A case of neurofibromatosis and breast cancer: loss of heterozygosity of NF1 in breast cancer

Lymphomas in patients with neurofibromatosis type 1 (NF1): another malignancy in the NF1 syndrome?

Neurofibromatosis type 1 (NF1) is an autosomal dominant multisystem syndrome caused by mutations in the neurofibromin 1 (NF1) gene that encodes for the protein neurofibromin acting as a tumour suppressor. Neurofibromin functions primarily as a GTPase-activating protein for the Ras family of oncogenes, which activates many signalling pathways for cell proliferation and differentiation; without neurofibromin, Ras is constitutively activated, thereby turning on many downstream signalling pathways related to oncogenesis. Patients with NF1 have a well known predisposition for certain types of malignancies including malignant peripheral nerve sheath tumours, gliomas, and breast cancers, as well as a potential association of NF1 with lymphoproliferative disorders such as lymphomas. In this article, we review the pathophysiology and tumourigenesis of NF1, previously reported cases of cutaneous lymphomas in NF1 patients along with our case demonstration of a NF1-associated scalp B-cell lymphoma, and NF1-associated extra cutaneous lymphomas. The diagnosis of lymphomas particularly cutaneous lymphomas may be difficult in NF1 patients as they often have skin lesions and/or cutaneous/subcutaneous nodules or tumours like neurofibromas, which raises the possibility of underdiagnosed cutaneous lymphomas in NF1 patients. We also comprehensively discuss the association between NF1 and lymphomas. In summary, most studies support a potential association between NF1 and lymphomas. Further investigation is needed to clarify the association between NF1 and lymphomas in order to bring clinical awareness of possibly underdiagnosed NF1-associated lymphomas and individualised management of NF1 patients to practice.

Breast cancer in the era of integrating “Omics” approaches

Worldwide, breast cancer is the leading cause of cancer-related deaths in women. Breast cancer is a heterogeneous disease characterized by different clinical outcomes in terms of pathological features, response to therapies, and long-term patient survival. Thus, the heterogeneity found in this cancer led to the concept that breast cancer is not a single disease, being very heterogeneous both at the molecular and clinical level, and rather represents a group of distinct neoplastic diseases of the breast and its cells. Indubitably, in the past decades we witnessed a significant development of innovative therapeutic approaches, including targeted and immunotherapies, leading to impressive results in terms of increased survival for breast cancer patients. However, these multimodal treatments fail to prevent recurrence and metastasis. Therefore, it is urgent to improve our understanding of breast tumor and metastasis biology. Over the past few years, high-throughput “omics” technologies through the identification of novel biomarkers and molecular profiling have shown their great potential in generating new insights in the study of breast cancer, also improving diagnosis, prognosis and prediction of response to treatment. In this review, we discuss how the implementation of “omics” strategies and their integration may lead to a better comprehension of the mechanisms underlying breast cancer. In particular, with the aim to investigate the correlation between different “omics” datasets and to define the new important key pathway and upstream regulators in breast cancer, we applied a new integrative meta-analysis method to combine the results obtained from genomics, proteomics and metabolomics approaches in different revised studies.

Impacts of NF1 Gene Mutations and Genetic Modifiers in Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1) is a tumor predisposition genetic disorder that directly affects more than 1 in 3,000 individuals worldwide. It results from mutations of the NF1 gene and shows almost complete penetrance. NF1 patients show high phenotypic variabilities, including cafe-au-lait macules, freckling, or other neoplastic or non-neoplastic features. Understanding the underlying mechanisms of the diversities of clinical symptoms might contribute to the development of personalized healthcare for NF1 patients. Currently, studies have shown that the different types of mutations in the NF1 gene might correlate with this phenomenon. In addition, genetic modifiers are responsible for the different clinical features. In this review, we summarize different genetic mutations of the NF1 gene and related genetic modifiers. More importantly, we focus on the genotype–phenotype correlation. This review suggests a novel aspect to explain the underlying mechanisms of phenotypic heterogeneity of NF1 and provides suggestions for possible novel therapeutic targets to prevent or delay the onset and development of different manifestations of NF1.

