Unsuspected pulmonary embolism in cancer patients: a narrative review with pooled data

Incidental pulmonary emboli are associated with a very high probability of progressive malignant disease on staging CT scans

PURPOSE

The link between malignancy and venous thromboembolism (VTE) is well established; the risk has been shown to be higher in certain tumour types and in patients receiving platinum-based chemotherapy regimens. 'Active' cancer is often quoted as being a particular risk factor for VTE, but the definition varies widely and the supporting evidence is weak. This study was conceived to establish whether incidental pulmonary emboli are associated with an increased likelihood of progressive disease on a staging computed tomography (CT) scan.

MATERIALS AND METHODS

All CT scans containing incidental PEs over the course of a year in a large specialist cancer hospital were examined (n = 306). An age-matched control group was assembled. Multivariate logistic regression analysis was performed to establish the relationship of several independent variables, including progressive disease, with the dependent variable of the presence or absence of incidental pulmonary emboli.

RESULTS

Progressive disease was present in 144 of 306 (47.1%) of the patients in the PE group but only 63 of 306 (20.6%) of the control group patients. Progressive disease on the staging CT scan was found to have an odds ratio for incidental PE of 3.46, with a 95% CI of 2.38-5.01. Receiving platinum-based chemotherapy resulted in an odds ratio of 3.89 (2.41-6.28) for PE. Receiving non-platinum-based systemic anti-cancer therapy (SACT) resulted in an odds ratio for PE of 1.71 (1.16-2.50).

CONCLUSION

The detection of an incidental PE on a staging CT scan is associated with a very high risk of progressive malignant disease.

Atypical bilateral ventilation/perfusion mismatches in an asymptomatic patient suffering from metastatic thyroid cancer

Background

Pulmonary embolism is indicated by ventilation/perfusion (V/P) mismatches in ventilation/perfusion scintigraphy. However, other pathologies may also evoke segmental or lobar mismatches. Thus, diagnosis can be difficult in asymptomatic patients with equivocal clinical presentation.

Case presentation

We present a case of multiple bilateral pulmonary ventilation/perfusion mismatches in a poorly differentiated thyroid cancer patient. Exact diagnosis was difficult, as the patient was asymptomatic and pulmonary embolism is commonly unilateral in tumour patients and not typical for thyroid cancer. External pulmonary artery compression by aortic aneurysm, multiple metastases or additional bronchopulmonary malignancies were considered as differential diagnosis. After unilateral pulmonary and hilar metastasectomy, perfusion normalised on the operated side. Pulmonary perfusion defects due to pulmonary artery compression by hilar metastases were finally diagnosed. Pulmonary embolism was deemed unlikely due to the left-sided post-operative normalisation, persistence of right-sided V/P mismatches, and the lack of clinical symptoms.

Conclusion

Pulmonary artery compression may mimic pulmonary artery embolism in lung perfusion scintigraphy and should be considered in bronchopulmonary tumour patients with hilar metastases and unilateral ventilation/perfusion mismatches affecting a complete lobe or even lung. Following the presented case, also bilateral segmental and subsegmental mismatches in patients with hilar metastases from non-bronchopulmonary cancer entities should be carefully evaluated.

Abdominal visceral adipose tissue is associated with unsuspected pulmonary embolism on routine CT scans in patients with gastrointestinal cancer

OBJECTIVE

Unsuspected pulmonary embolism (UPE) has been increasingly diagnosed as an incidental finding on CT scans for routine staging in cancer patients. Previous studies suggest that obesity is an independent risk factor for venous thromboembolism in patients with malignant tumors. In this study, we aimed to investigate the association between abdominal adipose tissue, especially visceral adipose tissue (VAT) and the occurrence of UPE in hospitalized patients with gastrointestinal cancer.

METHODS

Routine contrast-enhanced chest and abdominal CT scans of 1974 patients were retrospectively assessed for the presence of UPE, of which 58 patients were identified with UPE and 108 non-UPE patients were selected as the non-UPE control group based on several matching criteria. Abdominal adipose tissue was measured by volumes of VAT and subcutaneous adipose tissue (SAT) at the navel level.

RESULTS

VAT, SAT, indwelling venous catheters, surgery, chemotherapy, and bed rest or immobilization were associated with the occurrence of UPE. Higher VAT volumes were associated with increased risk of UPE (odds ratio: 1.96; 95% confidence interval: 1.25, 3.06; p = 0.003) adjusting body mass index (BMI), bed rest or immobilization, surgery, chemotherapy and smoking, while SAT was not associated with UPE adjusting the same confounders (p = 0.117). No statistical association was found between BMI and UPE (p = 0.102).

CONCLUSION

Higher VAT rather than SAT is associated with an increased risk of unsuspected pulmonary embolism on routine CT scans in hospitalized gastrointestinal cancer patients.

