0
$\begingroup$

Assuming cancer has its origins at a single malfunctioning cell, how long would it take for that cell to grow from the point at which it is malfunctioning enough so that it can be detected by the immune system, to the point at which it be detected with:

  1. Routine modern medical tests
  2. Cancer specific blood test
  3. Noticed by the host (symptoms)
$\endgroup$
  • $\begingroup$ Is the assumption that "cancer has its origin at a single malfunctioning cell" correct? $\endgroup$ – user37894 Feb 2 '18 at 7:49
  • $\begingroup$ This will probably be hard to tell - and depends strongly on the type of cell. Some cancers grow very slow, while other are rather fast. $\endgroup$ – Chris Feb 2 '18 at 8:59
  • $\begingroup$ I know some cancers grow fast, but I doubt there is any cancer type where the single cell becomes a symptomatic cancer overnight. Or within a month. I mean the single cell has some barriers to overcome, like the ability to grow blood vessels. I am not familiar with all the barriers however. If one is aware of them, it should be possible to get an average, and min, max estimates for the time. $\endgroup$ – user1581390 Feb 2 '18 at 10:15
1
$\begingroup$

The barriers you mention are outlined well in the classic Hallmarks of Cancer paper: http://www.cell.com/abstract/S0092-8674(11)00127-9

The main problem with finding a general answer to this question is the large diversity in cancers, and the resulting problem in defining what hallmarks are sufficient to call an individual cell cancerous. There are cancers that can't be detected by the immune system or blood tests and will hide for a very long time symptom-wise, and non-cancerous tumours that can be detected in various ways very early on.

Let's say for your timing reference you simply take the point of neoplasm diagnosis (for neoplasms that turn out to be cancers after testing). At this point, figuring out how much time this cancer has spent being cancerous is very difficult, and to my knowledge has never been done. It could be possible to determine:

  • The number of genetic or epigenetic malfunctions that made the difference between benign tumour and cancer for this particular neoplasm (once again, hard to define)
  • An approximate rate of acquiring those malfunctions. Conceptually, one could ex vivo culture the cancer and monitor the rate of aquisition of further mutations in cancer-related loci or epigenetic markers.

Depending on how that rate looks, it may be possible to reverse extrapolate the rate of acquisition before diagnosis, and thereby estimate an approximate timepoint of acquisition of the first proper cancerous malfunction.

Besides that, "it probably took more than a few days" is the only statement I can confidently make, although as far as biological theory goes, it's perfectly possible (though highly unlikely) for a cell to acquire a set of mutations sufficient to become cancerous in a single round of replication.

$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.