Experimental, Clinical and Morphological Analysis of H-Ras Oncoproteins for Locally Advanced Breast Cancer

BACKGROUND:

Activated forms of Ras are enhanced in both breast cancer as well as the cell lines with EGFR and HER2 expression. Therefore, H-Ras could be activated in breast tumours in the absence of direct mutational activation of Ras itself and could contribute to 20-50% of the cases. Expression inhibition, signal transduction interruption from H-Ras to the nucleus could become a promising therapeutic target.

AIM:

The aim of this study was to investigate the clinical and morphological criteria of locally advanced breast cancer and the expression of H-Ras oncoprotein in patients who have been subjected to different regimens of farnesyltransferase inhibitor.

METHODS:

H-Ras status was assessed by immunohistochemistry (IHC).

RESULTS:

An association between the expressions of H-Ras and Her2/neu (p = 0.001) as well as the tumour proliferation index Ki-67 (p = 0.001) in patients with breast cancer was established. Analysis of the relationship between H-Ras expression showed a relatively strong association with progression-free survival both before the treatment (V = 0.47; p = 0.001) and after the treatment (V = 0.45; p = 0.001). These results may indicate the clinical applicability of H-Ras as a prognostic factor or serve as a therapeutic target for breast cancer treatment.

CONCLUSION:

These results could indicate the potential clinical application of H-Ras as a prognostic factor or a therapeutic target for breast cancer treatment.

Increased breast cancer risk in women with neurofibromatosis type 1: a meta-analysis and systematic review of the literature

BACKGROUND

Neurofibromatosis type 1 (NF1) is a cancer predisposing syndrome. Studies suggest that women < 50 years old (y.o.) with NF1 have an increased breast cancer (BC) incidence and BC associated mortality. However, this has not been widely recognized secondary to small study populations.

METHODS

A systematic literature review was conducted through database searches for BC and NF1: 3456 articles identified, 166 reviewed, 58 used for descriptive analysis and 4 utilized for meta-analysis. Fisher's exact tests, Kaplan-Meier curves and random-effects meta-analysis models were used for analysis.

RESULTS

Two hundred eighty-six cases of NF1 and female BC were identified with a median age of 46 years at diagnosis; 53% were <  50. Peak age of BC diagnosis was between 34 to 44 years. Women < 50 y.o. presented with more advanced disease vs. those ≥50 (56% vs. 22% stage III-IV, respectively; p = 0.005). Median survival for the entire cohort was 5 years vs. the reported median BC survival of over 20 years in the general population using the SEER database. Median age at BC death was 48.5 years; 64% of deceased patients were <  50. Meta-analysis of a total of 4178 women with NF1 revealed a BC standardized incidence ratio (SIR) of 3.07 (95%CI 2.16-4.38) for women with NF1 vs. the general population. Women < 50 y.o. demonstrated a higher SIR of 5.08 (95%CI 3.77-6.81) compared to 1.92 (95%CI 1.40-2.63) if ≥50 y.o.

CONCLUSIONS

This systematic literature review and meta-analysis suggests that women with NF1 <  50 y.o. have a five-fold increased risk of BC, present with more advanced disease, and may have an increased BC related mortality. Increased awareness and implementation of recent National Comprehensive Cancer Network early BC screening guidelines for this high-risk patient population is essential. Additional evaluation on the influence of NF1 gene mutations identified in patients undergoing hereditary cancer genetic testing on breast cancer risk in individuals without clinical evidence of NF1 is needed.

Neurofibromatosis Type 1 - Association with Breast Cancer, Basal Cell Carcinoma of the Skin, and Low-Grade Peripheral Nerve Sheath Sarcoma: Case Report and Literature Review

Neurofibromatosis type 1 is a rare medical condition that raises the probability of having distinct types of malignant and benign neoplasms. Nevertheless, the association with breast cancer is rare, and metachronic neoplasia with a distinct histologic subtype is an association that has never been reported before. Here we describe a case of a primary breast tumor, with posterior development of basal cell carcinoma of the skin, and a low-grade peripheral nerve sheath sarcoma.

