Family history of cancer in Japanese gastric cancer patients

Frequency of Positive Familial Criteria in Patients with Adenocarcinoma of the Esophageal-Gastric Junction and Stomach: First Prospective Data in a Caucasian Cohort

Simple Summary

It is well known for gastric cancer patients with subtype of diffuse histology that a proportion of patients harbour an increased familial risk. Some patients and relatives even may be detected through a genetic testing. More precise studies about the frequency of hereditary criteria in a poplation with only European ancestries for adenocarcinoma of the esophagogastric junction and stomach are missing. In current guidelines regarding genetic testing criteria not all types of stomach cancer are considered as for example patients not with subtype of diffuse histology mostly have no detectable responsible gene. The aim of the current study was to register stomach cancer patients of all different types in a certain region (Berlin, Germany) and to estimate the frequency of positive familial criteria. Patients with esophageal cancer served as comparison group as familial or hereditary background, respectively, is not significant in these patients according to current knowledge. In our study, we identified positive familial criteria in about 15% of stomach cancer patients. In regard to all different types of stomach cancer, this number almost doubled. Furthermore, one third of all registered patients in this study might have a familial or hereditary background of their disease. We therefore conclude that guidelines regarding genetic testing criteria and screening examinations should be adjusted in future.

Abstract

Objectives: Current prospective studies investigating the frequency of hereditary criteria in a Caucasian population for adenocarcinoma of the esophagogastric junction (AEG) and stomach (GC) are missing. Genetic testing criteria (screening criteria) for hereditary diffuse gastric cancer (HDGC) were updated in 2020, but do not address patients with intestinal histology (familial intestinal gastric cancer FIGC). Thus, we prospectively screened patients residing in Berlin newly diagnosed with AEG or GC for hereditary criteria to gain insights into the frequency of HDGC. Methods: Prospective documentation of familial/clinical parameters in patients residing in Berlin with AEG or GC over three years was conducted. Besides HDGC criteria from 2015 and revised 2020, we also documented patients fulfilling these criteria but with intestinal type gastric cancer (FIGC). Statistical analysis was performed using X2-test. Results: One hundred fifty-three patients were finally included (92 GC; male: 50 (n.s.); 61 AEG; male: 47; p = 0.007). Hereditary criteria for HDGC were detected in 9/92 (9.8%) (2015 criteria) and in 14/92 (15.2%) (2020 criteria) of GC patients (AEG: 2015 criteria 3/61 (4.9%) versus 4/61 according to 2020 criteria (6.5%)). Patients fulfilling hereditary criteria but with intestinal histology (FIGC) increased from 8.7% (2015) to 14.1%, respectively (2020) (AEG: 3.2% (2015) versus 6.6% (2020)). Hereditary criteria including intestinal histology were found in 29.3% (GC) and 13.1% (AEG) (p = 0.03) according to the 2020 criteria. Conclusions: HDGC criteria were found in 15.2% of GC patients according to the 2020 criteria. Percentage increased to 29.3% including patients with intestinal histology among the GC group, and was 13.1% in cases with AEG. These data indicate that family history seems to be of utmost importance in GC to further detect potential hereditary genetic risks. This equally applies for patients with intestinal subtype GC.

Influence of Fasting Glucose Level on Gastric Cancer Incidence in a Prospective Cohort Study

BACKGROUND

High fasting glucose has been indicated in relation to a higher risk of gastric cancer, but the majority of studies have focused on diabetes (fasting glucose ≥126 mg/dL). Here, we investigated whether fasting glucose levels, including prediabetic and diabetic levels, influence gastric cancer incidence.

METHODS

A prospective study was conducted with 41,837 participants aged 16 and older who underwent health examinations at the National Cancer Center in South Korea from August 2002 to December 2014. Participants were followed up until December 2017 to identify incident gastric cancer cases. A fasting glucose test was performed based on venous blood samples taken from participants after 8 hours of fasting. We used the Cox proportional hazards regression model to explore the association of fasting glucose levels with gastric cancer incidence.

