Perilous potential: the chance to save lives, or lose them, through low dose computed tomography screening for lung cancer

A national survey of primary care physicians: Perceptions and practices of low-dose CT lung cancer screening

Soon after the National Lung Screening Trial, organizations began to endorse low-dose computed tomography (LCDT) screening for lung cancer in high-risk patients. Concerns about the risks versus benefits of screening, as well as the logistics of identifying and referring eligible patients, remained among physicians. This study aimed to examine primary care physicians' knowledge, attitudes, referral practices, and associated barriers regarding LDCT screening. We administered a national survey of primary care physicians in the United States between September 2016 and April 2017. Physicians received up to 3 mailings, 1 follow-up email, and received varying incentives to complete the survey. Overall, 293 physicians participated, for a response rate of 13%. We used weighted descriptive statistics to characterize participants and their responses. Over half of the respondents correctly reported that the US Preventive Services Task Force recommends LDCT screening for high-risk patients. Screening recommendations for patients not meeting high-risk criteria varied. Although 75% agreed that the benefits of LDCT screening outweigh the risks, fewer agreed that there is substantial evidence that screening reduces mortality (50%). The most commonly reported barriers to ordering screening included prior authorization requirements (57%), lack of insurance coverage (53%), and coverage denials (31%). The most frequently cited barrier to conducting LDCT screening shared decision making was patients' competing health priorities (42%). Given the impact of physician recommendations on cancer screening utilization, further understanding of physicians' LDCT screening attitudes and shared decision-making practices is needed. Clinical practice and policy changes are also needed to engage more patients in screening discussions.

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Most physicians had five or less lung cancer screening referrals in the past year

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Recommendation strategies varied, but often aligned with USPSTF or NCCN guidelines

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Physicians were uncertain about the efficacy and cost-effectiveness of screening

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Insurance coverage and costs were commonly cited as barriers to screening referral

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A common barrier to performing SDM was patients' competing health priorities

Circulating microRNA signature as liquid-biopsy to monitor lung cancer in low-dose computed tomography screening

Liquid biopsies can detect biomarkers carrying information on the development and progression of cancer. We demonstrated that a 24 plasma-based microRNA signature classifier (MSC) was capable of increasing the specificity of low dose computed tomography (LDCT) in a lung cancer screening trial. In the present study, we tested the prognostic performance of MSC, and its ability to monitor disease status recurrence in LDCT screening-detected lung cancers.Between 2000 and 2010, 3411 heavy smokers enrolled in two screening programmes, underwent annual or biennial LDCT. During the first five years of screening, 84 lung cancer patients were classified according to one of the three MSC levels of risk: high, intermediate or low. Kaplan-Meier survival analysis was performed according to MSC and clinico-pathological information. Follow-up MSC analysis was performed on longitudinal plasma samples (n = 100) collected from 31 patients before and after surgical resection.Five-year survival was 88.9% for low risk, 79.5% for intermediate risk and 40.1% for high risk MSC (p = 0.001). The prognostic power of MSC persisted after adjusting for tumor stage (p = 0.02) and when the analysis was restricted to LDCT-detected cases after exclusion of interval cancers (p < 0.001). The MSC risk level decreased after surgery in 76% of the 25 high-intermediate subjects who remained disease free, whereas in relapsing patients an increase of the MSC risk level was observed at the time of detection of second primary tumor or metastatic progression.These results encourage exploiting the MSC test for lung cancer monitoring in LDCT screening for lung cancer.

Community low-dose CT lung cancer screening: a prospective cohort study

BACKGROUND

The National Lung Screening Trial (NLST) in 2011 showed that low-dose CT (LDCT) screening in high-risk groups reduces lung cancer deaths. Major professional organizations, as well as the U.S. Preventative Services Task Force, have endorsed LDCT screening in these select populations. However, major questions remain about whether widespread deployment of CT screening can achieve results similar to the NLST, especially in the community setting.

METHODS

A prospective cohort study was initiated in November 2010. Participants at least 50 years old and with at least 20 pack-years of smoking history underwent LDCT screening in a community setting.

RESULTS

One hundred and fifty four participants underwent LDCT screening with median follow-up of 2.7 years. Compared with the NLST, there was a higher rate of positive screening tests (35.7 vs. 27.3 %), higher false positive rate (100 vs. 96.4 %), and poor adherence (43 vs. 95 %). Invasive diagnostic follow-up was uncommon and uncomplicated. No interval lung cancer was detected. Late follow-up was mostly attributed to participant or primary care provider preference (67.5 %), participants lost to follow-up (17.5 %), and lack of insurance (10 %).

CONCLUSIONS

These findings highlight the potential challenges of generalizing the NLST mortality benefits in the broad deployment of CT screening. Our results support current recommendations that LDCT screening be performed in a highly structured and integrated setting.

Comparative analyses of volatile organic compounds (VOCs) from patients, tumors and transformed cell lines for the validation of lung cancer-derived breath markers

Breath analysis for the purpose of non-invasive diagnosis of lung cancer has yielded numerous candidate compounds with still questionable clinical relevance. To arrive at suitable volatile organic compounds our approach combined the analysis of different sources: isolated tumor samples compared to healthy lung tissues, and exhaled breath from lung cancer patients and healthy controls. Candidate compounds were further compared to substances previously identified in the comparison of transformed and normal lung epithelial cell lines. For human studies, a breath sampling device was developed enabling automated and CO2-controlled collection of the end-tidal air. All samples were first preconcentrated on multibed sorption tubes and analyzed with gas chromatography mass spectrometry (GC-MS). Significantly (p < 0.05) higher concentrations in all three types of cancer samples studied were observed for ethanol and n-octane. Additional metabolites (inter alia 2-methylpentane, n-hexane) significantly released by lung cancer cells were observed at higher levels in cancer lung tissues and breath samples (compared to respective healthy controls) with statistical significance (p < 0.05) only in breath samples. The results obtained confirmed the cancer-related origin of volatile metabolites, e.g. ethanol and octane that were both detected at significantly (p < 0.05) elevated concentrations in all three kinds of cancer samples studied. This work is an important step towards identification of volatile breath markers of lung cancer through the demonstration of cancer-related origin of certain volatile metabolites.