EGFR mutation genotyping and ALK status determination in liquid-based cytology samples of non-small cell lung cancer.

Personalised medicine for primary lung cancers (PLCs) requires molecular analysis of cancer tissue or cells. The primary objective of the present prospective study was to assess the concordance between epidermal growth factor receptor (EGFR) gene mutation detection and echinoderm microtubule-associated protein-like (EML) 4-anaplastic lymphoma kinase protein (ALK) expression using liquid-based cytology (LBC) samples and matched histology samples of PLC patients. A total of 117 patients who underwent surgical resection of non-small cell PLC were enrolled. Cytological specimens scratched from the resected PLC lesion were fixed in CytoRich Red. DNA extracted from LBC samples was examined for EGFR gene mutations. Anaplastic lymphoma kinase arrangement was analysed by immunostaining and fluorescence in situ hybridisation. Our patient cohort comprised 93 cases of adenocarcinoma, 16 squamous cell carcinoma, three adenosquamous carcinoma, two large cell neuroendocrine carcinoma, one pleomorphic carcinoma and two other cases. Sixty-six (58.4%) LBC samples harboured EGFR gene mutations. The overall concordance rate in EGFR gene mutation status, including minor mutations, between histologic and paired LBC specimens (N = 105) was 100%. The overall concordance rate of EGFR gene mutation status, including minor mutations and ALK status according to immunostains between histologic and paired LBC specimens, was 100% (105/105) and 100% (48/48), respectively. Genotyping and protein expression studies can be reliably performed using LBC samples prepared with CytoRich Red. Analysis of such samples may guide individual therapy in PLC patients.

Genetic alterations of K-ras may reflect prognosis in stage III colon cancer patients below 60 years of age.

PURPOSE: Genetic alterations that are closely associated with patient prognosis can be landmarks of definitive therapeutic targets as well as useful biomarkers in human cancer clinics. METHODS: Three hundred seventy-eight colorectal cancer (CRC) patients were examined for K-ras mutations by single-strand conformation polymorphism (SSCP), with a subsequent 144 young colon cancer (YCC) patients added to validate its prognostic significance. RESULTS: K-ras mutations were identified in 161 (43%) of the 378 CRC patients and were significantly associated with tumor location (colon vs. rectum; 80/218 = 37% vs. 81/160 = 51%; P = 0.0068) and age (≥60 vs. <60; 103/220 = 47% vs. 58/158 = 37%; P = 0.049). The incidence of K-ras mutations was 30% in YCC patients as compared to 55% in elderly rectal cancer patients (P = 0.0004). K-ras mutations significantly correlated with a worse prognosis (P = 0.0014) only in 73 curatively resected YCC with stages I-III, but not in other CRCs, which was further validated in the independent set of the corresponding 144 YCC patients (P = 0.024). Both univariate and multivariate analyses identified K-ras mutations as an independent prognostic factor (HR = 5.5, P = 0.029; HR = 3.6, P = 0.011) in both learning and validation sets of the curatively resected YCC with stages I-III, respectively, and the prognostic relevance was marked in stage III YCC patients (P = 0.002), but not in stages I, II, and IV. CONCLUSION: In curative YCC, K-ras mutations could have excellent prognostic value. Hence, the K-ras mutation status could be a good indicator to predict the clinical outcome in curatively resected stage III YCC patients, and K-ras pathway inhibition may be a relevant therapeutic target in CRC, excluding YCC patients with no K-ras mutation.

Sporadic TP53 transition mutations in chronic cholecystitis are possibly linked to gallbladder carcinogenesis.

BACKGROUND/AIM: Gallbladder cancers are well known to frequently exhibit TP53 as well as K-ras gene mutations. This study performed a TP53 gene investigation by PCR-SSCP and direct sequencing using both bile supernatants and tissue samples from cholecystectomy specimens lacking gallbladder cancer, in order to investigate gallbladder carcinogenesis. MATERIALS AND METHODS: Eighteen out of 294 cases, mainly of cholecystitis, were extracted by screening SSCP of bile supernatants for TP53 mutations, and investigation of their tissue samples both SSCP and direct sequencing. RESULTS: Non-neoplastic mucosal samples demonstrated shifted bands in 11 cases (61%), and mutations were confirmed in 7 cases (64%). Unexpectedly, no cases showed identical point mutations in both bile and tissue samples. G:C to A:T transitions, thought to be sporadic mutations, predominated (77%). CONCLUSION: Sporadic TP53 transition mutations were demonstrated in non-neoplastic lesions such as severe cholecystitis, indicating an importance for a chronic cholecystitis-carcinoma sequence in gallbladder carcinogenesis.

Unique characteristics of rectal carcinoma cell lines derived from invasive carcinomas in ulcerative colitis patients.

To identify the characteristics of ulcerative colitis (UC)-associated carcinomas, 8 lesions, high-grade dysplasias and invasive carcinomas, were implanted into severely combined immunodeficient (SCID) mice and/or cultured in vitro. Intramucosal neoplasias consisting of high-grade dysplasia showed extremely slow proliferation after implantation (2/3 cases) and in vitro culture failed (4 cases). However, invasive carcinomas demonstrated rapid growth both after SCID mouse implantation and in vitro (4/4 cases). From two cases of invasive carcinomas, 6 cell lines were established, and these are the first to be described in the literature. In addition to variation in immunohistochemically determined phenotypic expression regarding alpha-fetoprotein, chromogranin A and estrogen receptors, the established cell lines showed varying differentiation (moderately or poorly differentiated adenocarcinoma, adenosquamous carcinoma and poorly differentiated adenocarcinoma with multinuclear giant cells and bone formation). The results are in contrast with findings for sporadic colorectal carcinomas. Although the prevalence of DNA alterations is not frequent, loss of heterozygosity (17p and 18q) and deletion of exons 8 to 11 in DPC-4 were revealed in all of 6 cell lines, suggesting relatively high genetic instability. We found loss or translocation of many chromosomes (#3, 5, 6, 8, 10, 11, 13, 16, 17, 18 and 19) other than chromosomes 1, 5, 8, 11, 13, 17 and 18, which are frequently involved in sporadic colorectal carcinoma cell lines. Thus, the established cell lines may be good models of tumorigenesis and progression in the chronic inflammation-carcinoma sequence.