RESULTS

We identified 263 incident gastric cancer cases during the follow-up period. A significant association of high fasting glucose with gastric cancer incidence was found for postmenopausal women [hazard ratio (HR) = 1.88; 95% confidence interval (CI) = 1.11-3.20]. There was also a significant association between high fasting glucose and gastric cancer incidence among all participants who were nonsmokers (HR = 1.89; 95% CI = 1.21-2.95), had a BMI < 25 kg/m² (HR = 1.45; 95% CI = 1.00-2.12), and did not have a first-degree family history of gastric cancer (HR = 1.45; 95% CI = 1.06-1.99).

CONCLUSIONS

Our findings support that high fasting glucose is a risk factor for gastric cancer development in postmenopausal women.

IMPACT

Our results provide evidence for future planning and management regarding cancer prevention.

Geographical Distribution of E-cadherin Germline Mutations in the Context of Diffuse Gastric Cancer: A Systematic Review

Simple Summary

E-cadherin (CDH1 gene) germline mutations are associated with the development of the autosomal cancer syndrome known as hereditary diffuse gastric cancer. About 30% of families fulfilling the clinical criteria established by the International Gastric Cancer Linkage Consortium have constitutional alterations of the CDH1 gene. Different patterns of CDH1 germline mutations have described as truncating, deletion, insertion, splice site, non sense, silence, and at last, missense alterations. The frequency of the different E-cadherin germline mutations in countries with different incidence rates for gastric carcinoma has reported extremely variable. In this study we aimed to assess the worldwide frequency of CDH1 germline mutations in gastric cancers coming from different geographical areas, using a systematic approach.

Abstract

Hereditary diffuse gastric cancer (HDGC) is a complex and multifactorial inherited cancer predisposition syndrome caused by CDH1 germline mutations. Nevertheless, current CDH1 genetic screening recommendations disregard an unbalanced worldwide distribution of CDH1 variants, impacting testing efficacy and patient management. In this systematic review, we collected and analyzed all studies describing CDH1 variants in gastric cancer patients originating from both high- and low-prevalence countries. Selected studies were categorized as family study, series study, and unknown study, according to the implementation of HDGC clinical criteria for genetic testing. Our results indicate that CDH1 mutations are more frequently identified in gastric cancer low-incidence countries, and in the family study group that encompasses cases fulfilling criteria. Considering the type of CDH1 alterations, we verified that the relative frequency of mutation types varies within study groups and geographical areas. In the series study, the missense variant frequency is higher in high-incidence areas of gastric cancer, when compared with non-missense mutations. However, application of variant scoring for putative relevance led to a strong reduction of CDH1 variants conferring increased risk of gastric cancer. Herein, we demonstrate that criteria for CDH1 genetic screening are critical for identification of individuals carrying mutations with clinical significance. Further, we propose that future guidelines for testing should consider GC incidence across geographical regions for improved surveillance programs and early diagnosis of disease.

Enrichment of CLDN18-ARHGAP fusion gene in gastric cancers in young adults

Gastric cancer in young adults has been pointed out to comprise a subgroup associated with distinctive clinicopathological features, including an equal gender distribution, advanced disease, and diffuse-type histology. Comprehensive molecular analyses of gastric cancers have led to molecular-based classifications and to specific and effective treatment options. The molecular traits of gastric cancers in young adults await investigations, which should provide a clue to explore therapeutic strategies. Here, we studied 146 gastric cancer patients diagnosed at the age of 40 years or younger at the Cancer Institute Hospital (Tokyo, Japan). Tumor specimens were examined for Helicobacter pylori infection, Epstein-Barr virus positivity, and for the expression of mismatch repair genes to indicate microsatellite instability. Overexpression, gene amplifications, and rearrangements of 18 candidate driver genes were examined by immunohistochemistry and FISH. Although only a small number of cases were positive for Epstein-Barr virus and microsatellite instability (n = 2 each), we repeatedly found tumors with gene fusion between a tight-junction protein claudin, CLDN18, and a regulator of small G proteins, ARHGAP, in as many as 22 cases (15.1%), and RNA sequencing identified 2 novel types of the fusion. Notably, patients with the CLDN18-ARHGAP fusion revealed associations between aggressive disease and poor prognosis, even when grouped by their clinical stage. These observations indicate that a fusion gene between CLDN18 and ARHGAP is enriched in younger age-onset gastric cancers, and its presence could contribute to their aggressive characteristics.

