A Decision Analysis Evaluating Screening for Kidney Cancer Using Focused Renal Ultrasound

Cost-effectiveness of one-off upper abdominal CT screening as an add-on to lung cancer screening in England

BACKGROUND

Low-dose computed tomography (CT) screening for lung cancer is available for high-risk individuals in England. Screening simultaneously for upper abdominal conditions, including cancer, is feasible. Here, we estimate the cost-effectiveness of one-off upper abdominal CT screening, added onto lung cancer screening, based on the Yorkshire Kidney Screening Trial (YKST) feasibility study.

METHODS

A multi-disease health economic model was developed. Ten cancers and abdominal aortic aneurysm (AAA) were modelled over a lifetime horizon. YKST data informed disease prevalence, resource use and screening costs. Costs, quality-adjusted life-years (QALYs) and cost-effectiveness were estimated probabilistically.

RESULTS

Screening per person costs £70.89, produces 0.0059 QALYs, and has 96% probability of being cost-effective, with an incremental cost-effectiveness ratio of £12,085. AAA contributes most to cost-effectiveness, followed by kidney cancer, but some cancer findings reduce cost-effectiveness. Screening is more cost-effective at younger ages. Screen-detectable disease prevalence, severity and mortality risk contribute most to uncertainty.

CONCLUSIONS

One-off upper abdominal CT screening is potentially cost-effective, but costs, harms and benefits vary between conditions. Cost-effectiveness is driven by early diagnosis of AAA, then kidney cancer, illustrating the importance of considering all relevant diseases in screening models. A larger trial would provide more robust data to refine the cost-effectiveness argument.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT05005195.

Abdominal Noncontrast Computed Tomography Scanning to Screen for Kidney Cancer and Other Abdominal Pathology Within Community-based Computed Tomography Screening for Lung Cancer: Results of the Yorkshire Kidney Screening Trial

BACKGROUND AND OBJECTIVE

The Yorkshire Kidney Screening Trial (YKST) assessed the feasibility of adding abdominal noncontrast computed tomography (NCCT) to lung cancer screening to screen for kidney cancer and other abdominal pathology.

METHODS

A prospective diagnostic study offered abdominal NCCT to 55-80-yr-old ever-smokers attending a UK randomised lung cancer screening trial (May 2021 to October 2022). The exclusion criteria were dementia, frailty, previous kidney/lung cancer, and computed tomography (CT) of the abdomen and thorax within previous 6 and 12 mo, respectively. Six-month follow-up was undertaken.

KEY FINDINGS AND LIMITATIONS

A total of 4438 people attended lung screening, of whom 4309 (97%) were eligible for and 4019 (93%) accepted abdominal NCCT. Only 3.9% respondents regretted participating. The additional time to conduct the YKST processes was 13.3 min. Of the participants, 2586 (64%) had a normal abdominal NCCT, whilst 787 (20%) required an abdominal NCCT imaging review but no further action and 611 (15%) required further evaluation (investigations and/or clinic). Of the participants, 211 (5.3%) had a new serious finding, including 25 (0.62%) with a renal mass/complex cyst, of whom ten (0.25%) had histologically proven kidney cancer; ten (0.25%) with other cancers; and 60 (1.5%) with abdominal aortic aneurysms (AAAs). Twenty-five (0.62%) participants had treatment with curative intent. Of the participants, 1017 (25%) had nonserious findings, most commonly benign renal cysts (727 [18%]), whereas only 259 (6.4%) had nonserious findings requiring further tests. The number needed to screen to detect one serious abdominal finding was 18; it was 93 to detect one suspicious renal lesion and 402 to detect one histologically confirmed renal cancer. Limitations of the cohort were fixed age range and being prior lung cancer screening attendees.

CONCLUSIONS AND CLINICAL IMPLICATIONS

In this first prospective risk-stratified screening study of abdominal NCCT offered alongside CT thorax, uptake and participant satisfaction were high. The prevalence of serious findings, cancers, and AAAs, is in the range of established screening programmes such as bowel cancer. Longer-term outcomes and cost effectiveness should now be evaluated.

