AIIMS research team develops e-Nose to detect lung cancer

When we breathe out, we release many of these compounds like alkanes and benzenes. However, their composition differs from person to person and disease to disease, explains Dr Anant Mohan, head of the Centre of Excellence in Breath Research, AIIMS. “Some of these VOCs may be up-regulated in people who have lung cancer and some of them may be down-regulated. Different diseases will produce different patterns or matrices of these VOCs. But once we recognise this pattern, we can diagnose the disease by just running the exhaled breath through eNose, which has several sensors to measure these VOCs,” he says.

The researchers have been collecting and comparing the VOCs of healthy people and those with lung cancer to identify the pattern that can signal the disease. Once this is done, lung cancer detection will just involve a quick and non-invasive test. “This test is years from coming close to the gold standard biopsy used for diagnosis but you can see the appeal. All a person needs to do is blow into the machine! It might help in early detection of lung cancer in developing countries like India where people reach the healthcare facilities in late stages,” says Dr Mohan.

About 70 per cent of his lung cancer patients come to him when the cancer has metastasised to other parts of the body. “Our studies have shown that the delay is because people seek treatment locally, the primary care doctor takes time to recommend the cases to the secondary care doctor and patients are given anti-tubercular treatment for two to three months before their final diagnosis,” he adds.

Although the researchers are currently looking at the eNose as just a diagnostic tool, they envision its applicability as a screening device too. At present, some countries have low-dose computer tomography based screening programmes for lung cancer. The Low Dose CT can be done annually in those at high risk of developing lung cancer – heavy smokers and those who are above the age of 50 years.

“Low-dose computed tomography (LDCT) has emerged as a screening tool for early lung cancer detection but may not be a feasible option for most developing countries. The breath-print analysis by electronic nose could be a potential biomarker for the early detection of lung cancer along with monitoring treatment response in a resource-limited setting,” a recently published review of the technique by the group said.

Screening for any disease is resource-intensive, and the current method, even if proven to be successful, would not solve the cost factor, says Dr Mohan. The collection tubes and chambers are expensive and the initial cost is high. But there is no recurrent cost. “It will become viable only when proven to work with good sensitivity and specificity. And, more companies come up to manufacture the device,” says Dr Mohan, whose centre is in touch with Indian technical partners to start manufacturing the components if not the device itself. Researchers are also working to develop the breath-print of other diseases such as asthma, TB, COPD, and sarcoidosis (a condition where tiny inflammatory cells grow on the lungs).