Metaplastic breast cancer in a patient with neurofibromatosis type 1 and somatic loss of heterozygosity

Metaplastic breast carcinoma (MBC) is rare and has a poor prognosis. Here we describe genetic analysis of a 41-yr-old female patient with MBC and neurofibromatosis type I (NF1). She initially presented with pT3N1a, grade 3 MBC, but lung metastases were discovered subsequently. To identify the molecular cause of her NF1, we screened for germline mutations disrupting NF1 or SPRED1, revealing a heterozygous germline single-nucleotide variant (SNV) in exon 21 of NF1 at c.2709G>A, Chr 17: 29556342. By report, this variant disrupts pre-mRNA splicing of NF1 transcripts. No pathogenic mutations were identified in SPRED1. A potential association between MBC and NF1 was reported in eight previous cases, but none underwent detailed genomics analysis. To identify additional candidate germline variants potentially predisposing to MBC, we conducted targeted exome sequencing of 279 established cancer-causing genes in a control blood sample, disclosing four rare SNVs. Analysis of her breast tumor showed markedly altered variant allelic fractions (VAFs) for two (50%) of them, revealing somatic loss of heterozygosity (LOH) at germline SNVs. Of these, only the VAF of the pathogenic SNV in NF1 was increased in the tumor. Tumor sequencing demonstrated five somatic mutations altering TP53, BRCA1, and other genes potentially contributing to cancer formation. Because somatic LOH at certain germline SNVs can enhance their impacts, we conclude that increased allelic imbalance of the pathogenic SNV in NF1 likely contributed to tumorigenesis. Our results highlight a need to assess predisposing genetic factors and LOH that can cause rare, aggressive diseases such as MBC in NF1.

Recurrent multiple neurofibromatosis type 1 of the right lower limb

Neurofibromatosis type 1 is an autosomal dominant inherited disease, which is characterized by the presence of multiple neurofibromas. We encountered a case in which a sporadic dispersed neurofibroma recurred locally on numerous occasions extending over 16 years. The patient developed multiple masses with a focus of neurofibroma on the right lower limb, which were excised. The patient was initially diagnosed with inflammatory changes via computed tomography and magnetic resonance imaging; however, subsequently, pathological and immunohistochemical examinations revealed an intraneural neurofibroma. The patient underwent a comprehensive and complete local resection several times. After a continuous postoperative follow-up strategy, the patient recovered well. This report describes a case of primary manifestations of multiple and recurrent neurofibromas. We aim to emphasize the possibility of a unique, recurrent, non-healing neurofibroma and review the diagnostic techniques utilized to reach a definitive diagnosis. Early and complete surgical resection is an effective method to treat and prevent this type of neurofibroma.

Repeated Multiple Neurofibromatosis Type 1 in the Right Lower Limb: A Case Report

Neurofibromatosis type 1 (NF1) is an autosomal-dominant genetic disease characterized by the presence of multiple neurofibromas. We encountered a unique case of NF1 that manifested as a recurrent soft tissue neurofibroma in the right lower limb that developed over a period of 16 years. The patient presented with a painless mass that was initially diagnosed as inflammatory changes via computed tomography and magnetic resonance imaging. However, the condition was subsequently diagnosed as an intraneural neurofibroma via pathological and immunohistochemical examination, which showed a focal to patchy lymphocytic chronic inflammatory infiltrate and several non-encapsulated masses with clear boundaries that were easily distinguishable from the adjacent neurofibroma. The mass relapsed three times over 3 years since it was discovered, for which the patient underwent comprehensive and complete local resection several times. Postoperative continuous follow-up confirmed that the patient recovered well. Early and complete surgical resection is an effective method for treating and preventing recurrent neurofibromas. However, because of the importance of pathologic examination in the diagnosis of such cases, this uncommon entity might be underreported in patients with NF1.

A Transposon-based Analysis Reveals RASA1 Is Involved in Triple-Negative Breast Cancer

RAS genes are mutated in 20% of human tumors, but these mutations are very rare in breast cancer. Here, we used a mouse model to generate tumors upon activation of a mutagenic T2Onc2 transposon via expression of a transposase driven by the keratin K5 promoter in a p53+/- background. These animals mainly developed mammary tumors, most of which had transposon insertions in one of two RASGAP genes, neurofibromin1 (Nf1) and RAS p21 protein activator (Rasa1). Immunohistochemical analysis of a collection of human breast tumors confirmed that low expression of RASA1 is frequent in basal (triple-negative) and estrogen receptor negative tumors. Bioinformatic analysis of human breast tumors in The Cancer Genome Atlas database showed that although RASA1 mutations are rare, allelic loss is frequent, particularly in basal tumors (80%) and in association with TP53 mutation. Inactivation of RASA1 in MCF10A cells resulted in the appearance of a malignant phenotype in the context of mutated p53. Our results suggest that alterations in the Ras pathway due to the loss of negative regulators of RAS may be a common event in basal breast cancer. Cancer Res; 77(6); 1357-68. ©2017 AACR.