Home Urine Dipstick Screening for Bladder and Kidney Cancer in High-Risk Populations in England: A Microsimulation Study of Long-Term Impact and Cost-Effectiveness

BACKGROUND

Testing high-risk populations for non-visible haematuria may enable earlier detection of bladder cancer, potentially decreasing mortality. This research aimed to assess the cost-effectiveness of urine dipstick screening for bladder cancer in high-risk populations in England.

METHODS

 A microsimulation model developed in R software was calibrated to national incidence data by age, sex and stage, and validated against mortality data. Individual risk factors included age, sex, smoking status and factory employment. We evaluated three one-time screening scenarios: (1) current and former smokers of different ages within the 55-70 years range, (2) a mixed-age cohort of smokers aged 55-80 years and (3) individuals aged 65-79 years from high-risk regions. Probabilistic and scenario analyses evaluated uncertainty. The incremental cost-effectiveness ratio (ICER) was calculated and compared with the standard £20,000/quality-adjusted life year (QALY) threshold using payer's perspective and 2022 year of evaluation with 3.5% discounting for both costs and effects.

RESULTS

 Screening all current and former smokers (scenario 1) and both mixed-age cohorts (scenarios 2 and 3) was not cost-effective at the threshold of £20,000/QALY. Screening at age 58 years had a 33% probability of being cost-effective at £20,000/QALY threshold and a 64% probability at £30,000/QALY threshold. Screening current and former smoking men aged 58 and 60 years was cost-effective, with ICERs of £18,181 and £18,425 per QALY, respectively. Scenario results demonstrated the high impact of assumptions on lead time, diagnostic pathway, and screening efficacy on predictions.

CONCLUSIONS

 Screening smoking men aged 58 or 60 years for bladder cancer using urine dipstick tests may be cost-effective.

Efficient extraction via titanium organic frameworks facilitates in-depth profiling of urinary exosome metabolite fingerprints

Urinary exosome metabolite analysis has demonstrated notable advantages in uncovering disease status, yet its potential in decoding the intricacies of clear cell renal cell carcinoma (ccRCC) remains untapped. To address this, a core-shell magnetic titanium organic framework was designed to capture urinary exosomes and assist laser desorption/ionization mass spectrometry (LDI MS) to decipher the exosomal metabolic profile of ccRCC, with high sensitivity, throughput, and speed. A total of 492 urinary exosome metabolite fingerprints (UEMFs) from 176 samples were extracted for exploring the differences between ccRCC and healthy individuals. Leveraging machine learning algorithms, the exosomal metabolic profile was disclosed, achieving accurate differentiation and prediction of ccRCC patients versus healthy individuals, with an accuracy exceeding 97.3%. Furthermore, an optimized algorithm panel comprising five key features demonstrated consistent and high diagnosing accuracy rates of over 94.0% both in the training and blind test sets for ccRCC, underscoring the remarkable effectiveness and superiority of this strategy in ccRCC detection. This study not only refines the LDI MS method for metabolite analysis in urinary exosomes but also introduces a promising technical approach for unraveling the mysteries of ccRCC.

Scoping Review of Economic Analyses of Rare Kidney Diseases

Introduction

Rare kidney diseases (RKDs) place a substantial economic burden on patients and health systems, the extent of which is unknown and may be systematically underestimated by health economic techniques. We aimed to investigate the economic burden and cost-effectiveness evidence base for RKDs.

Methods

We conducted a systematic scoping review to identify economic evaluations, health technology assessments, and cost-of-illness studies relating to RKDs, published since 2012.

Results

A total of 161 published studies, including 66 cost-of-illness studies and 95 economic evaluations; 72 grey literature reports were also included. Most published literature originated from high-income nations, particularly the USA (81 studies), and focused on a handful of diseases, notably renal cell carcinomas (70) and systemic lupus erythematosus (36). Limited evidence was identified from lower-income settings and there were few studies of genetic conditions, which make up most RKDs. Some studies demonstrated the cost-effectiveness of existing treatments; however, there were limited considerations of broader economic impacts on patients that may be important to those with RKDs. Included health technology assessments highlighted difficulties in obtaining high-quality clinical evidence for treatments in very small patient populations, and often considered equity issues and other patient impacts qualitatively alongside clinical and economic evidence in their recommendations.

