Call me crazy but I am of a firm belief that the cause of almost all cancers is viral in nature. It is a combination of a viral infection and a failure of the innate immune response to stop the virus. I believe we are stopping these viruses all the time in our daily life and it is only when our immune system is under duress (ex: age, smoking, chemical, etc.) that it fails to stop these viruses.
I'm not a virologist, or a medical practitioner, just someone who's interested casually in the subject of cancer and viruses.
This is not true. Some cancers are caused by viruses. Many oncogenes were initially discovered in viruses. But the majority of tumors are definitely not caused by viruses.
This was a hypothesis in the field for a number of years, and has been disproven. If you want a good overview of the history of cancer, I recommend “The Emperor of All Maladies” by Siddhartha Mukherjee.
* that science has proven the majority of tumors are definitely not caused by viruses.
could you kindly share a few of the studies disproving the majority case? in particular, i'm interested in the sample size and diversity powering these refutations.
to clarify, i'm not saying you're wrong. simply seeking to learn more.
my research has uncovered misleading conclusions based on studies with flawed methodology/logic. for example, this study [0] states, "epstein-barr virus plays no role in the tumorigenesis of small-cell carcinoma of the lung." based on a sample size of 23.
I'm not saying that there aren't other mechanisms (sustained inflammation, etc) that might contribute to the aetiology of some other cancers, even without clear viral integrations, but we can state pretty strongly that many cancers are not directly caused by cancer.
Sure, a 2020 study from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, looking for viral evidence in thousands of tumor genomes and transcriptomes[0]. Part of a massive, cross-institutional effort.
"Searching large pan-cancer genome and whole-transcriptome datasets enabled the identification of a high percentage of virus-associated cases (16%)".
based on ebv studies i have read (happy to share if you want), some papers use flawed methodologies for viral detection (e.g., checking for limited set of viral proteins).
to reiterate, we mostly agree, except i adopt a more restrained stance: the conclusion supported by science is that viral causation is provable in some cancers -- but not a majority.
which is a subtle, but crucial difference, from concluding that viruses do not cause a majority of cancers (much higher bar IMO).
for instance, past studies may have used flawed detection methods or extrapolated from unrepresentative samples like the lung cancer study shared earlier.
Sure, absence of evidence is not evidence of absence. But these PCAWG results have been discussed to death since they were published, and its pretty sound science.
You could also take the bottom-up approach of asking what DOES cause certain cancers. That's a whole other discussion.
Considering all this, if you still have doubts that "viruses do not cause the majority of cancers", I think you will likely be skeptical about pretty much all of biology.
i do think flawed studies are more common than people realize (e.g., lung cancer one linked above, ebv ones referenced).
i wouldn’t say i’m skeptical.
more willing to say “unsure” until the underlying methods and logic have been validated.
based on personal anecdotes only, scientists seem too rushed and overworked, forced by our broken system to cite without verifying logic or methods first.
to be honest, part of me hopes you are right and all the virus science is sound. it would save me a lot of time and money.
thanks for sharing your thoughts and providing resources to check out.
I'm a biochemist with a biomedical background. Everything that follows is a simplification, but it's truthy.
We understand pretty well what causes cancer in "otherwise healthy individuals" (eg.: assuming there aren't particularly bad genes involved... which is a whole thing on its own), it's not a big mystery. We know with total certainty that "cancer in general" is not usually caused by viruses, although some viruses are notorious for causing cancer.
What causes cancer is whatever causes tissue injury and inflammation, with some probability. This is why smoking causes cancer, why drinking alcohol causes cancer, why sunburns cause cancer, why ionizing radiation causes cancer... The more chronic or frequent the injury/inflammation, the more the odds stack up against you. Viruses that cause chronic inflammation cause cancer.
(There are also a bunch of things that directly cause mutations including some of the above, and those cause cancer too, with some probability, if they overwhelm error-correction mechanisms.)
I'm not a virologist, or a medical practitioner, just someone who's interested casually in the subject of cancer and viruses.