Metaplastic Carcinoma of Breast and Neurofibromatosis 1: A Rare Association

Neurofibromatosis 1 (NF1) patients are generally at higher risk of developing common malignant tumors such as brain and soft tissue tumors. These patients are 5-fold increased the risk of developing breast cancer by the age of 50 years after that the risk remains the same. The most common reported cancer is infiltrating duct carcinoma. We report a case of 61-year-old female with NF1 presented with pain and breast lump for the past 2 months. On mammography, a retroareolar solid cystic lesion measuring 32 mm × 30 mm × 30 mm was noted which was definitive for malignancy. Right-modified radical mastectomy with axillary lymph node dissection was done which revealed a neoplasm composed of glandular and squamous components. Immunohistochemically, these cells were triple negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2-neu and expressed markers of basal cell differentiation. The final pathological staging was T2N0M0. This is the fourth case report in the English literature with such association. In this case report, we discussed the importance of breast cancer screening in such patients along with a review of the literature.

Association between Neurofibromatosis Type 1 and Breast Cancer: A Report of Two Cases with a Review of the Literature

Neurofibromatosis type 1 (NF1) is one of the most common genetic diseases in humans and is associated with various benign and malignant tumors, including breast cancer. However, an increased risk of breast cancer in NF1 patients has not been widely recognized or accepted. Here, we report two cases of breast cancer in NF1 patients and review the literature on the association between NF1 and breast cancer.

Early-Onset Breast Cancer in a Family with Neurofibromatosis Type 1 Associated with a Germline Mutation in BRCA1

Neurofibromatosis type 1 (NF1), which may occur as an autosom-al dominant disorder, is caused by the absence of neurofibromin protein due to somatic mutations in the NF1 gene, and it has been associated with an increased risk of breast cancer. Herein we describe a family with two women affected by both NF1 and early-onset breast cancer. We evaluated whether the concomitance of NF1 and early-onset breast cancer could be due to disease-causing mutations in both NF1 and BRCA1 gene in a Korean family with clinical features of both NF1 and hereditary breast cancer. Mutation analyses identified nonsense mutations in NF1 and BRCA1 genes. Our findings indicate that an awareness of the possible concomitance of NF1 and BRCA1 gene mutations is important for identifying the genetic origin of early-onset breast cancer in patients with NF1 to achieve early detection of cancers and decrease breast cancer-associated morbidity and mortality in these patients.

Metaplastic breast cancer in a patient with neurofibromatosis

Metaplastic breast cancer is a rare malignancy in the breast. Neurofibromatosis Type 1 is an autosomal dominant multisystem disorder associated with multiple neoplasms such as optic gliomas and peripheral nerve sheath tumors. The association of breast cancer with neurofibromatosis is very rare. We present a case of a metaplastic breast cancer in a patient with Type 1 neurofibromatosis. The patient presented with a palpable mass in her left breast with suspicious findings on mammogram and ultrasound. Ultrasound-guided percutaneous biopsy showed metaplastic breast carcinoma with metastasis to an axillary lymph node. This is the third case report in the English literature to show metaplastic breast carcinoma in a patient with Type 1 neurofibromatosis. In this report we review recent literature and discuss the association between these two entities.

Breast cancer and neurofibromatosis type 1: a diagnostic challenge in patients with a high number of neurofibromas

BACKGROUND

Neurofibromatosis 1 is one of the most common genetic diseases in humans, presenting with multiple neurofibromas and an increased risk of various benign and malignant tumors, including breast cancer.

CASE PRESENTATION

In this paper we report a case of a woman with neurofibromatosis 1 and the challenge associated with detecting an advanced breast cancer because of numerous skin neurofibromas, which were responsible for a substantial delay in cancer diagnosis. Literature concerning the association of neurofibromatosis 1 and breast cancer is reviewed and discussed.

CONCLUSIONS

Best practice guidelines for breast cancer detection are not sufficient for the screening of neurofibromatosis 1 carriers. A more intensive clinical and imaging approach should be used if the same early detection rate as in non-neurofibromatosis 1 women is to be achieved.

