If smoking causes lung cancer, why has a decline in smoking not led to a decline in lung cancer? According to the CDC, smoking prevalence among US adults (18+) has decreased quite a bit over the years: 1974: 37.1% of the population 1980: 33.2 1990: 25.5 2000: 23.3 2010: 19.3 According to cancer.gov the rates of new cases of lung cancer in the US haven't consistently gone down over the years: 1975: 52.5/100,000 people 1980: 60.7 1990: 68.1 2000: 64.1 2010: 57.3 If smoking causes lung cancer - according to the CDC "cigarette smoking is linked to about 90% of lung cancers" - shouldn't such a clear decline in the number of smokers have also caused a clear decline in the incidence of lung cancer? How have experts/doctors/medical scientists/etc. addressed these statistics, if at all?

The cancer.gov site you referenced says that the median age of diagnosis is 70. That implies that you smoke and then, _later in life/time_ , you may be diagnosed with cancer.

Therefore, for example, Lung cancer incidence statistics from the UK says:

> **Trends in lung cancer** incidence rates reflect **past trends in cigarette smoking** prevalence. Smoking rates peaked earlier in males than in females, so lung cancer rates in men have been decreasing for some decades, but **this decrease is yet** to start in women.

Figure 1.2 in your cancer.gov report shows that cancer rates for all people _have_ been decreasing steadily, since 1992, and since 1986 for men.