Widespread somatic L1 retrotransposition occurs early during gastrointestinal cancer evolution.

Somatic L1 retrotransposition events have been shown to occur in epithelial cancers. Here, we attempted to determine how early somatic L1 insertions occurred during the development of gastrointestinal (GI) cancers. Using L1-targeted resequencing (L1-seq), we studied different stages of four colorectal cancers arising from colonic polyps, seven pancreatic carcinomas, as well as seven gastric cancers. Surprisingly, we found somatic L1 insertions not only in all cancer types and metastases but also in colonic adenomas, well-known cancer precursors. Some insertions were also present in low quantities in normal GI tissues, occasionally caught in the act of being clonally fixed in the adjacent tumors. Insertions in adenomas and cancers numbered in the hundreds, and many were present in multiple tumor sections, implying clonal distribution. Our results demonstrate that extensive somatic insertional mutagenesis occurs very early during the development of GI tumors, probably before dysplastic growth.

Clinical Characteristics of Multiple Colorectal Adenoma Patients Without Germline APC or MYH Mutations.

BACKGROUND: Patients with multiple colorectal adenomas (MCRA) without genetic cause are increasingly being diagnosed. The characteristics and natural history of this condition are not well studied. MATERIALS AND METHODS: Twenty-seven patients with MCRA, with cumulatively 10 to 99 colorectal adenomas and without deleterious mutations of APC or MYH genes, were investigated. Results of colonoscopies with a mean follow-up of 4.9 years (range, 0 to 27 y) were evaluated. Findings from esophagogastroduodenoscopy and extracolonic manifestations were assessed. RESULTS: The mean age at polyp diagnosis and MCRA diagnosis was 47.8±13.1 years (range, 21 to 72 y) and 50.4±14.6 years (range, 21 to 72 y), respectively. In 22% of patients another family member had MCRA. At first colonoscopy, the mean number of adenomas was 35.0±35.9 (range, 0 to 99). Serrated polyps were rare. Esophagogastroduodenoscopy revealed 47% of patients had upper tract neoplasia. Patients with upper tract findings were diagnosed with MCRA at significantly younger mean age than those without findings, P<0.05. Eighteen patients (67%) underwent colectomy with a mean time from diagnosis of MCRA of 3.1±1.3 years. After surgery, surveyed patients developed recurrent adenomas in retained colorectum. Nine patients (33%) had extracolonic cancers. CONCLUSIONS: MCRA patients have a similar clinicopathologic phenotype to known syndromes of attenuated adenomatous polyposis and the majority have need for colectomy. The management of MCRA patients and families should parallel that of attenuated familial adenomatous polyposis and MUTYH-associated polyposis including surveillance of the upper tract.

Pre- and post-operative plasma glial fibrillary acidic protein levels in patients with newly diagnosed gliomas.

Therapies that disrupt or repair blood-brain barrier integrity can result in major changes in MRI images even when the tumor volume remains constant. Thus, a reliable blood-based tumor biomarker could significantly improve clinical care and research studies in these patients. This study was performed to assess plasma concentrations of glial fibrillary acidic protein (GFAP) in patients with high- and low-grade gliomas before and after debulking surgery. Pre-operative plasma was collected from 33 patients with radiation- and chemotherapy-naïve gliomas. Additional plasma was collected 24-48 h post-operatively from 23 of these patients. Plasma GFAP (pGFAP) concentrations were determined using an electrochemiluminescent immunoassay and were analyzed as a function of tumor grade, tumor GFAP expression, the integrity of the blood-brain barrier, and post-operative status. Detectable pGFAP levels (≥ 0.04 ng/mL) were found pre-operatively in 52 % of patients and post-operatively in 96 %. Detectable pGFAP was more common in patients with WHO grade IV (100 %) than WHO grade III (56 %) or WHO grade II gliomas (20 %). No patient with undetectable GFAP had WHO grade IV glioma. Higher pGFAP concentrations were also associated with contrast enhancement but not related to tumor GFAP expression. GFAP is commonly detected in the plasma of patients with high-grade gliomas. pGFAP levels rise rather than fall following debulking surgery which is probably a result of surgical trauma. GFAP remains a potentially informative plasma biomarker for gliomas. Longitudinal studies are required to correlate pGFAP levels with patient outcomes.

MIC-1 serum level and genotype: associations with progress and prognosis of colorectal carcinoma.