Conclusion

We found large gaps in the economic evidence base for RKDs and limited adaptation of methods to account for the uniqueness of these diseases. There may be significant scope for innovation in building an investment case for RKD treatments, as well as in decision-making processes to inform investment decisions.

Polarization-sensitive optical coherence tomography for renal tumor detection in ex vivo human kidneys

Kidney cancer is a kind of high mortality cancer because of the difficulty in early diagnosis and the high metastatic dissemination in treatments. The surgical resection of tumors is the most effective treatment for renal cancer patients. However, precise assessment of tumor margins is a challenge during surgical resection. The objective of this study is to demonstrate an optical imaging tool in precisely distinguishing kidney tumor borders and identifying tumor zones from normal tissues to assist surgeons in accurately resecting tumors from kidneys during the surgery. 30 samples from six human kidneys were imaged using polarization-sensitive optical coherence tomography (PS-OCT). Cross-sectional, enface, and spatial information of kidney samples were obtained for microenvironment reconstruction. Polarization parameters (phase retardation, optic axis direction, and degree of polarization uniformity (DOPU) and Stokes parameters (Q, U, and V) were utilized for multi-parameter analysis. To verify the detection accuracy of PS-OCT, H&E histology staining and dice-coefficient was utilized to quantify the performance of PS-OCT in identifying tumor borders and regions. In this study, tumor borders were clearly identified by PS-OCT imaging, which outperformed the conventional intensity-based OCT. With H&E histological staining as golden standard, PS-OCT precisely identified the tumor regions and tissue distributions at different locations and different depths based on polarization and Stokes parameters. Compared to the traditional attenuation coefficient quantification method, PS-OCT demonstrated enhanced contrast of tissue characteristics between normal and cancerous tissues due to the birefringence effects. Our results demonstrated that PS-OCT was promising to provide imaging guidance for the surgical resection of kidney tumors and had the potential to be used for other human kidney surgeries in clinics such as renal biopsy.

Risk-stratified screening for the early detection of kidney cancer

Earlier detection and screening for kidney cancer has been identified as a key research priority, however the low prevalence of the disease in unselected populations limits the cost-effectiveness of screening. Risk-stratified screening for kidney cancer may improve early detection by targeting high-risk individuals whilst limiting harms in low-risk individuals, potentially increasing the cost-effectiveness of screening. A number of models have been identified which estimate kidney cancer risk based on both phenotypic and genetic data, and while several of the former have been shown to identify individuals at high-risk of developing kidney cancer with reasonable accuracy, current evidence does not support including a genetic component. Combined screening for lung cancer and kidney cancer has been proposed, as the two malignancies share some common risk factors. A modelling study estimated that using lung cancer risk models (currently used for risk-stratified lung cancer screening) could capture 25% of patients with kidney cancer, which is only slightly lower than using the best performing kidney cancer-specific risk models based on phenotypic data (27%-33%). Additionally, risk-stratified screening for kidney cancer has been shown to be acceptable to the public. The following review summarises existing evidence regarding risk-stratified screening for kidney cancer, highlighting the risks and benefits, as well as exploring the management of potential harms and further research needs.

Effect of smoking, hypertension and lifestyle factors on kidney cancer - perspectives for prevention and screening programmes

Renal cell carcinoma (RCC) incidence has doubled over the past few decades. However, death rates have remained stable as the number of incidental renal mass diagnoses peaked. RCC has been recognized as a European health care issue, but to date, no screening programmes have been introduced. Well-known modifiable risk factors for RCC are smoking, obesity and hypertension. A direct association between cigarette consumption and increased RCC incidence and RCC-related death has been reported, but the underlying mechanistic pathways for this association are still unclear. Obesity is associated with an increased risk of RCC, but interestingly, improved survival outcomes have been reported in obese patients, a phenomenon known as the obesity paradox. Data on the association between other modifiable risk factors such as diet, dyslipidaemia and physical activity with RCC incidence are conflicting, and potential mechanisms underlying these associations remain to be elucidated.

