Functional interaction between mouse erbB3 and wild-type rat c-<Emphasis Type="Italic">neu</Emphasis> in transgenic mouse mammary tumor cells

Introduction  

Co-expression of several receptor tyrosine kinases (RTKs), including erbB2 and erbB3, is frequently identified in breast cancers. A member of the RTK family, the kinase-deficient erbB3 can activate downstream signaling via heterodimer formation with erbB2. We studied the expression of RTK receptors in mammary tumors from the wild-type (wt) rat c-neu transgenic model. We hypothesized that physical and functional interactions between the wt rat neu/ErbB2 transgene and mouse ErbB3-encoded proteins could occur, activating downstream signaling and promoting mammary oncogenesis.     

HER-2/<Emphasis Type="Italic">neu</Emphasis> expression in primary and metastatic breast cancer

Introduction Trastuzumab is a highly effective therapy for the treatment of HER-2/neu positive breast cancer. To maximize benefit and minimize unnecessary toxicity, patient selection is essential. Currently HER-2/neu analysis is routinely performed only for primary invasive breast cancers, and trastuzumab therapy is recommended based on primary analysis only. Methods Using immunohistochemistry, we performed a retrospective study comparing HER-2/neu expression in original primary to subsequent metastatic breast cancers. Results Tumors from 382 patients with metastatic breast cancer were studied. In 254 cases (66%) both primary and metastatic lesions were concordant. In 90 cases the primary lesion was HER-2/neu positive with the metastatic lesion negative; whereas, in 37 cases the primary lesion was HER-2/neu negative and the metastatic lesion positive. Primary HER-2/neu immunostaining was associated with a negative predictive value of 35.7%. Although all four groups were similar at diagnosis, survival differences were noted with the best survival experienced by patients with initial primary lesions HER-2/neu negative and subsequent metastatic lesions positive. Patients with hormone receptor and HER-2/neu positive primary lesions who received tamoxifen were more likely to have HER-2/neu positive metastasis. Conclusions The significant discordance between HER-2/neu expression in primary and metastatic tumors suggests that determination of HER-2/neu status in metastatic disease should be attempted.     

Cyclin D1 is overexpressed in atypical teratoid/rhabdoid tumor with <Emphasis Type="Italic">hSNF5/INI1</Emphasis> gene inactivation

Object: Although atypical teratoid/rhabdoid tumor (AT/RT) is known to generate through inactivation of the hSNF5/INI1 gene on chromosome 22q, the downstream molecular mechanism remains unclear. We histologically and molecularly reviewed our pediatric brain tumors for unrecognized AT/RTs and evaluated the role of cyclin D1, a potential molecular target of hSNF5/INI1. Methods: We analyzed 16 tumors under three years of age: seven medulloblastomas, three anaplastic ependymomas (E IIIs), two each of supratentorial primitive neuroectodermal tumors (sPNETs) and choroid plexus carcinomas (CPCs), and one each of neuroblastoma and pineoblastoma. Immunohistochemistry for glial fibrillary acidic protein, vimentin, epithelial membrane antigen, smooth muscle actin and cyclin D1 was performed. Polymerase chain reaction (PCR)-single-strand conformation polymorphism analysis with direct sequencing, differential PCR and microsatellite analysis were conducted for hSNF5/INI1mutation, homozygous deletion and loss of heterozygosity (LOH) on 22q, respectively. Because of the presence of rhabdoid cells and the polyimmunophenotypic features, the diagnosis was revised to AT/RT in five (31%) tumors, namely, two E IIIs and one each of medulloblastoma, CPC and pineoblastoma. Three of them harbored such hSNF5/INI1 aberrations as germline single base deletion (492/6 delC) and missense mutation (C157T) together with LOH 22q or homozygous deletion. Cyclin D1 was overexpressed in those three tumors but not in the two that lacked hSNF5/INI1 inactivation. Conclusion: AT/RT can be misdiagnosed as a variety of tumors, including ependymoma that potentially harbors LOH 22q. Our data indicate that cyclin D1 is a target of hSNF5/INI1in primary tumors.     

