Prognostic value of INPP4B protein immunohistochemistry in ovarian cancer

PURPOSE OF INVESTIGATION

Ovarian cancer is associated with poor prognosis and altered protein expression patterns may be useful for identifying patients likely to have poor disease outcomes. The impact of altered INPP4B protein expression on prognosis is unclear. The aim of this study was to evaluate the implication of INPP4B expression changes in a large series of ovarian cancer tissue samples.

MATERIALS AND METHODS

Tissue microarrays were constructed from 599 epithelial ovarian tumors and stained with antibodies for INPP4B, p53, and PTEN. Proportional hazard models were used to estimate survival hazard ratios (HRs) associated with altered protein expression.

RESULTS

Seventy-nine percent of the ovarian cancers demonstrated loss of INPP4B, whereas 53% showed aberrant p53 expression (i.e., complete loss of p53 or over-expression of p53) and 8% showed loss of PTEN. INPP4B was frequently lost in serous and endometrioid cancer subtypes, aberrant p53 expression was most common among serous subtype, and loss of PTEN was most common among endometrioid tumors (p for all three proteins across histologic subtypes ≤ 0.0001). INPP4B loss or aberrant p53 expression were both associated with increased mortality (HR = 1.84; 95% CI 1.27 - 2.68 and HR = 3.10; 95% CI 2.33 - 4.11, respectively); however, in multivariate models, only the relationship with p53 achieved statistical significance (HR = 1.20; 95% CI 0.82 - 1.76 for INPP4B and HR = 1.73; 95% CI 1.28 - 2.34 for p53). Conclusion: The INPP4B protein is frequently lost in serous and endometrioid subtypes of ovarian cancer. A possible prognostic role of INPP4B for endometrioid ovarian tumors requires further evaluation.

Flavonoid intake and risk of pancreatic cancer in the National Institutes of Health-AARP Diet and Health Study Cohort

Background:

Limited epidemiological studies show inverse associations between dietary flavonoid intake and pancreatic cancer risk, but results are inconsistent and are based on few cases. We examined the association between intake of flavonoids and pancreatic cancer risk in the large, prospective National Institutes of Health-AARP Diet and Health Study Cohort.

Methods:

During follow-up through 2006 (median follow-up 10.6 years), 2379 pancreatic cancer cases were identified. We used Cox proportional hazards modelling to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results:

We found no association between total flavonoid intake (Q5 vs Q1 HR=1.09, 95% CI: 0.96–1.24) or any flavonoid subtypes and pancreatic cancer risk. Significant interactions were not observed by age, sex, smoking status, BMI or diabetes.

Conclusion:

Our results do not support the hypothesis that flavonoids have a protective role in pancreatic cancer carcinogenesis.

Glutathione S-transferase polymorphisms and ovarian cancer treatment and survival

OBJECTIVE

Members of the glutathione S-transferase (GST) family have been shown to have functional polymorphisms that may affect drug metabolism and influence the effects of chemotherapy and survival from cancer. GSTM1, GSTT1, and GSTP1 genotypes were evaluated for their role in ovarian cancer treatment and survival.

METHODS

DNA was extracted from tumor tissues of 215 patients diagnosed with primary epithelial ovarian cancer. GSTM1 and GSTT1 genotypes were determined by multiplex PCR; GSTP1 genotypes were assessed with PCR-RFLP. Associations between GST polymorphisms and risk of ovarian cancer progression or death were analyzed using Cox proportional hazards regression; subgroups of patients receiving different chemotherapeutics were also evaluated.

RESULTS

GST polymorphisms were not found to be associated with patient or tumor characteristics or response to treatment. However, GSTM1 null patients were less likely to have disease progression (HR: 0.65, 95% CI: 0.43-0.99) or to die (HR: 0.68, 95% CI: 0.45-1.03) compared to patients with GSTM1. Patients with GSTM1 null and GSTP1 ile/val or val/val (reduced function) had a further reduction in risk of disease progression compared to patients with GSTM1 or GSTP1 ile/ile (HR: 0.42, 95% CI: 0.24-0.75). A similar association was also suggested for overall survival (HR: 0.61, 95% CI: 0.36-1.05). Subgroup analyses indicated that the effects of GST on survival were more pronounced among patients treated with specific chemotherapeutics.

