Decision-making in active surveillance in kidney cancer: current trends and future urine and tissue markers

Metastatic risk in clear cell renal cell carcinoma: a tool incorporating sex, size, and grade

OBJECTIVE

To identify predictors of metastases, estimate the proportion of metastatic clear cell renal cell carcinoma (ccRCC) cases according to these predictors, and subsequently create a risk table showing the absolute difference in metastasis proportion for each 10 mm increase in tumour size.

PATIENTS AND METHODS

Patients diagnosed with histopathological confirmed ccRCC in 2010-2018 in Denmark identified in the nationwide Danish Multidisciplinary Renal Cancer Group (DaRenCa) Study-3. Association between diagnostic variables and metastases were assessed with logistic regression analyses. Proportion of cases with metastases were assess based on tumour sizes using a logistic regression model.

RESULTS

The study included 2109 cases with non-metastatic ccRCC at diagnosis and 450 cases with metastatic ccRCC. Multivariable logistic regression analyses found sex, tumour size and grade were associated with metastatic ccRCC, whereas age was not. The proportion of cases with metastasis increased with larger tumours sizes and higher grade. As an example, the proportion of metastases in female cases with tumour size of 40 mm was 2.9% (95% confidence interval [CI] 1.7-4.8%) in Grade 1 and 16% (95% CI 12-22%) in cases with Grade 4. Comparable numbers in cases with a tumour size of 70 mm were 6.6% (95% CI 4.0-11%) and 31% (95% CI 25-38). The absolute increase in the proportion of cases with metastases with a 10 mm increase in size was <2% for tumours <40 mm and Grade 1-2. In contrast, cases with tumour sizes >50 mm and/or Grade 3-4 had a moderate (2-<4%) to high (≥4%) absolute increase in the proportion of cases with metastases with each 10 mm increase.

CONCLUSION

The risk table presented offers a valuable tool for discussing the risk of progression to metastases in patients under expected management for ccRCC, enabling clinicians to make more informed, evidence-based decisions.

Non-Invasive Diagnostics of Renal Cell Carcinoma Using Ultrasensitive Immunodetection of Cancer-Retina Antigens

Renal cell carcinoma (RCC) is the most common urological malignancy with a high mortality and low detection rate. One of the approaches to improving its diagnostics may be the search for new non-invasive biomarkers in liquid biopsy and development of more sensitive methods for their detection. Cancer-retina antigens, which are known to be aberrantly expressed in malignant tumors, are present in liquid biopsy at extremely low concentrations. Using the developed multiplex immunoassay with a detection limit of 0.1 pg/ml, urine and serum samples of 89 patients with RCC and 50 non-cancer patients were examined for the presence of cancer-retina antigens (arrestin, recoverin, rhodopsin kinase, and transducin); the difference between the RCC and control groups was evaluated with the χ² test. The results showed high diagnostic efficiency of a combination of arrestin and recoverin: at a threshold of 0.1 pg/ml, the sensitivity was 96%, specificity 92%, and AUC = 0.96 (95% confidence interval, 0.93-0.99). Seven days after nephrectomy, the concentration of the antigens returned to the level characteristic of the control group. Therefore, arrestin in a combination with recoverin can serve as a diagnostic non-invasive urinary biomarker of RCC.