Familial aggregation of gastric cancer with microsatellite instability

BACKGROUND

Microsatellite instability (MSI) is currently a new molecular subtype of gastric cancer (GC). About 90% of GC cases appear sporadically. MSI seems to be responsible for both sporadic and familial GC. The aim of this study was to analyze the frequency of MSI in GC with familial history of GC.

METHODS

The MSI analysis was conducted using five quasi-monomorphic mononucleotide repeats: BAT-26, BAT-25, NR-24, NR-21 and NR-27. From our database, we analyzed 457 patients in terms of cancer history across family members, particularly focusing on GC.

RESULTS

MSI status in patients without familial history of GC was present in 22.1% of the cases, whereas in the patients with familial history of GC it was present in 28% of the cases (p = 0.220). For 1st or 2nd degree family members with GC, MSI was observed in 27.6% and in 30.8%, respectively (p = 0.812). MSI was observed in hereditary gastric cancer (HGC) in 33.3% and in familial gastric cancer (FGC) in 30%. No difference in survival rates was observed between the analyzed groups.

CONCLUSIONS

In our publication, we could not find any link between familial background and the MSI status in GC patients. More detailed molecular and genetic analysis of subgroups of these patients is required.

Prognostic significance of cancer family history for patients with gastric cancer: a single center experience from China

Family history of cancer is a risk factor for gastric cancer. In this study, we investigated the prognoses of gastric cancer patients with family history of cancer. A total of 1805 gastric cancer patients who underwent curative gastrectomy from 2000 to 2008 were evaluated. The clinicopathologic parameters and prognoses of gastric cancer patients with a positive family history (PFH) of cancer were compared with those with a negative family history (NFH). Of 1805 patients, 382 (21.2%) patients had a positive family history of cancer. Positive family history of cancer correlated with younger age, more frequent alcohol and tobacco use, worse differentiation, smaller tumor size, and more frequent tumor location in the lower 1/3 of the stomach. The prognoses of patients with a positive family history of cancer were better than that of patients with a negative family history. Family history of cancer independently correlated with better prognosis after curative gastrectomy in gastric cancer patients.

Unraveling genetic predisposition to familial or early onset gastric cancer using germline whole-exome sequencing

Recognition of individuals with a genetic predisposition to gastric cancer (GC) enables preventive measures. However, the underlying cause of genetic susceptibility to gastric cancer remains largely unexplained. We performed germline whole-exome sequencing on leukocyte DNA of 54 patients from 53 families with genetically unexplained diffuse-type and intestinal-type GC to identify novel GC-predisposing candidate genes. As young age at diagnosis and familial clustering are hallmarks of genetic tumor susceptibility, we selected patients that were diagnosed below the age of 35, patients from families with two cases of GC at or below age 60 and patients from families with three GC cases at or below age 70. All included individuals were tested negative for germline CDH1 mutations before or during the study. Variants that were possibly deleterious according to in silico predictions were filtered using several independent approaches that were based on gene function and gene mutation burden in controls. Despite a rigorous search, no obvious candidate GC predisposition genes were identified. This negative result stresses the importance of future research studies in large, homogeneous cohorts.

Historical Perspective on Familial Gastric Cancer

Gastric cancer is a common disease worldwide, typically associated with acquired chronic inflammation in the stomach, related in most instances to infection by Helicobacter pylori. A small percentage of cases occurs in familial clusters, and some of these can be linked to specific germline mutations. This article reviews the historical background to the current understanding of familial gastric cancer, focuses on the entity of hereditary diffuse gastric cancer, and also reviews the risks for gastric cancer related to a number of other familial genetic diseases.

