Catheter Related Thrombosis in Breast Cancer Patients: Risk Factors and Prognostic Implications
Authors: Cesarman-Maus Gabriela N. , Cornejo Patricia , Oñate Luis , Villa Rosario , Miranda Yolanda , Aguilar Jose Luis , Siñani Marianela , Volkow Patricia 
Published: October 2019

Abstract
Abstract 1139

Background:
Central venous catheters (CVC) are cornerstone for the management of cancer patients on chemotherapy, however their use may be associated with venous thrombosis (VTE). The incidence of symptomatic thrombosis varies widely depending on the threshold for ordering diagnostic tests and the population under study. As opposed to lower extremity thrombosis, which is a marker of underlying tumor aggressiveness portending a poor prognosis in cancer patients, it is not clear if CVC-related thrombosis leads to a detriment in patient survival.

Objectives:
In this retrospective study we address the prognostic implications of symptomatic CVC-and non CVC-related thrombosis. We also evaluate the relevance of thrombotic risk factors reported for cancer-related VTE.

Methods:
We included 1088 consecutive patients with cancer and CVC followed in the Catheter Clinic at the NCI-Mexico. Of these, only the 506 with breast cancer diagnosis were included in this report. Clinical criteria that prompted the request for a diagnostic doppler ultrasound were dysesthesia, pain, collateral venous circulation and or edema of any extent or duration, affecting the upper extremity, shoulder, or neck.

Results:
The prevalence of symptomatic CVC-related VTE was 26.1% (132/506), with 61% and 86.7% detected by 60 and 120 days of CVC placement, respectively. The side of catheter placement was not relevant for the development of thrombosis (Right:64/132, Left:68/132). Non-CVC-related upper extremity VTE (33/6.5%) and lower extremity VTE (20/3.9%) were confirmed by doppler ultrasound. Only leucocytosis (>11,000/mm3) prior to thrombosis (but not hemoglobin or platelet count) was more prevalent in individuals with CVC-related VTE, as compared to those without VTE (11.4% vs 4.3%, p=0.006). It is noteworthy that CVC-related upper extremity DVT did not impact overall survival (OS) when compared by bivariate analysis to patients without thrombosis (HR: 0.96, CI 9.75–1.2, p 0.760), with a median survival not reached in either group (18.7% and 18.3% deaths respectively). Non-CVC-related upper extremity VTE may also lack impact on survival (HR:1.16, CI 0.9–1.48, p 0.254), though the number of patients is small. In contrast, the detrimental effect of lower extremity DVT as compared to individuals without thrombosis was significant (HR: 4.6 CI 2.3–9.1 p<.0001, 62.5% deaths).

Conclusions:
CVC-associated VTE was detected in a fourth of patients primarily during initial treatment. The site of catheter placement did not affect the risk of VTE. Except for leucocytosis prior to thrombosis, other thrombosis risk score parameters useful for lower extremity VTE may not be applicable to CVC-related thrombosis. Importantly, CVC-related thrombosis was not associated with underlying enhanced aggressive tumor behavior as evidenced by a lack of impact on survival.

Disclosures:
No relevant conflicts of interest to declare.