Risk factors of occult malignancy in patients with unprovoked venous thromboembolism

Effect of testing for cancer on cancer- or venous thromboembolism (VTE)-related mortality and morbidity in people with unprovoked VTE

BACKGROUND

Venous thromboembolism (VTE) is a collective term for two conditions: deep vein thrombosis (DVT) and pulmonary embolism (PE). A proportion of people with VTE have no underlying or immediately predisposing risk factors and the VTE is referred to as unprovoked. Unprovoked VTE can often be the first clinical manifestation of an underlying malignancy. This has raised the question of whether people with an unprovoked VTE should be investigated for an underlying cancer. Treatment for VTE is different in cancer and non-cancer patients and a correct diagnosis would ensure that people received the optimal treatment for VTE to prevent recurrence and further morbidity. Furthermore, an appropriate cancer diagnosis at an earlier stage could avoid the risk of cancer progression and lead to improvements in cancer-related mortality and morbidity. This is the third update of the review first published in 2015.

OBJECTIVES

To determine whether testing for undiagnosed cancer in people with a first episode of unprovoked VTE (DVT of the lower limb or PE) is effective in reducing cancer- or VTE-related mortality and morbidity and to determine which tests for cancer are best at identifying treatable cancers early.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 5 May 2021. We also undertook reference checking to identify additional studies.

SELECTION CRITERIA

Randomised and quasi-randomised trials in which people with an unprovoked VTE were allocated to receive specific tests for identifying cancer or clinically indicated tests only were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed risk of bias and extracted data. We assessed the certainty of the evidence using GRADE criteria. We resolved any disagreements by discussion. The main outcomes of interest were all-cause mortality, cancer-related mortality and VTE-related mortality.

MAIN RESULTS

No new studies were identified for this 2021 update. In total, four studies with 1644 participants are included. Two studies assessed the effect of extensive tests including computed tomography (CT) scanning versus tests at the physician's discretion, while the other two studies assessed the effect of standard testing plus positron emission tomography (PET)/CT scanning versus standard testing alone. For extensive tests including CT versus tests at the physician's discretion, the certainty of the evidence, as assessed according to GRADE, was low due to risk of bias (early termination of the studies). When comparing standard testing plus PET/CT scanning versus standard testing alone, the certainty of evidence was moderate due to a risk of detection bias. The certainty of the evidence was downgraded further as detection bias was present in one study with a low number of events. When comparing extensive tests including CT versus tests at the physician's discretion, pooled analysis on two studies showed that testing for cancer was consistent with either benefit or no benefit on cancer-related mortality (odds ratio (OR) 0.49, 95% confidence interval (CI) 0.15 to 1.67; 396 participants; 2 studies; low-certainty evidence). One study (201 participants) showed that, overall, malignancies were less advanced at diagnosis in extensively tested participants than in participants in the control group. In total, 9/13 participants diagnosed with cancer in the extensively tested group had a T1 or T2 stage malignancy compared to 2/10 participants diagnosed with cancer in the control group (OR 5.00, 95% CI 1.05 to 23.76; low-certainty evidence). There was no clear difference in detection of advanced stages between extensive tests versus tests at the physician's discretion: one participant in the extensively tested group had stage T3 compared with four participants in the control group (OR 0.25, 95% CI 0.03 to 2.28; low-certainty evidence). In addition, extensively tested participants were diagnosed earlier than control group (mean: 1 month with extensive tests versus 11.6 months with tests at physician's discretion to cancer diagnosis from the time of diagnosis of VTE). Extensive testing did not increase the frequency of an underlying cancer diagnosis (OR 1.32, 95% CI 0.59 to 2.93; 396 participants; 2 studies; low-certainty evidence). Neither study measured all-cause mortality, VTE-related morbidity and mortality, complications of anticoagulation, adverse effects of cancer tests, participant satisfaction or quality of life. When comparing standard testing plus PET/CT screening versus standard testing alone, standard testing plus PET/CT screening was consistent with either benefit or no benefit on all-cause mortality (OR 1.22, 95% CI 0.49 to 3.04; 1248 participants; 2 studies; moderate-certainty evidence), cancer-related mortality (OR 0.55, 95% CI 0.20 to 1.52; 1248 participants; 2 studies; moderate-certainty evidence) or VTE-related morbidity (OR 1.02, 95% CI 0.48 to 2.17; 854 participants; 1 study; moderate-certainty evidence). Regarding stage of cancer, there was no clear difference for detection of early (OR 1.78, 95% 0.51 to 6.17; 394 participants; 1 study; low-certainty evidence) or advanced (OR 1.00, 95% CI 0.14 to 7.17; 394 participants; 1 study; low-certainty evidence) stages of cancer. There was also no clear difference in the frequency of an underlying cancer diagnosis (OR 1.71, 95% CI 0.91 to 3.20; 1248 participants; 2 studies; moderate-certainty evidence). Time to cancer diagnosis was 4.2 months in the standard testing group and 4.0 months in the standard testing plus PET/CT group (P = 0.88). Neither study measured VTE-related mortality, complications of anticoagulation, adverse effects of cancer tests, participant satisfaction or quality of life.

