BioCAST : le Bio-observatoire national du cancer bronchiques chez les patients non fumeurs (IFCT1002)

A Cross-Sectional Study on the Knowledge and Awareness of Lung Cancer and Screening in Jazan Region, Saudi Arabia

BACKGROUND

Lung cancer (LC) is the most common cause of cancer-related deaths worldwide. With lung cancer often diagnosed at advanced stages, understanding the local population's awareness levels is crucial for designing effective preventive strategies. By identifying gaps in knowledge, the research aims to inform targeted health education efforts, optimize resource allocation, influence policy development, and contribute to the limited body of research on lung cancer awareness in the region, ultimately fostering improved public health outcomes.

METHODS

This was a cross-sectional observational study conducted in Jazan region, Saudi Arabia, from July 2022 to June 2023, 671 participants over 18 years old, encompassing both genders, were gsurveyed. Data was collected through a questionnaire covering sociodemographic characteristics and LC-related awareness. SPSS 23 was used for analysis. Factors associated with knowledge scores were explored using independent t-tests and ANOVA, with the Tukey post-hoc test identifying specific group differences.

RESULTS

The study included 671 participants, most participants were between 18 and 35 years (73.5%), with 38.5% males and 61.5% females. Lung cancer (LC) awareness was high (95.1%), with 4.9% reporting a family history. Knowledge assessment revealed a mean score of 14.66, with 41.6% having low, 49.5% moderate, and 8.9% high knowledge levels. Correct responses were notable for recognizing LC as a common cancer, a leading cause of death, and associating smoking and shisha with risk. Symptoms were well identified. Screening awareness was at 63.5%, with 78.8% willing to undergo tests if at risk. Age, marital status, and occupation were associated with knowledge, while factors like gender, nationality, residency, education, income, and smoking status showed no significant associations.

CONCLUSION

The findings indicate that there are knowledge gaps related to LC and its screening in Jazan region in Saudi Arabia. Effective awareness programs targeting specific sociodemographic groups are needed to improve the early detection and outcomes.

Association between lung cancer somatic mutations and occupational exposure in never-smokers

Occupational exposure constitutes a common risk factor for lung cancer. We observed molecular alterations in 73% of never-smokers, 35% of men and 8% of women were exposed to at least one occupational carcinogen. We report herein associations between molecular patterns and occupational exposure.BioCAST was a cohort study of lung cancer in never-smokers that reported risk factor exposure and molecular patterns. Occupational exposure was assessed via a validated 71-item questionnaire. Patients were categorised into groups that were unexposed and exposed to polycyclic aromatic hydrocarbons (PAH), asbestos, silica, diesel exhaust fumes (DEF), chrome and paints. Test results were recorded for EGFR, KRAS, HER2, BRAF and PIK3 mutations, and ALK alterations.Overall, 313 out of 384 patients included in BioCAST were analysed. Asbestos-exposed patients displayed a significantly lower rate of EGFR mutations (20% versus 44%, p=0.033), and a higher rate of HER2 mutations (18% versus 4%, p=0.084). ALK alterations were not associated with any occupational carcinogens. The DEF-exposed patients were diagnosed with a BRAF mutation in 25% of all cases. Chrome-exposed patients exhibited enhanced HER2 and PIK3 mutation frequency.Given its minimal effects in the subgroups, we conclude that occupational exposure slightly affects the molecular pattern of lung cancers in never-smokers. In particular, asbestos-exposed patients have a lower chance of EGFR mutations.

[Liquid biopsy analysis using cell-free DNA (cfDNA): Opportunities and limitations]

Molecular biological analysis of nucleic acids in blood or other bodily fluids (i.e. liquid biopsy analyses) may supplement the pathologists' diagnostic armamentarium in a reasonable way-particularly in cancer precision medicine. Within the field of oncology, liquid biopsy can potentially be used to monitor tumor burden in the blood and to early detect emerging resistance in the course of targeted cancer therapies. An already approved application of liquid biopsy is the detection of epidermal growth factor receptor (EGFR) driver mutations in blood samples of lung cancer patients in those cases where no tissue biopsy is available. However, there is still currently considerable insecurity associated with blood-based DNA analytic methods that must be solved before liquid biopsy can be implemented for broader routine application in the diagnosis of cancer. In this article, the current state of development of liquid biopsy in molecular diagnostics from a pathology point of view is presented.

