Table 2. Secondary cancers occurring at least 6 months after an MCC diagnosis.

Cancer site	Observed	Expected	SIR	(95% CI)
All types	79	57.4	1.4	(1.1–1.72)
Non-melanoma of the skin	34	4.07	8.4	(5.97–11.68)
Female breast	6	4.91	1.2	(0.55–2.72)
Colorectal	6	7.88	0.8	(0.34–1.7)
Melanoma of skin	6	1.4	4.3	(1.93–9.56)
Lung	5	4.13	1.2	(0.5–2.91)
Prostate	3	7.72	0.4	(0.31–1.2)
Bladder etc.	3	3.19	0.9	(0.3–2.92)
Leukaemia	3	1.15	2.6	(0.84-8.09)
Larynx	2	0.21	9.5	(2.38–38.04)
Brain central nervous system	1	0.84	1.2	(0.17–8.44)
Kidney	1	0.91	1.1	(0.15–7.79)
Liver	1	0.52	1.9	(0.27–13.74)
Non-Hodgkin lymphoma	1	1.43	0.7	(0.1–4.97)
Other female genital organs	1	0.34	2.9	(0.41–20.9)
Ovary etc.	1	1.46	0.7	(0.1–4.87)

Abbreviations: CI=confidence interval; MCC=merkel cell carcinoma; SIR=standardized incidence ratio.