Histopathological, Molecular, and Genetic Profile of Hereditary Diffuse Gastric Cancer: Current Knowledge and Challenges for the Future

Familial clustering is seen in 10 % of gastric cancer cases and approximately 1-3 % of gastric cancer arises in the setting of hereditary diffuse gastric cancer (HDGC). In families with HDGC, gastric cancer presents at young age. HDGC is predominantly caused by germline mutations in CDH1 and in a minority by mutations in other genes, including CTNNA1. Early stage HDGC is characterized by a few, up to dozens of intramucosal foci of signet ring cell carcinoma and its precursor lesions. These include in situ signet ring cell carcinoma and pagetoid spread of signet ring cells. Advanced HDGC presents as poorly cohesive/diffuse type carcinoma, normally with very few typical signet ring cells, and has a poor prognosis. Currently, it is unknown which factors drive the progression towards aggressive disease, but it is clear that most intramucosal lesions will not have such progression.Immunohistochemical profile of early and advanced HDGC is often characterized by abnormal E-cadherin immunoexpression, including absent or reduced membranous expression, as well as "dotted" or cytoplasmic expression. However, membranous expression of E-cadherin does not exclude HDGC. Intramucosal HDGC (pT1a) presents with an "indolent" phenotype, characterized by typical signet ring cells without immunoexpression of Ki-67 and p53, while advanced carcinomas (pT > 1) display an "aggressive" phenotype with pleomorphic cells, that are immunoreactive for Ki-67 and p53. These features show that the IHC profile is different between intramucosal and more advanced HDGC, providing evidence of phenotypic heterogeneity, and may help to define predictive biomarkers of progression from indolent to aggressive, widely invasive carcinomas.

Accuracy of Hereditary Diffuse Gastric Cancer Testing Criteria and Outcomes in Patients With a Germline Mutation in CDH1

BACKGROUND & AIMS

Germline mutations in the cadherin 1, type 1, E-cadherin gene (CDH1) cause a predisposition to gastric cancer. We evaluated the ability of the internationally accepted hereditary diffuse gastric cancer (HDGC) criteria to identify individuals with pathogenic mutations in CDH1, and assessed their outcomes. The criteria were as follows: families with 2 or more cases of gastric cancer, with at least 1 patient diagnosed with diffuse gastric cancer (DGC) before age 50; families with 3 or more cases of DGC; families with 1 DGC before the age of 40; and families with a history of DGC and lobular breast cancer, with 1 diagnosis before the age of 50.

METHODS

We collected results of a CDH1 mutation analysis of 578 individuals from 499 families tested in The Netherlands between 1999 and 2014 (118 families met the HDGC criteria for testing and 236 did not; there were 145 families with incomplete data and/or availability of only first-degree relatives). Data were linked with family histories and findings from clinical and pathology analyses. The Kaplan-Meier method and Cox regression analysis were used to evaluate the overall survival of patients with and without CDH1 mutations.

RESULTS

In a cohort study in The Netherlands, the HDGC criteria identified individuals with a germline CDH1 mutation with a positive predictive value of 14% and 89% sensitivity. There were 18 pathogenic CDH1 mutations in 499 families (4%); 16 of these mutations were detected in the 118 families who met the HDGC criteria for testing. One pathogenic CDH1 mutation was detected in the 236 families who did not meet HDGC criteria and 1 in the 145 families with incomplete data and/or availability of only first-degree relatives. No CDH1 mutations were found in the 67 families whose members developed intestinal-type gastric cancer, or in the 22 families whose families developed lobular breast cancer. Among patients who fulfilled the HDGC criteria and had pathogenic CDH1 mutations, 36% survived for 1 year and 4% survived for 5 years; among patients who fulfilled the HDGC criteria but did not carry pathogenic CDH1 mutations, 48% survived for 1 year and 13% survived for 5 years (P = .014 for comparative survival analysis between patients with and without a CDH1 mutation).

