Objective:To explore factors affecting port venous thrombosis in breast cancer patients. Methods:Data of 172 breast cancer patients admitted to the First Affiliated Hospital of Chongqing Medical University from November2013 to December 2014 were collected and analyzed in regard of gender

age

implantable sites

tumor location

chemotherapy regimens and colorful ultrasound results.Results:Catheter-related thrombosis occurred in 42 out of 172 patients(42/172

24.4%)with implantable intravenous port including16 cases(16/48

33.3%) of left side internal jugular vein

26 cases(26/124

21.0%) on the right side(P >0.05)

32 cases(32/42

76.2%)with TEC/ECT scheme

5 cases(5/42

11.9%)with the TAC scheme

2 cases(2/42

4.8%)with CEF/FEC scheme

3 cases(3/42

7.1%)with EC scheme(P<0.001)

5 cases(5/42

11.9%)in 2nd chemotherapy cycle

8 cases(8/42

19.0%)and 6 cases(6/42

14.3%)in 5th and 6th chemotherapy cycles

respectively(P >0.05). Conclusion:Catheter-related thrombosis is a common complication in breast cancer patients with implantable intravenous port and the left side is the predilection site. There is no correlation between venous thrombosis and chemotherapy cycles. Chemotherapy drugs may be responsible for formation of thrombosis and TEC/ECT regime is the most likely cause.