Screening for renal cell carcinoma in renal transplant recipients: a single-centre retrospective study

OBJECTIVES

The primary objective of our study was to evaluate the effectiveness of renal cell carcinoma (RCC) screening in renal transplant (RT) recipients.

DESIGN

Single-centre retrospective study.

SETTING AND PARTICIPANTS

1998 RT recipients who underwent RT at Memorial Hermann Hospital (MHH) Texas Medical Center (TMC) between 1 January 1999 and 31 December 2019 were included and we identified 16 patients (0.8%) with RCC. An additional four patients with RCC who underwent RT elsewhere but received follow-up at MHH TMC were also included. Subject races included white (20%), black (50%), Hispanic (20%) and Asian (10%).

OUTCOME MEASURES

The RCC stage at diagnosis and outcomes were compared between patients who were screening versus those who were not.

RESULTS

We identified a total of 20 patients with post-RT RCC, 75% of whom were men. The median age at diagnosis was 56 years. RCC histologies included clear cell (75%), papillary (20%) and chromophobe (5%). Patients with post-RT RCC who had screening (n=12) underwent ultrasound or CT annually or every 2 years, whereas eight patients had no screening. All 12 patients who had screening had early-stage disease at diagnosis (stage I (n=11) or stage II (n=1)) and were cured by nephrectomy (n=10) or cryotherapy (n=2). In patients who had no screening, three (37.5%) had stage IV RCC at diagnosis and all of whom died of metastatic disease. There was a statistically significant difference in RCC-specific survival in patients who were screened (p=0.01) compared with those who were not screened.

CONCLUSION

All RT recipients who had RCC diagnosed based on screening had early-stage disease and there were no RCC-related deaths. Screening is an effective intervention in RT recipients to reduce RCC-related mortality.

Screening programs for renal cell carcinoma: a systematic review by the EAU young academic urologists renal cancer working group

PURPOSE

To systematically review studies focused on screening programs for renal cell carcinoma (RCC) and provide an exhaustive overview on their clinical impact, potential benefits, and harms.

METHODS

A systematic review of the recent English-language literature was conducted according to the European Association of Urology guidelines and the PRISMA statement recommendations (PROSPERO ID: CRD42021283136) using the MEDLINE, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases. Risk-of-bias assessment was performed according to the QUality In Prognosis Studies (QUIPS) tool.

RESULTS

Overall, nine studies and one clinical trials were included. Eight studies reported results from RCC screening programs involving a total of 159 136 patients and four studies reported screening cost-analysis. The prevalence of RCC ranged between 0.02 and 0.22% and it was associated with the socio-demographic characteristics of the subjects; selection of the target population decreased, overall, the screening cost per diagnosis.

CONCLUSIONS

Despite an increasing interest in RCC screening programs from patients and clinicians there is a relative lack of studies reporting the efficacy, cost-effectiveness, and the optimal modality for RCC screening. Targeting high-risk individuals and/or combining detection of RCC with other health checks represent pragmatic options to improve the cost-effectiveness and reduce the potential harms of RCC screening.

Validation and public health modelling of risk prediction models for kidney cancer using the UK Biobank

OBJECTIVES

To externally validate risk models for the detection of kidney cancer, as early detection of kidney cancer improves survival and stratifying the population using risk models could enable an individually tailored screening programme.

METHODS

We validated the performance of 30 existing phenotypic models predicting the risk of kidney cancer in the UK Biobank cohort (n = 450 687). We compared the discrimination and calibration of models for men, women, and a mixed-sex cohort. Population level data were used to estimate model performance in a screening scenario for a range of risk thresholds (6-year risk: 0.1-1.0%).

