Roles for active surveillance in renal cancer

Development of modified multi-parametric CT algorithms for diagnosing clear-cell renal cell carcinoma in small solid renal masses

OBJECTIVE

To refine the existing CT algorithm to enhance inter-reader agreement and improve the diagnostic performance for clear-cell renal cell carcinoma (ccRCC) in solid renal masses less than 4 cm.

METHODS

A retrospective collection of 331 patients with pathologically confirmed renal masses were enrolled in this study. Two radiologists independently assessed the CT images: in addition to heterogeneity score (HS) and mass-to-cortex corticomedullary attenuation ratio (MCAR), measured parameters included ratio of major diameter to minor diameter at the maximum axial section (Major axis / Minor axis), tumor-renal interface, standardized heterogeneity ratio (SHR), and standardized nephrographic reduction rate (SNRR). Spearman's correlation analysis was performed to evaluate the relationship between SHR and HS. Univariate and multivariate logistic regression analyses were employed to identify independent risk factors and then CT-score was adjusted by those indicators. The diagnostic efficacy of the modified CT-scores was evaluated using ROC curve analysis.

RESULTS

The SHR and heterogeneity grade (HG) of mass were correlated positively with the HS (R = 0.749, 0.730, all P < 0.001). Logistic regression analysis determined that the Major axis / Minor axis (> 1.16), the tumor-renal interface (> 22.3 mm), and the SNRR (> 0.16) as additional independent risk factors to combine with HS and MCAR. Compared to the original CT-score, the two CT algorithms combined tumor-renal interface and SNRR showed significantly improved diagnostic efficacy for ccRCC (AUC: 0.770 vs. 0.861 and 0.862, all P < 0.001). The inter-observer agreement for HG was higher than that for HS (weighted Kappa coefficient: 0.797 vs. 0.722). The consistency of modified CT-score was also superior to original CT-score (weighted Kappa coefficient: 0.935 vs. 0.878).

CONCLUSION

The modified CT algorithms not only enhanced inter-reader consistency but also improved the diagnostic capability for ccRCC in small renal masses.

Clear cell likelihood score may improve diagnosis and management of renal masses

The detection of solid renal masses has increased over time due to incidental findings during imaging studies conducted for unrelated medical conditions. Approximately 20% of lesions measuring less than 4 cm are benign and 80% are malignant. Clear cell renal cell carcinoma (ccRCC) is the most frequent among renal carcinomas, responsible for 65-80% of cases. The increased detection of renal masses facilitates early diagnosis and treatment. However, it also leads to more invasive interventions, which result in higher morbidity and costs. Currently, only histological analysis can offer an accurate diagnosis. Surgical nephron loss significantly elevates morbidity and mortality rates. Active surveillance represents a conservative management approach for patients diagnosed with a solid renal mass that is endorsed by both American Urological Association and the European Society for Medical Oncology. However, active surveillance is used in a minority of patients and varies across institutions. The lack of clinical studies using a standardized approach to incidentally detected small renal masses precludes the widespread use of active surveillance. Hence, there is an urgent need for better patient selection, distinguishing those who require surgery from those suitable for active surveillance. The clear cell likelihood score (ccLS) represents a novel MRI tool for assessing the probability of a renal mass being a ccRCC. In this study, we present a comprehensive review of renal masses and their evaluation using the ccLS to facilitate shared decision between urologists and patients.

Xpert Bladder Cancer Monitor May Avoid Cystoscopies in Patients Under "Active Surveillance" for Recurrent Bladder Cancer (BIAS Project): Longitudinal Cohort Study

Objectives

To test the hypothesis that patients under active surveillance (AS) for Non-muscle Invasive Bladder Cancer (NMIBC) who were negative on longitudinal re-testing by the Xpert^® Bladder Cancer Monitor (Xpert BC Monitor) assay may avoid unnecessary cystoscopies and urine cytology (UC).

Subjects/Patients (or Materials) and Methods

This is a prospective cohort study of patients enrolled in the AS protocol for recurrent NMIBC (Bladder Cancer Italian Active Surveillance, BIAS project), whose urine samples were analyzed by Xpert BC Monitor upon entry in the study (T0). Patients who had a negative Xpert test and did not fail AS, underwent additional Xpert tests after 4 (T1), 8 (T2), and 12 (T3) months. The clinical utility of Xpert was assessed by determining the number of cystoscopies and UC that could be avoided within 1 year.

Results

Overall, 139 patients were tested with Xpert at T0. Median follow-up was 23 (IQR 17–27) months. Sixty-eight (48.9%) patients failed AS, 65 (46.7%) are currently on AS, and 6 (4.3%) were lost at follow-up. At T0 57 (41.0%) patients had a negative test and 36 (63.2%) are still in AS. In patients with 2 consecutives negative Xpert tests, we could have avoided 73.9% of unnecessary cystoscopies, missing 26.4% failure, up to avoid all cystoscopies with 4 negative tests missing only 12% of failure. All the patients with negative Xpert had negative UC. Failure-free-survival at median follow-up (23 month) stratified for having 0, 1, or ≥2 negative tests was 67.0, 55.1. and 84.1, respectively.