Breast cancer associated with neurofibromatosis type 1: a case series and review of the literature

INTRODUCTION

Neurofibromatosis type 1, also known as Von Recklinghausen's disease, is a rare neuroectodermal disease that mainly affects the skin and the nervous system. Patients with neurofibromatosis type 1 have a higher risk of developing various types of cancers, especially tumors derived from the embryogenic neural crest. However, its association with breast cancer has seldom been reported.

CASE PRESENTATION

We report the cases of three white Arabic women diagnosed with neurofibromatosis type 1, with a median age of 40-years-old (range: 39 to 43), who sought treatment at our centre for breast cancer.

CONCLUSIONS

The association between neurofibromatosis type 1 and breast cancer is uncommon. In our case series we readdress this association through a literature review.

Age-specific risk of breast cancer in women with neurofibromatosis type 1

Background:

Young women with neurofibromatosis type 1 (NF1) are reported to have a higher risk of breast cancer than others, and this might have implications for screening programmes. Our aim was to calculate this risk.

Methods:

An all-England linked data set of hospital admissions and deaths was analysed to determine age-specific rates of breast cancer in women with NF1 and controls.

Results:

The age-specific excess risk of breast cancer, comparing the NF1 cohort with the control cohort, was elevated 6.5-fold (95% confidence interval 2.6–13.5) in women aged 30–39 years. There was a 4.4 (2.5–7.0) times higher risk among women aged 40–49.

Conclusions:

Women with NF1 develop breast cancer at younger ages than the general population.

Oral metastasis of metaplastic breast carcinoma in a patient with neurofibromatosis 1

Neurofibromatosis type 1 (NF1) has been associated with an increased risk for development of malignancy, especially malignant peripheral nerve sheath tumors. In addition, recently, literature has demonstrated an increased risk of breast cancer in women with NF1. The present paper shows a 53-year-old woman with NF1 who presented with metaplastic breast carcinoma and developed multiple metastases, including mandible. Furthermore, we reviewed the English literature, found 63 cases showing the association between NF1 and breast cancer, and added one more case. The present study demonstrated an important association between NF1 and breast cancer. Until the present time, there has been only one case of metaplastic breast carcinoma associated with NF1. Curiously, in our case the oral metastasis corresponded to sarcomatous component of metaplastic breast carcinoma.

Neurofibromatosis type I with breast cancer: not only for women!

The association of neurofibromatosis type I with invasive male breast cancer is a rare clinical entity with only one case in literature reported in 1953. Women with NF1 are at risk of developing breast cancer and men also may be at risk but there is scarce data on the risk and association of NF1 with male breast cancer due to its rarity. Established clinical trials in male breast cancer patients are lacking and the results are extrapolated from female breast cancer patients. The treatment of male breast cancer is followed as per the guidelines of premenopausal female breast cancer and tamoxifen is the hormone treatment in them. Mendes et al suggests that silencing of NF1 gene confers resistance to tamoxifen. Our conclusions are that since NF1 is mutated or deleted in one third of sporadic breast cancers, its role as a molecular driver for treatment has to be further explored.

Cutaneous squamous cell carcinoma in a patient with neurofibromatosis type 1: A case report

Neurofibromatosis type 1 (NF1) is an autosomal dominant inherited disease that is characterized by the presence of multiple neurofibromas, café-au-lait spots and iris hamartomas. It is well established that the incidence of tumors in patients with NF1 is high compared with the normal population and that the majority of the tumors are non-epithelial neoplasms, including neurofibromas, malignant peripheral nerve sheath tumors, gliomas and leukemia. Studies have suggested that patients with NF1 also have a significantly higher risk of certain types of carcinomas. However, the occurrence of cutaneous squamous cell carcinoma (SCC) in a patient with NF1 is extremely rare. The present study describes the second documented case of a cutaneous SCC adjacent to a neurofibroma of the forehead with histopathological analyses in a patient with NF1. An 80-year-old female with NF1 presented with a rapidly growing skin tumor of the forehead. Histopathological study of the resected forehead tumor demonstrated that there were two tumorous lesions. One was an invasive SCC and the other was a neurofibroma. The lesions were adjacent, but no continuity was present. NF1 is caused by inactivating mutations in the NF1 gene and loss of heterozygosity of this gene has been reported in neurofibromas, malignant peripheral nerve sheath tumors, gliomas and pheochromocytomas in patients with NF1. However, the genetic mechanism of carcinoma development in patients with NF1 is not well understood. Studies have suggested the role of the NF1 and/or the BRCA gene in the occurrence of breast cancer. Additional studies are required to elucidate these mechanisms.