Evaluation of the CD107 cytotoxicity assay for the detection of cytolytic CD8<Superscript>+</Superscript> cells recognizing HER2/<Emphasis Type="BoldItalic">neu</Emphasis> vaccine peptides

Summary The recently reported FACS-based CD107 assay has been used in human HIV and CMV antigen models as well as in the ex vivo analysis of tumor cytolytic T cells in a melanoma model by a single group. The purpose of our study was to validate this assay and to use it in previously untested viral and tumor antigen models. Specifically, we investigated the use of the novel CD107 cytotoxicity assay in the detection of influenza and HER2/neu tumor-specific cytolytic CD8⁺ T cells. CD8⁺ T cells from HLA-A2⁺ healthy donors were stimulated with autologous dendritic cells pulsed with FluM or the HER2/neu peptides, E75 or GP2. These CD8⁺ T cells were then tested in cytotoxicity assays at varying effector:target (E:T) ratios against T2 targets. Cytotoxicity was measured by detection of CD107a and b on the surface of CD8⁺ T cells. An E:T of 1:5 was found to optimize the resulting percentage of CD8⁺CD107⁺ T cells. E75- and GP2-stimulated CD8⁺ T cells were then tested in cytotoxicity assays with MCF-7 (HER2/neu⁺HLA-A2⁺) and AU565 (HER2/neu⁺HLA-A2^-) tumor cells. Cytotoxicity was measured by both the CD107 assay and the ⁵¹Cr release assay. Results of cytotoxicity were then correlated between these two assays. In representative experiments, the CD107 assay identified average specific increases for E75- and GP2-stimulated cells of 4.26 and 3.57%, respectively. These results correlated favorably with cytotoxicity as measured by the traditional ⁵¹Cr assay. These findings confirm preliminary reports of the CD107 assay and suggest its usefulness for monitoring cancer trials.Funded by the Clinical Breast Care Project, a Congressionally funded program of the Henry M. Jackson Foundation for the Advancement of Military Medicine (Rockville, Maryland). Supported by the United States Army Medical Research and Materiel Command, and the Department of Clinical Investigations at the Walter Reed Army Medical Center. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or reflecting the views of the Department of the Army or the Department of Defense.     

Long-term satisfaction and quality of life following risk reducing surgery in <Emphasis Type="Italic">BRCA1/2</Emphasis> mutation carriers

Background

As BRCA1/2 testing becomes more routine, questions remain about long-term satisfaction and quality of life following testing. Previously, we described long term distress and risk management outcomes among women with BRCA1/2 mutations. This study addresses positive psychological outcomes in BRCA1/2 carriers, describing decision satisfaction and quality of life in the years following testing.

Methods

We evaluated satisfaction with testing and management decisions among 144 BRCA1/2 carriers. Prior to genetic testing, we assessed family history, sociodemographics and distress. At a mean of 5.3 years post-testing, we assessed management decisions, satisfaction with decisions and, among women with cancer, quality of life.

Results

Overall, satisfaction with decision making was high. Women who had risk reducing mastectomy or oophorectomy were more satisfied with management decisions. Participants who obtained a risk reducing oophorectomy were more satisfied with their genetic testing decision. Among affected carriers, high pretest anxiety was associated with poorer quality of life and having had risk reducing mastectomy prior to testing was associated with better quality of life. The negative impact of pre-test anxiety was diminished among women who had mastectomies before testing.

Conclusions

BRCA1/2 carriers are satisfied with their testing and risk management decisions and report good quality of life years after testing. Having risk reducing surgery predicts increased satisfaction and improved quality of life.

     

<Emphasis Type="Italic">BRCA1/2</Emphasis> mutation testing in breast cancer patients: a prospective study of the long-term psychological impact of approach during adjuvant radiotherapy

This study assessed psychological distress during the first year after diagnosis in breast cancer patients approached for genetic counseling at the start of adjuvant radiotherapy and identified those vulnerable to long-term high distress. Of the approached patients some chose to receive a DNA test result (n = 58), some were approached but did not fulfill criteria for referral (n = 118) and some declined counseling and/or testing (n = 44). The comparative group consisted of patients not eligible for genetic counseling (n = 182) and was therefore not approached. Patients actively approached for genetic counseling showed no more long-term distress than patients not eligible for such counseling. There were no differences between the subgroups of approached patients. Predictors for long-term high distress or an increase in distress over time were pre-existing high distress and a low quality of life, having children, and having no family members with breast cancer. It is concluded that breast cancer patients can be systematically screened and approached for genetic counseling during adjuvant radiotherapy without imposing extra psychological burden. Patients vulnerable to long-term high distress already displayed high distress shortly after diagnosis with no influence of their medical treatment on their level of distress at long-term.     