CONCLUSIONS

All individuals with a CDH1 mutation had a personal or family history of diffuse gastric cancer. Patients with gastric cancer and germline CDH1 mutations had shorter survival times than patients who met the HDGC criteria but did not have CDH1 mutations.

Differences in the levels of gastric cancer risk factors between Nanjing and Minqing counties, China

OBJECTIVES

In Fujian Province, China, gastric cancer is one of the leading causes of mortality among all malignant tumors. Nanjing county and Minqing county are located in inland Fujian and have similar general demographics. However, the adjusted mortality rate of gastric cancer in Minqing was found to be much higher than that in Nanjing. We sought to explore factors associated with this increased risk of gastric cancer between the two counties.

METHODS

We recruited 231 and 224 residents from Nanjing and Minqing, respectively, and analyzed differences between their dietary habits, Helicobacter pylori infection rates, and concentrations of serum pepsinogen I, pepsinogen II, gastrin-17, and ratio of pepsinogen I:II.

RESULTS

Subjects in Minqing had more first-degree relatives who had been diagnosed with upper gastrointestinal tumor, more unhealthy dietary habits, a higher Helicobacter pylori positive rate, and greater proportion of abnormal serum gastrin-17 than those in Nanjing did.

CONCLUSIONS

The factors that differed between these two counties might indicate that residents in Minqing have a higher risk for developing gastric cancer than those in Nanjing do.

Clinical factors related with helicobacter pylori infection--is there an association with gastric cancer history in first-degree family members?

BACKGROUND

The aim of this study was to assess clinical factors associated with Helicobacter pylori positivity and to evaluate the incidence of gastric carcinoma in first-degree family members of infected patients. A total of 580 patients (mean age:38±17) with gastrointestinal complaints underwent C-14 urea breath test (UBT). Patients were grouped as: Group-1, untreated patients (n:384); and Group-2, patients who previously treated with eradication triple therapy (n:196). C-14 UBT was performed 1-2 months after the completion of eradication therapy. Associations of H pylori positivity with age, gender, ABO and Rhesus groups, smoking, dietary habits, and history of gastric cancer in first-degree family members were evaluated. The frequency of H pylori positivity was significantly higher in group-1 (58%) compared to group-2 (20%), p=0.001. There were no correlations between H pylori positivity and age, gender, ABO groups, Rhesus subgroups, smoking and dietary habits in both patient groups. The frequency of gastric cancer in family members was significantly higher in patients with H pylori infection among group-1, compared to infected patients among group-2 (56% vs. 28.6% respectively, p=0.03). We observed a significant association between H pylori positivity and the presence of gastric cancer in first-degree relatives of group-1 patients. Our results provide some confirmation of the presence of a link between gastric cancer development and H pylori. C-14 UBT is a sensitive, reliable and a widely recommended test for the detection of H pylori infection and recurrence. We suggest that detection and eradication of H pylori may contribute to a reduced risk of gastric cancer in the family members of infected patients.

Family history of malignant neoplasm and its relation with clinicopathologic features of gastric cancer patients

Background

Few studies to date have evaluated gastric cancer(GC)-related malignant neoplasm family history (MN-FH), and their findings have been largely inconsistent. The aim of this study is to evaluate the prevalence of MN-FH and its relation to the clinicopathologic features of GC.

Methods

A total of 104 hospitalized patients with primary gastric adenocarcinoma was prospectively analyzed from 2008 to 2009. Positive MN-FH was defined as MN-affected first- and second-degree relatives of the current GC cases. The relation between prevalence of positive MN-FH and clinicopathologic features in the current GC patients was assessed using the Chi-square test with Cramer’s V coefficient.

Results

Thirty-seven (35.6%) of the GC patients had positive MN-FH, with 42 associated tumors in first- and second-degree relatives. Twenty-six (61.9%) of the associated tumors were located in the digestive system, including the esophagus (26.2%), stomach (23.8%), liver (9.5%) and colon (2.4%). Lung cancers were the most prevalent non-digestive system-associated tumors (9.5%). Correlation analysis revealed no significant relations with prevalence of MN-FH and any of the clinicopathologic features (all, P > 0.05), including sex (V = 0.044), age (V = 0.060) and histological subtypes (V = 0.109).

