Sputum microbiota may help diagnose lung cancer


An English pilot study suggests that the microbiota present in sputum could become a screening tool for lung cancer. Lung cancer, one of the most common types of cancer worldwide, is extremely deadly –largely because of late diagnosis. The five-year survival rate is 15%, a number that has not made any significant progress in thirty years. Clearly there is a significant clinical need for early diagnostic tools. Given the already-established link between certain bacteria and certain cancers, researchers wondered if the bacterial composition of sputum could be a source of information on the presence of lung cancer, or even the kind of tumor and its stage of development. They analyzed samples from 10 people presenting with symptoms suggestive of lung cancer. Of the 10 people included in the study, 4 were ultimately diagnosed with lung cancer. Genome sequencing analysis of the microbiota present in the sputum revealed significant differences between the two groups. The abundance of Granulicatella adiacens and the presence of six other species (Enterococcus sp. 130, Streptococcus intermedius, Escherichia coli, Streptococcus viridans, Acinetobacter junii, and Streptococcus sp. 6), in particular, were positively correlated with lung cancer and gave information on its stage of development. Nevertheless, the small sample size requires these results to be confirmed and studied more in depth, particularly to obtain early-stage markers for this cancer.


Cameron SJS et al. A pilot study using metagenomic sequencing of the sputum microbiome suggests potantial bacterial biomarkers for lung cancer. PLoS One. 2017 May 25;12(5):e0177062