RESULTS

In all, 10 models had reasonable discrimination (area under the receiver-operating characteristic curve >0.60), although some had poor calibration. Modelling demonstrated similar performance of the best models over a range of thresholds. The models showed an improvement in ability to identify cases compared to age- and sex-based screening. All the models performed less well in women than men.

CONCLUSIONS

The present study is the first comprehensive external validation of risk models for kidney cancer. The best-performing models are better at identifying individuals at high risk of kidney cancer than age and sex alone; however, the benefits are relatively small. Feasibility studies are required to determine applicability to a screening programme.

Risk Prediction Models for Kidney Cancer: A Systematic Review

CONTEXT

Early detection of kidney cancer improves survival; however, low prevalence means that population-wide screening may be inefficient. Stratification of the population into risk categories could allow for the introduction of a screening programme tailored to individuals.

OBJECTIVE

This review will identify and compare published models that predict the risk of developing kidney cancer in the general population.

EVIDENCE ACQUISITION

A search identified primary research reporting or validating models predicting the risk of kidney cancer in Medline and EMBASE. After screening identified studies for inclusion, we extracted data onto a standardised form. The risk models were classified using the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) guidelines and evaluated using the PROBAST assessment tool.

EVIDENCE SYNTHESIS

The search identified 15 281 articles. Sixty-two satisfied the inclusion criteria; performance measures were provided for 11 models. Some models predicted the risk of prevalent undiagnosed disease and others future incident disease. Six of the models had been validated, two using external populations. The most commonly included risk factors were age, smoking status, and body mass index. Most of the models had acceptable-to-good discrimination (area under the receiver-operating curve >0.7) in development and validation. Many models also had high specificity; however, several had low sensitivity. The highest performance was seen for the models using only biomarkers to detect kidney cancer; however, these were developed and validated in small case-control studies.

CONCLUSIONS

We identified a small number of risk models that could be used to stratify the population according to the risk of kidney cancer. Most exhibit reasonable discrimination, but a few have been validated externally in population-based studies.

PATIENT SUMMARY

In this review, we looked at mathematical models predicting the likelihood of an individual developing kidney cancer. We found several suitable models, using a range of risk factors (such as age and smoking) to predict the risk for individuals. Most of the models identified require further testing in the general population to confirm their usefulness.

Acceptability and potential impact on uptake of using different risk stratification approaches to determine eligibility for screening: A population-based survey

BACKGROUND

Using risk stratification approaches to determine eligibility has the potential to improve efficiency of screening.

OBJECTIVES

To compare the public acceptability and potential impact on uptake of using different approaches to determine eligibility for screening.

DESIGN

An online population-based survey of 668 adults in the UK aged 45-79 including a series of scenarios in the context of a potential kidney cancer screening programme in which eligibility was determined by age, sex, age and sex combined, a simple risk score (age, sex, body mass index, smoking status), a complex risk score additionally incorporating family history and lifestyle, or a genetic risk score.

OUTCOME MEASURES

We used multi-level ordinal logistic regression to compare acceptability and potential uptake within individuals and multivariable ordinal logistic regression differences between individuals.

RESULTS

Using sex, age and sex, or the simple risk score were less acceptable than age (P < .0001). All approaches were less acceptable to women than men. Over 70% were comfortable waiting until they were older if the complex risk score or genetics indicated a low risk. If told they were high risk, 85% would be more likely to take up screening. Being told they were low risk had no overall influence on uptake.

CONCLUSIONS

Varying the starting age of screening based on estimated risk from models incorporating phenotypic or genetic risk factors would be acceptable to most individuals and may increase uptake.

PATIENT OR PUBLIC CONTRIBUTION

Two members of the public contributed to the development of the survey and have commented on this paper.