CONCLUSION

These findings support the idea that reduced GST function may improve ovarian cancer survival after post-operative chemotherapy; evaluation of GST functional polymorphisms may help to predict ovarian cancer prognosis.

Histopathologic features of genetically determined ovarian cancer

Inheritance of germline mutations of BRCA1 or BRCA2 genes account for approximately 10% of ovarian carcinomas, but the characterization of these genetically determined cancers is incomplete. The objective of our study was to characterize the histologic features of ovarian carcinomas associated with germline mutations of BRCA1 and BRCA2. Thirty-two ovarian carcinomas associated with germline BRCA1 or BRCA2 mutations and 40 ovarian carcinomas from patients screened as negative for germline mutations were obtained from three centers. A gynecologic pathologist, blinded to mutation status, reviewed each case, with documentation of the histologic type, Gynecologic Oncology Group (GOG) grade, architectural and nuclear grade, Silverberg grade, and mitotic activity. All BRCA1 and BRCA2 mutation-associated cases were invasive serous carcinomas, and of these 50% were GOG grade 3, 41% had an architectural grade of 3 (predominant solid architecture), 84% a nuclear grade of 3, 72% a mitotic score of 3 (>25 mitoses per 10 HPF), and 75% a Silverberg grade of 3. The differences in histologic type (p = 0.001) and Silverberg grade (p = 0.002) between these tumors and the control group were statistically significant and remained so when comparisons between BRCA carriers and noncarriers were restricted to carcinomas of serous histology alone. Ovarian carcinomas associated with germline mutations of BRCA1/BRCA2 are, in this study, invasive serous carcinomas, with a statistically significant higher histologic grade than ovarian carcinomas without BRCA mutations when using the recently proposed Silverberg grading system.

Progesterone receptor variant increases ovarian cancer risk in BRCA1 and BRCA2 mutation carriers who were never exposed to oral contraceptives

Oral contraceptives have been shown to be protective against hereditary ovarian cancer. The variant progesterone receptor allele named PROGINS is characterized by an Alu insertion into intron G and two additional mutations in exons 4 and 5. The PROGINS allele codes for a progesterone receptor with increased stability and increased hormone-induced transcriptional activity. We studied the role of the PROGINS allele as a modifying gene in hereditary breast and ovarian cancer. The study included 195 BRCA1 and BRCA2 carriers with a prior diagnosis of ovarian cancer, 392 carriers with a diagnosis of breast cancer and 249 carriers with neither cancer. Fifty-eight women had both forms of cancer. Five hundred and ninety-five women had a BRCA1 mutation and 183 women had a BRCA2 mutation. Overall, there was no association between disease status and the presence of the PROGINS allele. Information on oral contraception use was available for 663 of the 778 carriers of BRCA1 or BRCA2 mutations. Among the 449 subjects with a history of oral contraceptive use (74 cases and 365 controls), no modifying effect of PROGINS was observed [odds ratio (OR) 0.8; 95% confidence interval (CI) 0.5-1.3]. Among the 214 carriers with no past exposure to oral contraceptives, the presence of one or more PROGINS alleles was associated with an OR of 2.4 for ovarian cancer, compared to women without ovarian cancer and with no PROGINS allele (P = 0.004; 95% CI 1.4-4.3). The association was present after adjustment for ethnic group and for year of birth.

Prevalence and risk factors of hepatitis C virus infection among Koreans in rural area of Korea

