Arto Kokkola

The Risk of Gastric Carcinoma and Carcinoid Tumours in Patients with Pernicious Anaemia: A Prospective Follow-Up Study

BACKGROUND This endoscopic follow-up study was undertaken to evaluate the risk of gastric cancer (GC) and carcinoids in patients with pernicious anaemia (PA) and to analyse whether early detection of GC could be provided by regular endoscopic follow-up. METHODS Screening gastroscopy was performed in 71 patients with pernicious anaemia, and thereafter they were followed up with gastroscopies at 3-year intervals for a mean time of 5.8 years. Standardized incidence ratios (SIR) were calculated, the expected number being based on incidence rates in the whole Finnish population. RESULTS Two GCs were found during the follow-up period; one of these patients was asymptomatic and the other had abdominal symptoms. The SIR was 5.0 (95% confidence interval, 0.6-18). Eight carcinoids were detected, and all but one were removed endoscopically, and no metastases were found. The patients who had carcinoid tumours were younger at the diagnosis of PA than those who did not develop carcinoids (mean, 40 versus 55 years). Additionally, the patients with carcinoids had longer duration of PA (mean, 11 versus 5 years). CONCLUSIONS During the follow-up period the risk of GC was increased. The risk of gastric carcinoids seems to be very high in patients with pernicious anaemia when compared with a normal population, but they are mostly relatively benign tumours. Regular routine gastroscopic follow-up is not indicated in patients with pernicious anaemia.

Spontaneous disappearance of Helicobacter pylori antibodies in patients with advanced atrophic corpus gastritis

Background. Only a few reported studies focus on the natural history and course of advanced and severe chronic atrophic gastritis. Methods. In this study we followed 47 men (mean age 62 years) with advanced (moderate or severe) Helicobacter pylori‐positive atrophic corpus gastritis. Duration of endoscopic follow‐up was 6 years and follow‐up based on serum levels of pepsinogen I and antibodies to H. pylori covered a period of 10 years. None of the patients was treated for H. pylori infection prior to end of follow‐up. Results. The median H. pylori antibody titre declined (IgG from 4000 to 1300; IgA from 200 to 50) in the study population, and 11 men (23%) converted to seronegative (p=0.0005, Fishers exact test). There was a small but significant (p=0.0004, Pages test) declining trend in mean atrophy score of the corpus during follow‐up (from 2.5 to 2.2). However, no significant changes were observed in grade of atrophy or intestinal metaplasia of the antral mucosa or in grade of intestinal metaplasia in the corpus. The mean SPGI level remained at the initial low level during the entire follow‐up. Conclusions. H. pylori antibodies disappear spontaneously within 10 years in almost one fourth of patients with advanced atrophic corpus gastritis. The disappearance of H. pylori antibodies is accompanied by no or more than a mild improvement of the gastric mucosa.

Cyclooxygenase-2 Is an Independent Prognostic Factor in Gastric Cancer and Its Expression Is Regulated by the Messenger RNA Stability Factor HuR

Purpose: Cyclooxygenase-2 (COX-2) promotes carcinogenesis and its expression associates with clinicopathologic characteristics in gastric cancer. HuR is an mRNA binding protein that controls the stability of certain transcripts including COX-2. We evaluated the prognostic significance of COX-2 and HuR expressions in gastric cancer and whether there exists a link between HuR and COX-2 expressions. Experimental Design: The study included 342 consecutive patients with histologically confirmed gastric adenocarcinoma, of whom 321 patients had tissue specimens available for COX-2 and 316 for HuR immunohistochemistry. Specimens were stained by COX-2– and HuR-specific monoclonal antibodies and scored by two independent observers. Correlation to clinical data and survival was assessed. TMK-1 gastric adenocarcinoma cells were treated with small interfering RNA against HuR and expressions of HuR and COX-2 were detected by immunofluorescence and Western blot analysis. Results: Patients with low COX-2 expression had a cumulative 5-year survival of 53% and those with high COX-2 expression had 16% (P < 0.0001). In multivariate analysis, COX-2 was an independent prognostic factor (P = 0.003). Cytoplasmic HuR expression was associated with high COX-2 expression (P < 0.0001) and with reduced survival (P = 0.004) whereas nuclear positivity for HuR was not. When TMK-1 cells were treated with HuR small interfering RNA, expressions of HuR and COX-2 were reduced. Conclusions: High COX-2 is an independent prognostic factor in gastric cancer. Cytoplasmic expression of HuR associates with high COX-2 expression and with reduced survival, and tissue culture experiments show that HuR can regulate expression of COX-2 in gastric cancer cells.

