"Idiopathic" deep venous thrombosis: the value of routine abdominal and pelvic computed tomographic scanning

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.

Is extensive screening for cancer in idiopathic venous thromboembolism warranted?

BACKGROUND

Patients with a first episode of idiopathic venous thromboembolism (IVTE) have an estimated 10% incidence of cancer within 12 months after diagnosis. However, the utility of screening for cancer in this population is controversial.

METHODS

In this prospective concurrently controlled cohort study, limited and extensive cancer screening strategies were compared. All 630 patients underwent baseline screening consisting of history, physical examination, basic laboratory tests and chest X-ray. In the extensive screening group abdominal and chest CT scan and mammography were added. Outcomes were incidence and curability of cancer, and cancer-related and overall mortality.

RESULTS

In 12 of the 342 (3.5%) patients in the extensive screening group malignancy was diagnosed at baseline compared with 2.4% (seven of 288 patients) in the limited screening group. Extensive screening detected six additional cancers (2.0%; 95% CI, 0.74-4.3), of which three were potentially curable. During a median 2.5 years of follow-up, cancer was diagnosed in 3.7% and 5.0% in the extensive and limited screening groups, respectively. In the extensive screening group 26 patients (7.6%) died compared with 24 (8.3%) in the limited screening group; adjusted hazard ratio 1.22 (95% CI, 0.69-2.22). Of these deaths 17 (5.0%) in the extensive screening group and 8 (2.8%) in the limited screening group were cancer related; adjusted hazard ratio 1.79 (95% CI, 0.74-4.35).

CONCLUSIONS

The low yield of extensive screening and lack of survival benefit do not support routine screening for cancer with abdominal and chest CT scan and mammography in patients with a first episode of IVTE.

Report on a patient with pre-existing venous thrombosis and incidental malignancy undergoing urgent laparotomy: preoperative concerns

The management of a patient with pre-existing deep venous thrombosis (DVT) who was subsequently found to have a malignancy planned for urgent laparotomy is reported.A 30-year-old woman presented to the emergency room and was diagnosed to have a DVT. During work-up, she was found to have a malignanacy and was scheduled for urgent laparotomy. The patient was put on enoxaprin (injection) and warfarin (tablets). The patient was started on heparin (injection) 1000 IU/h at 72 h prior to operation, stopped 6 h prior to surgery. Anaesthesia and surgery were uneventful.A number of issues related to pre-existing DVTs prior to gynaecological surgery require further clarification; the optimal duration of pharmacological treatment, and the optimal duration/modality of prophylaxis to prevent thromboembolism in high-risk patients with cancer.Patients presenting for DVT must be evaluated for its causative factor(s), and malignancy in particular, based on clinical findings and investigations. Before planning surgical procedures, adequate anticoagulation must be achieved to prevent further complications of DVT, thromboembolism and pulmonary embolism in particular.

Venous thromboembolic events and organ-specific occult cancers: a review and meta-analysis

BACKGROUND

Despite a recognized association between venous thromboembolic events (VTE) and cancer, little is known about the strength and the features of this association. We performed a meta-analysis in order to clarify this issue.

METHODS

We retrieved data from 40 reports published between 1982 and 2007: 12 contained cancer risk estimates for patients with either idiopathic or secondary VTE vs. subjects without VTE and 17 for patients with idiopathic vs. secondary VTE. We also pooled risk estimates from four cohort studies to assess the association between VTE and specific forms of cancer and conducted a proportional incidence study, based on the remaining 28 reports, which did not provide risk estimates.

RESULTS

The pooled relative risk (RR) of cancer was 3.2 [95% confidence interval (95% CI) 2.4-4.5] for patients with any form of VTE vs. no VTE, 2.7 (95% CI 1.9-3.9) for patients with idiopathic vs. no VTE and 3.8 (95% CI 2.6-5.4) for patients with idiopathic vs. secondary VTE. In the pooled cohort studies, RRs for VTE vs. no VTE were significantly elevated for cancers of the ovary (RR 7.0), pancreas (RR 6.1), liver (RR 5.6), blood (4.2), brain (RR 3.8), kidney (RR 3.4), lung (3.1), colon (2.9), and esophagus (2.1). In the proportional incidence study, cancers of the pancreas, colon, and blood were significantly more frequently observed than in the general population.