A high frequency of germline <Emphasis Type="Italic">BRCA1/2</Emphasis> mutations in western Sweden detected with complementary screening techniques

Dominant inheritance is presumed in 6–10% of breast and ovarian cancers. Mutations in BRCA1 and BRCA2 genes are the most commonly identified causative genes in such families. The frequency of mutation carriers with breast/ovarian cancer depends on the population studied, and display considerable variation that coincides with ethnic and geographical diversity. Mutation analyses were performed in 143 families registered at the Cancer Genetic Counseling Clinic of western Sweden. In a thorough mutation screening procedure, the entire BRCA1 and BRCA2 genes were analyzed using a combination of complementary mutation detection techniques. Mutations in either BRCA1 or BRCA2 were detected in 36% (52 out of 143) of all screened families. All families were clinically evaluated regarding age at diagnosis, type of cancer and number of cancer cases in the family. Among high-risk families, the mutation detection rate was 39% (46 out of 117). The detection rate observed among families with cases of ovarian cancer (42 out of 62, 68%), was substantially higher than in families with only breast cancer (10 out of 81, 12%). Age at ovarian cancer did not seem to have an effect on the detection rate. The analyses revealed 11 frameshift mutations, 4 nonsense mutations and 2 large deletions. Notably, the BRCA1 c.3171ins5 mutation accounted for 34 of 52 (65%) identified mutations. Seven mutations are novel: BRCA1c.409_410del; c.1912T>G; c.2228_2229del; c.3029delA; c.3433delA, a large deletion covering exons 1–3 of BRCA1and one BRCA2 mutation; BRCA2c.6287_6290del. We have shown that the founder mutation BRCA1 c.3171ins5 has a great influence on western Swedish breast/ovarian cancer families along with a high number of mutations unique for the region. In order to achieve a high mutation detection rate we suggest a combination of several detection techniques.     

Advanced stages and poorly differentiated grade are associated with an increased risk of HER2/<Emphasis Type="Italic">neu</Emphasis> positive breast carcinoma only in White women: findings from a prospective cohort study of African-American and White-American women

Objective The primary objective of this study was to evaluate the race-specific risk associated with HER2/neu positive breast carcinoma in a prospective cohort design. Our secondary objectives were to assess prevalence of different breast cancer phenotypes between African-American and White women and to determine if race was associated with the risk of basal-like breast carcinoma phenotype in this cohort. Methods Demographic, clinical and pathologic data were collected from existing databases. The status of HER2/neu and hormone receptors was dichotomized as either positive or negative. Immunohistochemistry taxonomy was used to assess prevalence of different breast carcinoma phenotypes. Risk estimates were calculated using the multivariable logistic regression statistics. Conclusions The risk of HER2/neu positive breast carcinoma differs between African-American and White women. For White women only, this risk was statistically significant and increased almost linearly within each TNM stage with grade dedifferentiation. The statistically significantly higher prevalence of “ER⁻/PR⁻, HER2⁻ ” phenotype in African American women potentially is the attributing factor to observed lack of an association between the risk of HER2/neu positive breast carcinoma with advanced stages and poorly differentiated grade. Among women diagnosed with “ER⁻/PR⁻, HER2⁻” phenotype the odds ratios of being African-American and pre-menopausal was 1.72 (95% CI 1.17–2.54, P = 0.006) and 1.94 (95% CI 1.27–2.96, P = 0.002), respectively. The histologic features of basal-like and ER⁻/HER2⁺ carcinomas overlaps. Differences in the biology of breast carcinoma between African American and White women are partially attributed to the disparity in more adverse pathologic prognostic indicators at the initial clinical presentation of this disease.