Conclusions

More than one-third of the GC patients in our hospital had positive MN-FH. The most frequent forms of MN-FH were esophageal cancer and GC. The prevalence of positive MN-FH was not correlated to any of the clinicopathologic features, including sex, age and histological subtypes in the study population of GC patients.

Gastric precancerous lesions in first degree relatives of patients with known gastric cancer: a cross-sectional prospective study in Guilan Province, north of Iran

BACKGROUND AND OBJECTIVES

In patients with gastric cancer, the most frequently reported family history of cancer also involves the stomach. The aim of this study was to assess the presence of gastric precancerous lesions in first-degree relatives of patients with gastric cancer and to compare the obtained results with those of individuals with no such family history.

METHODS

Between 2007 and 2009, 503 consecutive persons more than 30 years old were enrolled in the study covering siblings, parents or children of patients with confirmed adenocarcinoma of stomach. The control group was made up of 592 patients who were synchronously undergoing upper gastrointestinal endoscopy for evaluation of dyspepsia without gastric cancer or any family history. All subjects were endoscopically examined.

RESULTS

The overall prevalence of Helicobacter pylori was 77.7% in the cancer relatives and in 75.7% in the control group. Chronic gastritis was found in 90.4% vs. 81.1% (P<0.001). Regarding histological findings, 37(7.4%) of the study group had atrophy vs. 12(1.7%) in the control group (P<0.001), while no difference was observed for intestinal metaplasia (20.3%vs. 21.6%, P=0.58). Dysplasia were shown in 4% of cancer relatives but only 0.4% of the control group (P<0.001). There was no gender specificity.

CONCLUSIONS

Findings of our study point to great importance of screening in relatives of gastric cancer patients in Iran.

Association of family history with cancer recurrence and survival in patients with gastric cancer

PURPOSE

Family history of gastric cancer is a major risk factor for the disease. In this study, we investigated the prognoses of patients with gastric cancer with a family history.

PATIENTS AND METHODS

We retrospectively reviewed data from 1,273 patients with gastric adenocarcinoma who had undergone gastrectomy between 2001 and 2005 at a tertiary cancer center hospital. A positive family history was defined as a self-reported history of cancer in first- or second-degree relatives. Patients were followed up until December 2009 for death or recurrence. Clinicopathologic characteristics were compared by family history. Kaplan-Meier plots and Cox proportional hazards regressions were applied for disease-free survival (DFS), recurrence-free survival (RFS), and overall survival (OS).

RESULTS

Of 1,273 patients, 263 patients (20.6%) had first-degree relatives with a history of gastric cancer. First-degree family history of gastric cancer was associated with better DFS, RFS, and OS (P = .012, .006, and .005, respectively). In patients with stage I or II gastric cancer, first-degree family history was not associated with survival. However, it was associated with a reduced risk of recurrence or mortality in patients with stage III or IV gastric cancer. Compared with patients without a family history, the adjusted hazard ratios for those with a first-degree family history of gastric cancer were 0.49 (95% CI, 0.29 to 0.84) for DFS, 0.51 (95% CI, 0.30 to 0.87) for RFS, and 0.47 (95% CI, 0.26 to 0.84) for OS in patients with stage III or IV gastric cancer.

CONCLUSION

A first-degree family history of gastric cancer is associated with improved survival after curative-intent surgery in patients with stage III or IV gastric cancer.

