Treatment Algorithm in Cancer-Associated Thrombosis: Updated Canadian Expert Consensus

Abstract

Patients with cancer-associated thrombosis (CAT) are at high risk of recurrent venous thromboembolism (VTE) and major bleeding complications. Risks vary significantly between individuals based on cancer status, treatment, and other characteristics. To facilitate the evidence-based management of anticoagulant therapy in this patient population, a committee of 11 Canadian clinical experts updated a consensus-based algorithm for the acute and extended treatment of symptomatic and incidental CAT that was developed in 2018. Following a systematic review of the literature, updates to the algorithm were discussed during an online teleconference, and the algorithm was subsequently refined based on feedback from committee members. Clinicians using this treatment algorithm should consider bleeding risk, type of cancer, and drug–drug interactions, as well as patient and clinician preferences, in tailoring anticoagulation for patients with CAT. Anticoagulant therapy should be adapted as the patient’s cancer status and management change over time.

Unanswered questions in cancer‐associated thrombosis

“…While there are numerous guidelines available, the most recent ones are summarized in Table 2. [29][30][31][32] Overall, they are consistent and recommend using DOACs over LMWHs for most patients with cancer-associated VTE and using VKAs only if DOAC and LMWH are not appropriate or available. There is a preference for LMWHs in patients with GI or GU intraluminal (particularly unresected) tumours, those with high bleeding risk for other reasons (e.g.…”

Practical Considerations for the Management of Cancer-Associated Venous Thromboembolism: A Guide for the General Oncology Practitioner

“…With increasing evidence supporting the use of DOACs as an effective and safe treatment option for select patients with CAT, international and national societies have released clinical practice guidelines outlining recommendations to facilitate the evidence-based management of CAT [ 25 , 26 , 27 , 28 , 29 ]. While these guidelines are an excellent resource to help inform clinicians, it is imperative that clinicians recognize that determining the most suitable anticoagulation treatment plan for patients with CAT requires a thorough evaluation of patient-related, cancer-related, and treatment-related factors [ 25 , 26 , 27 , 28 , 29 ]. Of utmost importance, the decision around anticoagulation should be a shared decision between the patient and their physician.…”

“…One of the first factors to consider when deciding on the type of anticoagulation for a CAT event is the location and burden of the VTE event. In patients who have severe or life-threatening presentations (e.g., iliofemoral DVT, sub-massive PE, or need for thrombolysis), treatment with LMWH is suggested as the initial anticoagulation treatment, and a DOAC can be considered when the patient’s clinical status has improved [ 25 ].…”

“…Notably, incidental VTE events were included in all the major randomized control trials looking at LMWH vs. DOAC, and while the rate of recurrent VTE is lower in patients with incidental VTE compared to those with symptomatic VTE, the overall rate of recurrent events remains high [ 18 , 19 , 20 , 21 , 22 , 23 , 30 , 31 ]. As per national and international society guidelines, it is suggested that patients with incidental CAT receive the same initial and long-term anticoagulation as patients with symptomatic CAT [ 25 , 26 , 27 , 28 , 31 ].…”

“…An increased risk of catheter-related thrombosis has been reported with left-sided catheters, placement of the catheter tip above the junction between the superior vena cava and the right atrium, improper catheter tip placement as well as with peripherally implanted central venous catheters (PICCs) and catheter with multiple lumens, as well as patients with a high BMI and non-breast cancers [ 37 , 38 , 39 , 40 , 41 ]. For the treatment of catheter-related thrombosis in patients with cancer, society guidelines suggest that the choice of agent, DOAC or LMWH, should be individualized similarly to other CAT events and that duration should be at least 3 months or for as long as the catheter remains in place [ 25 , 26 , 27 , 28 , 29 , 38 , 42 ]. The catheter does not need to be removed and can continue to be used if it is functioning properly and when there is no sign of infection [ 25 , 26 , 27 , 28 , 29 , 38 , 42 ].…”