Exhaled Breath Test for Cancer Detection

Researchers from Flinders University, Australia develop a non-invasive exhaled breath test that accurately diagnoses head and neck cancer through mass spectrometry of samples obtained from 181 patients.

A breath sample is obtained and analyzed to detect cancer-related molecules. Photo from Getty Images.

Volatile organic compounds (VOCs) emitted by humans may serve as markers for cancer detection.[1] Recently, around 250 VOCs were identified to hold potential in detecting cancer through breath analysis.[2] Flinders University researchers further explored this by developing an accurate and practical breath test to detect early-stage head and neck squamous cell carcinoma (HNSCC), with a sensitivity of 80% and specificity of 86%.[1]

The standardized breath samples obtained from 181 patients suspected of HNSCC were analyzed with an ion flow-tube mass spectrometer. Only 50 out of 181 samples were further analyzed since some were excluded due to certain factors like previous history of cancer, high grade dysplasia (abnormal development of cells), and poor carbon dioxide concentration.[1] As shown in Table 1, formaldehyde, which has been previously reported as a marker for lung cancer; and methyl mercaptan, which is indicative of periodontal disease and halitosis, were identified as potential cancer-related VOCs.[1]

Using statistical analysis, the breath test was developed and could correctly differentiate cancer patients from benign disease patients with results showing that 66% of the patients had early-stage primary tumours (T1 and T2) and 58% had regional node metastasis.[1] However, this diagnosis must be further confirmed by tissue biopsies.[1] "With these strong results, we hope to trial the method in primary care settings… to further develop its use in early-stage screening for HNSCC in the community,” shares one of the researchers, Dr. Nuwan Dharmawardana.[3] “In time, [this] may result in a simple method to improve treatment outcomes and patient morbidity," lead researchers Dr Roger Yazbek and Associate Professor Eng Ooi add.[3]

There are various Implications of this breath test on patient care. First, it could help patients with nonspecific symptoms in having more specialized treatments upon diagnosis.[2] Second, it could be used as a screening procedure since it is non-invasive and easily performed.[2] Moreover, it may also be used to monitor responses to cancer therapy, such as in detecting cancer recurrence.[2] As HNSCC accounts for around 6% of all cancers[3], this breath test could greatly improve patient care and treatment when implemented in the healthcare setting.

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References:

[1] Dharmawardana, N., Goddard, T., Woods, C., Watson, D. I., Ooi, E. H., & Yazbeck, R. (2020). Development of a non-invasive exhaled breath test for the diagnosis of head and neck cancer. British Journal of Cancer. https://doi.org/10.1038/s41416-020-01051-9.

[2] Hanna, G. B., Boshier, P. R., Markar, S. R., & Romano, A. (2019). Accuracy and Methodologic Challenges of Volatile Organic Compound–Based Exhaled Breath Tests for Cancer Diagnosis. JAMA Oncology, 5(1), e182815. https://doi.org/10.1001/jamaoncol.2018.2815.

[3] Flinders University. (October 5, 2020). Promising breath-test for cancer: Potential for early warning of head, neck cancer. ScienceDaily. Retrieved from www.sciencedaily.com/releases/2020/10/201005101544.htm.