# How many people have cancer? **URL:** \ **Category:** Factual Questions\ **Created:** [October 29, 2023, 1:36pm UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264 "2023-10-29T13:36:34Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [October 29, 2023, 1:36pm UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/1 "2023-10-29T13:36:34Z")
I need a good estimate, doesn’t have to be exact. I can find how many people will get cancer in there lifetime and how many people will get cancer this year. But what I need is how many people right now in the world have the big C. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [October 29, 2023, 2:22pm UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/2 "2023-10-29T14:22:57Z")
My back-of-the-envelope estimate: The number of cancer “survivors” in the U.S. is around 20 million (easy to find). So far as I can tell this includes everyone who has ever had a diagnosis of invasive cancer, whether in remission or not. That’s 6% of the U.S. population diagnosed. The true figure including undiagnosed cases will be somewhat higher, but the U.S. probably gets most of them, at least once they become symptomatic. Maybe total incidence 7-8%? In order to extrapolate US numbers to the world, the most significant adjustment will be for the age structure of the population, since the [median age of diagnosis is around 66](https://www.cancercenter.com/community/blog/2023/06/cancer-risk-by-age). This says [17% of the US population is over 65, but only 10% of the world population](https://www.statista.com/statistics/265759/world-population-by-age-and-region/). There would also be a significant downward adjustment for lower survival rates without advanced care. I think if you adjust the U.S. 7-8% estimate down to maybe 3-4% worldwide that will be a reasonable ballpark. That’s 250-300 million people with invasive cancer. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [October 29, 2023, 5:06pm UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/3 "2023-10-29T17:06:40Z")
Depends what you mean… I had cancer a while ago - but the most benign form, at most a 2% chance of bad outcome. They cut it out within 6 months and I’ve been fine for almost a decade. Not really “The Big C”. Worst manifestation was a big wart that would bleed a lot. OTOH, the theory is that many elderly men have slow prostate cancer that can take a decade or two to become a problem. As the doctor tells Sam Waterston in _Grace and Frankie_ “The good news is something else will probably kill you first.” So devil in details as usual. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [October 29, 2023, 7:49pm UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/4 "2023-10-29T19:49:36Z")
Yeah, I think you need to define more clearly what you mean by “have cancer”. I had a spot of basal cell carcinoma, a mild form of skin cancer. The doctor cut it out. Do I have cancer by your definition? Did I have cancer before the carcinoma was removed? ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [October 29, 2023, 8:16pm UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/5 "2023-10-29T20:16:31Z")
If you have cancer then yes you have cancer. If they cut it out, you no longer have cancer ---
**Author:** ![XOldiesJock](https://avatars.discourse-cdn.com/v4/letter/x/ec9cab/32.png) [@XOldiesJock](https://boards.straightdope.com/u/XOldiesJock)\ **Post date:** [October 30, 2023, 12:35am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/6 "2023-10-30T00:35:14Z")
> [@md-2000](#): > > _OTOH, the theory is that many elderly men have slow prostate cancer that can take a decade or two to become a problem. As the doctor tells Sam Waterston in Grace and Frankie “The good news is something else will probably kill you first.”_ I had surgery for prostate cancer five years ago. When recently my PSA level went up, I was understandably worried. I questioned my doctor, who reassured me by saying “Someday, you’ll die of something. It will not be prostate cancer.” I’m hoping he’s right. ---
**Author:** ![Reeses\_Monkey](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reeses_monkey/32/2885_2.png) [@Reeses\_Monkey](https://boards.straightdope.com/u/Reeses_Monkey)\ **Post date:** [October 30, 2023, 12:43am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/7 "2023-10-30T00:43:14Z")
I had thyroid cancer (note my avatar) in 2015. One total thyroidectomy later and I no longer have cancer. The ten-year survival rate is around 97% so I’m not overly worried about my prognosis. To be honest, I’m more worried about the tick bite I got on Wednesday. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [October 30, 2023, 12:51am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/8 "2023-10-30T00:51:21Z")
> [@Saint\_Cad](#): > > If you have cancer then yes you have cancer. If they cut it out, you no longer have cancer A lot of cancer patients (but perhaps not the leukemia patients) will be delighted to know that cancer never recurs after a tumor is removed. If you think it’s this simplistically clear cut then an order of magnitude estimate of between 100 million and 500 million should be good enough for your purposes. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 30, 2023, 2:18am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/9 "2023-10-30T02:18:31Z")
@Riemann nailed it. The OP is utterly confused about the nature of cancer. Cancer is not a disease. Cancer is a descriptive umbrella term for hundreds of diseases. You may was well ask “what percentage of the populace is infected right now?” ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [October 30, 2023, 2:22am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/10 "2023-10-30T02:22:43Z")
