[Ablative therapy of small renal masses]

Pulsed Electric Fields in Oncology: A Snapshot of Current Clinical Practices and Research Directions from the 4th World Congress of Electroporation

The 4th World Congress of Electroporation (Copenhagen, 9-13 October 2022) provided a unique opportunity to convene leading experts in pulsed electric fields (PEF). PEF-based therapies harness electric fields to produce therapeutically useful effects on cancers and represent a valuable option for a variety of patients. As such, irreversible electroporation (IRE), gene electrotransfer (GET), electrochemotherapy (ECT), calcium electroporation (Ca-EP), and tumour-treating fields (TTF) are on the rise. Still, their full therapeutic potential remains underappreciated, and the field faces fragmentation, as shown by parallel maturation and differences in the stages of development and regulatory approval worldwide. This narrative review provides a glimpse of PEF-based techniques, including key mechanisms, clinical indications, and advances in therapy; finally, it offers insights into current research directions. By highlighting a common ground, the authors aim to break silos, strengthen cross-functional collaboration, and pave the way to novel possibilities for intervention. Intriguingly, beyond their peculiar mechanism of action, PEF-based therapies share technical interconnections and multifaceted biological effects (e.g., vascular, immunological) worth exploiting in combinatorial strategies.

Frailty predicts outcome of partial nephrectomy and guides treatment decision towards active surveillance and tumor ablation

PURPOSE

To examine frailty and comorbidity as predictors of outcome of nephron sparing surgery (NSS) and as decision tools for identifying candidates for active surveillance (AS) or tumor ablation (TA).

METHODS

Frailty and comorbidity were assessed using the modified frailty index of the Canadian Study of Health and Aging (11-CSHA) and the age-adjusted Charlson-Comorbidity Index (aaCCI) as well as albumin and the radiological skeletal-muscle-index (SMI) in a cohort of n = 447 patients with localized renal masses. Renal tumor anatomy was classified according to the RENAL nephrometry system. Regression analyses were performed to assess predictors of surgical outcome of patients undergoing NSS as well as to identify possible influencing factors of patients undergoing alternative therapies (AS/TA).

RESULTS

Overall 409 patient underwent NSS while 38 received AS or TA. Patients undergoing TA/AS were more likely to be frail or comorbid compared to patients undergoing NSS (aaCCI: p < 0.001, 11-CSHA: p < 0.001). Gender and tumor complexity did not vary between patients of different treatment approach. 11-CSHA and aaCCI were identified as independent predictors of major postoperative complications (11-CSHA ≥ 0.27: OR = 3.6, p = 0.001) and hospital re-admission (aaCCI ≥ 6: OR = 4.93, p = 0.003) in the NSS cohort. No impact was found for albumin levels and SMI. An aaCCI > 6 and/or 11-CSHA ≥ 0.27 (OR = 9.19, p < 0.001), a solitary kidney (OR = 5.43, p = 0.005) and hypoalbuminemia (OR = 4.6, p = 0.009), but not tumor complexity, were decisive factors to undergo AS or TA rather than NSS.

CONCLUSION

In patients with localized renal masses, frailty and comorbidity indices can be useful to predict surgical outcome and support decision-making towards AS or TA.

Small renal carcinoma: the "when" and "how" of operation, active surveillance, and ablation

Small, locally restricted renal cell carcinoma less than 4 cm in size should ideally be removed operatively by nephron-sparing tumour enucleation (partial kidney resection). In an increasingly elderly population, there is a growing trend toward parallel incidence of renal cell carcinoma and chronic renal insufficiency, with the latter's associated general comorbidities. Thus, for some patients, the risks of the anaesthesia and operation increase, while the advantage in terms of survival decreases. Transcutaneous radio-frequency ablation under local anaesthesia, transcutaneous afterloading high-dose-rate brachytherapy under local anaesthesia, and percutaneous stereotactic ablative radiotherapy may offer a less invasive alternative therapy. Active surveillance is to be regarded as no more than a controlled bridging up to definitive treatment (operation or ablation), while watchful waiting, on account of the lack of prognostic relevance and the symptomatology of renal cell carcinoma, with its comorbidity-related, clearly reduced life expectancy, does not involve any further diagnostic or therapeutic measures.

Progression to chronic kidney disease in patients undergoing nephrectomy for small renal masses: a price to pay for a therapeutic success?

Nephrectomy, which constitutes a gold-standard procedure for the treatment of renal-cell carcinoma (RCC), has been widely discussed in the past decade as a significant risk factor of the development of chronic kidney disease (CKD). RCC is the third most common genitourinary cancer in the United States, with an estimated more than 65,000 new cases and 14,970 deaths. The aim of this review was to precisely and comprehensively summarize the status of current knowledge in CKD risk factors after nephrectomy, the advantages of minimally invasive vs. radical nephrectomy, post-nephrectomy biomarkers of CKD, ways of post-operative CKD prevention and, therefore, better understand why various aspects of CKD after nephrectomy. The majority of current studies indicated a better long-term kidney function preservation in patients undergoing partial nephrectomy in comparison to those after radical nephrectomy. Furthermore, a nephron-sparing surgery should be a preferred first-line procedure among young patients with small renal masses. As partial nephrectomy is followed by a greater risk of adverse outcomes relative to radical nephrectomy, a potential survival benefit should always be considered especially in the elderly or patients with comorbidities.

[Small renal cell carcinoma-active surveillance and ablation]

The incidence of renal cell carcinoma has been rising for years. At the same time there is an increasing prevalence of chronic renal failure with subsequent higher morbidity and shorter life expectancy in those affected. In the last decades the gold standard has thus shifted from radical to partial nephrectomy or tumor enucleation. A treatment alternative can be advantageous for selected patients with high morbidity and an increased risk of complications in anesthesia or surgery. Active surveillance represents a controlled delay in the initiation of treatment with a curative intention. Percutaneous radiofrequency ablation and laparoscopic cryoablation are currently the most commonly used treatment alternatives. Newer ablation procedures, such as high-intensity focused ultrasound, irreversible electroporation, microwave ablation, stereotactic ablative radiotherapy and high-dose brachytherapy have a high potential in some cases but are still considered experimental for the treatment.