Conclusion

Our findings suggest that Xpert BC Monitor assay, when it is longitudinally repeated, could significantly reduce the number of unnecessary cystoscopies and UC during their follow-up.

Circulating RNA in Kidney Cancer: What We Know and What We Still Suppose

Renal cancer represents the 7th most common tumor worldwide, affecting 400,000 people annually. This malignancy, which is the third most frequent cancer among urological diseases, displays a completely different prognosis if the tumor is detected in the early stages or advance phases. Unfortunately, more than 50% of renal cancers are discovered incidentally, with a consistent percentage of cases where the tumor remains clinically silent till the metastatic process is established. In day-to-day clinical practice, no available predictive biomarkers exist, and the existent imaging diagnostic techniques harbor several gaps in terms of diagnosis and prognosis. In the last decade, many efforts have been reported to detect new predictive molecular biomarkers using liquid biopsies, which are less invasive in comparison to renal biopsy. However, until now, there has been no clear evidence that a liquid biopsy biomarker could be relevant to the creation of a precise and tailored medical management in these oncological patients, even though circulating RNA biomarkers remain among the most promising. Given the idea that liquid biopsies will play a future key role in the management of these patients, in the present review, we summarize the current state of circulating RNA (miRNA, lncRNAs, and circRNAs) as possible biomarkers of renal cancer presence and aggressiveness in patients.

Update on First-Line Combination Treatment Approaches in Metastatic Clear-Cell Renal Cell Carcinoma

OPINION STATEMENT

The treatment for metastatic renal cell carcinoma (mRCC) has significantly evolved in recent years with a deeper understanding of the molecular make-up of the disease and the clinical development of therapies with novel mechanisms of action. While some patients with more indolent disease may benefit from local therapy such as metastasectomy or cytoreductive nephrectomy, others may safely embark on an active surveillance program or be offered targeted therapy. Yet, a combination regimen including an ICI is the most effective regimen and should be considered in most mRCC cases. Ongoing studies will help determine which factors can be further used to optimize treatment selection and personalize disease management.

[Radical nephrectomy and partial nephrectomy]

Renal cell carcinoma is the 2nd most frequent urological malignancy in women and the third most frequent in men, with an age peak in the seventh decade of life. If detected early in a local non-metastatic stage, options for complete recovery are excellent. While two decades ago, even locally limited cancers of the kidney were cured by radical nephrectomy, treatment today mostly consists of local treatment for locally confined cancers. Guidelines today recommend local surgical excision (open or minimally-invasive) or - in selected cases - topical energy application (radio-frequency ablation, cryoablation). The surgeon's expertise is most important in the selection of the appropriate kind of surgery and different guidelines have slightly different recommendations.Treatment decisions should be made on an individual basis in due consideration of an individual's age and co-morbidities. This may lead to the recommendation that, due to low perioperative morbidity, even localised carcinomas should be treated by (minimally-invasive) radical nephrectomy instead of nephron-sparing surgery and, in other cases, a non-interventional, active surveillance strategy may be pursued without compromising the patient's life expectancy. For higher-grade renal cell carcinomas, there is usually an indication for radical nephrectomy, as long as no metastases are detected. This also applies to carcinomas with venous thrombi extending into the atrium of the heart. Complications in the treatment of renal carcinomas are usually rare and easily treatable in most cases.

Small Renal Mass Surveillance: Histology-specific Growth Rates in a Biopsy-characterized Cohort

BACKGROUND

Most reports of active surveillance (AS) of small renal masses (SRMs) lack biopsy confirmation, and therefore include benign tumors and different subtypes of renal cell carcinoma (RCC).

OBJECTIVE

We compared the growth rates and progression of different histologic subtypes of RCC SRMs (SRM^RCC) in the largest cohort of patients with biopsy-characterized SRMs on AS.

DESIGN, SETTING, AND PARTICIPANTS

Data from patients in a multicenter Canadian trial and a Princess Margaret cohort were combined to include 136 biopsy-proven SRM^RCC lesions managed by AS, with treatment deferred until progression or patient/surgeon decision.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Growth curves were estimated from serial tumor size measures. Tumor progression was defined by sustained size ≥4 cm or volume doubling within 1 yr.

RESULTS AND LIMITATIONS

Median follow-up for patients who remained on AS was 5.8 yr (interquartile range 3.4-7.5 yr). Clear cell RCC SRMs (SRM^ccRCC) grew faster than papillary type 1 SRMs (0.25 and 0.02 cm/yr on average, respectively, p =  0.0003). Overall, 60 SRM^RCC lesions progressed: 49 (82%) by rapid growth (volume doubling), seven (12%) increasing to ≥4 cm, and four (6.7%) by both criteria. Six patients developed metastases, and all were of clear cell RCC histology. Limitations include the use of different imaging modalities and a lack of central imaging review.

CONCLUSIONS

Tumor growth varies between histologic subtypes of SRM^RCC and among SRM^ccRCC, which likely reflects individual host and tumor biology. Without validated biomarkers that predict this variation, initial follow-up of histologically characterized SRMs can inform personalized treatment for patients on AS.

PATIENT SUMMARY

Many small kidney cancers are suitable for surveillance and can be monitored over time for change. We demonstrate that different types of kidney cancers grow at different rates and are at different risks of progression. These results may guide better personalized treatment.