Breast cancer and other neoplasms in women with neurofibromatosis type 1: a retrospective review of cases in the Detroit metropolitan area

Neurofibromatosis type 1 (NF1) is one of the most common cancer predisposing syndromes with an incidence of 1 in 3,500 worldwide. Certain neoplasms or malignancies are over-represented in individuals with NF1; however, an increased risk of breast cancer has not been widely recognized or accepted. We identified 76 women with NF1 seen in the Henry Ford Health System (HFHS) from 1990 to 2009, and linked them to the Surveillance Epidemiology and End Results (SEER) registry covering the metropolitan Detroit area. Fifty-one women (67%) were under age 50 years at the time of data analysis. Six women developed invasive breast cancer before age 50, and three developed invasive breast cancer after age 50. Using standardized incidence ratios (SIRs) calculated based on the SEER age-adjusted invasive breast cancer incidence rates, our findings demonstrated a statistically significant increase of breast cancer incidence occurring in NF1 women (SIR = 5.2; 95% CI 2.4-9.8), and this relative increase was especially evident among those with breast cancer onset under age 50 (SIR = 8.8; 95% CI 3.2-19.2). These data are consistent with other reports suggesting an increase in breast cancer risk among females with NF1, which indicate that breast cancer screening guidelines should be evaluated for this potentially high-risk group.

Comparative oncogenomics implicates the neurofibromin 1 gene (NF1) as a breast cancer driver

Identifying genomic alterations driving breast cancer is complicated by tumor diversity and genetic heterogeneity. Relevant mouse models are powerful for untangling this problem because such heterogeneity can be controlled. Inbred Chaos3 mice exhibit high levels of genomic instability leading to mammary tumors that have tumor gene expression profiles closely resembling mature human mammary luminal cell signatures. We genomically characterized mammary adenocarcinomas from these mice to identify cancer-causing genomic events that overlap common alterations in human breast cancer. Chaos3 tumors underwent recurrent copy number alterations (CNAs), particularly deletion of the RAS inhibitor Neurofibromin 1 (Nf1) in nearly all cases. These overlap with human CNAs including NF1, which is deleted or mutated in 27.7% of all breast carcinomas. Chaos3 mammary tumor cells exhibit RAS hyperactivation and increased sensitivity to RAS pathway inhibitors. These results indicate that spontaneous NF1 loss can drive breast cancer. This should be informative for treatment of the significant fraction of patients whose tumors bear NF1 mutations.

Neoplasms associated with germline and somatic NF1 gene mutations

INTRODUCTION

Neurofibromatosis 1 is a tumor predisposition genetic syndrome with autosomal dominant inheritance and virtually 100% penetrance by the age of 5 years. NF1 results from a loss-of-function mutation in the NF1 gene, resulting in decreased levels of neurofibromin in the cell. Neurofibromin is a negative regulator of various intracellular signaling pathways involved in the cellular proliferation. Although the loss of heterozygosity in the NF1 gene may predispose NF1 patients to certain malignancies, additional genetic alterations are a prerequisite for their development. The precise nature of these additional genetic alterations is not well defined, and genetic testing of all malignancies in NF1 patients becomes an essential component of future research in this subset of patients. In addition to germline NF1 mutations, alteration of the somatic NF1 gene is associated with sporadic malignancies such as adenocarcinoma of the colon, myelodysplastic syndrome, and anaplastic astrocytoma.

MATERIALS AND METHODS

A comprehensive English and non-English language search for all articles pertinent to malignancies associated with NF1 was conducted using PubMed, a search engine provided by the U.S. National Library of Medicine and the National Institutes of Health. Key words searched included the following: "malignancies associated with NF1", "tumors associated with NF1", and "NF1 and malignancies". A comprehensive analysis in terms age and mode of presentation, investigation and therapeutic modalities, and outcome of the published data was performed and compared with similar information on the sporadic cases.

RESULTS

Malignancies in NF1 patients typically occur at an earlier age and, with an exception of optic pathway gliomas, certain types of malignancies carry a poor prognosis compared with their sporadic counterparts. Malignancies are the leading cause of death in NF1 patients, resulting in a 10- to 15-year decreased life expectancy compared with the general population.

