Every year, the deaths caused by this cancer tumors are more than 1.8 million worldwide – outnumber those that jointly cause cancers of the breast, prostate and colorectal. The reason for this high mortality is mainly explained by the delay in the diagnosis of the disease. And is that the longer the detection is delayed, or what is the same, the more the tumor has progressed, the less effective the treatments are. Hence the vital importance of early diagnosis of lung cancer. And, better yet, to ‘anticipate’ which people will eventually develop it.International Agency for Research on Cancer (IARC). And for that, you just have to take a blood sample.
As explained by Mattias Johansson, co-author of this research published in the journal ” JAMA Oncology “, “by combining the analysis of four protein biomarkers and information on smoking, we were able to identify 63% of future cases of lung cancer among the smoker and former smoker population . A percentage, therefore, higher than the 42% achieved with the current selection criteria for screening by imaging tests in the United States.
Look in the blood
The United States Preventive Services Task Force guidelines(USPSTF) recommend the performance of computerized tomography imaging in all adults between the ages of 55 and 80 and a history of smoking – consumption of at least 30 packs per year for the past 15 years. Both smokers and former smokers. And is that the snuff is responsible for up to 90% of cases of lung cancer. Thus, what is involved with these imaging tests is to assess the damage caused by tobacco in the lungs and predict which smokers – and former smokers – will eventually develop a tumor. Which is achieved in 42% of cases. But is not there a way to identify the population at risk without having to submit it to radiation, even at low doses? And if possible, with greater efficiency?
The aim of the new study was to evaluate if the analysis of molecules present in the blood – or what is the same, a “liquid biopsy” – can facilitate the identification of smokers and ex-smokers who will suffer lung cancer in the future . And to do this, the authors analyzed the blood samples taken from 108 adult smokers who were diagnosed with lung cancer in the 12 months following the blood draw and compared them with those of 216 other people who, equally smokers, did not develop the tumor – the usual ‘control group’ -. And what happened? Well, according to the results, patients who ended up suffering from cancer had abnormal levels of four proteins in the blood: the ‘precursor form of the surfactant protein B’ (Pro-SFTPB), the ‘cancer antigen 125’ (CA125), the ‘fragment of cytokeratin 19’ (CYFRA 21-1), and the ‘carcinoembryonic antigen’ (CEA) ).
As Sam Hanash, co-author of the research, points out, “in our work we have compared smokers with lung cancer with smokers who did not have this tumor, and we have seen that there are differences between the biomarkers of both groups. Therefore, these are differences that do not only have to do with tobacco. In fact, when we compared cancer cases with the general population, we found the same differences in biomarkers again. ”
Therefore, once these four proteins or ‘biomarkers’ were identified, the next step was to confirm their usefulness in predicting future cases of lung cancer. And to do this, the authors analyzed the blood samples of 63 patients with a history of smoking who were also diagnosed with lung cancer within a year from the blood draw and compared them with those of 90 other people who, equally smokers or former smokers, did not suffer a lung tumor. And according to the results, the evaluation of these four biomarkers allowed identifying 63% of the patients who ended up suffering from cancer .
In short, the new liquid biopsy allows identifying the population at very high risk of developing lung cancer. And with more precision than the tests that, as with the imaging tests, only rely on the smoking history. Then, and once an alteration in the levels of the biomarkers is detected, do patients not have to undergo computed tomography? Yes, given that this risk must be confirmed by imaging tests. But in case the liquid biopsy yields a negative result, it could prevent the smoker -or ex-smoker- from having to be irradiated. Anyway, what you have to do is, plain and simple, no smoking.
As Christopher Wild, director of IARC concludes, ” the best way to reduce the risk of lung cancer is to avoid tobacco , but among smokers and ex-smokers at high risk, early detection plays a key role when it comes to reducing the risk of lung cancer. reduce deaths from this disease. In this context, the results achieved with these biomarkers offer new opportunities to improve the survival of patients with lung cancer ».