Investigators at Massachusetts General Hospital (MGH) have examined blood samples along with tumor tissues of the patients suffering from non-small-cell lung cancer and have identified markers that can distinguish between major subtypes of lung cancer and can accurately identify the stage of the lung cancer. The proof-of-concept test accurately predicted whether the blood samples they examined came from patients with shorter or longer survival following lung surgery, including patients with early-stage disease.
The finding will be helpful for the physicians in deciding whether an individual patient with lung cancer can benefit from standard treatment or may need higher therapy. The study is published in the open-access journal Scientific Reports.
The US Preventive Services Task Force currently recommends that middle-age older person with a history of heavy smoking be screened annually for lung cancer with low dose CT, that is effective at detecting small lung tumors, but the cost of the CT screening and the risks of repeated radiation exposure prevent its use for screening of the general population. This leads to a low cost need, minimally invasive method for identifying people who may require further CT screening to catch, the disease much earlier, more readily treatable stages, as per said by co-principal investigator Leo L. Cheng, PhD, and associate biophysicist in the departments of Pathology and Radiology at MGH.
“You cannot use CT as a screening tool for every patient or even for evert at-risk patient every year, so what we’re trying to do is to develop biomarkers from blood samples that could be incorporated into physical exams, and if there is any suspicion of lung cancer, then we would put the patient through CT,” Cheng says.
Cheng, David C. Christiani, MD, MPH, a physician in the Department of Medicine at MGH, and other colleagues studied paired blood samples and tumor tissues taken at the time of surgery and looked for unique metabolomic markers using high-resolution magnetic resonance spectroscopy (MRS), a sensitive technique for characterizing the chemical composition of tissues.
Cheng says that although other research groups have used MRS to identify potential biomarkers of lung cancer in serum, “the uniqueness of our study is that we have paired samples from patients obtained at the same time as surgery.”
The paired specimens were taken from 42 patients with squamous cell carcinomas (SCC) of the lung, and 51 patients with adenocarcinomas of the lung. The investigators also tested blood samples from 29healthy volunteers who served as controls. The patients included 58 with early (Stage I) lung cancer, and 35 with more advanced disease (Stage II, III, or IV).
The designing of the experiments were to see whether blood samples and tumor tissue samples from the same patient had common features that would identify the presence or absence of lung cancer, discriminate between cancer subtypes, and confirm the diagnostic accuracy of a simple blood test.
Specific profiles of metabolites common to both types of samples were identified and the investigators showed the differences between the profiles could signal whether a patient had SCC or adenocarcinoma, which require different treatments. It is also found that the profiles could distinguish between early-stage disease, which is often highly treatable, and later disease stages which require more experimental treatments.
Importantly, the tests also identified whether the samples came from patients who lived an average of 41 months after surgery, or from those patients who lived longer than 41 months. This finding, if validated in further studies, could identify early on those patients at especially high risk for early death, who might benefit from clinical trials of new drugs.
The study has the ultimate goal to develop a blood test that could be included as part of a standard physical and could indicate whether a specific patient has suspicious signs pointing to lung cancer. Patients identified by the blood screen would then be referred for CT.
Source: Massachusetts General Hospital