CONCLUSIONS

The lack of well-defined screening tests for early detection and the nonspecific clinical presentation contributes to a poorer outcome in malignancies associated with NF1. Small study group size, mixed patient population, and a lack of uniformity in reporting research results make comparison of treatment outcome for this group difficult. An International Consensus Meeting to address and recommend best practices for screening, diagnosis, management, and follow-up of malignancies associated with NF1 is needed.

Neurofibromin physically interacts with the N-terminal domain of focal adhesion kinase

The NF1 gene that is altered in patients with type 1 neurofibromatosis (NF1) encodes a neurofibromin protein that functions as a tumor suppressor. In this report, we show for the first time physical interaction between neurofibromin and focal adhesion kinase (FAK), the protein that localizes at focal adhesions. We show that neurofibromin associates with the N-terminal domain of FAK, and that the C-terminal domain of neurofibromin directly interacts with FAK. Confocal microscopy demonstrates colocalization of NF1 and FAK in the cytoplasm, perinuclear and nuclear regions inside the cells. Nf1+/+ MEF cells expressed less cell growth during serum deprivation conditions, and adhered less on collagen and fibronectin-treated plates than Nf1(-/-) MEF cells, associated with changes in actin and FAK staining. In addition, Nf1+/+ MEF cells detached more significantly than Nf1(-/-) MEF cells by disruption of FAK signaling with the dominant-negative inhibitor of FAK, C-terminal domain of FAK (FAK-CD). Thus, the results demonstrate the novel interaction of neurofibromin and FAK and suggest their involvement in cell adhesion, cell growth, and other cellular events and pathways.

Breast cancer associated with type 1 neurofibromatosis

The association between breast cancer and type 1 neurofibromatosis (NF1) is a rare clinical entity. We herein present the case of a 59-year-old woman, with typical clinical manifestations of NF1, who presented with a painless lump in her right breast, which she had first noticed 8 months earlier. Clinical examination and diagnostic workup were suggestive of a breast carcinoma, and a modified radical mastectomy was performed. Histopathological examination revealed a poorly differentiated invasive ductal breast carcinoma and multiple neurofibromas. The pathological staging was pT2N1a according to TNM/UICC. Delayed presentation of the patient was the result of her mistakenly identifying the breast tumor as a manifestation of NF1 neurofibromatosis.

Skin findings in internal malignant diseases

PURPOSE

A skin finding may be an indicator of internal malignant diseases. In this report, we investigated the skin findings of the cases who have had internal malignancy within the last 1 month.

PATIENTS AND METHODS

Seven hundred cases who were diagnosed as internal malignancy and who did not have any treatment for the malignancy were enrolled in our study between February 2002 and September 2003. A form was completed for all of the cases, including name, surname, and the carcinoma type. All cases were examined in detail, and the observed skin findings or dermatosis was recorded.

RESULTS

The most frequent skin findings among the cases were tinea pedis/onychomycosis, followed by xerosis and pruritus. The skin findings in terms of frequency were determined mostly in hematological malignancies (68.96%).

CONCLUSION

We would like to emphasize that the skin is an indicator of the functions of internal organs and their disorders.

Myxoid neurofibromas of the breast: mammographical, sonographical and MRI appearances

Neurofibromas arise from elements in the peripheral nervous system and are rarely detected in the breast. Neurofibromatosis is a phakomatosis that displays a wide spectrum of clinical expression with neurocutaneous abnormalities and involvement of multiple organ systems. Neurofibromas are more common in neurofibromatosis Type 1. They can show variable amounts of myxoid change, which affect their radiological findings. In this paper, we present a patient with neurofibromatosis Type 1 with mammographical, sonographical and MRI findings of myxoid neurofibromas in her left breast.