AUTHORS' CONCLUSIONS

Specific testing for cancer in people with unprovoked VTE may lead to earlier diagnosis of cancer at an earlier stage of the disease. However, there is currently insufficient evidence to draw definitive conclusions concerning the effectiveness of testing for undiagnosed cancer in people with a first episode of unprovoked VTE (DVT or PE) in reducing cancer- or VTE-related morbidity and mortality. The results could be consistent with either benefit or no benefit. Further good-quality large-scale randomised controlled trials are required before firm conclusions can be made.

Screening for occult cancer: where are we in 2020?

The relationship between venous thromboembolism (VTE) and cancer has become an area of intense debate due to the importance and the potential benefits of the identification of occult cancer following the diagnosis of unprovoked VTE. At present, extended screening is not recommended in patients with unprovoked VTE. However, if we were able to identify a group at greater risk of presenting cancer during follow-up, these patients would benefit from extended screening. The creation of a trans-organ screening model enables the unification of metrics of quality in the screening of cancer in different localizations. Likewise, it can incorporate cancer screening for other localizations or other specific situations of risk such as unprovoked VTE. This study summarizes the contribution of the Population-based Research Optimizing Screening through Personalized Regimens (PROSPR) initiative aimed at improving the cancer screening process. Likewise, we have carried out an updated review of unprovoked VTE and occult cancer. Finally, we discuss the studies currently ongoing aimed at identifying the population at greatest risk of presenting cancer during follow-up. The identification of this population at high risk could help to determine the following steps to undertake in order to implement screening in this population.

Screening for Occult Cancer in Patients with Venous Thromboembolism

Unprovoked venous thromboembolism (VTE) can be the first sign of an occult cancer. The rate of occult cancer detection within 12 months of a newly diagnosed unprovoked VTE is approximately 5%. Therefore, it is appealing for clinicians to screen patients with unprovoked VTE for occult cancer, as it could potentially decrease cancer-related mortality and morbidity and improve quality of life. However, several randomized controlled trials have failed to report that an extensive occult cancer screening strategy (e.g., computed tomography of the abdomen/pelvis) is improving these patient-important outcomes. Therefore, clinical guidance documents suggest that patients should only undergo a limited screening strategy including a thorough medical history, physical examination, basic laboratory investigations (i.e., complete blood count and liver function tests), chest X-ray, as well as age- and gender-specific cancer screening (breast, cervical, colon and prostate). More intensive occult cancer screening including additional investigations is not routinely recommended. This narrative review will focus on the epidemiology, timing, and evidence regarding occult cancer detection in patients with unprovoked VTE.

Cancer Screening in Patients with Unprovoked Thromboembolism: How to do it and Who Benefits?

Introduction: Unprovoked venous thromboembolism (uVTE) may be the first manifestation of cancer. The main objectives of this study were to compare limited screening (LS) and extended screening (ES) and to make a protocol to approach these patients.

Methods: This is a retrospective, unicentric observational study that included 245 patients with venous thromboembolism (VTE) admitted to an Internal Medicine Service for five years. The incidence of cancer and mortality during hospitalization, and at one and three years after admission were calculated in both LS and ES groups and compared.