CONCLUSIONS

Overall we found a 3-fold excess risk of occult cancer in patients with VTE. The risk varies according to tumor site and is highest for cancers of the ovary, pancreas, and liver.

Cancer and thrombosis: from molecular mechanisms to clinical presentations

Although the bidirectional association between cancer and venous thromboembolism (VTE) has been known for almost two centuries, recent advances in our understanding of the clinical, laboratory, and epidemiologic aspects of this association have created a renewed interest in this topic. This review consists of two parts. The first part discusses the occurrence, determinants and significance of VTE in those with cancer, as well as the risk of developing and the possible need to detect cancer in those presenting with VTE. The second part reviews the role of hemostatic constituents (coagulation and fibrinolytic proteins and platelets) in promoting growth and progression of cancer, as well as the effects and possible mechanisms of the low molecular weight heparins (LMWH) in this process.

Cancer procoagulant in patients with adenocarcinomas

Cancer procoagulant (CP) is a cysteine proteinase that may be produced by malignant and foetal tissue. The possible role of CP in the pathogenesis of cancer-related thrombosis has been suggested recently. The purpose of the study was to evaluate coagulation prothrombotic markers and their relation to CP concentration in the blood of patients with gastrointestinal adenocarcinomas (GIAC). The study group consisted of 45 patients with confirmed diagnosis of adenocarcinoma (stomach, 18 patients; colon, 27 patients) and without evident metastatic disease. In 24 patients further observation showed metastases. The control group for CP was composed of 10 healthy subjects. Blood samples were drawn on the admission day, before any treatment. Among 45 patients with GIAC, deep venous thrombosis was observed in two (4.4%). In all patients the CP activity in the serum was found, and the mean CP activity shortened the coagulation time almost three times compared with the healthy control group. Also, the mean thrombin-antithrombin complex concentration was above the normal range. A significant elevation of the mean prothrombin fragment 1+2 plasma content in this group of patients was noticed. Despite these observations, CP remained within the normal range and did not correlate with thrombin-antithrombin complex or prothrombin fragment 1+2 plasma concentrations. A positive correlation was observed between serum CP and fibrinogen concentration, and a negative correlation between CP and free protein S plasma content (P = 0.04 and P = 0.025, respectively). A negative correlation between activated protein C resistance ratio and protein C activity in the plasma was confirmed. Protein C activity in the plasma showed a correlation with free protein S plasma content. Analysis of factors influencing the activated partial thromboplastin time revealed the presence of antiphospholipid antibodies in seven persons from the study group (in three cases of IgG and in four cases of IgM class). Our data suggest that CP is a minor risk factor for deep venous thrombosis in GIAC patients. To confirm this, however, the number of patients and controls should be larger. After 3 years of observation, the follow-up in 10 living GIAC patients showed nobody with thromboembolic disease.

Decision analysis for cancer screening in idiopathic venous thromboembolism

BACKGROUND

The SOMIT trial randomized patients with idiopathic venous thromboembolism (IVTE) and without signs of cancer at routine medical examination, to extensive screening for cancer plus 2 years of follow-up or to just 2-year follow-up.

METHODS

The data of the SOMIT-trial were used to perform a decision analysis. The screening tests were divided in several possible strategies. The number of detected cancer patients and the number of patients investigated further for an eventually benign condition were calculated for each strategy. The total costs for the screening strategy and for each detected cancer patient were determined. Based on the tumor type, stage, age and gender of the individual cancer patient, the difference in live years gained (LYG) was calculated between the two study groups.

RESULTS

Computed tomography (CT) of the abdomen combined with sputum cytology and mammography detected 12 of the 14 patients with cancer and had one false-positive result. In general, screening strategies including abdominal/pelvic ultrasonography (US) or tumor markers yielded a higher number of patients needed to screen in comparison with those using abdominal/pelvic CT. Furthermore, the strategies which included colonoscopy, tumor markers, and abdominal/pelvic US were significantly more costly, had inferior LYG and higher costs per LYG, when compared with strategies using abdominal/pelvic CT.

