Test performance of faecal occult blood testing for the detection of bowel cancer in people with chronic kidney disease (DETECT) protocol

Factors Associated With Advanced Colorectal Neoplasia in Patients With CKD

RATIONALE & OBJECTIVE

The risk of developing colorectal cancer in patients with chronic kidney disease (CKD) is twice that of the general population, but the factors associated with colorectal cancer are poorly understood. The aim of this study was to identify factors associated with advanced colorectal neoplasia in patients with CKD.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Patients with CKD stages 3-5, including those treated with maintenance dialysis or transplantation across 11 sites in Australia, New Zealand, Canada, and Spain, were screened for colorectal neoplasia using a fecal immunochemical test (FIT) as part of the Detecting Bowel Cancer in CKD (DETECT) Study.

EXPOSURE

Baseline characteristics for patients at the time of study enrollment were ascertained, including duration of CKD, comorbidities, and medications.

OUTCOME

Advanced colorectal neoplasia was identified through a 2-step verification process with colonoscopy following positive FIT and 2-year clinical follow-up for all patients.

ANALYTICAL APPROACH

Potential factors associated with advanced colorectal neoplasia were explored using multivariable logistic regression. Sensitivity analyses were performed using grouped LASSO (least absolute shrinkage and selection operator) logistic regression.

RESULTS

Among 1,706 patients who received FIT-based screening-791 with CKD stages 3-5 not receiving kidney replacement therapy (KRT), 418 receiving dialysis, and 497 patients with a functioning kidney transplant-117 patients (6.9%) were detected to have advanced colorectal neoplasia (54 with CKD stages 3-5 without KRT, 34 receiving dialysis, and 29 transplant recipients), including 9 colorectal cancers. The factors found to be associated with advanced colorectal neoplasia included older age (OR per year older, 1.05 [95% CI, 1.03-1.07], P<0.001), male sex (OR, 2.27 [95% CI, 1.45-3.54], P<0.001), azathioprine use (OR, 2.99 [95% CI, 1.40-6.37], P=0.005), and erythropoiesis-stimulating agent use (OR, 1.92 [95% CI, 1.22-3.03], P=0.005). Grouped LASSO logistic regression revealed similar associations between these factors and advanced colorectal neoplasia.

LIMITATIONS

Unmeasured confounding factors.

CONCLUSIONS

Older age, male sex, erythropoiesis-stimulating agents, and azathioprine were found to be significantly associated with advanced colorectal neoplasia in patients with CKD.

Health-Related Quality of Life in People Across the Spectrum of CKD

Introduction

People with chronic kidney disease (CKD) experience reduced quality of life (QoL) because of the high symptom and treatment burden. Limited data exist on the factors associated with overall and domain-specific QoL across all CKD stages.

Methods

Using data from a prospective, multinational study (Australia, New Zealand, Canada, and Spain) in 1696 participants with CKD, we measured overall and domain-specific QoL (pain, self-care, activity, mobility, anxiety/depression) using the EuroQoL, 5 dimension, 3 level. Multivariable linear regression and logistic modeling were used to determine factors associated with overall and domain-specific QoL.

Results

QoL for patients with CKD stages 3 to 5 (n = 787; mean, 0.81; SD, 0.20) was higher than in patients on dialysis (n = 415; mean, 0.76; SD, 0.24) but lower than in kidney transplant recipients (n = 494; mean, 0.84; SD, 0.21). Factors associated with reduced overall QoL (β [95% confidence intervals]) included being on dialysis (compared with CKD stages 3–5: –0.06 [–0.08 to –0.03]), female sex (–0.03 [–0.05 to –0.006]), lower educational attainment (– 0.04 [–0.06 to –0.02), lacking a partner (–0.04 [–0.06 to –0.02]), having diabetes (–0.05 [–0.07 to –0.02]), history of stroke (–0.09 [–0.13 to –0.05]), cardiovascular disease (–0.06 [–0.08 to –0.03]), and cancer (–0.03 [–0.06 to –0.009]). Pain (43%) and anxiety/depression (30%) were the most commonly affected domains, with dialysis patients reporting decrements in all 5 domains. Predictors for domain-specific QoL included being on dialysis, presence of comorbidities, lower education, female sex, and lack of a partner.

