Partial nephrectomy (PN) is the standard treatment for localized renal masses and should be preferred in clinical T1 (<7 cm tumor diameter) renal tumors over radical nephrectomy (RN) whenever technically feasible. Nonetheless, indications, approaches, techniques for PN, and correct reporting of outcomes, are still a matter of great debate within the urology community. Concurrently, case-report series suggested that alternative strategies for the treatment of localized renal tumors (ablation techniques (AT), watchful waiting (WW), active surveillance (AS)) could be feasible with acceptable oncologic outcomes in particular settings of patients with localized renal tumors. In this complex clinical scenario, the role surgeon-related and environmental factors (such as surgical experience, hospital resources, countries' social background and performance of health system) are important to address the best personalized approach in patients with renal tumors.

In the light of current evidence, many unsolved questions still remain and many unmet needs must be addressed. In particular, 1) the risk-benefit trade-offs between PN and RN for anatomically complex renal localized tumors; 2) the definition of evidence-based strategies to tailor the management strategy (AT vs WW vs AS vs surgery) in different subset of patients with particular clinical conditions (i.e. old, frail, comorbid patients); and 3) the definition of evidence-based recommendations to adapt surgical approach (open vs laparoscopic vs robotic) and resection techniques to different patient-, tumor-, and surgeon-specific characteristics.

To meet the challenges, to overcome the limitations of current kidney cancer literature (such as the retrospective study design, potential risk of biases, and heterogeneous follow-up of most series), and to provide high-quality evidence for future development of effective clinical practice Guidelines, we designed the international REgistry of COnservative or Radical treatment of localized kiDney tumors (i-RECORD) Project.

The expected impact of the i-RECORD project is to provide robust evidence on the leading clinical and environmental factors driving selection of the management strategy in patients with kidney cancer, and the differential impact of different management strategies (including AS, WW, AT, PN and RN) on functional, perioperative and oncological outcomes, as well as quality of life assessment, at a mid-long term follow-up (5-10 years).

Study design

The overall objective of the i-RECORD project is to build a multicentre multi-arm multi-stage prospective observational registry collecting data on the management of kidney cancer in consecutive patients treated at 50 tertiary referral Centers worldwide over a 2 years-period and with 5 years of follow-up

. On this registry, six prospective trials with specific objectives have been built.

The i-RECORd project is designed as an observational prospective longitudinal trial involving 50 international, very-high-volume tertiary referral Centers with extensive experience in management of kidney cancer. Centers will be included in the project only if they will be able to certify at least to: 1) perform 150 partial and radical nephrectomy/year, or 2) to perform 80 ATs/year, or 3) to include 50 patients in WW/AS protocols/year.

The enrollment and follow-up periods will be 2 and 5 years, respectively. The estimate of patients' enrollment over the study period is 10'000 inclusions.

The 50 Centers finally enrolled in the i-RECORD project will be given the access to a web-based platform for data collection for 24 months from the starting date of the project.

A web-based e-form platform will be used for data collection.

Data collection

This observational study aims to obtain controlled, qualitative and quantitative, data of the enrolled patients through a web-based e-form platform. For all patients it will be asked to complete a data collection form specifically designed for this study, consisting of some subfolders:

1. Anthropometric, pre-operative and comorbidity data (patient characteristics).
2. Imaging data e and pre-operative tumor features (tumor characteristics).
3. Intra-operative and post-operative data (treatment characteristics).
4. Histopathological analysis (tumor histopathological characteristics).
5. Patients follow-up variables (at 6, 12, 24 and 60 months from the treatment) (follow-up characteristics).

Decision Analysis Modeling

Beyond traditional descriptive and inferential statistical analyses, the i-RECORd project will provide a comprehensive overview of the current selection criteria for each type of management option by applying innovative statistical methods (Decision Analysis Modeling through discrete choice models) to determine the differential impact of all potential relevant variables on the choice of treatment. To do so, we will consider specific clinical scenarios (clinical clusters) made of the integration of patient characteristics (comorbidity score, performance status, age, gender, etc.), patient-reported outcomes measures (PROMs), tumors anatomical features (degree of complexity, clinical diameter, side, location within the kidney, involvement of renal sinus or collecting system, etc.), surgeon-related factors (surgical experience and background), hospital economic availabilities (i.e. open, laparoscopic, robotic surgery) and other country-specific socio-economical features in order to determine the impact of such variables on the final choice of treatment.

By applying the discrete choice model to the analysis of the prospective dataset, the i-RECORd project will overcome the current state of the art in the treatment of localized renal tumors as it will show how the choice of treatment is performed by the decision-maker (at a surgeon- and hospital-level) in each specific clinical cluster of patients, why that choice was performed according to a careful analysis of the personalized patient setting and whether that choice will influence the postoperative outcomes.

Adapted MAMS Registry

The i-RECORD will be designed adapting the innovative concept of multi-arm, multi-stage (MAMS) platform randomized trials (used, for instance, for the design of the Systemic Therapy in Advancing or Metastatic Prostate cancer: Evaluation of Drug Efficacy (STAMPEDE) Trial) to create a dynamic, observational registry evaluating simultaneously different management options in different patient- and/or tumor-related scenarios.

Inclusion Criteria:

• Radiological diagnosis of renal tumor susceptible to active treatment or AS/WW.
• Age ≥18 years
• Informed consent signed

Exclusion Criteria:

• Patient refuse to participate in clinical research.
• Urothelial renal carcinoma.

The study population include patients with a radiological diagnosis of kidney tumor susceptible to surgical treatment (RN or PN) or AT or WW/AS will be eligible.

The study protocol has been shared on the web platform of the i-RECORd project. The study has been shared with a specific Twitter page for the study.

The data will be available after Clinical.trial.gov study acceptance

Access to the study protocol will be free to any researcher.