CONCLUSIONS

Despite the limitations of this analysis, the screening for cancer with a strategy including abdominal/pelvic CT with or without mammography and/or sputum cytology appears potentially useful for cancer screening in patients with IVTE. The cost-effectiveness analysis of this strategy needs confirmation in a large trial.

Long-term follow-up of patients with suspected deep vein thrombosis of the upper extremity: survival, risk factors and post-thrombotic syndrome

BACKGROUND: The outcome of upper extremity thrombosis in terms of morbidity, mortality and arm functionality is virtually unknown. We investigated mortality, risk factors, recurrent thrombosis and post-thrombotic syndrome (PTS) in patients with suspected upper extremity thrombosis. METHODS: Consecutive patients suspected of having deep vein thrombosis (DVT) of the upper extremity were followed for up to 53 months (mean 21 months). Venography and/or ultrasonography was used for diagnosis. Risk factors were identified from history and thrombophilia laboratory screening. PTS was assessed using a scoring system. Death, recurrent thrombosis and PTS were primary outcome measures. RESULTS: DVT of the upper extremity was diagnosed in 50 of 116 consecutive patients (43%). Malignancy and/or central venous lines were present in 37 of 50 (74%) patients with thrombosis. Inherited thrombophilia was diagnosed in 6 of 30 (20%) and 4 of 33 (12%) of the investigated patients with and without thrombosis, respectively (not significant). Twenty-five patients (50%) with thrombosis died during the follow-up period; this was associated with cancer in 84% of the deaths. Recurrent thrombosis was observed in four patients (8%) during follow-up. Symptoms of PTS were present in 4 of 22 patients (18%) with thrombosis and in 14 of 36 patients (39%) in whom thrombosis was excluded. CONCLUSIONS: Malignancy and central venous lines are major risk factors of upper extremity thrombosis. Thrombophilia seems to be unrelated to the presence or absence of upper extremity thrombosis. Thrombosis in combination with malignancy predicts poor survival. A scoring system can be used to assess the severity of PTS, but it does not discriminate PTS from other causes of arm complaints.

Screening for occult cancer in patients with acute deep vein thrombosis or pulmonary embolism

Patients with acute venous thromboembolism have an increased risk for occult malignancy. Limited screening for these malignancies has become common practice but little is known about its usefulness. This is a prospective cohort follow-up study in consecutive patients with acute venous thromboembolism. All patients underwent a routine clinical evaluation for malignancy, if negative, followed by a limited diagnostic work-up consisting of abdominal and pelvic ultrasound and laboratory markers for malignancy. Clinical follow-up was conducted to detect screening failures. The routine clinical evaluation was performed in 864 patients and revealed malignancy in 34 (3.9%) of them. Among the remaining 830 patients the limited diagnostic work-up revealed 13 further malignancies. During follow-up, cancer became symptomatic in 14 patients who were negative for cancer at screening (sensitivity of limited diagnostic work-up, 48.1%). Malignancies that were identified by the limited diagnostic work-up were early stage in 61% of cases vs. 14% in cases occurring during follow-up. Most patients with occult cancer had idiopathic venous thromboembolism and were older than 70 years. A limited diagnostic work-up for occult cancer in patients with venous thromboembolism has the capacity to identify approximately one-half of the malignancies. Identified malignancies were predominantly in an early stage.

The hypercoagulable state of malignancy: pathogenesis and current debate

A hypercoagulable or prothrombotic state of malignancy occurs due to the ability of tumor cells to activate the coagulation system. It has been estimated that hypercoagulation accounts for a significant percentage of mortality and morbidity in cancer patients. Prothrombotic factors in cancer include the ability of tumor cells to produce and secrete procoagulant/fibrinolytic substances and inflammatory cytokines, and the physical interaction between tumor cell and blood (monocytes, platelets, neutrophils) or vascular cells. Other mechanisms of thrombus promotion in malignancy include nonspecific factors such as the generation of acute phase reactants and necrosis (i.e., inflammation), abnormal protein metabolism (i.e., paraproteinemia), and hemodynamic compromise (i.e., stasis). In addition, anticancer therapy (i.e., surgery/chemotherapy/hormone therapy) may significantly increase the risk of thromboembolic events by similar mechanisms, e.g., procoagulant release, endothelial damage, or stimulation of tissue factor production by host cells. However, not all of the mechanisms for the production of a hypercoagulable state of cancer are entirely understood. In this review, we attempt to describe what is currently accepted about the pathophysiology of the hypercoagulable state of cancer. We also discuss whether or not to screen patients with idiopathic deep venous thrombosis for an underlying malignancy, and whether this would be beneficial to patients. It is hoped that a better understanding of these mechanisms will ultimately lead to the development of more targeted treatment to prevent thromboembolic complications in cancer patients. It is also hoped that antithrombotic strategies may also have a positive effect on the process of tumor growth and dissemination.