Results: Of the 245 patients with VTE, 59 (24.1%) had uVTE: 35 (59.3%) were submitted to LS and 24 (40.7%) to ES, with 10 (4.1%) diagnosis of cancer. In the following three years, 10 more patients were diagnosed. There were no statistically significant differences in inpatient diagnosis rates (8.6% vs. 4.2%; p=0.51) or in-hospital mortality (2.9% vs. 4.2%; p=0.79) or mortality at one year (8.6% vs. 8.3%; p=0.97) and three years (20.0% vs. 20.8%; p = 0.94) between LS and ES groups respectively. The Computerized Registry of Patients with Venous Thromboembolism (RIETE) score was equal or superior to 3 in 69.5% (N=41) of the population with uVTE.

Discussion: The results of our study are consistent with the literature; there are no differences between screenings, as the difference in the number of diagnoses does not reflect on mortality.

Conclusion: There were no statistically significant differences between the two types of screening in this population. We suggest a protocol that includes the RIETE score to better select the patients who might benefit the most from an ES.

Prothrombotic fibrin clot properties associated with increased endogenous thrombin potential and soluble P-selectin predict occult cancer after unprovoked venous thromboembolism

BACKGROUND

Compact fibrin clots relatively resistant to lysis are observed in patients at increased risk of venous thromboembolism (VTE) including malignancy. The citrullinated histone H3 (H3Cit) predicts VTE in cancer patients.

OBJECTIVES

We performed a cohort study to investigate whether abnormal clot properties predict cancer diagnosis following unprovoked VTE.

METHODS

In 369 consecutive patients aged <70 years without malignancy detected during routine screening, we determined plasma clot permeability (Ks ) and clot lysis time (CLT), along with several prothrombotic markers and H3Cit after 2 to 8 months since VTE.

RESULTS

During follow-up (median, 37; interquartile range, 33-39 months), malignancy was diagnosed in 22 patients (6%), who were older. This group had denser fibrin networks (-13% Ks ), impaired fibrinolysis (+25.5% CLT), increased endogenous thrombin potential (ETP,+7%), soluble P-selectin (+40.3%), and H3Cit (+169.2%) measured off anticoagulation after median 4 months since VTE. The Ks and CLT correlated with H3Cit (r = -.58 and r = .31, P < .05, respectively). The Kaplan-Meier survival analysis showed that reduced Ks (the first quartile, ≤6.2 × 10-9  cm2 ), prolonged CLT (the top quartile, >106 min), and higher ETP (the top quartile, >1657 nM × min) were predictors of cancer diagnosed during follow-up. The multivariable Cox proportional hazards model showed that patients with the prothrombotic clot phenotype (low Ks and long CLT) had the highest risk of cancer diagnosis [hazard ratio(HR), 23.4; 95% confidence interval (CI), 6.67-82.15].

CONCLUSIONS

Prothrombotic clot properties following unprovoked VTE might help identify patients at risk of a diagnosis of cancer within the first 3 years of follow-up.

Cancer-associated thrombosis: the when, how and why

Cancer-associated thrombosis (CAT) is a condition in which relevance has been increasingly recognised both for physicians that deal with venous thromboembolism (VTE) and for oncologists. It is currently estimated that the annual incidence of VTE in patients with cancer is 0.5% compared to 0.1% in the general population. Active cancer accounts for 20% of the overall incidence of VTE. Of note, VTE is the second most prevalent cause of death in cancer, second only to the progression of the disease, and cancer is the most prevalent cause of deaths in VTE patients. Nevertheless, CAT presents several peculiarities that distinguish it from other VTE, both in pathophysiology mechanisms, risk factors and especially in treatment, which need to be considered. CAT data will be reviewed in this review.

Cancer-associated thrombosis (CAT) presents peculiar features (risk factors and pathophysiology) that distinguish it from common VTE cases. Treatment of CAT requires a different approach, since the patients are more prone to recurrence and bleeding.http://ow.ly/j1Lu30nYmd5

Effect of testing for cancer on cancer- or venous thromboembolism (VTE)-related mortality and morbidity in people with unprovoked VTE

BACKGROUND

Venous thromboembolism (VTE) is a collective term for two conditions: deep vein thrombosis (DVT) and pulmonary embolism (PE). A proportion of people with VTE have no underlying or immediately predisposing risk factors and the VTE is referred to as unprovoked. Unprovoked VTE can often be the first clinical manifestation of an underlying malignancy. This has raised the question of whether people with an unprovoked VTE should be investigated for an underlying cancer. Treatment for VTE is different in cancer and non-cancer patients and a correct diagnosis would ensure that people received the optimal treatment for VTE to prevent recurrence and further morbidity. Furthermore, an appropriate cancer diagnosis at an earlier stage could avoid the risk of cancer progression and lead to improvements in cancer-related mortality and morbidity. This is an update of a review first published in 2015.

