Retroperitoneal fibrosis (RPF) is characterized by a highly fibrotic retroperitoneal mass and encompasses the idiopathic form and secondary to malignancies. Because we have limited knowledge whether RPF is associated with malignancy, we aimed to investigate the relationship between RPF and malignancy and to compare the characteristics and prognosis of cancers among patients with RPF. Medical records of 111 patients diagnosed as having RPF were reviewed and 38 cases of cancer, confirmed by biopsy, were identified. Standardized incidence ratios (SIRs) were calculated for cancers and stratified according to cancer type and RPF-cancer diagnosis interval. Cancer characteristics and outcomes were compared between RPF-cancer diagnosis intervals. The average age at RPF diagnosis was 59.2 ± 15.0 years, and 69.4% of the patients were male. The cancer SIRs in patients with RPF relative to age- and sex-matched individuals in the general population was 2.2 (1.6–3.1). SIRs of renal pelvis cancer and multiple myeloma were significantly higher than in the general population. When stratified by RPF-cancer intervals, the SIR for cancer was 9.9 within 1 year of RPF diagnosis, while no significant increase in the SIR was found after 1 year from RPF diagnosis. Cancer stage was more advanced at the time of diagnosis in patients within a 1-year interval for RPF than those with cancer within a >5-year interval, with a correspondingly increased mortality in the former patients. RPF was significantly associated with malignancy, particularly those diagnosed within 1 year of RPF diagnosis. Cancer stages at diagnosis were more advanced and the mortality rate was higher in patients within a 1-year interval between RPF and cancer diagnosis than in those with a >5-year interval between diagnoses.

中文翻译：

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腹膜后纤维化与恶性肿瘤的关系及其结果

腹膜后纤维化 (RPF) 的特征是高度纤维化的腹膜后肿块，包括特发性和继发于恶性肿瘤。由于我们对 RPF 是否与恶性肿瘤相关的了解有限，我们旨在研究 RPF 与恶性肿瘤之间的关系，并比较 RPF 患者的癌症特征和预后。审查了 111 名诊断为 RPF 的患者的医疗记录，并确定了 38 例经活检证实的癌症。计算癌症的标准化发病率 (SIR) 并根据癌症类型和 RPF-癌症诊断区间进行分层。在 RPF 癌症诊断间隔之间比较癌症特征和结果。RPF 诊断的平均年龄为 59.2 ± 15.0 岁，69.4% 的患者为男性。相对于一般人群中年龄和性别匹配的个体，RPF 患者的癌症 SIR 为 2.2 (1.6-3.1)。肾盂癌和多发性骨髓瘤的 SIR 显着高于一般人群。当按 RPF-癌症间隔分层时，RPF 诊断后 1 年内癌症的 SIR 为 9.9，而 RPF 诊断后 1 年未发现 SIR 显着增加。RPF 1 年间隔内的患者在诊断时的癌症分期比> 5 年间隔内的癌症患者更晚期，前者患者的死亡率相应增加。RPF 与恶性肿瘤显着相关，尤其是那些在 RPF 诊断后 1 年内诊断出的恶性肿瘤。