Venous thromboembolism and occult malignancy

Trousseau is considered to be the first to have recognised a relation between venous thromboembolism (VTE) and malignancy. Illtyd James and Matheson in 1935 were the first in the Anglo-Saxon literature, at least to our knowledge, to report the observation of a patient with occult cancer at time of his venous thrombosis. Meanwhile, cancer has become an established risk factor for VTE. The prevalence of concomitant cancer in patients presenting with VTE varies considerably between the studies due to differences in, for instance, threshold of suspicion, screening methods, and characteristics of the patients like age. A consistent observation is the low prevalence of concomitant cancer in patients with secondary thrombosis, comparable to the prevalence in the general population. A 3-19-fold increase in prevalence of concomitant cancer has been reported in patients presenting with an idiopathic VTE. The same applies for occult cancer in patients with secondary and idiopathic VTE. The prevalence of occult cancer in patients with secondary VTE is comparable with the prevalence of cancer in the general population, while the prevalence of occult cancer in patients with idiopathic VTE is 4-10%. It seems possible to detect a substantial number of additional cancer patients, at time of diagnosis of idiopathic VTE, by means of extensive screening. However, results of randomised trials, evaluating the effect on survival rate, are lacking.

Lack of association between venous thrombosis and subsequent malignancy in a retrospective cohort study in young patients

Since the publication of Trousseau in 1865, several studies have documented an increased incidence of cancer in patients with deep venous thrombosis (DVT) especially those with idiopathic or recurrent DVT, but in young patients this association is not clear and is therefore a subject of controversy. We performed a retrospective study in a consecutive cohort of 40 young patients (age <40 years) with a DVT and without a known cancer. All patients were diagnosed in our hospital during the period of 1988-1992. At the time of diagnosis, a routine examination to detect the presence of malignant disease was made. For the follow-up, all patients included in the study were asked to return to our unit and were interviewed for symptoms that could suggest a malignant disease. The mean follow-up was five years (from three to eight years). Twenty-four patients had DVT in the lower limbs and three in the upper extremities, nine had pulmonary embolism (six of them with DVT) and four had DVT in other sites. Sixteen patients (40%) had secondary DVT due to nonbiological causes, abnormalities in hemostasis were found in 14 patients (35%), and biological or environmental triggering factors were not identified in 10 patients (25%). Malignancies were not detected at diagnosis and in the follow-up. In our experience, venous-thrombotic patients under the age of 40 have a low incidence of subsequent cancer. Further studies should be performed to confirm this observation and to ascertain whether extensive screening for cancer is a cost-effective approach.

Extended deep vein and inferior vena cava thrombosis in a 15-year-old boy: successful lysis with recombinant tissue-type plasminogen activator 2 weeks after onset of symptoms

We present the case of a 15-year-old boy with thrombosis of the inferior vena cava, the femoral, inguinal, and renal veins of unknown origin. Although the thrombosis was 2 weeks old, thrombolytic therapy with recombinant tissue-type plasminogen activator (maximum dosage: 0.4 mg/kg/h) was started as this appeared to be the only change to re-establish normal kidney function. After 1 week, treatment was discontinued because of generalized bleeding. At this time, the infrarenal inferior vena cava was again patent with complete lysis of all other clots. Phlebography 3 months after lysis documented an abnormal renal vein, a tubular, subhepatical stenosis of the inferior vena cava and a large collateral vessel between the inferior vena cava and the azygos vein.