The Importance of Cancer Registry Linkage for Studying Rare Cancers in Prospective Cohorts

Table 3

Self-reported cancer site and year of diagnosis accuracy among ATP participants who correctly report overall, common, and rare cancer status.

	Including those with cancer diagnoses before baseline^a				Excluding those with cancer diagnoses before baseline^a
	% TP’s that also have correct				% TP’s that also have correct
	# TP’s	Site only	Site and	Site and year	# TP’s	Site only	Site and	Site and year
Common	649	97.5	95.1	73.3	645	97.5	95.0	73.5
Common (excl. skin)	600	97.8	95.5	73.7	596	97.8	95.5	73.8
Rare	54	77.8	74.1	61.1	53	77.4	73.6	60.4
Rare (excl. cervix)	52	76.9	73.1	61.5	51	76.5	72.5	60.8
Overall^b	746	90.5	88.1	68.2	741	90.4	88.0	68.3

ATP: Alberta’s Tomorrow Project; TP: true positive; excl.: excluding. ^a A participant had a diagnosis before baseline if their age of first cancer diagnosis in the ACR was before their age at baseline. ^b Overall TP does not equal common TP plus rare TP. An overall TP reported cancer and had cancer in the ACR, regardless of type. A participant with a common cancer in the ACR had to report a common cancer in order to be a common TP. Similar criterion defines a rare cancer TP.