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Duration of thromboprophylaxis following major abdominopelvic cancer-related surgery

Duration of thromboprophylaxis following major abdominopelvic cancer-related surgery – an aid to informed clinical decisionmaking

Key Takeaway

Decision on use of extended duration thromboprophylaxis following major abdominopelvic cancer surgery should be made on individual patient basis.* Post-abdominopelvic cancer surgery:

Extended duration LMWH thromboprophylaxis vs standard duration:

Significantly reduces 30-day incidence of clinical VTE. No significant increase in 30-day post-operative incidences of clinically relevant bleeding

Risk prediction:

In the post-operative period, risk prediction scores like the Caprini score are not used regularly in clinical practice to decide the duration of thromboprophylaxis.

Why This Matters

Risk of post-operative VTE is 2-fold higher and risk of fatal PE is 3-fold higher in patients with cancer vs those undergoing similar surgical procedures for benign disease:

In patients with cancer undergoing abdominopelvic surgery, VTE was noted as the greatest cause of 30-day post-operative mortality

This systematic review and meta-analysis:

Provides clinicians with event rates of symptomatic VTE and clinically relevant bleeding for shared decisionmaking on the duration of thromboprophylaxis in surgical cancer patients

Key Highlights

Systematic Review and Meta-Analysis:

68 Studies (9 RCTS and 59 Observational Studies): 1,631,118 Adult Patients Who Underwent Cancer-Related Abdominopelvic Surgery

30-Day post-operative incidences†
of clinical VTE

Overall rate With extended
duration
Thromboprophylaxis
vs without
Extended duration
Thromboprophylaxis vs standard
RCTs Observational
studies
1.7%
(95% CI: 1.5–1.9)
0.5% vs 1.8%
(95% CI: 0.2–0.9) vs
(95% CI: 1.3–2.4)
Non significant
reduction
0.3% vs 1.4%

(RR: 0.33)
Statistically significant
reduction
1.0% vs 2.1%

(RR: 0.48)
30-Day post-operative incidences†
of clinically-relevant bleeding complications
Overall rate With extended
duration
Thromboprophylaxis
vs without
Extended duration
Thromboprophylaxis vs standard
RCTs Observational
studies
3.5%
(95% CI: 1.6–6.1)
2.4% vs 3.5%
(95% CI: 0.9–4.7) vs
(95% CI: 2.0–5.4)
Non significant
reduction
2.4% vs 2.0%

(RR: 1.2)
Statistically significant
reduction
4.0% vs 4.9%

(RR: 1.0)

Including observational studies in this systematic review, may be more representative of current clinical practice and better capture the real-world effectiveness of LMWH prophylaxis by including a much broader patient population.

30-day event rates remain important information to establish risk-benefit ratio on the duration of thromboprophylaxis for adult patients who underwent abdominopelvic cancer surgery.

Study findings suggest:

  • Although, extended duration thromboprophylaxis reduces VTE risk, the absolute clinical benefit of reduction in symptomatic VTE events is relatively low

Limitations

Possibility of bias due to inclusion of observational studies and RCTs together with studies reporting of asymptomatic events

High levels of statistical heterogenecity§ in the pooled analysis

Absence of detailed description of patient population or procedures performed in most studies

The rates of fatal pulmonary embolism were not consistently reported and could not be assessed with the meta-analysis.

* Based on underlying risk of bleeding, costs and patient's values and preferences.

† Subgroup analysis of VTE incidence data from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) have not been provided as they did not report on thromboprophylaxis.

‡ Selection bias, confounding and misdiagnosis bias.

§ With respect to different cancer types, modes of surgical intervention and type/dose/duration of thromboprophylaxis.

Abbreviations

CL, confidence interval; ED, extended duration; LMWH, low molecular weight heparin; PE, pulmonary embolism; RCTs, randomized controlled trials; RR, risk ratio; SD, standard duration; VTE, venous thromboembolism

Reference

  1. Knoll W, Fergusson N, Ivankovic V, Wang TF, Caiano L, Auer R, et al. Extended thromboprophylaxis following major abdominal/pelvic cancer-related surgery: A systematic review and meta-analysis of the literature. Thromb Res. 2021;204:114–122. doi:10.1016/j.thromres.2021.06.010. PMID: 34175749.
MAT-BH-2300482/V1/Aug2023