Smoking, environmental tobacco smoke, and risk of renal cell cancer: a population-based case-control study.

BMC Cancer · 2008 · PMC2633310 · PMID 19108730

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marginally significantno p-value reported

Those who smoked 20 or more pack-years experienced a marginally significant 30% risk increase compared with never-smokers.

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an observed trendno p-value reported

Low response among controls is a significant limitation in the present study, but it should be noted that our response rate reflects an observed trend in epidemiologic studies over the past thirty years [ 12 , 33 , 34 ], with participation rates for population-based case-control studies declining nearly 2% per year [ 33 ].

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