PURPOSE: Macrophage inhibitory cytokine-1 (MIC-1) is a divergent member of the tumor growth factor beta (TGF-beta) superfamily. Several observations suggest that it plays a role in colorectal carcinoma (CRC). In particular, MIC-1 is markedly up-regulated in colorectal cancers as well as in premalignant adenomas. This study examines the relationship of serum MIC-1 levels and genotypes to clinical and pathologic features of colonic neoplasia. EXPERIMENTAL DESIGN: We confirmed the presence of MIC-1 in CRC tissue and the cell line CaCo-2. The normal range for serum MIC-1 levels was defined in 260 healthy blood donors, and the differences between normal subjects and 193 patients having adenomatous polyps or CRC were then determined. In a separate cohort of 224 patients, we evaluated the relationship of MIC-1 serum level and genotype to standard tumor parameters and outcome measures. RESULTS: MIC-1 was expressed in CRC tissue and the cancer cell line CaCo-2. There was a progressive increase in serum MIC-1 levels between normal individuals [mean (M) = 495 pg/ml, SD = 210), those with adenomatous polyps (M = 681 pg/ml, SD = 410), and those with CRC (M = 783 pg/ml, SD = 491)]. Serum MIC-1 level was correlated with the extent of disease so that the levels were higher in patients with higher Tumor-Node-Metastasis stage. There were significant differences in time to relapse and overall survival between subjects with different MIC-1 levels and genotypes. CONCLUSIONS: This study identifies a strong association between MIC-1 serum levels and neoplastic progression within the large bowel. We suggest that the measurement of serum MIC-1 levels and determination of MIC-1 genotype may have clinical use in the management of patients with CRC.

Risk of colorectal cancer in juvenile polyposis.

BACKGROUND: Juvenile polyposis (JP) is an autosomal-dominant syndrome characterised by the development of hamartomatous gastrointestinal polyps and is associated with colorectal cancer. However, the relative and absolute risk of colorectal malignancy in these patients is not known. METHODS: The incidence rates of colorectal cancer in patients with JP were compared with that of the general population through person-year analysis with adjustment for demographics. RESULTS: In patients with JP, the RR (95% CI) of colorectal cancer was 34.0 (14.4 to 65.7). Similar risks were noted in both males (30.0, 9.6 to 68.6) and females (43.7, 8.8 to 125). The cumulative life-time risk for colorectal cancer was 38.7%. The mean (SD) age of diagnosis of colorectal cancer was 43.9 (10.4) years. Other gastrointestinal malignancies were not noted in this cohort. CONCLUSION: Patients with JP have a markedly increased RR and absolute risk for colorectal cancer and require vigilant colorectal surveillance starting at young age. A low threshold for recommending surgery with consideration for removal of the entire colorectum seems warranted.

Oral contraceptives and polyp regression in familial adenomatous polyposis.

Epidemiologic and experimental reports suggest that female hormones protect against the development of colorectal cancer, but studies are limited. We describe a patient in the placebo arm of a 4-year primary chemoprevention trial who developed adenomatous polyps and then had eradication of polyps after the administration of oral contraceptives. No change in the prostaglandin levels in the colonic mucosa was noted after polyp elimination, making nonsteroidal anti-inflammatory drug ingestion unlikely as a cause. This report represents the regression of colorectal adenomas with the use of estrogen/progesterone compounds.

Counting alleles to predict recurrence of early-stage colorectal cancers.

BACKGROUND: Chromosome imbalances occur in many cancers and represent important biological properties of tumours. However, measurements of such imbalances are difficult. We used a new, quantitative approach to investigate the prognostic value of chromosome imbalances in early-stage colorectal cancers. METHODS: We studied 180 patients with no evidence of lymph-node or distant metastases at the time of surgery. DNA from paraffin-embedded tumours was tested for imbalances of chromosome 8p and 18q by digital SNP (single-nucleotide polymorphism)-a technique in which each allele in a sample is directly counted. Surviving patients had median follow-up of 68 months, and disease recurrence was used as the clinical endpoint. FINDINGS: Tumours were divided into three groups: "L" tumours (n=93) had allelic imbalances of chromosomes 8p and 18q, "L/R" tumours (n=60) had allelic imbalances of either chromosome 8p or 18q but not both, and "R" tumours (n=27) retained allelic balance for both chromosomes. 5-year disease-free survival was 100% (95% CI 80-100) for patients with R tumours, 74% (61-87) for patients with L/R tumours, and 58% (47-69) for those with L tumours. These differences were significant (p<0.0001) and were independent of other variables--eg, Duke's stage A tumours of class L were much more likely to recur than Duke's stage B tumours of class R (p=0.002). INTERPRETATION: In patients without metastasis, allelic imbalance is a better predictor of prognosis than histopathological stage.