#2849 A change in the paradigm of onconephrology
Authors: Martínez Jordi Calabia , Saltos Jehimy Jean Alvarez , Ribas Ana Merino , Carcasi Mara Lisbet Cabana , Alemany Nadia Martín , Barrera Joaquim Bosch , Cantalejo Leyre Garcia , Soler Laura Boix , Suárez Gabriel Manuel González , Paez Cristina Noboa , Devia Claudia Marcela Castillo , Baptista Yanel Adriana Acosta 
Published: May 2024

Abstract

Background and Aims
Recently, with the emergence of checkpoint inhibitors and other new oncological therapies, the cancer paradigm has changed. These new treatment possibilities have led to an improvement in the life expectancy of patients with cancer. However, these new oncological treatments are often linked to adverse renal events that require a specifical nephrological evaluation at the onconephrology units. These renal adverse events may increase the morbidity and mortality of cancer patients. Therefore, the aim of this study was to analyze the changes in renal involvement of patients with solid organ malignancy who underwent kidney biopsy after the onset of new oncological therapies.

Method
A retrospective observational study was performed analyzing kidney biopsies conducted in a 9.2-year period. This study included patients with history of solid organ malignancy before and one year after kidney biopsy. All the results are represented as mean ± standard deviation for variables with a normal distribution, or in percentage (%). Normality was assessed by the Shapiro-Wilk test. Group comparisons were conducted using Student´s t test for normally distributed quantitative variables and chi-square for qualitative variables. The statistical software utilized was SPSS version 27.

Results
Six patients who underwent a kidney biopsy before 2019 (Group A) were compared to 22 patients who underwent a kidney biopsy in 2019 and after (Group B). In Group A, the mean age was 68.5 ± 7.1 years old, while in Group B, it was 70.7 ± 7.1. In Group A, there was a predominance of females (66.7%), whereas in Group B, there was a higher proportion of males (81.8%). In Group A, higher intake of statins and acetylsalicylic acid were observed compared to Group B (83.3% vs. 31.8%, p = 0.024; 33.3% vs. 4.5%, p = 0.043). At the time of kidney biopsy, concerning the history of solid organ malignancy, 66.7% patients in Group A were disease-free, while in Group B they were predominantly stable (50%) (p &lt; 0.001). In Group A, all nephropathies were caused by factors unrelated to oncological disease, while in Group B 63.6% nephropathies were secondary to oncospecific treatment (p = 0.003). In Group A, longer time from oncological diagnosis to death was observed compared to Group B (3033 ± 1889.09 days vs. 692 ± 719.47 days, p = 0.012). Regarding renal function at the time of kidney biopsy, we observed predominantly normal or stable renal function in Group A (66.7%), while Group B showed a higher frequency of renal dysfunction (77.3%) (p = 0.041); resulting in creatinine levels of 1.82 ± 0.68 mg/dl in Group A and 3.95 ± 2.48 mg/dl in Group B (p = 0.049). Finally, kidney biopsies in Group A showed acute tubular necrosis and acute or chronic tubulointerstitial nephritis in 16.7%, while in Group B these diagnoses were found in 81.8% of kidney biopsies (p = 0.002).

Conclusion
After the onset of new oncospecific therapies, the paradigm of kidney disease in cancer patients in terms of diagnosis and treatment has changed. Kidney biopsy may be a useful diagnostic and prognostic tool. But also, a specialized onconephrologist may have a key role to discern the different etiologies of kidney damage and provide the best management to these patients. This new trend may lead to a growth and an empowerment of onconephrology subspecialty.