| A recent in the US is offering hope for | | | | response' a major factor in survival rates, |
| testing for lung cancer. US scientists have | | | | there are many who wonder why dogs are not |
| now developed and already tested a prototype | | | | trained to detect VOCs in the same manner |
| breath test to detect lung cancer. This may | | | | that dogs are trained to detect drugs and |
| enable doctors to detect lung cancer at | | | | other compounds. |
| earlier stages. | | | | |
| | | | The prototype of this device was developed by |
| The results of the US study test was | | | | Dr Peter Mazzone of the The Cleveland Clinic |
| published in the international journal of | | | | in Ohio in collaboration with the private |
| respiratory medicine Thorax. | | | | company ChemSensing of Champaign, Illinois. |
| | | | The private company customizes |
| In the tests, the colour testing device, | | | | Metalloporphyrins, a chemically reactive dye |
| which is the size of a coin and is | | | | family that are sensitive to VOCs. |
| surprisingly inexpensive, had a 75 per cent | | | | |
| success rate in detecting people with | | | | They are working to develop an inexpensive |
| different cancers. | | | | device. The only equipment available to the |
| | | | public are mass spectrometers or gas |
| However, the tests were not 100 per cent | | | | chromatographs. These are expensive and |
| accurate. The device showed false positives | | | | require the services of an expert to analyse |
| on people who did not have lung cancer. This | | | | the results. |
| reduces the device's effectiveness removing | | | | |
| doctor's ability to start immediate | | | | The new device resembles a 2 cm square key |
| treatments. | | | | fob with a 6 by 6 pattern of coloured dots |
| | | | visible through the plastic casing. Changes |
| The technique called a "colorimetric sensor | | | | in the pattern of the dots indicate the |
| array" picks up the chemical fingerprint of | | | | presence of VOCs in the breath based on the |
| the breath of people with lung cancer that | | | | gas makeup of the breath. |
| are caused by the tumours. | | | | |
| | | | Scientists tested 143 patients. Patients |
| Cancers produce volatile organic compounds | | | | needed to breathe into the device for 12 |
| (VOCs) that are different from normal cells. | | | | minutes. The test group was divided into |
| Tumours in the lungs are more likely to | | | | three groups. Some patients had lung cancer |
| contain increased signs of these abnormal | | | | at various stages, some had other forms of |
| compounds. This increases the potential for | | | | respiratory illnesses like emphysema. The |
| the device to pick up a lung cancer | | | | rest were healthy. |
| "fingerprint" in the breath. | | | | |
| | | | The device spotted 73 per cent of the lung |
| Surprisingly, dogs are able to detect VOCs | | | | cancer patients and cleared 72 per cent of |
| and differentiate between people with lung | | | | the non-lung cancer patients. This is not 100 |
| cancer and healthy people. With 'early | | | | per cent, but the results are acceptable. |