LKB1 Somatic Mutations in Sporadic Tumors

Germline mutations of LKB1/Peutz-Jeghers syndrome gene predispose carriers to hamartomatous polyposis of the gastrointestinal tract as well as to cancer of different organ systems. Although Peutz-Jeghers syndrome patients frequently present with neoplasms of the colon, stomach, small intestine, pancreas, breast, ovaries, and cervix, somatic mutations appear to be rare in the sporadic tumor types thus far studied (colorectal, gastric, testicular, and breast cancers). To evaluate whether somatic mutations of LKB1 contribute to the tumorigenesis of yet unstudied tumor types, we screened 14 cell lines and 129 tumor specimens from different cancers for a genetic defect in LKB1. Six melanoma and eight myeloma cell lines were scrutinized for LKB1 somatic mutations by genomic sequencing. No changes were found in the coding LKB1 sequence and exon/intron boundaries. Next, we analyzed 12 pancreatic, 8 gastric, 12 ovarian granulosa cell, 26 cervical, 28 lung, 24 soft tissue, and 19 renal tumors by single-strand conformational polymorphism analysis. Three changes in LKB1 coding nucleotide sequence were identified. One base pair deletion at A957 and G958 substitution by T occurred in a cervical adenocarcinoma sample, resulting in a frameshift and premature stop codon at position 335. Substitution of A581 by T occurred in a lung adenocarcinoma sample, resulting in the change of aspartic acid at position 194 to valine. A loss of another allele was detected in this sample. One silent change, C1257T, was found in a pancreatic carcinoma sample. The changes were not present in the matched normal tissue DNA samples. Our results suggest that mutational inactivation of LKB1 is a rare event in most sporadic tumor types.

The effect of Helicobacter pylori eradication on the natural course of atrophic gastritis with dysplasia

There are few data on the natural course of Helicobacter pylori‐related atrophic gastritis.

Epithelial and stromal syndecan-1 expression as predictor of outcome in patients with gastric cancer.

The prognostic value of the immunohistochemical expression of epithelial and stromal syndecan‐1 was evaluated in 296 patients with gastric carcinoma. Formalin‐fixed, paraffin‐embedded specimens of gastric adenocarcinomas were stained with mouse monoclonal antibody B‐B4 against human syndecan‐1. Loss of immunoreactivity (≤60% of cancer cells stained) was observed in 197 (67%) patients. Stromal immunoreactivity was observed in 28 (9%) patients. Loss of epithelial syndecan‐1 immunoreactivity correlated with a higher stage of disease (stages II–IV), tumour location in the upper third of the stomach, nodal metastases (N1 or N2), positive stromal syndecan‐1 staining, deep tumour penetration (to subserosa or deeper = T2–T4), larger tumour size (≥5 cm) and intestinal type of cancer. No correlation between epithelial syndecan‐1 immunoreactivity and age, gender, distant metastases, grade of differentiation or Borrmann classification was observed. Positive stromal syndecan‐1 immunoreactivity correlated with decreased epithelial syndecan‐1 expression, intestinal type of cancer and Borrmann type I. Patients with low epithelial syndecan‐1 expression in cancer cells had worse overall survival than patients with strong epithelial syndecan‐1 staining (p = 0.0012). Stromal syndecan‐1‐positive patients had a worse outcome than patients with syndecan‐1‐negative stroma (p = 0.0193). In Cox multivariate analysis, stromal syndecan‐1 immunoreactivity was a prognostic factor independent of TNM stage, surgery for cure and tumour size. Thus, the immunohistochemical expression of syndecan‐1 might be a predictor of outcome in patients with gastric adenocarcinoma.

Diagnosis of Helicobacter pylori Infection in Patients with Atrophic Gastritis: Comparison of Histology, 13C-Urea Breath Test, and Serology

BACKGROUND Atrophic gastritis, a risk factor for gastric cancer, is a late consequence of Helicobacter pylori infection in approximately one-third of the infected patients. It has been suggested that gastric cancer would develop less frequently if H. pylori were eradicated. However, the prevalence of H. pylori infection may be underestimated in patients with atrophic gastritis and intestinal metaplasia if only biopsy-based diagnostic methods are used. METHODS We compared histology, 13C-urea breath test (13C-UBT), and serology in H. pylori diagnostics in 50 male patients with atrophic corpus gastritis. RESULTS H. pylori was detected in 15 (30%) patients by histology and in 14 (28%) by 13C-UBT, whereas increased serum antibody levels indicating H. pylori infection were found in 41 (82%) patients (P < 0.0001 between serology and both histology and 13C-UBT). H. pylori infection was associated with atrophic corpus gastritis in 84% of the present patients (in one patient with normal antibody titres H. pylori was defined histologically). CONCLUSIONS H. pylori infection would have been missed in most patients with atrophic gastritis without the analysis of H. pylori antibodies. Therefore, in patients with atrophic gastritis, the use of serology is encouraged in diagnosing H. pylori infection.Background: Atrophic gastritis, a risk factor for gastric cancer, is a late consequence of Helicobacter pylori infection in approximately one-third of the infected patients. It has been suggested that gastric cancer would develop less frequently if H. pylori were eradicated. However, the prevalence of H. pylori infection may be underestimated in patients with atrophic gastritis and intestinal metaplasia if only biopsy-based diagnostic methods are used. Methods: We compared histology, 13C-urea breath test (13C-UBT), and serology in H. pylori diagnostics in 50 male patients with atrophic corpus gastritis. Results: H. pylori was detected in 15 (30%) patients by histology and in 14 (28%) by 13C-UBT, whereas increased serum antibody levels indicating H. pylori infection were found in 41 (82%) patients (P < 0.0001 between serology and both histology and 13C-UBT). H. pylori infection was associated with atrophic corpus gastritis in 84% of the present patients (in one patient with normal antibody titres H. pylori was defined histologically). Conclusions: H. pylori infection would have been missed in most patients with atrophic gastritis without the analysis of H. pylori antibodies. Therefore, in patients with atrophic gastritis, the use of serology is encouraged in diagnosing H. pylori infection.

