Open Access Highly Accessed Research article

Evaluation of FTIR Spectroscopy as a diagnostic tool for lung cancer using sputum

Paul D Lewis1*, Keir E Lewis12, Robin Ghosal2, Sion Bayliss1, Amanda J Lloyd3, John Wills1, Ruth Godfrey1, Philip Kloer2 and Luis AJ Mur3

Author Affiliations

1 School of Medicine, Swansea University, Swansea, SA2 8PP, UK

2 Department of Respiratory Medicine, Prince Phillip Hospital, Llanelli, SA14 8LY, UK

3 Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, SY23 2AX, UK

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BMC Cancer 2010, 10:640  doi:10.1186/1471-2407-10-640

Published: 23 November 2010



Survival time for lung cancer is poor with over 90% of patients dying within five years of diagnosis primarily due to detection at late stage. The main objective of this study was to evaluate Fourier transform infrared spectroscopy (FTIR) as a high throughput and cost effective method for identifying biochemical changes in sputum as biomarkers for detection of lung cancer.


Sputum was collected from 25 lung cancer patients in the Medlung observational study and 25 healthy controls. FTIR spectra were generated from sputum cell pellets using infrared wavenumbers within the 1800 to 950 cm-1 "fingerprint" region.


A panel of 92 infrared wavenumbers had absorbances significantly different between cancer and normal sputum spectra and were associated with putative changes in protein, nucleic acid and glycogen levels in tumours. Five prominent significant wavenumbers at 964 cm-1, 1024 cm-1, 1411 cm-1, 1577 cm-1 and 1656 cm-1 separated cancer spectra from normal spectra into two distinct groups using multivariate analysis (group 1: 100% cancer cases; group 2: 92% normal cases). Principal components analysis revealed that these wavenumbers were also able to distinguish lung cancer patients who had previously been diagnosed with breast cancer. No patterns of spectra groupings were associated with inflammation or other diseases of the airways.


Our results suggest that FTIR applied to sputum might have high sensitivity and specificity in diagnosing lung cancer with potential as a non-invasive, cost-effective and high-throughput method for screening.

Trial Registration NCT00899262