The rationale for case‐control methodology in epidemiological studies of cancer risk (response to Speirs et al., 1990) [see comments]

Debrisoquine oxidation phenotype and susceptibility to lung cancer [letter; comment]

“…In the fourth study (Roots et al, 1988) (Speirs et al, 1990) apart, there are two other independent studies which disagree with the results of Ayesh et al (1984). Caporaso & Idle (1990) are critical of much of the methodology used in our study. They state that 'determination of the DBR (debrisoquine metabolic ratio) metabolic phenotype is crucially dependent on the phenotyping procedure employed'.…”

“…We are responding to the criticisms of our recent article (Speirs et al, 1990) on the question of a possible association between debrisoquine oxidation phenotype and susceptibility to lung cancer made by Dr Caporaso and Professor Idle (Caporaso & Idle, 1990 (Ayesh et al, 1984;Law et al, 1989) cannot be considered as independent, as drug analysis was conducted in the same laboratory. A third study (Caporaso et al, 1988) is reported only as an abstract, and has not been subjected to peer review.…”

“…However, they are content to combine the results of studies utilising different procedures themselves, to obtain a global estimate of the frequency of poor metabolisers in lung cancer patients (Caporaso & Idle, 1990), a procedure that has been adopted by others who have sought to establish a relationship between lung cancer and debrisoquine metabolic phenotype (Law, 1990).…”