Observed and expected cases of cancer after the onset of giant cell arteritis (GCA) in a cohort of 830 patients with GCA in southern Sweden diagnosed between 1997 and 2010.
| Category | Observed | Expected | SIR | 95% CI |
|---|---|---|---|---|
| Upper GI tract | 1 | 6.14 | 0.16 | 0.00–0.91 |
| Lower GI tract | 18 | 18.14 | 0.99 | 0.59–1.57 |
| Liver, gallbladder, pancreas, peritoneum | 0 | 4.01 | NA | NA |
| Respiratory | 8 | 10.43 | 0.76 | 0.33–1.51 |
| Breast | 6 | 18.13 | 0.33 | 0.12–0.72 |
| Female reproductive system | 8 | 7.31 | 1.09 | 0.47–2.16 |
| Prostate | 15 | 11.52 | 1.30 | 0.73–2.15 |
| Male reproductive system | 0 | 0.17 | NA | NA |
| Kidneys | 2 | 2.07 | 0.96 | 0.12–3.49 |
| Urinary tract without kidneys | 6 | 7.08 | 0.84 | 0.31–1.85 |
| Skin | 34 | 24.93 | 1.36 | 0.94–1.91 |
| Eyes | 0 | 0.18 | NA | NA |
| CNS | 1 | 1.3 | 0.76 | 0.02–4.29 |
| Endocrine system | 0 | 1.7 | NA | NA |
| Sarcomas | 0 | 0.75 | NA | NA |
| Unspecified | 4 | 4.95 | 0.80 | 0.22–2.07 |
| Lymphoma | 3 | 4.32 | 0.69 | 0.14–4.25 |
| Multiple myeloma | 2 | 1.7 | 1.17 | 0.14–2.03 |
| Leukemia | 9 | 3.89 | 2.31 | 1.06–4.39 |
| Myelofibrosis | 1 | 0.47 | 2.12 | 0.05–11.85 |
| Total | 118 | 120.8 | 0.98 | 0.81–1.17 |
SIR: standardized incidence ratio; GI: gastrointestinal; CNS: central nervous system; NA: not applicable.