2557 Clinical and histological findings in cancer patients—a single center study

Abstract Background and Aims During the last years, there has been an outstanding improvement in cancer treatment. As patients’ survival has been elongated, the prevalence of kidney injury is increasing. However, clinicopathological data are limited in these patients. We aimed to assess the spectrum of kidney biopsy findings in cancer patients and their relation to treatment. Method Single center retrospective study of all patients with solid and hematologic malignancies, who underwent kidney biopsy due to renal impairment, from September 2015 to July 2023. Clinical, laboratory, histopathological and therapeutic data were evaluated Results Fifty-four patients were biopsied, 35 men and 21 women, of median age 66 (42-84) years and follow up 15 (3-84) months. Median serum creatinine was 3 (0.5-22) mg/dl and proteinuria 3 (0.1-23) gr per day at the time of biopsy. Among the solid malignancies (38/54), lung cancer was the commonest (11), followed by gastrointestinal (5), breast (4), sarcoma (5) and melanoma (3); the rest 10 included other solid malignant tumors. Hematologic malignancies (16/54) were mainly multiple myeloma (6) and lymphomas (5), followed by lymphoblastic leukemia (3) and AL amyloidosis (2). The most frequent indication of biopsy was acute kidney injury (AKI) (29/54), followed by both AKI and proteinuria (15/54) and proteinuria with preserved kidney function (9/54); out of 24 patients with proteinuria, 12 exhibited nephrotic range proteinuria (median 10, 3.5-23 gr/day). At the time of biopsy, more than half of patients (30/54) were on cancer treatment; 5 on immunotherapy, 11 on immunotherapy combined to chemotherapy, 10 on chemotherapy solely and four of them received other kind of treatment. Glomerulonephritis (GN) was shown on 24/54 patients. Among GN, focal segmental glomerulosclerosis (FSGS) was the most common lesion (7), followed by light chain deposit disease (LCDD, 3) and membranous nephropathy (MN, 2); among the last, a rare case of MN with a full-house immunoflorescence pattern was reported. Notably, four patients showed amyloidosis (three AL-amyloidosis linked to multiple myeloma and one AA-amyloidosis possibly related to immunotherapy). A rare case of bevacizumab-induced hyaline occlusive glomerular microangiopathy is also reported. The rest 7/24 cases included glomerulosclerosis (1), minimal change disease (MCD, 1), IgA nephropathy (1), diabetic nephropathy (2) and membranoproliferative glomerulonephritis (2). Tubulointerstitial les