How has the incidence of cancer risen over the past half century? Not the death rate from cancer, which has gone down because of better treatments, but the actual number of new cancers. Here it is:
Between 1975 and 2020, cancer has risen by about 20% in women but only 5% in men. However, men showed a huge rise from 1975 through 1990 and then a big decline. What's up with that?
It's all about prostate cancer and it's all about detection. When PSA tests were approved and became widely used, prostate cancer diagnosis surged—but then dropped. Why? Too many harmless, asymptomatic cancers were being detected, so doctors became more rigorous about how high a PSA score needed to be before they suggested treatment.
Then, in 2007, new recommendations were published that advised against screening in men over 75 in order to reduce harms from overdiagnosis and overtreatment. So the detection rate dropped again.
This is apropos of nothing. It's just an example of how raw data can be misleading if you don't know the history behind the data collection. Cancer in men didn't really rise starting in the early '80s, we just got better at detecting one particular variety. Then we decided we were overdiagnosing and pulled back. Underneath it all, the actual incidence of cancer was about the same all along. You could draw a straight line from 1985 to 2015 and the chart would probably be more accurate.
This is the danger of meta studies, too. Different screening procedures can mix bad with good, or just vastly different targets with each other.
That can make you think a treatment was bad, but if the diagnostic criteria were different between the positive and negative studies... it just proves the diagnostic criteria was wrong in some studies.
Any researcher worth a pinch of "salt" would sniff that aggregate trend out immediately. Big jumps across years are usually methods related. Of course, the news media would blast it for days and probably have.
Interesting re melanoma increase. More people in the south? More old people per capita?
The rise of tanning. It takes decades of sun damage to start seeing cancer. Our social expectations around being tanned changed, and then they invented the tanning bed, making a permanent tan widely available. Social views changed again post -2000, so I expect rates to level off in a couple decades.
Good hypothesis.
Seems nominally testable. Kevin, can you provide the appropriate graphs :).
Except that the proportion of the population that spends long hours working outdoors has fallen, which I would expect would offset the rise of tanning for cosmetic reasons.
"However, men showed a huge rise from 1975 through 1990 and then a big decline. What's up with that?"
Lead! 😉
So with regard to prostate cancer we were looking too hard.
Interesting insights. I disagree/do not believe the data supports
"Crime didn't skyrocket in the '70s and '80s because of drugs or poverty or family breakdown. It skyrocketed because of an increase in lead poisoning that had begun decades earlier."
IF this statement was true then:
- this pattern would be seen globally. The international data does not support this.
- if this concept was true, then places such as Eastern Europe, which had huge lead exposure, should see a more robust effect. Once again, the data does not support this.
- if you look a industrial cities, for example such as Aichi (large industrial Japanese city) and compare crime to Tokyo, Osaka etc the pattern is not supported.
- if this concept was true, then within the US there would be significant variation based on lead levels. Yes, for example, Miami despite not having a lot of manufacturing/relatively low lead exposure, crime spiked more than industrial parts of Los Angeles (yes, LA USED to have real manufacturing).
https://www.sciencedirect.com/science/article/pii/S0166046222000667#:~:text=Our%20findings%20suggest%20that%2C%20while,other%20explanations%20require%20further%20investigation.
There is probably a real drop in the amount of cancer caused by cigarette smoking.