Background/Purpose: Retroperitoneal fibrosis (RPF) is a periaortic sclerotic disease that encases adjacent structures, particularly the ureters. Because it is unclear whether RPF is associated with malignancy, we examined standardized incidence ratios (SIRs) of cancers in patients with RPF compared with age- and sex-matched general population. Subsequently, pathological differences between malignancy with RPF and malignancy without RPF were investigated.

Methods: Medical records of 111 patients diagnosed as having RPF by computed tomography, positron emission tomography (PET), and/or histological evaluation were reviewed. Forty one cases of cancers, which were confirmed by biopsies, were identified in 35 patients with RPF. Cancer incidence rates were calculated and compared with that observed in the Korean general population, computing the standardized incidence ratios (SIRs), which were then stratified according to RPF-cancer intervals. Cancer specimens with RPF (n=3) and cancer specimens without RPF (n=15), which were controls for age, sex, and cancer stage, were examined for the expression of interleukin (IL)-4, IL-10, PD-1, PD-L1, and IgG4/IgG by immunohistochemistry (IHC).

Results: The mean ± SD age at RPF diagnosis was 59.2 ± 15.0 years, and 69.4% of the patients were male. Ninety two cases (82.9%) showed peri-aortitis, and 65 cases (58.6%) presented with hydronephrosis. The cancer SIR (95% confidence intervals) in patients with RPF relative to age- and sex-matched individuals in the general population was 3.18 (2.23-4.41) [2.65 (1.70 – 3.94) in men; 5.34 (2.76 – 9.32) in women]. The most frequent cancer was unspecified urinary organ cancers with SIR of 733 (238 – 1711). SIRs of multiple myeloma [27.6 (3.34 – 99.6)], renal cell cancers [9.53, (1.15-34.4)] and adenocarcinoma of unknown primary cancers [16.9, (2.05 – 61.1)] were also significantly higher than in the general population. When stratified by RPF-cancer intervals, SIR was 10.4 (6.59 – 15.60) within 1 year of RPF diagnosis, while no significant increase in SIR was found out of 1 year around RPF. IHC analysis showed that the expressions of IL-4 and IL-10 in cancer tissues with RPF were higher than those in cancer tissues without RPF. However, there are no differences in the expression of PD-1, PD-L1 and IgG4/IgG between cancer tissues with RPF and those without RPF.

Conclusion: RPF was strongly associated with cancers within 1 year of RPF diagnosis. Immune environment of cancer tissues with RPF is different from that without RPF. That may contributed to the occurrence of RPF.

« Back to 2018 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/association-of-retroperitoneal-fibrosis-with-malignancy-and-the-pathologic-features-of-malignancy-with-retroperitoneal-fibrosis/