Increased Cancer Risk in Patients with Kidney Disease and Venous Thromboembolism: A Population-Based Cohort Study

Abstract

Background Venous thromboembolism (VTE) may be a harbinger of cancer in the general population. Patients with kidney disease have an a priori increased VTE risk. However, it remains unknown how a VTE affects subsequent cancer risk in these patients. Objectives To examine the cancer risk in patients with kidney disease following a VTE. Methods We conducted a nationwide population-based cohort study in Denmark (1996–2017), including all VTE patients with a diagnosis of kidney disease. We calculated absolute risks of cancer (accounting for competing risk of death) and age-, sex-, and calendar-period standardized incidence ratios (SIRs) comparing the observed cancer incidence with national cancer incidence rates and cancer incidence rates of VTE patients without kidney disease. Results We followed 3,362 VTE patients with kidney disease (45.9% females) for a median follow-up time of 2.4 years (interquartile range: 0.6–5.4). During follow-up, 464 patients were diagnosed with cancer, of whom 169 (36.4%) were diagnosed within the first year. The 1-year absolute risk of any cancer was 5.0% (95% confidence interval [CI]: 4.3–5.8), with a SIR of 2.9 (95% CI: 2.5–3.4) when compared with the general population, and 2.0 (95% CI: 1.8–2.4) when compared with VTE patients without kidney disease. During subsequent years of follow-up, the SIRs declined to 1.5 (95% CI: 1.3–1.6) when compared with the general population, and 1.1 (95% CI: 0.9–1.2) compared with VTE patients without kidney disease. Conclusions Patients with hospital-diagnosed kidney disease have increased cancer risk after VTE, especially within the first year following the VTE diagnosis.

Kidney Disease and Cancer Risk in Patients with Venous Thromboembolism: What Does It Mean for Clinical Practice?

“…(versus planned visit), record versus no record of dialysis or kidney transplantation, provoked versus unprovoked VTE, or early versus late (within versus beyond the first 30 days of follow-up) cancer diagnosis; the consistency of the results further strengthens the message of the main analysis (6). On the other hand, several limitations, which are partly unavoidable in this type of research, need to be kept in mind before drawing conclusions:  Firstly, due to the lack of data regarding the severity of kidney disease and that of the VTE episode, it is unclear whether these parameters affected the reported association between nephropathy and cancer, and consequently to what extent they should be considered for planning the intensity of cancer screening and frequency of follow-up.…”

“…A total of 464 patients were diagnosed with cancer, with more than one third of the cases (36%) being confirmed within the first year of follow-up (6). The main finding of this study is undoubtedly the high (5.0%; 95% confidence interval [CI]: 4.3-5.8) one-year absolute risk of any cancer.…”

“… Thirdly, the origin of kidney disease remained poorly specified in almost half of the population studied, hardly permitting the formulation of hypotheses on the pathophysiological background of the association detected. In this regard, one has to acknowledge that the most common forms of kidney disease are part of pathologic processes elicited by diabetes or hypertension and affecting the entire organism (6), and other diseases such as glomerulonephritis or pyelonephritis may be closely associated with systemic inflammatory or autoimmune processes which are related to an increased incidence of malignancies as well (17,18). Kidney disease in patients with (as well as in those without) VTE is frequently an indicator of significant comorbidity which may, among other adverse effects on the patients' prognosis, increase the risk of cancer.…”

“…were available with the exception of the few patients for whom a history of dialysis was reported (6).…”

Incidence and Risk Factors for Pregnancy-Associated Venous Thromboembolism: Are There Differences between East and West?

“…1 Even in this journal there has been much interest in the epidemiology, prognosis, and risk factors for VTE, as well as the pathophysiological mechanisms underlying the propensity to develop this common condition. [2][3][4][5][6][7] Pregnancy is an important risk factor for VTE. Several previous studies reported the incidence of pregnancy-associated VTE (PA-VTE) for Western population.…”