Contribution of the BRCA1 and BRCA2 mutations to breast cancer in Tunisia

Hereditary breast cancer accounts for 3-8% of all breast cancers, with mutations in the BRCA1 and BRCA2 genes responsible for up to 30% of these. To investigate the prevalence of BRCA1 and BRCA2 gene mutations in breast cancer patients with affected relatives in Tunisia, we studied 36 patients who had at least one first degree relative with breast and/or ovarian cancer Thirty-four 34 patients were suggestive of the BRCA1 mutation and two were suggestive of the BRCA2 mutation, based on the presence of male breast cancer detected in their corresponding pedigrees. Four mutations in BRCA1 were detected, including a novel frame-shift mutation (c.211dupA) in two unrelated patients and three other frameshift mutations--c.4041delAG, c.2551delG and c.5266dupC. Our study is the first to describe the c.5266dupC mutation in a non-Jewish Ashkenazi population. Two frameshift mutations (c.1309del4 and c.5682insA) were observed in BRCA2. Nineteen percent (7/36) of the familial cases had deleterious mutations of the BRCA1 or BRCA2 genes. Almost all patients with deleterious mutations of BRCA1 reported a family history of breast and/or ovarian cancer in the index case or in their relatives. Our data are the first to contribute to information on the mutation spectrum of BRCA genes in Tunisia, and we give a recommendation for improving clinical genetic testing policy.

Neurofibromatosis type 1 in genetic counseling practice: recommendations of the National Society of Genetic Counselors

The objective of this document is to provide recommendations for the genetic counseling of patients and families undergoing evaluation for neurofibromatosis type 1 (NF1) or who have received a diagnosis of NF1. These recommendations are the opinions of a multi-center working group of genetic counselors with expertise in the care of individuals with NF1. These recommendations are based on the committee's clinical experiences, a review of pertinent English language medical articles, and reports of expert committees. These recommendations are not intended to dictate an exclusive course of management, nor does the use of such recommendations guarantee a particular outcome. These recommendations do not displace a health care provider's professional judgment based on the clinical circumstances of an individual patient.

Women with neurofibromatosis 1 are at a moderately increased risk of developing breast cancer and should be considered for early screening

BACKGROUND

Malignancy risks in patients with neurofibromatosis 1 (NF1) are increased, but those occurring outside of the nervous system have not been clearly defined.

AIM

To evaluate the risk of breast cancer in women with NF1 in a population-based study.

METHODS

The risk of breast cancer in a cohort of 304 women with NF1 aged >or=20 years was assessed and compared with population risks over the period 1975-2005 using a person-years-at-risk analysis.

RESULTS

There were 14 cases of breast cancers in the follow-up period, yielding a standardised incidence ratio (SIR) of 3.5 (95% CI 1.9 to 5.9). However, six breast cancers occurred in women in their 40s, and the SIR of breast cancer in women aged <50 years was 4.9 (95% CI 2.4 to 8.8).

INTERPRETATION

Women with NF1 aged <50 years have a fivefold risk of breast cancer, are in the moderate risk category and should be considered for mammography from 40 years of age.

The genetic and molecular pathogenesis of NF1 and NF2

Neurofibromatosis types 1 and 2 (NF1 and NF2) are autosomal dominant phakomatoses. The NF1 and NF2 genes encode for neurofibromin and merlin, respectively. These 2 functionally unrelated proteins both act as tumor suppressor genes, possibly through modulation of the RAS/RAC oncogenic pathways. Improved understanding of the mechanisms by which these tumor suppressors act may allow for medical therapies for neurofibromatosis and may offer insights for cancer therapeutics.

Hereditary breast cancer syndromes in a Turkish population. Results of molecular germline analysis

Breast cancer is the most common malignancy which affects women. In 5-10% of all cases, breast cancer presents as a hereditary cancer syndrome. Since 1996, 68 families with suspicion of familial breast cancer have been referred to our department. In 5 of the 68 families (7.4%), the clinical diagnosis was hereditary breast ovarian cancer syndrome. In 17 families (25%), two or more breast cancer cases were present. Mutation screening of BRCA1 and BRCA2 in these families revealed a BRCA1 mutation (185delAG) in one family. Three families (4.4%) had a diagnosis of Li-Fraumeni syndrome and germline mutations in TP53 (Lys292Ile, Pro278Ser and Pro278Thr). Breast cancer occurred in a family with hereditary nonpolyposis colon carcinoma (HNPCC; Lynch syndrome) carrying an MLH1 mutation (IVS17-3G>C). Most of our families (41 families; 60.2%) had only one case with breast cancer or cystic adenoma (or both) and did not need counseling and DNA testing. In summary, in 10 of the 68 families in our series (14.7%), a germline mutation in a breast cancer predisposing gene was detected. Our data show the importance of detailed examination of clinical data, pedigree analyses, and molecular germline diagnostics for the counseling of breast cancer cases.