Venous Thromboembolism After Surgical Treatment of Breast Cancer.

Background: Venous thromboembolism (VTE) remains a serious complication after the surgical treatment of breast cancer. Contemporary guidelines limit VTE chemoprophylaxis to the period of hospitalization. We conducted this study to evaluate the frequency of postdischarge VTE among surgically treated breast cancer patients and identify patient level factors associated with postdischarge VTE.

Methods: Using Arkansas, Florida, Nebraska, and New York state inpatient databases, we conducted a retrospective cohort study of adult women who underwent surgical treatment for breast cancer between October 1, 2008, and September 30, 2013. The primary outcome was a VTE event within 90 days of discharge. Multivariable logistic regression modeling was used to identify patient factors associated with VTE development.

Results: The final sample included 52,547 women with most undergoing mastectomy without reconstruction (n = 25,665), followed by mastectomy with implant based reconstruction (n = 16,851), lumpectomy (n = 5319), and mastectomy with autologous reconstruction (n = 4622). There were 395 patients (0.8%) who developed at least 1 VTE. Of the 395 VTEs, 32.9% (n = 130) were identified before discharge, whereas 67.1% were identified within 90 days after discharge. Patients with respiratory disease (adjusted odds ratio [AOR] = 1.56 [1.22-1.98]), hypothyroidism (AOR = 1.31 [1.01-1.70]), a hospital stay of more than 5 days (AOR = 8.07 [5.99-10.89]), previous VTE (AOR = 6.26 [3.95-9.91]), or mastectomy with autologous reconstruction (AOR = 1.50 [1.03-2.19]) more frequently developed postdischarge VTEs.

Conclusions: Nearly two thirds of all 90-day VTE events after breast cancer surgery occur after discharge. Further research should determine whether a longer course of VTE prophylaxis is warranted among specific populations including those with prolonged hospitalizations, previous VTE, and those undergoing autologous reconstruction.