Clinicopathological and patient characteristics of early gastric neoplasia endoscopically resected with loss of Mlh1 expression

Hypermethylation of the promoter region of the MLH1 gene leads to loss of Mlh1 protein expression and plays a key role in the development of gastric cancer. Little is known about the association between Mlh1 expression and the clinicopathological and patient characteristics in early gastric neoplasia, particularly in endoscopically resected tumors. Immunohistochemistry was used to examine Mlh1 expression in 140 early gastric neoplasias obtained by endoscopic resection and comprising 31 gastric adenomas (GAs) and 109 early gastric cancers (EGCs), and compared them to corresponding clinicopathological and patient data. P53 expression and phenotypic profiles were also analyzed. The rate of reduced Mlh1 expression and P53 overexpression was 9.6 and 6.5% in GAs, and 27.5 and 27.5% in EGCs, respectively. In elderly patients (≥65 years of age), the aberrant expression of Mlh1 in EGCs was more significant in female than in male patients (59.9 vs. 29.8%; P=0.016). In addition, the frequency of aberrant Mlh1 expression in EGCs increased significantly in patients with oncological family histories and elevated gross type (P=0.033 and P=0.04, respectively). Moreover, a significant correlation was observed among aberrant Mlh1, P53-negative and HGM expression. The present findings suggest that loss of Mlh1 expression is associated with age, gender, oncological family history and tumor growth pattern in EGC. Patient and tumor characteristics are key factors in the screening, surveillance and diagnosis of early gastric neoplasia, particularly in elderly individuals.

Comparison of patients by family history with gastric and non-gastric cancer

AIM: To compare the gastric cancer (GC) patients by their family history with gastric and non-GC.

METHODS: Positive family histories within second-degree relatives and clinicopathological features were obtained for 256 patients.

RESULTS: Of the 256 probands, 112 (76 male, 36 female) were incorporated into familial GC (FGC) group: at least two GC members; 144 (98 male, 46 female) were included in the non-FGC group (relatives only affected with non-GCs). Of 399 tumors in relatives (181 from FGC against 212 from non-FGC), GC was the most frequent, followed by esophageal, hepatocellular, and colorectal cancer. Nasopharyngeal cancer was next to lung cancer but prior to breast and urogenital cancers. Most affected members aggregated within first-degree relatives (FGC: 66 siblings, 48 fathers, 31 mothers, four offspring; non-FGC: 56 fathers, 55 siblings, 43 mothers, and 15 offspring). The ratio of males to females in affected first-degree relatives was usually higher in male probands. Paternal history of GC was a slight risk for GC in males (OR = 1.19, 95% CI: 0.53-2.69), while risk of GC by maternal history of non-GCs was increased in females (OR = 0.46, 95% CI: 0.22-0.97). Diffuse-GC was the major histological type in all subgroups. Difference in tumor sites between the two groups was derived from an excess of upper sites in non-FGC female probands.

CONCLUSION: Distribution of associated non-GCs in a family history of GC may vary with geographic areas. GC may have different genetic and/or environmental etiology in different families, and a certain subtype may be inherited in a female-influenced fashion.

Evidence of tumor microsatellite instability in gastric cancer with familial aggregation

About 90% of gastric cancer (GC) cases appear in a sporadic setting. Nonetheless, in high incidence areas high familial aggregation rates have been recently described. Microsatellite instability (MSI) is thought to be an important molecular phenotype both in sporadic GC and in tumors of the HNPCC spectrum. The aim of this study was to assess the frequency of MSI in GC with familial aggregation. Five quasimonomorphic mononucleotide repeats (BAT-26, BAT-25, NR-24, NR-21 and NR-27) were analyzed in 250 GC patients. Seventy-five patients (30%) had at least one-first-degree family member affected by GC and 63 patients (25.2%) showed MSI. The frequency of MSI was significantly higher in patients with a positive family history of GC (38.7%) compared to patients with other tumor types within the family (15.7%) or with a negative oncological familial history (21.9%, P = 0.004). Within cases with a positive familial oncological history, the MSI frequency in families with GC only was similar to the one observed in families with GC and colon cancer (P = 0.96). Nonetheless, in families with GC and lung cancer, the frequency of MSI was significantly lower (5.6%, P = 0.007). MSI occurs in GCs with familial aggregation. Similar MSI rates have been observed in GC patients with other family members affected by GC or colon cancer. The same does not occur in families with other members affected by lung cancer. Our data seem to suggest that familial aggregation for either GC alone or gastric and colon cancer share common etiological factors in contrast to families with gastric and lung cancers.