ADVANCES IN KNOWLEDGE

Our findings indicate that VAT is a stronger risk factor for unsuspected pulmonary embolism than BMI and SAT in hospitalized patients with gastrointestinal cancer.

Prevalence and outcomes of incidental imaging findings: umbrella review

OBJECTIVE

To provide an overview of the evidence on prevalence and outcomes of incidental imaging findings.

DESIGN

Umbrella review of systematic reviews.

DATA SOURCES

Searches of MEDLINE, EMBASE up to August 2017; screening of references in included papers.

ELIGIBILITY CRITERIA

Criteria included systematic reviews and meta-analyses of observational studies that gave a prevalence of incidental abnormalities ("incidentalomas"). An incidental imaging finding was defined as an imaging abnormality in a healthy, asymptomatic patient or an imaging abnormality in a symptomatic patient, where the abnormality was not apparently related to the patient's symptoms. Primary studies that measured the prevalence of incidentalomas in patients with a history of malignancy were also considered in sensitivity analyses.

RESULTS

20 systematic reviews (240 primary studies) were identified from 7098 references from the database search. Fifteen systematic reviews provided data to quantify the prevalence of incidentalomas, whereas 18 provided data to quantify the outcomes of incidentalomas (13 provided both). The prevalence of incidentalomas varied substantially between imaging tests; it was less than 5% for chest computed tomography for incidental pulmonary embolism in patients with and without cancer and whole body positron emission tomography (PET) or PET/computed tomography (for patients with and without cancer). Conversely, incidentalomas occurred in more than a third of images in cardiac magnetic resonance imaging (MRI), chest computed tomography (for incidentalomas of thorax, abdomen, spine, or heart), and computed tomography colonoscopy (for extra-colonic incidentalomas). Intermediate rates occurred with MRI of the spine (22%) and brain (22%). The rate of malignancy in incidentalomas varied substantially between organs; the prevalence of malignancy was less than 5% in incidentalomas of the brain, parotid, and adrenal gland. Extra-colonic, prostatic, and colonic incidentalomas were malignant between 10% and 20% of the time, whereas renal, thyroid, and ovarian incidentalomas were malignant around a quarter of the time. Breast incidentalomas had the highest percentage of malignancy (42%, 95% confidence interval 31% to 54%). Many assessments had high between-study heterogeneity (15 of 20 meta-analyses with I2 >50%).

CONCLUSIONS

There is large variability across different imaging techniques both in the prevalence of incidentalomas and in the prevalence of malignancy for specific organs. This umbrella review will aid clinicians and patients weigh up the pros and cons of requesting imaging scans and will help with management decisions after an incidentaloma diagnosis. Our results can underpin the creation of guidelines to assist these decisions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42017075679.

Thromboembolism in Patients with Bladder Cancer: Incidence, Risk Factors and Prevention

Patients with bladder cancer are at high risk of developing both venous and arterial thromboembolic events. Factors that contribute to this phenomenon include the hypercoagulable state induced by the malignancy itself, medical comorbidities that are common in this predominantly elderly patient population as well as treatments such as prolonged pelvic surgery and cisplatin-based chemotherapy. While formal guidelines address prevention of venous thromboembolism in patients undergoing radical cystectomy, consensus regarding the role of pharmacologic prophylaxis in patients with bladder cancer being treated with chemotherapy, either with neoadjuvant or adjuvant intent in conjunction with radical cystectomy, as part of bladder preservation protocols or for metastatic disease, has proved elusive. The present narrative review was undertaken to define the incidence of and identify risk factors for thromboembolism among patients with bladder cancer, as well as to assess the efficacy of pharmacologic prophylaxis in reducing the risk of thromboembolism in this patient population.

Discharge or admit? Emergency department management of incidental pulmonary embolism in patients with cancer: a retrospective study

BACKGROUND

Hospitalization and early anticoagulation therapy remain standard care for patients who present to the emergency department (ED) with pulmonary embolism (PE). For PEs discovered incidentally, however, optimal therapeutic strategies are less clear-and all the more so when the patient has cancer, which is associated with a hypercoagulable state that exacerbates the threat of PE.

METHODS

We conducted a retrospective review of a historical cohort of patients with cancer and incidental PE who were referred for assessment to the ED in an institution whose standard of care is outpatient treatment of selected patients and use of low-molecular-weight heparin for anticoagulation. Eligible patients had received a diagnosis of incidental PE upon routine contrast enhanced chest CT for cancer staging. Survival data was collected at 30 days and 90 days from the date of ED presentation and at the end of the study.