OBJECTIVES

To determine whether testing for undiagnosed cancer in people with a first episode of unprovoked VTE (DVT of the lower limb or PE) is effective in reducing cancer or VTE-related mortality and morbidity and to determine which tests for cancer are best at identifying treatable cancers early.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 11 July 2018. We also undertook reference checking to identify additional studies.

SELECTION CRITERIA

Randomised and quasi-randomised trials in which people with an unprovoked VTE were allocated to receive specific tests for identifying cancer or clinically indicated tests only were eligible for inclusion. Primary outcomes included all-cause mortality, cancer-related mortality and VTE-related mortality.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed risk of bias and extracted data. We resolved any disagreements by discussion.

MAIN RESULTS

No new studies were identified for this 2018 update. In total, four studies with 1644 participants are included. Two studies assessed the effect of extensive tests including computed tomography (CT) scanning versus tests at the physician's discretion, while the other two studies assessed the effect of standard testing plus positron emission tomography (PET)/CT scanning versus standard testing alone. For extensive tests including CT versus tests at the physician's discretion, the quality of the evidence, as assessed according to GRADE, was low due to risk of bias (early termination of the studies). When comparing standard testing plus PET/CT scanning versus standard testing alone, the quality of evidence was moderate due to a risk of detection bias. The quality of the evidence was downgraded further as detection bias was present in one study with a low number of events.When comparing extensive tests including CT versus tests at the physician's discretion, pooled analysis on two studies showed that testing for cancer was consistent with either benefit or no benefit on cancer-related mortality (odds ratio (OR) 0.49, 95% confidence interval (CI) 0.15 to 1.67; 396 participants; 2 studies; P = 0.26; low-quality evidence). One study (201 participants) showed that, overall, malignancies were less advanced at diagnosis in extensively tested participants than in participants in the control group. In total, 9/13 participants diagnosed with cancer in the extensively tested group had a T1 or T2 stage malignancy compared to 2/10 participants diagnosed with cancer in the control group (OR 5.00, 95% CI 1.05 to 23.76; P = 0.04; low-quality evidence). There was no clear difference in detection of advanced stages between extensive tests versus tests at the physician's discretion: one participant in the extensively tested group had stage T3 compared with four participants in the control group (OR 0.25, 95% CI 0.03 to 2.28; P = 0.22; low-quality evidence). In addition, extensively tested participants were diagnosed earlier than control group (mean: 1 month with extensive tests versus 11.6 months with tests at physician's discretion to cancer diagnosis from the time of diagnosis of VTE). Extensive testing did not increase the frequency of an underlying cancer diagnosis (OR 1.32, 95% CI 0.59 to 2.93; 396 participants; 2 studies; P = 0.50; low-quality evidence). Neither study measured all-cause mortality, VTE-related morbidity and mortality, complications of anticoagulation, adverse effects of cancer tests, participant satisfaction or quality of life.When comparing standard testing plus PET/CT screening versus standard testing alone, standard testing plus PET/CT screening was consistent with either benefit or no benefit on all-cause mortality (OR 1.22, 95% CI 0.49 to 3.04; 1248 participants; 2 studies; P = 0.66; moderate-quality evidence), cancer-related mortality (OR 0.55, 95% CI 0.20 to 1.52; 1248 participants; 2 studies; P = 0.25; moderate-quality evidence) or VTE-related morbidity (OR 1.02, 95% CI 0.48 to 2.17; 854 participants; 1 study; P = 0.96; moderate-quality evidence). Regarding stage of cancer, there was no clear difference for detection of early (OR 1.78, 95% 0.51 to 6.17; 394 participants; 1 study; P = 0.37; low-quality evidence) or advanced (OR 1.00, 95% CI 0.14 to 7.17; 394 participants; 1 study; P = 1.00; low-quality evidence) stages of cancer. There was also no clear difference in the frequency of an underlying cancer diagnosis (OR 1.71, 95% CI 0.91 to 3.20; 1248 participants; 2 studies; P = 0.09; moderate-quality evidence). Time to cancer diagnosis was 4.2 months in the standard testing group and 4.0 months in the standard testing plus PET/CT group (P = 0.88). Neither study measured VTE-related mortality, complications of anticoagulation, adverse effects of cancer tests, participant satisfaction or quality of life.

