancer center.
METHODS: A single-institution retrospective cohort study was completed. Women of any age who underwent at least a unilateral mastectomy (UM) for primary unilateral breast carcinoma between January 1, 2004 and December 31, 2010 were included. Patients who underwent CPM on the same day as UM were isolated to create two distinct cohorts. Patient and procedure characteristics were compared across groups using R software (version 3.1.0). The percentage of CPMs per year was determined. The Cochrane-Armitage test was used to assess the trend of CPMs over time. A P value of < 0.05 was considered significant.
RESULTS: A total of 811 women met the inclusions/exclusion criteria; 759 (93.6%) underwent UM alone and 52 (6.4%) underwent UM with immediate CPM. The absolute number of procedures (UM and UM + CPM) increased over time, from 83 in 2004 to 147 in 2010 reflecting an increase in mastectomy volume. Annual CPM rates did not increase over time (P = 0.7) and varied between 2.6% to 10.7%. Family history of breast cancer [OR 3.6 (1.8-7.3)] and immediate reconstruction [10.0 (5.2-19.3)] were both significantly associated with CPM. Women who underwent CPM were younger (median age CPM 49 years vs UM 52 years, P < 0.0001) but age less than 50 years was not statistically associated with increased rates of CPM.
CONCLUSION: CPM rates from 2004 to 2010 at a high-volume Canadian breast cancer center did not increase over time, in contrast to trends observed in the United States.
Core tip: Contralateral prophylactic mastectomy rates from 2004 to 2010 at a high-volume Canadian breast cancer center do not demonstrate the same rising trend observed in the United States.