RESULTS

We identified 193 patients, 135 (70%) of whom were discharged and 58 (30%) of whom were admitted to the hospital. The 30-day survival rate was 92% overall, 99% for the discharged patients and 76% for admitted patients. Almost all (189 patients, 98%) commenced anticoagulation therapy in the ED; 170 (90%) of these received low-molecular-weight heparin. Patients with saddle pulmonary artery incidental PEs were more likely to die within 30 days (43%) than were those with main or lobar (11%), segmental (6%), or subsegmental (5%) incidental PEs. In multivariate analysis, Charlson comorbidity index (age unadjusted), hypoxemia, and incidental PE location (P = 0.004, relative risk 33.5 (95% CI 3.1-357.4, comparing saddle versus subsegmental PE) were significantly associated with 30-day survival. Age, comorbidity, race, cancer stage, tachycardia, hypoxemia, and incidental PE location were significantly associated with hospital admission.

CONCLUSIONS

Selected cancer patients presenting to the ED with incidental PE can be treated with low-molecular-weight heparin anticoagulation and safely discharged. Avoidance of unnecessary hospitalization may decrease in-hospital infections and death, reduce healthcare costs, and improve patient quality of life. Because the natural history and optimal management of this condition is not well described, information supporting the creation of straightforward evidence-based practice guidelines for ED teams treating this specialized patient population is needed.

[Clinically relevant incidental cardiovascular findings in CT examinations]

BACKGROUND AND METHOD

Incidental cardiovascular findings are a frequent phenomenon in computed tomography (CT) examinations. As the result of a dedicated PubMed search this article gives a systemic overview of the current literature on the most important incidental cardiovascular findings, their prevalence and clinical relevance.

RESULTS

The majority of incidental cardiovascular findings are of only low clinical relevance; however, highly relevant incidental findings, such as aortic aneurysms, thromboses and thromboembolic events can also occasionally be found, especially in oncology patients.

CONCLUSION

The scans from every CT examination should also be investigated for incidental findings as they can be of decisive importance for the further clinical management of patients, depending on their clinical relevance.

Venous thromboembolism at time of diagnosis of ovarian cancer: Survival differs in symptomatic and asymptomatic cases

OBJECTIVES

To determine the impact on survival of symptomatic and asymptomatic venous thromboembolism (VTE) at time of diagnosis of primary ovarian malignancy.

MATERIALS AND METHODS

The clinical records of 397 consecutive cases of primary ovarian malignancy were studied. Clinical, pathological and survival data were obtained.

RESULTS AND CONCLUSIONS

Of 397 cases, 19 (4.8%) were found to have VTE at diagnosis, of which 63.2% (n=12) were asymptomatic. VTE was significantly associated with reduced overall median survival (28 vs. 45 months, p=0.004). Decreased survival was associated with symptomatic VTE compared to patients with asymptomatic VTE (21 vs. 36 months, p=0.02) whose survival was similar to that of patients without VTE. Decreased survival remained significant in symptomatic patients after controlling for stage of disease at diagnosis, cytoreductive status and adjuvant chemotherapy use. Overall these data suggest for the first time that symptomatic but not asymptomatic VTE prior to primary treatment of ovarian cancer is an independent adverse prognostic factor.

Early venous thromboembolic events are associated with worse prognosis in patients with lung cancer

OBJECTIVES

Venous thromboembolic events (VTE) are a leading cause of death in cancer patients. We hypothesized that early VTE (EVTE, within 3 months of diagnosis) in patients with lung cancer (LC) are associated with worse overall survival (OS).

MATERIALS AND METHODS

We identified 727 patients with LC between 1998 and 2011. Late VTE (LVTE) were defined as VTE occurring after 3 months from LC diagnosis. Advance disease (AD) was defined as patients with Stage IV non-small cell lung cancer (NSCLC) or extensive stage small cell lung cancer (SCLC), and non-advanced disease (non-AD) was defined as ≤ Stage III NSCLC or limited stage SCLC.

RESULTS

Out of 727 patients included in our review, 617 patients had NSCLC (85%), 94 (13%) SCLC, and 16 (2%) low grade neuroendocrine tumors. Ninety five patients (13%) experienced VTE, 44 (6%) experienced an EVTE and 49 (7%) had a LVTE. Patients with an EVTE had worse OS when compared to all other patients (medians 4 vs. 17 months, p < 0.0001). EVTE were associated with worse OS in patients with non-AD (medians 12 vs. 42 months, p = 0.01) and AD (medians 4 vs. 6 months, p = 0.02). When considering patients with NSCLC only, in a multivariate model that included age, stage, performance status >2, administration of chemotherapy and Charlson comorbidity index, EVTE were an independent predictor of increased mortality (HR 2.4; 95% CI 1.6-3.3).

CONCLUSIONS

EVTE are associated with worse OS, irrespective of stage of the disease. Our findings underscore the need for an efficient preventive strategy for VTE among patients with lung cancer.