Table 1.

Site-specific risk of developing SPM in patients with cholangiocarcinoma

Site of second malignancy	Observed	Expected	SIR	95% CI
All sites	96	75.66	1.27a	1.03–1.55
All solid tumors	78	67.27	1.16	0.92–1.45
Oral cavity and pharynx	2	1.8	1.11	0.13–4.02
Digestive system	26	15.12	1.72a	1.12–2.52
Respiratory system	15	11.98	1.25	0.7–2.07
Bones and joints	0	0.07	0	0–53.61
Soft tissue including heart	0	0.39	0	0–9.4
Skin excluding basal and squamous	1	3.21	0.31	0.01–1.74
Breast	9	9.36	0.96	0.44–1.83
Female genital system	2	3.70	0.54	0.07–1.95
Male genital system	11	13.23	0.83	0.41–1.49
Urinary system	8	6.52	1.23	0.53–2.42
Eye and orbit	0	0.11	0	0–32.46
Brain and other nervous system	0	0.77	0	0–4.78
Endocrine system	5	1.07	4.69a,b	1.52–10.94
Lymphoma	6	3.33	1.8	0.66–3.92
Leukemia	3	2.11	1.42	0.29–4.16
Mesothelioma	0	0.2	0	0–18.88
Kaposi sarcoma	0	0.06	0	0–61.22
Miscellaneous	5	1.5	3.33a	1.08–7.77

Note:

^aP<0.05; risk of SPM in transverse colon (SIR 5.42, 95% CI 1.12–15.84) and intrahepatic bile duct and other biliary (SIR 11.97, 95% CI 4.39–26.06) significantly increased;

^brisk of SPM in thyroid (SIR 5.05, 95% CI 1.64–11.79) significantly increased.

Abbreviations: SIR, standardized incidence ratio; SPM, second primary malignancy.