17q12‐21 amplicon, a novel recurrent genetic change in intestinal type of gastric carcinoma: A comparative genomic hybridization study

We studied DNA copy number changes in gastric cancer (GC) using comparative genomic hybridization (CGH) analysis on 35 resected gastric carcinomas (22 of the intestinal type and 13 of the diffuse type). Eighty‐three percent of the cases showed DNA copy number changes. Gains were more common than losses (median of 3 and 1 in primary tumors of the intestinal and diffuse type, respectively). The most common gains were detected on 20q [46%; 12 intestinal type (55%) and four diffuse type (31%)], 8q [37%; 10 intestinal type (45%) and three diffuse type (23%)], and 17q12‐21 [29%; all but one intestinal type (41%)]. The most frequent losses were detected on 18q [26%; all intestinal type (41%)] and on 4q [23%; all intestinal type (32%)]. High‐level amplifications were observed in the intestinal type of tumors at 17q12‐21 (three tumors), 20q (three tumors), 2p (one tumor), and 18q (one tumor). In the diffuse type, high‐level amplification was detected once at 13q. Genes Chromosom. Cancer 20:38–43, 1997.

Risk of gastric carcinoma in patients with mucosal dysplasia associated with atrophic gastritis: a follow up study.

AIMS: To assess the risk of gastric carcinoma in patients with histologically verified dysplasia and atrophic gastritis of the stomach. METHODS: One hundred and one patients with mild (n = 84), moderate (n = 14), or severe (n = 3) dysplasia among 359 elderly men who smoked underwent gastroscopy because of low serum pepsinogen. Patients with dysplasia were prospectively followed up for an average of four years with repeated gastroscopies and multiple biopsies. RESULTS: Four of the 84 (4.8%) cases of mild dysplasia had progressed to moderate dysplasia during the follow up. Most of the cases of mild dysplasia had resolved spontaneously. No surgical intervention was required. Three of the 14 (21%) cases of moderate dysplasia had progressed to severe dysplasia, but no carcinomas were observed during follow up. Five moderately dysplastic lesions were removed surgically or endoscopically. In two of these five cases, moderate or severe dysplasia recurred. Two of the three severe dysplasias progressed to carcinoma. CONCLUSIONS: In atrophic gastritis progression of mild and moderate dysplastic lesions seems to be a slow process and is rare in mild dysplasia. However, severe dysplasia is highly predictive of subsequent cancer. It is suggested that a five year follow up interval is sufficient in cases with mild dysplasia and two years in those with moderate dysplasia. Local removal of moderate dysplasia is indicated but does not guarantee that the lesion will not progress. Severe dysplasia requires immediate surgical intervention.

Integrated gene copy number and expression microarray analysis of gastric cancer highlights potential target genes

We performed an integrated array comparative genomic hybridization (aCGH) and expression microarray analysis of 8 normal gastric tissues and 38 primary tumors, including 25 intestinal and 13 diffuse gastric adenocarcinomas to identify genes whose expression is deregulated in association with copy number alteration. Our aim was also to identify molecular genetic alterations that are specific to particular clinicopathological characteristics of gastric cancer. Distinct molecular genetic profiles were identified for intestinal and diffuse gastric cancers and for tumors obtained from 2 different locations of the stomach. Interestingly, the ERBB2 amplification and gains at 20q13.12‐q13.33 almost exclusively discriminated intestinal cancers from the diffuse type. In addition, the 17q12‐q25 gain was characteristic to cancers located in corpus and the 20q13.12‐q13.13 gain was more common in the antrum. Statistical analysis was performed using integrated copy number and expression data to identify genes showing differential expression associated with a copy number alteration. Genes with the highest statistical significance included ERBB2, MUC1, GRB7, PPP1R1B and PPARBP with concomitant changes in copy number and expression. Immunohistochemical analysis of ERBB2 and MUC1 on a tissue microarray containing 78 independent gastric tissues showed statistically significant differences (p < 0.05 and <0.001) in immunopositivity in the intestinal (31 and 70%) and diffuse subtypes (14 and 41%), respectively. In conclusion, our results demonstrate that intestinal and diffuse type gastric cancers as well as cancers located in different sites of the stomach have distinct molecular profiles which may have clinical value.