Current evidence on screening for renal cancer

Renal cell carcinoma (RCC) incidence is increasing worldwide. A high proportion of individuals are asymptomatic at diagnosis, but RCC has a high mortality rate. These facts suggest that RCC meets some of the criteria for screening, and a new analysis shows that screening for RCC could potentially be cost-effective. Targeted screening of high-risk individuals is likely to be the most cost-effective strategy to maximize the benefits and reduce the harms of screening. However, the size of the benefit of earlier initiation of treatment and the overall cost-effectiveness of screening remains uncertain. The optimal screening modality and target population is also unclear, and uncertainties exist regarding the specification and implementation of a screening programme. Before moving to a fully powered trial of screening, future work should focus on the following: developing and validating accurate risk prediction models; developing non-invasive methods of early RCC detection; establishing the feasibility, public acceptability and potential uptake of screening; establishing the prevalence of RCC and stage distribution of RCC detected by screening; and evaluating the potential harms of screening, including the impact on quality of life, overdiagnosis and over-treatment.

Public attitudes towards screening for kidney cancer: an online survey

BACKGROUND

Kidney cancer is often asymptomatic, leading to proposals for a screening programme. The views of the public towards introducing a new screening programme for kidney cancer are unknown. The aim of this study was to explore attitudes towards kidney cancer screening and factors influencing intention to attend a future screening programme.

METHODS

We conducted an online population-based survey of 1021 adults aged 45-77 years. The main outcome measure was intention to attend four possible screening tests (urine, blood, ultrasound scan, low-dose CT) as well as extended low-dose CT scans within lung cancer screening programmes. We used multivariable regression to examine the association between intention and each screening test.

RESULTS

Most participants stated that they would be 'very likely' or 'likely' to undergo each of the screening tests [urine test: n = 961 (94.1%); blood test: n = 922 (90.3%); ultrasound: n = 914 (89.5%); low-dose CT: n = 804 (78.8%); lung CT: n = 962 (95.2%)]. Greater intention to attend was associated with higher general cancer worry and less perceived burden/inconvenience about the screening tests. Less worry about the screening test was also associated with higher intention to attend, but only in those with low general cancer worry (cancer worry scale ≤ 5). Compared with intention to take up screening with a urine test, participants were half as likely to report that they intended to undergo blood [OR 0.56 (0.43-0.73)] or ultrasound [OR 0.50 (0.38-0.67)] testing, and half as likely again to report that they intended to take part in a screening programme featuring a low dose CT scan for kidney cancer screening alone [OR 0.19 (0.14-0.27)].

CONCLUSION

Participants in this study expressed high levels of intention to accept an invitation to screening for kidney cancer, both within a kidney cancer specific screening programme and in conjunction with lung cancer screening. The choice of screening test is likely to influence uptake. Together these findings support on-going research into kidney cancer screening tests and the potential for combining kidney cancer screening with existing or new screening programmes.

Challenges of early renal cancer detection: symptom patterns and incidental diagnosis rate in a multicentre prospective UK cohort of patients presenting with suspected renal cancer

OBJECTIVES

To describe the frequency and nature of symptoms in patients presenting with suspected renal cell carcinoma (RCC) and examine their reliability in achieving early diagnosis.

DESIGN

Multicentre prospective observational cohort study.

SETTING AND PARTICIPANTS

Eleven UK centres recruiting patients presenting with suspected newly diagnosed RCC. Symptoms reported by patients were recorded and reviewed. Comprehensive clinico-pathological and outcome data were also collected.

OUTCOMES

Type and frequency of reported symptoms, incidental diagnosis rate, metastasis-free survival and cancer-specific survival.

RESULTS

Of 706 patients recruited between 2011 and 2014, 608 patients with a confirmed RCC formed the primary study population. The majority (60%) of patients were diagnosed incidentally. 87% of patients with stage Ia and 36% with stage III or IV disease presented incidentally. Visible haematuria was reported in 23% of patients and was commonly associated with advanced disease (49% had stage III or IV disease). Symptomatic presentation was associated with poorer outcomes, likely reflecting the presence of higher stage disease. Symptom patterns among the 54 patients subsequently found to have a benign renal mass were similar to those with a confirmed RCC.

CONCLUSIONS

Raising public awareness of RCC-related symptoms as a strategy to improve early detection rates is limited by the fact that related symptoms are relatively uncommon and often associated with advanced disease. Greater attention must be paid to the feasibility of screening strategies and the identification of circulating diagnostic biomarkers.