Table 5. Risk of cancer of unknown primary of specific histology when a parent or a sibling was diagnosed with lung cancer or melanoma with a matching histology.

	Parental history				Sibling history
Lung squamous cell	73	1.29	1.01	1.63	4	1.90	0.49	4.92
Lung adenocarcinoma	41	1.12	0.81	1.53	62	1.67	1.28	2.15
Melanoma	21	2.15	1.33	3.29	19	2.14	1.29	3.35