AUTHORS' CONCLUSIONS

Specific testing for cancer in people with unprovoked VTE may lead to earlier diagnosis of cancer at an earlier stage of the disease. However, there is currently insufficient evidence to draw definitive conclusions concerning the effectiveness of testing for undiagnosed cancer in people with a first episode of unprovoked VTE (DVT or PE) in reducing cancer- or VTE-related morbidity and mortality. The results could be consistent with either benefit or no benefit. Further good-quality large-scale randomised controlled trials are required before firm conclusions can be made.

Revisiting occult cancer screening in patients with unprovoked venous thromboembolism

Unprovoked venous thromboembolism (VTE) can be the first manifestation of an unknown cancer. A recently published individual patient data meta-analysis (IPDMA) reported a prevalence of occult cancer detection of 5.2% (95% CI, 4.1% to 6.5%) over a one-year follow-up period, approximately 50% lower than the previously reported 12-month period prevalence. Although an extensive screening strategy was associated with a 2-fold higher probability of cancer detection at initial screening in the IPDMA, not enough evidence exists yet to support the routine use of these tests in patients with unprovoked VTE. It is likely that a subgroup of patients with unprovoked VTE is at higher risk of occult cancer detection and might benefit from closer clinical surveillance. A newly derived and validated clinical predictive rule seems to be able to stratify patients with unprovoked VTE accordingly to their underlying risk of occult cancer detection. The low incidence of occult cancer detection (<3%) in the low-risk group is reassuring for clinicians. Future studies are required to better define the risks and benefits of an extensive occult cancer screening strategy in high risk patients sub-group with unprovoked VTE. To date, the Scientific and Standardized Committee from the International Society of Thrombosis and Haemostasis suggests that patients with unprovoked VTE should only undergo a limited cancer screening including thorough medical history and physical examination, basic laboratory investigations, chest X-ray as well as age- and gender-specific cancer screening according to national guidelines.

Screening cancer after venous thromboembolism: How many abnormal tests before diagnosing cancer? An analysis of practice

INTRODUCTION

Since Trousseau, we knows that venous thrombemboembolism (VTE) can reveal occult cancer. Different strategies of cancer screening have been evaluated: they are often time-consuming, cause stress and anxiety, and frequently require second-look examinations (due to the risk of false positives), with ultimately a very low yield (about 5%). We evaluated the number of suspect cancer tests before reporting them to the number of cancers finally diagnosed, after a VTE, in the setting of practice's analysis.

METHODS

We studied retrospectively patients hospitalized for a VTE and with a cancer screening, between 2011 and 2012. Screening cancer was defined by performing at least one of the following tests: PSA, fecal occult blood test, mammography, abdominopelvic iconography (abdominal ultrasound and/or abdominal CT scan). We recorded the suspected cancer tests, the cancers diagnosed, their stage and the survival. These results were expressed as a percentage with a 95% confidence interval.

RESULTS

Out of the 491 patients treated for a VTE, screening cancer was performed on 295 patients (median age 66.2 years). Nineteen PSA (16.7%, 95% CI [10.3-25]) were abnormal, with 2 localized prostate cancers. Nineteen fecal occult blood tests (15.3%, 95% CI [9.5-23]) were positive, with 2 local cancers. Five mammograms suspected cancer (4.7% 95% CI [1.6-10.8]) for one confirmed. Thirty-eight abdomino-pelvic iconographies (14.4% 95% CI [10.4-19.2]) were suspect, with 7 confirmed cancers, 6 being metastatic at times of diagnostic.

CONCLUSION

Among the 607 tests performed, 81 were suspected of cancer (13.3%) for only 12 cancers confirmed (2.0%). Screening cancer exposes patients to several false positive tests.