Background: Pericarditis may be a serious complication of malignancy. Its significance as a first symptom of occult cancer and as a prognostic factor for cancer survival is unknown.

Methods: Using Danish medical databases, we conducted a nationwide cohort study of all patients with a first-time diagnosis of pericarditis during 1994 to 2013. We excluded patients with previous cancer and followed up the remaining patients for subsequent cancer diagnosis until November 30, 2013. We calculated risks and standardized incidence ratios of cancer for patients with pericarditis compared with the general population. We assessed whether pericarditis predicts cancer survival by the Kaplan-Meier method and Cox regression using a matched comparison cohort of cancer patients without pericarditis.

Results: Among 13 759 patients with acute pericarditis, 1550 subsequently were diagnosed with cancer during follow-up. The overall cancer standardized incidence ratio was 1.5 (95% confidence interval [CI], 1.4–1.5), driven predominantly by increased rates of lung, kidney, and bladder cancer, lymphoma, leukemia, and unspecified metastatic cancer. The <3-month cancer risk among patients with pericarditis was 2.7%, and the standardized incidence ratio was 12.4 (95% CI, 11.2–13.7). The 3- to <12-month standardized incidence ratio of cancer was 1.5 (95% CI, 1.2–1.7), subsequently decreasing to 1.1 (95% CI, 1.0–1.2). Three-month survival after the cancer diagnosis was 80% and 86% among those with and without pericarditis, respectively, and the hazard ratio was 1.5 (95% CI, 1.3–1.8). One-year survival was 65% and 70%, respectively, corresponding to a 3- to <12-month hazard ratio of 1.3 (95% CI, 1.1–1.5).

Conclusions: Pericarditis may be a marker of occult cancer and augurs increased mortality after a cancer diagnosis.

背景：心包炎可能是恶性肿瘤的严重并发症。其作为隐匿性癌症的第一症状和作为癌症存活的预后因素的意义尚不清楚。

方法：使用丹麦的医学数据库，我们对1994年至2013年首次诊断为心包炎的所有患者进行了全国性队列研究。我们排除了先前有癌症的患者，并对其余患者进行随访，直至2013年11月30日进行癌症诊断我们计算了心包炎患者与一般人群相比的癌症风险和标准化的癌症发生率。我们使用无心包炎的癌症患者的匹配对照队列，通过Kaplan-Meier方法和Cox回归评估了心包炎是否能预测癌症的生存。

结果：在13 759例急性心包炎患者中，随后有1550例在随访期间被诊断出患有癌症。总体癌症标准化发生率为1.5（95％置信区间[CI]为1.4-1.5），主要是由肺癌，肾癌和膀胱癌，淋巴瘤，白血病和未指明的转移性癌症的发病率增加所致。心包炎患者中＜3个月的癌症风险为2.7％，标准发生率为12.4（95％CI，11.2–13.7）。3个月至<12个月的癌症标准发病率是1.5（95％CI，1.2-1.7），随后下降到1.1（95％CI，1.0-1.2）。有心包炎和无心包炎的癌症诊断后三个月生存率分别为80％和86％，危险比为1.5（95％CI，1.3-1.8）。一年生存率分别为65％和70％，

结论：心包炎可能是隐匿性癌症的标志物，预示着癌症诊断后死亡率的增加。