Another question is whether the OP means diagnosed cancer, or simply currently has. Cancer isn’t a simple answer. Your immune system is constantly killing off mutations and cancerous cells. It is the ones that evade, and continue to evade, the immune system that cause problems. (At least to a good approximation.). Growth is at least initially exponential. Some may be cheerfully growing away for a long time before they become symptomatic and diagnosed. At one extreme, everyone currently carries some cancerous cells. In the middle, a lot of people are currently asymptomatic but carry a cancer that in some years may become apparent. Some cancers go into spontaneous remission. Some may come and go without symptoms. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [October 30, 2023, 2:25am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/11 "2023-10-30T02:25:22Z")
Then let’s say cancer at a level that requires treatment, whether diagnosed or undiagnosed. ---
**Author:** ![glowacks](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/glowacks/32/5548_2.png) [@glowacks](https://boards.straightdope.com/u/glowacks)\ **Post date:** [October 30, 2023, 2:31am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/12 "2023-10-30T02:31:56Z")
> [@Saint\_Cad](#): > > Then let’s say cancer at a level that requires treatment OK, it’s good that you said that, because for that I was going to point out that an unknown percentage of people probably have a very small undetectable tumor somewhere that might qualify as cancer, but it doesn’t grow particularly fast and so it never ends up being detected. I recall reading about issues that have arisen when cancer detection methods improve, such that they detect cancers that will never cause any harm because they grow far too slowly. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [October 30, 2023, 2:40am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/13 "2023-10-30T02:40:06Z")
> [@Saint\_Cad](#): > > Then let’s say cancer at a level that requires treatment, whether diagnosed or undiagnosed. It might be more useful if you explain the purpose of the estimate. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [October 30, 2023, 2:47am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/14 "2023-10-30T02:47:02Z")
I am teaching my students Bayes’ Theorem and part of my example uses p(cancer). I prefer to use real number with my students rather than made up numbers. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [October 30, 2023, 2:51am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/15 "2023-10-30T02:51:22Z")
So why the need for worldwide numbers? Why not stick to the U.S. where reliable statistics are available? ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [October 30, 2023, 2:55am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/16 "2023-10-30T02:55:17Z")
I would if I could find those but I can’t . Maybe my google fu is weak but all I can find is the probability of getting cancer sometime in your life OR new cases this year. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [October 30, 2023, 3:04am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/17 "2023-10-30T03:04:51Z")
That makes little sense. Why would the inability to find US statistics prompt you to ask for worldwide statistics? ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [October 30, 2023, 7:03am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/18 "2023-10-30T07:03:43Z")
Because that’s what I originally looked for. If I can’t find those stats then I could adapt to number in US, Colorado or Denver. I just need something. ---
**Author:** ![Pardel-Lux](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pardel-lux/32/20182_2.png) [@Pardel-Lux](https://boards.straightdope.com/u/Pardel-Lux)\ **Post date:** [October 30, 2023, 9:54am UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/19 "2023-10-30T09:54:07Z")
> [@Saint\_Cad](#): > > If you have cancer then yes you have cancer. If they cut it out, you no longer have cancer Have you considered [myeloproliferative diseases](https://emedicine.medscape.com/article/204714-overview?form=fpf) like myelofibrosis or agnogenic myeloid metaplasia? They are similar to leukemia, they are proliferative diseases, that is, some cells reproduce beyond the normal rate, but they develop no tumors and consequently do not develop metastasis either. What is cancer for you? Perhaps I could recommend the book [“Cancer. The Emperor of All Maladies. A Biography of Cancer”](https://www.amazon.de/Emperor-All-Maladies-Biography-Cancer/dp/0007250924/ref=sr_1_1?__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=2TTP2FNUMQ94H&keywords=cancer+the+king+of+maladies&qid=1698658403&sprefix=cancer+the+king+of+maladies%2Caps%2C124&sr=8-1), by Siddhartha Mukherjee from 2011, it may lead you to the conclusion that your question does not have a simple, clear answer. Cancer is a human made, artificial, somewhat arbitrary concept that groups together many different pathologies. As a corollary, the idea of waging War Against Cancer is crap. Perhaps your project could be more focused on a single type of cancer, like for instance lung cancer, ovarian cancer, breast cancer or malignant gioblastomas in the brain. That would make it easier to obtain data. As a bonus, several diseases could lead to comparative studies. ---
**Author:** ![Kent\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kent_clark/32/105_2.png) [@Kent\_Clark](https://boards.straightdope.com/u/Kent_Clark)\ **Post date:** [October 30, 2023, 3:00pm UTC](https://boards.straightdope.com/t/how-many-people-have-cancer/992264/20 "2023-10-30T15:00:11Z")
Here’s one report that says, “[In 2020, there were an estimated 17,113,494 people living with cancer of any site in the United States.](https://seer.cancer.gov/statfacts/html/all.html)” Given a 2020 U.S. population of [331,449,520](https://www.census.gov/quickfacts/fact/table/US/LFE046221) that works out to 5.16%. I make no claim that the numbers are accurate, so feel free to dive deep into the source. [Next page](https://boards.straightdope.com/t/how-many-people-have-cancer/992264.md?page=2)