Often lately, I have been hearing many people suffering from cancer especially in US. What might be the reason for this? Why are so many people in US affected by cancer?
It's hard to die from cancer when you already died from something else.
People are living longer. The older you are the more likely you are to have cancer. It is hypothesized that given enough time everyone develops some kind of cancer even if microscopic (more on that later)
Automobile fatalities (the thing most likely to kill young adults) are down dramatically. This is due to safer cars and a decrease of things like DUIs due to public awareness and a huge increase in prosecution. My grandpa told me in the 70s police would routinely pull him over, see he was drunk, and tell him just to go home. New safety features are required almost every year on automobiles. People take infant car seats very seriously nowadays. When I was a kid as soon as I could sit upright by myself I was out of the car seat.
2)There's not a lot we don't know about cancer still. We know that it is a combination of genes and environment that cause it and there are things you can do to lessen your likelihood of getting it such as not smoking... but overall we haven't done a whole lot to prevent most types of cancer and still have a lot to go in completely understanding it. Which specific genes and which specific environmental factors are still somewhat of a mystery, I mean we know some stuff but still not enough. Some types like cervical cancer are largely (but not completely) preventable with routine pap tests but that's the exception.
3) Increased screening leads to an increase in detection of benign and asymptomatic cancer. This turns people into cancer patients who wouldn't have otherwise been cancer patients without screening. This is kinda a new thing. We used to believe that cancer runs one course - that it started at stage 1 and grew continuously until it spread all over your body and killed you - so catching cancer while it is small and treatable will prevent it from spreading and becoming deadly. We are learning from experience that isn't always the case, some can develop so slowly that there's no way it will cause problems in your lifetime. Take prostate cancer for example - the PSA test is a blood test that was developed to detect asymptomatic prostate cancer. The PSA test is no longer recommended because it lead to an increase in cancer diagnoses but a very modest corresponding decrease in cancer related deaths. That tells us that some men who would be diagnosed with prostate cancer if they had the PSA test wouldn't ever be diagnosed without it. Routine mammograms have detected thousands more very early stage cancer (Ductal Carcinoma In Situ) than ever before. The numbers tell us some of these new diagnoses wouldn't have progressed (and maybe would have regressed). Everything requires treatment though because we don't know which small tumor will become deadly and which one won't. More info on this is here: http://www.newyorker.com/magazine/2015/05/11/overkill-atul-g...
>we’ve assumed, he says, that cancers are all like rabbits that you want to catch before they escape the barnyard pen. But some are more like birds—the most aggressive cancers have already taken flight before you can discover them, which is why some people still die from cancer, despite early detection. And lots are more like turtles. They aren’t going anywhere. Removing them won’t make any difference.
>Over the past two decades, we’ve tripled the number of thyroid cancers we detect and remove in the United States, but we haven’t reduced the death rate at all. In South Korea, widespread ultrasound screening has led to a fifteen-fold increase in detection of small thyroid cancers. Thyroid cancer is now the No. 1 cancer diagnosed and treated in that country. But, as Welch points out, the death rate hasn’t dropped one iota there, either. (Meanwhile, the number of people with permanent complications from thyroid surgery has skyrocketed.) It’s all over-diagnosis. We’re just catching turtles.
The other thing is you may just be hearing about it more or it might just be talked about more than it used to be.
I'd rather have the knowledge than not, but I know that doesn't always make sense from a large statistical POV.
Simply knowing you have a certain type of cancer though could also prevent misdiagnosis for other things with similar/related symptoms. Beyond that, if I knew I had a certain type of cancer, you can bet your ass I'd do whatever my doctor recommended to reduce my risk for the future. So it could be a great way to convince people to live a healthier lifestyle (albeit out of fear) which I'd be willing to bet would cause them to live longer potentially than if they had not made lifestyle changes.
>So it could be a great way to convince people to live a healthier lifestyle (albeit out of fear)
That fear can't be discounted. Anxiety leads people to have symptoms of anxiety - which are very significant from a medical point of view and a quality of life point of view.
Take a look here:
https://www.sciencebasedmedicine.org/a-skeptical-look-at-scr...
>Another doctor wrote about the opposite experience: his patient had insisted on testing. He was diagnosed with low-grade localized cancer, the kind that can be observed without treating. But he couldn’t face living with the knowledge that he was harboring an untreated cancer. He was afraid of surgery and opted for radiation treatment. He developed radiation proctitis and had rectal pain and bleeding for years. He became impotent and lost bladder control. He told his doctor he would rather be dead than live wearing adult diapers.
>Prostate cancer is very common but isn’t always harmful. It is found in 80% of autopsies where the men died of something else. Many more men die with prostate cancer than because of it.
And yeah, thyroid cancer and prostate cancers are way way over diagnosed and over treated to no positive effect.