NICE vs BSH: Management of Venous Thromboembolism in Cancer (2025)

This guideline comparison provides a factual, UK-focused overview for clinicians of the key recommendations from the National Institute for Health and Care Excellence (NICE) NG158 (updated 2025) and the British Society for Haematology (BSH) guideline (2020, with ongoing relevance) for the management of venous thromboembolism (VTE) in adults with cancer. The aim is to highlight areas of alignment and divergence to support clinical decision-making.

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Diagnosis and Initial Assessment

Both guidelines emphasise the importance of prompt and accurate diagnosis, acknowledging the challenges of interpreting D-dimer results and imaging in cancer patients.

NICE NG158 (2025)

• D-dimer: Recommends against using a D-dimer test to rule out VTE in patients with cancer, due to its likely elevated baseline and low specificity in this population.
• Imaging: Advocates for immediate compression duplex ultrasound for suspected DVT. For suspected PE, recommends immediate computed tomography pulmonary angiography (CTPA).
• Risk Assessment: Does not specify a particular risk assessment tool for bleeding prior to anticoagulation initiation, but advises a clinical assessment of bleeding risk.

BSH Guideline (2020)

• D-dimer: Similarly, states that D-dimer should not be used to exclude VTE in cancer patients.
• Imaging: Aligns with NICE, recommending ultrasound for DVT and CTPA for PE.
• Risk Assessment: More explicitly recommends the use of a validated bleeding risk score, such as the RIETE or Ottawa scores, to stratify patients before starting anticoagulation.

Key Difference: BSH provides more specific guidance on using formal bleeding risk assessment tools, while NICE relies on broader clinical assessment.

Anticoagulation Treatment

This is the area of greatest alignment, with both guidelines strongly favouring Direct Oral Anticoagulants (DOACs) for most patients.

First-line Treatment for Established VTE

• NICE and BSH (Alignment): Both guidelines recommend a DOAC (apixaban, rivaroxaban, or edoxaban) or Low Molecular Weight Heparin (LMWH) as first-line treatment options.
• Preference for DOACs: Both express a preference for DOACs over LMWH due to oral administration and comparable efficacy/safety, unless contraindicated.
• Treatment Duration: Recommend anticoagulation for at least 6 months for cancer-associated VTE. Beyond 6 months, treatment should be continued indefinitely as long as the cancer is active and/or the patient is receiving anticancer treatment.

Key Differences and Nuances

• LMWH in High-Risk GI Cancers: Both guidelines caution against DOACs in patients with luminal gastrointestinal (GI) malignancies at high risk of bleeding. However, BSH is more emphatic, strongly recommending LMWH as the preferred agent in this subgroup. NICE advises discussing the increased risk of bleeding with the patient and considering LMWH.
• Drug-Specific Recommendations: BSH provides slightly more detailed commentary on individual DOACs, noting the stronger evidence base for apixaban and rivaroxaban in cancer populations at the time of publication. NICE treats the recommended DOACs as a class.

Special Situations

Thrombocytopenia

• NICE (2025): Provides a clear, practical table for management based on platelet count:
  • ≥50 x 10⁹/L: Full-dose anticoagulation.
  • 25-50 x 10⁹/L: Reduce dose of LMWH by 50%.
  • <25 x 10⁹/L: Temporarily withhold anticoagulation and consider platelet transfusion if anticoagulation is essential.
• BSH: Offers similar principles but is less prescriptive regarding the exact dose reduction threshold, focusing more on clinical judgement and individualised risk-benefit analysis.

Renal Impairment

• Both Guidelines: Recommend dose adjustment for DOACs based on renal function and manufacturer's SPC. For patients with severe renal impairment (CrCl <15-30 ml/min, depending on the drug), LMWH is preferred.

Central Venous Catheters (CVCs)

• Both Guidelines (Alignment): Recommend against routine anticoagulant prophylaxis for CVCs. If CVC-associated thrombosis occurs, treat with therapeutic anticoagulation as for any other VTE; catheter removal is not necessary if it is functional and required.

Practical Clinical Flow and Monitoring

NICE Approach

NICE structures its guidance around a clear care pathway, from suspicion of VTE through to long-term management. It heavily integrates patient choice and shared decision-making, especially regarding the choice between DOAC and LMWH.

BSH Approach

BSH provides a more detailed, haematologist-focused perspective on monitoring. It emphasises:

• Close monitoring of renal function and platelet count, especially in the first few weeks of treatment.
• The role of specialist haematology/pharmacist-led anticoagulation clinics in managing complex cases.
• Vigilance for drug-drug interactions, particularly with cytochrome P450 3A4 and P-gp inhibitors, which are common with DOACs and anticancer therapies.

Practical Takeaway: While NICE provides the overarching pathway, BSH offers granular advice for ongoing management, particularly for patients under specialist care.

Frequently Asked Questions (FAQs)

1. Which guideline should I follow if they conflict?

In the UK, NICE guidelines generally take precedence for defining standard of care within the NHS. However, the BSH guideline offers valuable, detailed expert consensus, particularly for complex cases. For most situations, they are highly aligned. In areas of nuance (e.g., high-risk GI cancer), local trust protocols often synthesise both, but the BSH recommendation for LMWH in this scenario is widely adopted.

2. Is there a preferred DOAC?

Neither guideline officially ranks the DOACs. NICE lists apixaban, rivaroxaban, and edoxaban as options. BSH, in its text, notes the pivotal trial evidence for apixaban (ADAM VTE) and rivaroxaban (SELECT-D). In practice, the choice may depend on drug acquisition cost, dosing regimen (once vs. twice daily), and local formulary decisions.

3. How should I manage a patient with a platelet count of 30 x 10⁹/L?

Both guidelines recommend dose modification. Follow the clear NICE (2025) recommendation: reduce the therapeutic dose of LMWH by 50%. For DOACs, evidence is more limited, but the same principle of caution and potential dose reduction or temporary interruption (with LMWH bridge) is applied, often under specialist guidance.

4. When should I refer to a specialist?

BSH provides more explicit guidance here. Referral to a haematologist or specialist anticoagulation service is recommended for: recurrent VTE despite anticoagulation, severe thrombocytopenia, major bleeding, severe renal impairment, or complex drug interactions.

5. How long do we treat VTE in a patient with metastatic disease?

Indefinitely. Both guidelines are clear that anticoagulation should be continued as long as the cancer is "active" (a term encompassing metastatic, recurrent, or locally advanced disease) and/or the patient is receiving systemic anticancer therapy. The decision to stop should be reassessed periodically, considering the patient's overall prognosis and preferences.

Source Links

• NICE Guideline NG158 (2025 - Updated): Venous thromboembolism in adults: diagnosis and management (NICE NG158). This is the primary reference.
• BSH Guideline (2020): British Journal of Haematology: Guideline for the management of venous thromboembolism in patients with cancer. This provides the specialist haematology perspective.

Summary and Key Takeaways

• Alignment is High: For diagnosis and first-line treatment (DOACs preferred), NICE and BSH are largely consistent.
• Key Divergence: BSH takes a stronger stance on using LMWH over DOACs for patients with high-risk luminal GI cancers.
• NICE for Pathway: NICE offers a clear, patient-focused care pathway with very practical advice on thrombocytopenia.
• BSH for Nuance: BSH provides deeper detail on bleeding risk assessment, drug interactions, and specialist management of complex cases.
• Duration is Long-term: Treatment is for a minimum of 6 months and often indefinite in the context of active cancer.

Clinicians are advised to be familiar with both documents, using the NICE guideline as the foundational standard and the BSH guideline for expert nuance in managing complex scenarios.