Cancer as parasite is an analogy I’ve been aware of, but I’ve never seen a cancer spreading between animals as a direct parasite (generally contagious spread is a result of viral hijacking causing changes in DNA that then leads to cancer).

Interesting — and potentially a disruptive way to think about cancer biology.

Scientists Report Findings on Origin of a Cancer in Tasmanian Devils – NYTimes.com.

The Tasmanian devil, the spaniel-size marsupial found on the Australian island of Tasmania, has been hurtling toward extinction in recent years, the victim of a bizarre and mysterious facial cancer that spreads like a plague.

Now Australian scientists say they have discovered how the cancer originated. The finding, being reported Friday in the journal Science, sheds light on how cancer cells can sometimes liberate themselves from the hosts where they first emerged. On a more practical level, it also opens the door to devising vaccines that could save the Tasmanian devils.

The cancer, devil’s facial tumor disease, is transmitted when the animals bite one another’s faces during fights. It grows rapidly, choking off the animal’s mouth and spreading to other organs. The disease has wiped out 60 percent of all Tasmanian devils since it was first observed in 1996, and some ecologists predict that it could obliterate the entire wild population within 35 years.

When the tumor disease was discovered, many scientists assumed that it was caused by a rapidly spreading virus. Viruses cause 15 percent of all cancers in humans and are also widespread in animals.

But subsequent studies failed to turn up a virus. Instead, Anne-Maree Pearse and Kate Swift, of the Department of Primary Industries, Water and Environment in Tasmania, discovered something strange about the tumor cells. The chromosomes looked less like those in the animal’s normal cells and more like those in the tumors growing in other Tasmanian devils.

In 2007, Dr. Belov and her colleagues compared DNA from 26 sick and healthy Tasmanian devils with DNA from the tumors. They found that cancer cells from different animals shared distinctive genetic markers not found in the animals themselves.

When I was a kid, I hit my head a fair bit, including getting knocked out once at football practice.  Initial care involved an evaluation, but scans weren’t the norm.  Now that they’ve become increasingly common in the evaluation of head injuries in youth, have we gained much?

The  Value of CT Scans in Youths Is Questioned in this study in the Lancet (article in NYTimes).

The study, one of the largest of its kind, enrolled 42,412 children ages 18 and younger who sought emergency care at dozens of medical centers after suffering mild head injuries in bike collisions, car crashes, falls and other accidents. Of the total group, 14,969 of the children, or just over one-third, had CT scans, but only 780 of the scans, or about 5 percent, picked up traumatic brain injuries, the study found.

The paper, published online in the Sept. 15 issue of The Lancet, offered a list of six indicators that could be used to determine whether a child was at risk for a serious brain injury, with a separate list for children under 2. The highest risk factors for children of all ages are an altered mental state and signs of a skull fracture.

Other factors to consider are loss of consciousness and whether the child was involved in a serious incident like a car crash. Vomiting and headaches are predictors in older children, while swelling of the scalp and abnormal behavior are warning signs in younger children.

The surprising stat to me was that after triage, only 5% of those who received a CT scan actually showed an issue (we’ll ignore potential false positives).

42,412 went to the emergency room

14,969 had a CT scan (35%)

780 showed traumatic brain injury (1.8% of ER visitors, 5.2% of those scanned)

It would seem that better triage would get us closer than a 1 out of 20 hit rate.  But in the current environment, why would a medical staff take the time to run through the 6 indications and risk a bad outcome?

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• Vital Signs: Screening: Value of CT Scans in Youths Is Questioned (nytimes.com)
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I keep hearing about Comparative Effectiveness and how evidence needs to used in medical practice.  Then I remember my days in the clinic/hospital, where complex patients presented in ways that didn’t fit textbook definitions and whose multitude of issues offered contradictory readings from the literature.

So how are we to move forward?  I’m a strong believer that the best evidence needs to be used in clinical decision-making…the issue is in making this evidence usable in the field in a way that doctors can trust will be relevant to the person in front of them (as opposed to 300 carefully selected and studied patients in Finland).

So what will the new paradigm look like?  My sense is the RCT will fade as consumer-focused care comes into play.  If the best of science is directed to the patient sitting in front of a doctor, the goal will be to combine the information of others just like them (across multiple segments and disease phases) to predict both the natural course as well as the potential options for improvement (and their predicted results).

After all, isn’t it less important to know what a treatment does for the average study patient in Finland and more about what it does in people just like you in the real world?

Real-world data from Patients Like Me

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