In a Korean rural area with a high incidence of liver cancer, a molecular epidemiological study was conducted to estimate the prevalence of hepatitis C virus (HCV) infection and to determine the distribution of HCV genotype and transmission routes of HCV infection. The study population is those who volunteered to participate in a health survey in 1993 and were over 10 years of age. Those who were anti-HCV-positive and 20 of their spouses were re-examined in 1995 and tested for HCV genotype. A phylogenetic tree was constructed after sequencing analysis of core and envelope regions from the subjects with genotype 2a without a blood transfusion history. The age- and sex-standardized prevalence of anti-HCV was 5.52%. In a multivariate analysis, transfusion history was not associated with anti-HCV-positivity, but a history of acupuncture (adjusted odds ratio=2.2, 95% confidence interval=1.0, 4.7) and a history of surgical operation (adjusted odds ratio=2.0, 95% confidence interval=1.0, 4.1) were associated. The prevalence of HCV genotype 2a was the highest, and genotype 1b was less frequent. The phylogenetic tree showed strong homology among our samples with Japanese HCV strains. The present study suggests that there is a highly endemic area of HCV infection in Korea and that this endemicity is probably associated with a parenteral source of HCV infection other than blood transfusion. The study also suggests that some of the HCV infection was spread through non-sterilized or non-disposable acupuncture needles in this HCV endemic area.

BRCA1 and BRCA2 mutation analysis of 208 Ashkenazi Jewish women with ovarian cancer

Ovarian cancer is a component of the autosomal-dominant hereditary breast-ovarian cancer syndrome and may be due to a mutation in either the BRCA1 or BRCA2 genes. Two mutations in BRCA1 (185delAG and 5382insC) and one mutation in BRCA2 (6174delT) are common in the Ashkenazi Jewish population. One of these three mutations is present in approximately 2% of the Jewish population. Each mutation is associated with an increased risk of ovarian cancer, and it is expected that a significant proportion of Jewish women with ovarian cancer will carry one of these mutations. To estimate the proportion of ovarian cancers attributable to founding mutations in BRCA1 and BRCA2 in the Jewish population and the familial cancer risks associated with each, we interviewed 213 Jewish women with ovarian cancer at 11 medical centers in North America and Israel and offered these women genetic testing for the three founder mutations. To establish the presence of nonfounder mutations in this population, we also completed the protein-truncation test on exon 11 of BRCA1 and exons 10 and 11 of BRCA2. We obtained a detailed family history on all women we studied who had cancer and on a control population of 386 Ashkenazi Jewish women without ovarian or breast cancer. A founder mutation was present in 41.3% of the women we studied. The cumulative incidence of ovarian cancer to age 75 years was found to be 6.3% for female first-degree relatives of the patients with ovarian cancer, compared with 2.0% for the female relatives of healthy controls (relative risk 3.2; 95% CI 1.5-6.8; P=.002). The relative risk to age 75 years for breast cancer among the female first-degree relatives was 2.0 (95% CI 1.4-3.0; P=.0001). Only one nonfounder mutation was identified (in this instance, in a woman of mixed ancestry), and the three founding mutations accounted for most of the observed excess risk of ovarian and breast cancer in relatives.

Intron variants of the p53 gene are associated with increased risk for ovarian cancer but not in carriers of BRCA1 or BRCA2 germline mutations

Two biallelic polymorphisms in introns 3 and 6 of the p53 gene were analysed for a possible risk-modifying effect for ovarian cancer. Germline DNA was genotyped from 310 German Caucasian ovarian cancer patients and 364 healthy controls. We also typed 124 affected and 276 unaffected female carriers with known deleterious BRCA1 or BRCA2 germline mutation from high-risk breast-ovarian cancer families. Genotyping was based on PCR and high-resolution gel electrophoresis. German ovarian cancer patients who carried the rare allele of the MspI restriction fragment length polymorphism (RELP) in intron 6 were found to have an overall 1.93-fold increased risk (95% confidence internal (CI) 1.27-2.91) which further increased with the age at diagnosis of 41-60 years (odds ratio (OR) 2.71, 95% CI 1.10-6.71 for 41-50 and OR 2.44, 95% CI 1.12-5.28 for 51-60). The 16 bp duplication polymorphism in intron 3 was in a strong linkage to the MspI RFLP. In BRCA1 or BRCA2 mutation carriers, no difference in allele frequency was observed for carriers affected or unaffected with ovarian cancer. Our data suggest that intronic polymorphisms of the p53 gene modify the risk for ovarian cancer patients but not in carriers with BRCA1 or BRCA2 mutations.

