Tag: diagnosis

are mammograms worth it?

A new study published in the British Medical Journal suggests perhaps they are not. From the New York Times:

[The study] found that the death rates from breast cancer and from all causes were the same in women who got mammograms and those who did not. And the screening had harms: One in five cancers found with mammography and treated was not a threat to the woman’s health and did not need treatment such as chemotherapy, surgery or radiation.

Researchers sought to determine whether there was any advantage to finding breast cancers when they were too small to feel. The answer is no, the researchers report.

Many of the cancers found by mammography posed no threat to women’s health and led to costly interventions that may not have been necessary. The study is not expected to change mammography guidelines though.

fighting tuberculosis with rats

Image from NPR. Abdullah Mchumvu trains African giant pouched rats in Morogoro, Tanzania

Tuberculosis still kills 1.4 million people a year, mostly in the developing world. So it is still beneficial to create new diagnostic techniques, especially when they can be used in rural communities. NPR recently reported on a team of scientists who train African giant pouch rats to sniff out the bacterium in patients’ sputum:

The team trains the critters with a Pavlovian click-and-reward approach. When the rats are just a few weeks old, technicians teach the animals to associate a click sound with a small bite of mashed bananas and a special pellet of food. The next step is to link the scent of TB with the reward.

A trained rat can correctly pick out a TB sample about two-thirds of the time, Beyene says. The rate increases to about 80 percent when two or three animals are put on the task.

The rats aren’t as good as a trained pathologist in the U.S. with a microscope, but they get better results than many clinicians working in rural Africa can achieve, Beyene says. “In an African setting, the sensitivity of the microscopy ranges between 30 to 40 percent,” he explains.

So far APOPO only has around 32 rats in their TB program.

Currently the rats are being used to verify positive test results obtained from microscopic samples.

breath test for stomach cancer

Cancer breathalyzer

A breath test for cancer.

Researchers are reporting a new test for gastric cancer in the British Journal of Cancer (Abstract is free, subscription required for full article). In the study the researchers looked at 130 patients with different gastric conditions. Of the patients 37 had gastric cancer, 32 had ulcers and 61 had less serious complaints. As it turns out, the cancer causes an identify chemical identifier.  Patients diagnosed with cancer produced elevated levels of the following volatile organic compounds: 2-propenenitrile, 2-butoxy-ethanol, furfural, 6-methyl-5-hepten-2-one and isoprene. These levels can be detected by gas chromatography, but the researchers developed a special nanoparticle sensor that could detect these compounds at the parts per billion level. This study seems to bolster previous research where dogs were able to identify cancer patients with ~71% accuracy based on breath samples. It is also supported by a study where lung cancer was detected using a breathalyzer type test. But, since this was a small study these results will have to be confirmed using a larger sample.

//groutaissou.net/4/4535925