We can try. Sometimes the cancer doesn't come back, and sometimes it does, and in no case do we understand why. This is not what most people mean by "cure".
I don't think we have very many treatments that are 100% efficacious and durable for most conditions, even ones that are generally considered curative.
If you take antibiotics-- sometimes it doesn't seem to work at all, and some other times the infection comes back after the cessation of treatment. This is true because of some reasons that are well-understood, and others that aren't.
Yes, most cancers are worse on these metrics than most uses of antibiotics, but not always ridiculously so. There are cancers with 5 year survival rates of >95%, and with very low recurrence rates after 5 years.
Earnest curiosity - when someone is cured of cancer, and it comes back, is that different from me being cured of the flu and then catching the flu again later? Obviously it's different sorts of malady, but is it that the same cancer comes back, or is it just that if you had kidney cancer once, it's likely you might get it again? Or do we just not know enough about cancer to say/it varies on the sort of cancer?
It's not like being cured normally means "and you'll never get that again ever".
We're mostly talking about it coming back. A treatment might eliminate the vast amount of cancer cells, but some can be lying dormant and wake back up at some later time (and since they survived, the ones that are more resistant to treatment have been selected-- prognosis is then much worse the second time around). Or sometimes those "seeds" of recurrent cancer never awake.
Of course, people who get one cancer are, on average, more genetically and environmentally exposed to cancer risk. Cancer treatments themselves can even increase the risk of new cancer in some cases. So getting an entirely independent cancer is possible, too.
That was mostly what I had in mind. There's plenty of diseases where you're cured in the sense that your body can passively take care of it from here, but there's a chance it flares up again. I was unclear if most cancers were a "you got rid of it, but a different part of your kidney developed a cancer now" as compared to "that cancer you had before is back"
The general thinking is not that the cancer will hopefully stay dormant but there's a chance it will flare up in the future. The act of flaring up is what makes the tumor a malignant cancer as opposed to a benign cyst. A cancer cell is already flaring up by definition.
Rather, the usual model is that you physically extract the cancer, or you poison it, and you hope that you removed or killed all of the living cancer cells. If one is left, the cancer will grow back over time. This is why a metastatic cancer is so much worse than one that hasn't yet metastasized - after metastasis, cancer cells can be located pretty much anywhere in your body, but before metastasis, they are all localized to wherever the cancer originally developed, and if you remove enough tissue, it's plausible that you might get them all.
This model is somewhat in tension with (part of) the concept of partial remission, where the growth of a cancer becomes slower. But in such a case, it is even more obvious than usual that the cancer of the future is the same cancer as the cancer of the past, since we could observe it the whole time.
You might also consider the implications of the fact that the terminology for what appears to be a total absence of cancer is "cancer in remission". We say that because we can't know whether the cancer is actually gone. If it isn't gone, it will come back.
Sometimes you get better from a sickness, but it stays idle in your body and resurfaces later. If you get chickenpox as a child, it'll stay in you and eventually come back as shingles when you're an adult.
Others like herpes are lifelong afflictions whose symptoms can clear up, become inactive and eventually reactivate and flare up again.
That’s kind of a flippant answer. I hope you know that viruses (particularly the herpes family) cause at least some forms of cancer and herpes is super transmissible and most people have some form (in particular familial herpes but also chicken pox). Can you catch it from riding a bus? Probably not. But I don’t think you were talking about literally from riding a bus but we don’t know if it’s a viral infection that’s untreated and has flare ups or if you can treat the viral infection and get reinfected. It wouldn’t surprise me if it’s both - typically it’s a flare up but even if you cured the viral infection you could get reinfected and get cancer expressed again.
Yea, no shit. That's not the question I was asking. You can choose to be an annoying literalist, or you can be informative, or you can be quiet. You've chosen the least socially reasonable of them.