Accumulation of p53 protein is frequent in ovarian cancers associated with BRCA1 and BRCA2 germline mutations

BACKGROUND

Mutations in the BRCA1 or BRCA2 genes are responsible for up to 95% of hereditary ovarian cancer cases. Both genes function as tumour suppressor genes, and development of a cancer is thought to require an accumulation of somatic genetic events in addition to the inherited germline predisposition. It is unknown whether these somatic events in BRCA associated ovarian cancer are similar to or distinct from those in sporadic cases. The most frequent somatic genetic event in ovarian cancer is a mutation of the p53 gene.

AIM

To study the role of p53 in hereditary ovarian cancer, by analysing accumulation of the p53 protein in ovarian cancers which occurred in BRCA1 or BRCA2 germline mutation carriers and comparing the results with a panel of ovarian cancers from patients who tested negative for both BRCA1 and BRCA2.

METHODS

The study group consisted of 39 ovarian cancer patients in whom a BRCA mutation had been confirmed previously. p53 Immunohistochemistry was performed on archival tissue using a standard microwave antigen retrieval technique. The rate of p53 accumulation was compared with 40 ovarian cancer cases who tested negative for BRCA1 and BRCA2 germline mutations.

RESULTS

P53 Accumulation was similar in BRCA related ovarian cancers and BRCA negative controls. Overall 27 of 39 BRCA1 or BRCA2 positive cases (69%) had evidence of p53 accumulation, compared with 24 of 40 invasive ovarian cancer cases (60%) which tested negative for BRCA1 and BRCA2 germline mutations. BRCA1 related ovarian cancers showed p53 accumulation in 22 of 30 cases (73%); p53 accumulation was present in five of nine BRCA2 related ovarian cancers.

CONCLUSIONS

In addition to germline BRCA1 and BRCA2 mutations, somatic p53 alterations leading to p53 accumulation are an important event in hereditary ovarian cancer and are as frequent as in non-BRCA-related ovarian cancer.

Oral contraceptives and the risk of hereditary ovarian cancer. Hereditary Ovarian Cancer Clinical Study Group

BACKGROUND

Women with mutations in either the BRCA1 or the BRCA2 gene have a high lifetime risk of ovarian cancer. Oral contraceptives protect against ovarian cancer in general, but it is not known whether they also protect against hereditary forms of ovarian cancer.

METHODS

We enrolled 207 women with hereditary ovarian cancer and 161 of their sisters as controls in a case-control study. All the patients carried a pathogenic mutation in either BRCA1 (179 women) or BRCA2 (28 women). The control women were enrolled regardless of whether or not they had either mutation. Lifetime histories of oral-contraceptive use were obtained by interview or by written questionnaire and were compared between patients and control women, after adjustment for year of birth and parity.

RESULTS

The adjusted odds ratio for ovarian cancer associated with any past use of oral contraceptives was 0.5 (95 percent confidence interval, 0.3 to 0.8). The risk decreased with increasing duration of use (P for trend, <0.001); use for six or more years was associated with a 60 percent reduction in risk. Oral-contraceptive use protected against ovarian cancer both for carriers of the BRCA1 mutation (odds ratio, 0.5; 95 percent confidence interval, 0.3 to 0.9) and for carriers of the BRCA2 mutation (odds ratio, 0.4; 95 percent confidence interval, 0.2 to 1.1).

CONCLUSIONS

Oral-contraceptive use may reduce the risk of ovarian cancer in women with pathogenic mutations in the BRCA1 or BRCA2 gene.

Breast cancer risk factors according to combined estrogen and progesterone receptor status: a case-control analysis

Breast cancers demonstrate a gradient of responsiveness to endocrine therapy according to hormone receptor status, with tumors positive for both estrogen and progesterone receptors responding most favorably. The authors hypothesized that reproductive risk factors, which are probably mediated by endogenous hormones, would also differ according to receptor status, and that tumors positive for both receptors would exhibit the highest risk. Information on risk factors was obtained from 1,154 breast cancer cases and 21,714 cancer-free controls at the Aichi Cancer Center Hospital, Nagoya, Japan between 1988 and 1992. Receptor status was known for 40% of cases. For a given risk factor, odds ratios with respect to the common control group for breast cancers of differing receptor status were compared using multiple polytomous logistic regression. Risk factors did not differ significantly according to estrogen receptor status. However, age at diagnosis/interview, occupation, age at menarche, menstrual regularity at ages 20-29 years, and cigarette smoking differed significantly or borderline significantly in effect according to progesterone receptor status. Stratification of cases according to joint estrogen and progesterone receptor status indicated that estrogen receptor status did not modify this difference in effect. This study did not support the hypothesis of a gradient of risk for reproductive factors according to hormone receptor status. The authors recommend that the finding that some risk factors differ according to progesterone receptor status should be pursued in further studies.

