Evaluating the Need for Anticoagulation Beyond 6 Months for Patients with Cancer-Associated Venous Thromboembolism: A Retrospect of Real Life (EXTEND Study)
Bibliographic record
Abstract
Abstract Background: The association between cancer and venous thromboembolism (VTE) has been well documented. In patients with cancer, the risk for a first cancer- associated thrombosis is 5 to 28-fold higher than in non-cancer patients. Current oncology clinical practice guidelines recommend that patients with cancer- associated thrombosis be treated for a minimum of 6 months with low molecular weight heparin (LMWH) provided they do not have any contraindications to anticoagulant therapy. The length of anticoagulation beyond the initial 6 months is controversial due to the absence of clinical trials data. Panel consensus from the ASCO 2013 clinical practice guidelines recommends continuing anticoagulation if malignancy remains active or patient is still on active anticancer treatment. There is clear equipoise in which type of anticoagulation approach, if any, is the best beyond 6 months of anticoagulation for these patients. In this retrospective analysis we sought to evaluate what has been the extended anticoagulation therapy of choice in our thrombosis clinic over the past 5 years and its efficacy in preventing late recurrent venous thromboembolism. Methods: We conducted a single- centre retrospective cohort study (London, Canada) to collect data from adult patients with cancer -associated VTE who received anticoagulation with therapeutic LMWH for at least 6 months. We collected data from January 2008 to December 2013. We included patients 18 years old or older; with any type of active cancer (except basal cell and squamous cell carcinoma of the skin) or stage. Follow up period started at 6 months of anticoagulation and finished at 12 months (total of 6 months of study follow-up), or at time of a recurrent VTE, or death or last follow up in clinic, whichever came first. We used SAS 9.2 to perform the data analysis. Results: In total 417 patients were potentially eligible but 149 fulfilled our inclusion criteria. 78 (52%) were males, median age was 65 (range 25-86). 123 (82.4%) patients had solid tumors and 26 (17.6%) hematological malignancy. Of the patients with solid tumors, 98 (80.3%) had stage III or IV disease. The most frequent primary tumor sites were colorectal (n= 36; 34%), lung (n=29;20%) and pancreas (n= 17; 11%) among others (n= 41). After the first 6 months of anticoagulation, 20 (13%) patients were considered to be in complete remission of their cancer. In total, 45 of 149 (31%) patients discontinued anticoagulant therapy. 64 (43%) remained on full weight-adjusted dose LMWH, 10 (6%) on prophylactic dose, 29 (19%) were switched to warfarin and 1 (1%) to rivaroxaban. Of the 45 patients that discontinued anticoagulation, 7 were considered to be in complete remission. Overall, there were 21 (14%) VTE recurrences after the first 6 months of anticoagulation. 12 (57%) occurred in patients using full dose LMWH. Patients in complete remission had a lower risk for VTE recurrence (OR= 0.31; 95%CI: 0.102 - 0.920; p= 0.0349). Although not statistically significant, there is a trend of high VTE recurrence risk in patients with lung or colon cancer, or stage III/IV and for patients on full doseLMWH (Table). A post-hoc power calculation of our study demonstrated 84% power with a 2-sided alpha of 0.05. Conclusion: Our study demonstrated a significant increased risk for recurrent VTE (14%) in after the firs 6 months of anticoagulation in patients with cancer-associated VTE irrespective of anticoagulation approach. Being in complete remission is significantly associated with a low risk for recurrence. Having lung or colon cancer or advanced stage may increase recurrence risk. Interestingly, patients on full LMWH also showed trend to high VTE recurrence risk. This may reflect a sicker subset of patients with an inherent higher VTE risk. Further prospective trials are warranted to better study the best anticoagulation approach for patients with cancer-associated VTE beyond the first 6 months of anticoagulation. Table. Univariate analysis for the association of VTE recurrence and tunor and patients characteristics Variables OR (95%CI)# P -value Female 0.58 (0.2 - 1.7) 0.321 Warfarin 0.97 (0.3 - 3.1) 0.958 Prophylactic LMWH^ 0.75 (0.09 - 6.3) 0.791 Full LMWH^ 1.56 (0.62 - 3.9) 0.348 Colorectal* 1.69 (0.4 - 6.4) 0.443 Lung* 1.76 (0.4 - 7.0) 0.422 Pancreas* 0.90 (0.15 - 5.5) 0.909 stageIII or IV 1.93 (0.67 - 5.5) 0.223 #odds ratio ( 95% confidence interval) ^ reference: no anticoagulation * reference: hematological cancer Disclosures No relevant conflicts of interest to declare.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".