Lung cancer remains the leading cause of cancer-related death worldwide. Since prognosis and treatment outcomes rely on fast and accurate diagnosis, there is a need for more costeffective, sensitive, and specific method for lung cancer detection. Thus, this study aimed to determine the ability of ATR-FTIR in discriminating malignant from benign lung tissues and evaluate its concordance with H&E staining. Three (3) 5μm-thick sections were cut from formalin fixed paraffin embedded (FFPE) cell or tissue blocks from patients with lung lesions. The outer sections were H&E-stained and sent to two (2) pathologists to confirm the histopathologic diagnosis. The inner section was deparaffinized by standard xylene method and then subjected to ATR-FTIR analysis. Distinct spectral profiles that distinguished (p<0.05) one sample from another, called the "fingerprint region", were observed in five (5) peak patterns representing the amides, lipids, and nucleic acids. Principal component analysis and hierarchical cluster analysis evidently clustered the benign from malignant tissues. ATR-FTIR showed 97.73% sensitivity, 92.45% specificity, 94.85% accuracy, 91.49% positive predictive value and 98.00% negative predictive value in discriminating benign from malignant lung tissue. Further, strong agreement was observed between histopathologic readings and ATR-FTIR analysis. This study shows the potential of ATR-FTIR spectroscopy as a potential adjunct method to the gold standard, the microscopic examination of hematoxylin and eosin (H&E)-stained tissues, in diagnosing lung cancer.

No abstract

Type of article: Full paper 12 Running head: Clostridioides difficile antibodies and colorectal cancer 13 Abstract 28 29Dysbiosis, defined as an imbalance in the gut microbiota caused by too few beneficial 30 bacteria and an overgrowth of bad bacteria, yeast, and/or parasites, is now being associated with 31 several diseases, including the development of colorectal carcinoma (CRC). In this study, the 32 potential association of Clostridioides difficile (formerly Clostridium difficile) with CRC was 33 investigated. Plasma samples obtained from preoperative histologically confirmed CRC patients 34 (n=39) and their age-and sex-matched clinically healthy controls (n=39) were analyzed for 35 antibodies to toxin B of C. difficile (anti-tcdB) by enzyme-linked immunosorbent assay (ELISA). 36A significantly greater number (p=0.012) of CRC cases (n=26/39, 66.7%) had anti-tcdB IgG 37 levels above the cutoff value compared with controls (n=12/39, 30.8%). Eight cases (8/39, 38 20.5%) and none of the controls registered anti-tcdB IgA levels above the cutoff value 39 (p=0.0039). Anti-tcdB IgG and IgA levels were not shown to be significantly associated with 40 tumor grade or tumor stage. Anti-tcdB IgG showed 66.7% sensitivity and 69.2% specificity. For 41 anti-tcdB IgA, sensitivity and specificity were 20.5% and 100%, respectively. The positive 42 predictive values for anti-tcdB IgA and IgG were 100% and 68.4%, respectively. The anti-tcdB 43 IgA and IgG negative predictive values were 55.7% and 67.5%, respectively. The results suggest 44 the potential association of C. difficile with CRC and anti-tcdB levels, particularly the IgA level. 45Hence, anti-tcdB antibodies can be candidate serologic markers for CRC. 46 47 48 51Colorectal cancer (CRC) is one of the most prevalent cancers in the world [1]. Diet, 52 particularly the consumption of poultry and animal products, has been linked to increased cases 53 of CRC [2]. Imbalance in chromosome number, genomic amplifications in the subchromosomal 54 region, and high frequency of heterozygous loss also lead to mutation and malignant transition of 55 cells in the colon [3, 4]. 56In addition, the potential role of gut microbes in CRC development has been a hot topic 57 lately. Several hypotheses have emerged on how these bacteria promote carcinogenesis. 58 Dysbiosis and alterations in the normal microbial community remodel the whole microbiome, 59 initiating inflammation and cell differentiation which could eventually lead to cancer [5]. The 60 "driver-passenger" model proposes that some bacteria classified as "bacterial drivers" initiate the 61 development of colonic tumors through gene damage, stimulating the colonization of passenger 62 bacteria in the tumoral microenvironment [5, 6]. Some "keystone pathogens" that emerge during 63 dysbiosis and are likely to be part of carcinogenesis include Bacteroides, Enterococcus, 64 Fusobacterium, Streptococcus, Escherichia coli, and Clostridium [5, 7]. 65 Clostridioides difficile (formerly Clostridium difficile) is a gram-positive, ana...