Behind the scenes: a year in a onco-nephrology outpatient clinic in Italy

Background and Aims: The progressive increasing awareness of the need for a multidisciplinary management of cancer pts, the rapid development of new anti-cancer therapies, the prolongation of oncological pts’ survival and the increased incidence of chronic kidney disease (CKD) over the years, have created a breeding ground for the affirmation of onco-nephrology. This subspeciality of Nephrology aims to fully deal with the complex and bidirectional relationship between cancer and the kidneys: indeed, while on one hand the tumor presence or its treatment can cause renal damage, on the other hand a kidney disease can alter the bioavailability and therefore the effectiveness of the treatment itself. Well-defined multidisciplinary management of cancer pts with kidney disease can thus ensure that the highest quality of care could be administered by a dedicated team with experience in these complex issues. The objective of our study was to describe pts who were referred to our onco-nephrology clinic during 2021, in order to offer an analysis of their main characteristics, with the overall aim of providing experience-based considerations that will initiate further discussion on this growing subspecialty area. Method: We performed a retrospective data collection of naive pts attending our onco-nephrology outpatient clinic over a 1-year period. We collected data regarding epidemiological characteristics, renal function, primary tumor, cancer therapy, and reason why they were referred for a nephrological evaluation. Pts’ main characteristics are summarized in TAB 1. Results: A cohort of 323 consecutive visits was analyzed; 175 new cases; 110 males and 65 females, with an average age of 70 yrs. eGFR by CKD-EPI was 43 ml/min/1,73 mq (5% CKD stage I, 12% stage II, 19% stage IIIA, 39% stage IIIB, 21% stage IV, and 4% stage V – FIG 1A); pts’ primary tumor are summarized in FIG 1B. 37 first- and 81 subsequent consultations were performed for clinical evaluation, 30 vs 7 for worsening CKD, 23 vs 10 for a pre-contrast enhanced Computed Tomography, 19 vs 16 for renal toxicity from cancer treatment, 15 vs 5 for electrolyte disturbances, 13 vs 9 in light of the possible initiation of an oncological therapy, 12 vs 9 for Acute Kidney Injury, as summarized in FIG 1 C. Overall 93 pts (53%) were not on active oncological therapy, while, among the others, 18 received cytotoxic chemotherapy, 25 molecularly targeted agents, 22 immunotherapy, 8 hormone therapy, and 9 combination of agents of multiple classes (FIG 1 D). Conclusion: The above retrospective results shed light on the main causes of access to an onco-nephrology outpatient clinic, once again confirming both the relevance of onconephrological issues, as well as the increasing necessity to address them in a dedicated setting. Since onco-nephrology is presently more experience-based than evidence-based, and since only with a thorough knowledge of the issues of onco-nephrology, together with a tight inter-specialty collaboration, we can provide these pts better treatment and management, the representative set of pts we presented can be useful to understand their commonest needs and to increase the awareness on these issues, still too often underrecognized and undermanaged, due to a certain nihilistic attitude towards cancer pts with kidney issues. Finally, preliminary efficacy results (not reported here) suggest a clinically relevant benefit in terms of nephrological outcome.