No impact of passive smoke on the somatic profile of lung cancers in never-smokers

EGFR and HER2 mutations and ALK rearrangement are known to be related to lung cancer in never-smokers, while KRAS, BRAF and PIK3CA mutations are typically observed among smokers. There is still debate surrounding whether never-smokers exposed to passive smoke exhibit a “smoker-like” somatic profile compared with unexposed never-smokers.

Passive smoke exposure was assessed in the French BioCAST/IFCT-1002 never-smoker lung cancer cohort and routine molecular profiles analyses were compiled.

Of the 384 patients recruited into BioCAST, 319 were tested for at least one biomarker and provided data relating to passive smoking. Overall, 219 (66%) reported having been exposed to passive smoking. No significant difference was observed between mutation frequency and passive smoke exposure (EGFR mutation: 46% in never exposed versus 41% in ever exposed; KRAS: 7% versus 7%; ALK: 13% versus 11%; HER2: 4% versus 5%; BRAF: 6% versus 5%; PIK3CA: 4% versus 2%). We observed a nonsignificant trend for a negative association between EGFR mutation and cumulative duration of passive smoke exposure. No association was found for other biomarkers.

There is no clear association between passive smoke exposure and somatic profile in lifelong, never-smoker lung cancer.

BioCAST/IFCT-1002: epidemiological and molecular features of lung cancer in never-smokers

Lung cancer in never-smokers (LCINS) (fewer than 100 cigarettes in lifetime) is considered as a distinct entity and harbours an original molecular profile. However, the epidemiological and molecular features of LCINS in Europe remain poorly understood.

All consecutive newly diagnosed LCINS patients were included in this prospective observational study by 75 participating centres during a 14-month period. Each patient completed a detailed questionnaire about risk factor exposure. Biomarker and pathological analyses were also collected. We report the main descriptive overall results with a focus on sex differences.

384 patients were included: 65 men and 319 women. 66% had been exposed to passive smoking (significantly higher among women). Definite exposure to main occupational carcinogens was significantly higher in men (35%versus8% in women). A targetable molecular alteration was found in 73% of patients (without any significant sex difference):EGFRin 51%,ALKin 8%,KRASin 6%,HER2in 3%,BRAFin 3%,PI3KCAin less than 1%, and multiple in 2%.

We present the largest and most comprehensive LCINS analysis in a European population. Physicians should track occupational exposure in men (35%), and a somatic molecular alteration in both sexes (73%).

Noninvasive diagnosis of actionable mutations by deep sequencing of circulating free DNA in lung cancer from never-smokers: a proof-of-concept study from BioCAST/IFCT-1002

PURPOSE

Tumor somatic mutation analysis is part of the standard management of metastatic lung cancer. However, physicians often have to deal with small biopsies and consequently with challenging mutation testing. Circulating free DNA (cfDNA) is a promising tool for accessing the tumor genome as a liquid biopsy. Here, we evaluated next-generation sequencing (NGS) on cfDNA samples obtained from a consecutive series of patients for the screening of a range of clinically relevant mutations.

EXPERIMENTAL DESIGN

A total of 107 plasma samples were collected from the BioCAST/IFCT-1002 lung cancer study (never-smokers cohort). Matched tumor DNA (tDNA) was obtained for 68 cases. Multiplex PCR-based assays were designed to target specific coding regions in EGFR, KRAS, BRAF, ERBB2, and PI3KCA genes, and amplicon sequencing was performed at deep coverage on the cfDNA/tDNA pairs using the NGS IonTorrent Personal Genome Machine Platform.

RESULTS

CfDNA concentration in plasma was significantly associated with both stage and number of metastatic sites. In tDNA, 50 mutations (36 EGFR, 5 ERBB2, 4 KRAS, 3 BRAF, and 2 PIK3CA) were identified, of which 26 were detected in cfDNA. Sensitivity of the test was 58% (95% confidence interval, 43%-71%) and the estimated specificity was 87% (62%-96%).

CONCLUSION

These data demonstrate the feasibility and potential utility of mutation screening in cfDNA using IonTorrent NGS for the detection of a range of tumor biomarkers in patients with metastatic lung cancer.