Canadian National Breast Screening Study: first screen results as predictors of future breast cancer risk

Characteristics of women aged 40-59, recorded at an initial breast screen, were compared with the outcome of incident, invasive breast cancer occurring up to 3 years after the initial screen. The study design was case-control, nested within the study population of the Canadian National Breast Screening Study. Screening consisted of a two-view mammographic examination and physical examination of the breasts; additional risk factor information was obtained from self-administered questionnaires. Of the etiological risk factors considered only age at entry or years menstruating were significant risk factors for breast cancer (P < 0.0025). Years menstruating accounted for much of the age effect and all of the menopausal status effect. Risk factors obtainable from mammography and physical examination were more significant than self-reported risk factors, other than age or years menstruating. In spite of possible misclassification of the variable parenchymal pattern, women with a mammographic film classified as either P2 or DY had a 2-fold risk of breast cancer (odds ratio = 2.1; 95% confidence interval = 1.5-2.9, P = 2.9E-05). An abnormality reported by either the radiologist [odds ratio = 1.7 (1.3-2.3)] or nurse examiner [odds ratio = 1.9 (1.4-2.6)] was also associated with an independent significant risk.

A hospital-based case-control study of breast-cancer risk factors by estrogen and progesterone receptor status

It has been proposed that breast cancers may differ in their pathogenesis and etiology according to their estrogen receptor (ER) and progesterone receptor (PR) status. This hospital-based case-control study in Japan assessed the relationship between known and suspected breast-cancer risk factors and ER and PR status. Information on risk factors was collected from histologically confirmed breast-cancer cases (n = 519) and from cancer-free controls (n = 9,506). Of 160 cases with known ER status, 58 percent were ER-positive; 38 percent of 157 cases with known PR status were PR-positive. No statistically significant differences were found between ER-positive cf ER-negative cases. However, statistically significant differences between PR-positive cf PR-negative cases were observed for number of full-term pregnancies (P = 0.01), menstrual regularity as a teenager (P = 0.024), and occupation as housewife (P = 0.036). Borderline differences were observed for age at menopause (P = 0.074), and age at menarche (P = 0.083). This study provides some evidence that etiologic distinctions may be greater between PR-positive and PR-negative breast cancers than between ER-positive and ER-negative breast cancers.

The correlation between relatives under assortative malting for an X-linked and autosomal trait

Correlations between various relatives are derived for phenotypic assortative mating at equilibrium for a trait determined by additive autosomal and X-linked loci without dominance, with proportional gene effects in the two sexes, and with an uncorrelated environment. It is assumed that genotype and environment are normally distributed, that phenotypes of mates are bivariate-normally distributed, and that regression of an individual's phenotype or genotype on the phenotype or genotype of any of his relatives is linear.

The influence of epiphytic bacteriae on auxin metabolism

Plants are settled by epiphytic bacteriae able to convert tryptophan to IAA. This bacterial activity is abolished by chloramphenicol and streptomycin but not by penicillin. Tryptophan conversion to IAA by plant parts or enzyme preparations is far more intensive in non-sterile conditions than in sterile ones. This is true for all investigated objects: Helianthus annuus, Phaseolus vulgaris, Pisum sativum, Triticum vulgare, Zea mays, Enteromorpha compressa, Fucus vesiculosus, Furcellaria fastigiata. From pea plants, 58 strains of IAA producing bacteriae were isolated and partly identified.While non-sterile plants (Pisum, Zea) contain considerable amounts of IAA (extraction, thin layer chromatography, biotest), hardly any traceable auxin can be extracted of sterile plants. But sterile plants re-infected with mixtures or single strains of suitable bacteriae again contain considerable amounts of extractable IAA.