Conclusions

Being on dialysis, women with CKD, those with multiple comorbidities, lack of a partner, and lower educational attainment were associated with lower QoL across all stages of CKD.

One-Time Fecal Immunochemical Screening for Advanced Colorectal Neoplasia in Patients with CKD (DETECT Study)

BACKGROUND

In patients with CKD, the risk of developing colorectal cancer is high and outcomes are poor. Screening using fecal immunochemical testing (FIT) is effective in reducing mortality from colorectal cancer, but performance characteristics of FIT in CKD are unknown.

METHODS

To determine the detection rates and performance characteristics of FIT for advanced colorectal neoplasia (ACN) in patients with CKD, we used FIT to prospectively screen patients aged 35-74 years with CKD (stages 3-5 CKD, dialysis, and renal transplant) from 11 sites in Australia, New Zealand, Canada, and Spain. All participants received clinical follow-up at 2 years. We used a two-step reference standard approach to estimate disease status.

RESULTS

Overall, 369 out of 1706 patients who completed FIT (21.6%) tested positive; 323 (87.5%) underwent colonoscopies. A total of 1553 (91.0%) completed follow-up; 82 (4.8%) had died and 71 (4.2%) were lost. The detection rate of ACN using FIT was 6.0% (5.6%, 7.4%, and 5.6% for stages 3-5 CKD, dialysis, and transplant). Sensitivity, specificity, and positive and negative predictive values of FIT for ACN were 0.90, 0.83, 0.30, and 0.99, respectively. Of participants who underwent colonoscopy, five (1.5%) experienced major colonoscopy-related complications, including bowel perforation and major bleeding.

CONCLUSIONS

FIT appears to be an accurate screening test for patients with CKD, such that a negative test may rule out the diagnosis of colorectal cancer within 2 years. However, the risk of major complications from work-up colonoscopy are at least ten-fold higher than in the general population.

Beliefs and Attitudes to Bowel Cancer Screening in Patients with CKD: A Semistructured Interview Study

BACKGROUND AND OBJECTIVES

Bowel cancer is a leading cause of cancer-related death in people with CKD. Shared decision making regarding cancer screening is particularly complex in CKD and requires an understanding of patients' values and priorities, which remain largely unknown. Our study aimed to describe the beliefs and attitudes to bowel cancer screening in patients with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Face to face, semistructured interviews were conducted from April of 2014 to December of 2015 with 38 participants ages 39-78 years old with CKD stages 3-5, on dialysis, or transplant recipients from four renal units in Australia and New Zealand. Thematic analysis was used to analyze the transcripts.

RESULTS

Five themes were identified: invisibility of cancer (unspoken stigma, ambiguity of risk, and absence of symptomatic prompting); prioritizing kidney disease (preserving the chance of transplantation, over-riding attention to kidney disease, protecting graft survival, and showing loyalty to the donor); preventing the crisis of cancer (evading severe consequences and cognizant of susceptibility); cognitive resistance (reluctance to perform a repulsive procedure, intensifying disease burden threshold, anxiety of a positive test, and accepting the inevitable); and pragmatic accessibility (negligible financial effect, convenience, and protecting anonymity).

CONCLUSIONS

Patients with CKD understand the potential health benefits of bowel cancer screening, but they are primarily committed to their kidney health. Their decisions regarding screening revolve around their present health needs, priorities, and concerns. Explicit consideration of the potential practical and psychosocial burdens that bowel cancer screening may impose on patients in addition to kidney disease and current treatment is suggested to minimize decisional conflict and improve patient satisfaction and health care outcomes in CKD.