Strangely, shorter telomeres is not actually a new idea here AFAIK. I would also be interested in a very rough guess of whether this may be an expensive or cheap test.
Biiiiig cloud of points showing a statistically-distinguishable trend by which those in the cancer group had telomere length attrition with age slightly higher than those that did not get cancer. But the variation from patient to patient is much larger than the average variation with age.
In contrast to the previous trend with age, average blood telomere length in patients who later went on to get cancer was statistically distinguishably longer for ~3 years before cancer diagnosis. Again, population averages. The distributions are not shown but I would not be surprised if variations are large enough that for most values a diagnostic test wouldn’t be terribly conclusive.
Blood is a funny tissue, its stem cells maintain telomerase activity and the balance of telomere extension and wear-down can be shifted one way or another by conditions. This could be a readout of other deeper things happening elsewhere in the body at a systemic level or might reflect a generalized telomere extension effect in the early stages of cancer as a contributing cause or an effect.
“Interestingly, one longitudinal study of telomere length and cancer development (albeit a cancerous complication of lymphoma treatment) found a similar temporal pattern, with increasing BTL in cases before and immediately (100 days) after treatment, followed by accelerated telomere attrition in cancer cases compared to controls (Chakraborty et al., 2009). The complexity of the relationship between BTL attrition and cancer incidence found here is also similar to that reported in our previous study of BTL and air pollution, where short-term pollution exposure increased BTL but long-term exposure decreased it (Hou et al., 2012b). This underscores the complex “give and take” at the heart of telomere regulation, and reiterates the importance of timing BTL collection relative to diagnosis (and potentially exposure and treatment).”
The contrast is the type of trend. In samples from people who got cancer age had a greater correlation with short telomeres. However, in samples from patients in the three or four years immediately before cancer diagnosis, there was a significantly longer telomere length.
People who will get cancer’s telomeres shorten more rapidly with age, but are longer right before they get cancer. It’s a dynamic process and it’s apparently got some weird complications to it. Mostly interesting to me because it suggests body-wide mechanisms of telomere regulation that have something to do with cancer genesis.
Oh, whether short vs long is associated with cancer. I guess that should have been clear from De Vliegende Hollander’s query.
On a different note, that second graph looks like nonsense to me. The cancer group holds steady, while the control group bobs up and down. The effect is in the control group, not in the cancer group. This graph tells nothing about cancer. 95% it’s pure nonsense, but maybe it tells something about the control group—it’s predicting their censoring by death. Which is why it’s crazy to use time to censoring as the metric for the control group.
Strangely, shorter telomeres is not actually a new idea here AFAIK.
Just because a mainstream news article says that something is a new method doesn’t mean it is.
If you use the word “strangely” when reading a mainstream media article about science it’s a good heuristic to instead go to the actual study.
I would also be interested in a very rough guess of whether this may be an expensive or cheap test.
Rather cheap. They describe their method:
BTL was measured using quantitative real-time polymerase chain reaction (qPCR) (Cawthon, 2002). Relative BTL was measured by the ratio of the telomere (T) repeat copy number to single-copy gene (S) copy number (T:S ratio) in a given sample and reported as relative units expressing the ratio between test DNA BTL and reference pooled DNA BTL. [...]
Taking blood samples and running PCR are both not complicated things.
A bit googling around finds 400$ as a retail price (http://www.repeatdx.com/products/pricing-and-cpt-codes/) for telomere testing. There seems to be a failed Indigogo campaign that used 99$ as the default price but was target at salvia instead of blood.
Anyone esp. @CellBioGuy having anything interesting to add to new method to predict cancer? http://www.telegraph.co.uk/news/11574893/New-test-can-predict-cancer-up-to-13-years-before-disease-develops.html
Strangely, shorter telomeres is not actually a new idea here AFAIK. I would also be interested in a very rough guess of whether this may be an expensive or cheap test.
Check the following figures:
http://ars.els-cdn.com/content/image/1-s2.0-S2352396415001024-gr1.jpg
Biiiiig cloud of points showing a statistically-distinguishable trend by which those in the cancer group had telomere length attrition with age slightly higher than those that did not get cancer. But the variation from patient to patient is much larger than the average variation with age.
http://ars.els-cdn.com/content/image/1-s2.0-S2352396415001024-gr2.jpg
In contrast to the previous trend with age, average blood telomere length in patients who later went on to get cancer was statistically distinguishably longer for ~3 years before cancer diagnosis. Again, population averages. The distributions are not shown but I would not be surprised if variations are large enough that for most values a diagnostic test wouldn’t be terribly conclusive.
Blood is a funny tissue, its stem cells maintain telomerase activity and the balance of telomere extension and wear-down can be shifted one way or another by conditions. This could be a readout of other deeper things happening elsewhere in the body at a systemic level or might reflect a generalized telomere extension effect in the early stages of cancer as a contributing cause or an effect.
What’s the contrast? Isn’t the situation exactly the same, statistically distinguishable, but practically meaningless?
The contrast is the type of trend. In samples from people who got cancer age had a greater correlation with short telomeres. However, in samples from patients in the three or four years immediately before cancer diagnosis, there was a significantly longer telomere length.
People who will get cancer’s telomeres shorten more rapidly with age, but are longer right before they get cancer. It’s a dynamic process and it’s apparently got some weird complications to it. Mostly interesting to me because it suggests body-wide mechanisms of telomere regulation that have something to do with cancer genesis.
Oh, whether short vs long is associated with cancer. I guess that should have been clear from De Vliegende Hollander’s query.
On a different note, that second graph looks like nonsense to me. The cancer group holds steady, while the control group bobs up and down. The effect is in the control group, not in the cancer group. This graph tells nothing about cancer. 95% it’s pure nonsense, but maybe it tells something about the control group—it’s predicting their censoring by death. Which is why it’s crazy to use time to censoring as the metric for the control group.
Just because a mainstream news article says that something is a new method doesn’t mean it is. If you use the word “strangely” when reading a mainstream media article about science it’s a good heuristic to instead go to the actual study.
In this case http://www.sciencedirect.com/science/article/pii/S2352396415001024 (open-access)
Rather cheap. They describe their method:
Taking blood samples and running PCR are both not complicated things.
A bit googling around finds 400$ as a retail price (http://www.repeatdx.com/products/pricing-and-cpt-codes/) for telomere testing. There seems to be a failed Indigogo campaign that used 99$ as the default price but was target at salvia instead of blood.