Maria Chosia

Germline 657del5 mutation in the NBS1 gene in breast cancer patients

In this report the proportion of consecutive and familial breast cancer cases harboring the 657del5 of exon 6 of the NBS1 gene was determined to assess whether it is associated with the increased risk of breast cancer development. The study consisted of 3 groups of patients: a series of consecutive 150 patients with histologically confirmed breast cancer, diagnosed under the age of 50 in the city of Szczecin; a series of 80 breast cancer patients with a family history of breast cancer in their first‐degree relatives; and a series of 530 consecutive individuals without the diagnosis of breast cancer selected at random by family doctors from the city of Szczecin. Molecular examination included allele‐specific PCR assay for the common Slavic NBS1 mutation (657del5), LOH analysis using denucleotide CA repeat microsatellite markers, haplotype analysis and sequencing. The NBS1 founder mutation was detected in 2 of 150 (1.3%) consecutive breast cancer cases diagnosed under the age of 50 years; in 3 of 80 familial breast cancer cases (3.7%); and in 3 of 530 individuals (0.6%) from the general population. Examination of tumor DNA from patients with the NBS1 mutation (groups A and B) revealed loss of heterozygosity (LOH) in all cases. Additional haplotype analysis revealed that allelic loss affects specifically wild‐type alleles. The majority of probands with breast cancer and the NBS1 mutation had a positive family history of breast cancer in their first‐degree relatives. It appears that the 657del5 mutation in exon 6 of the NBS1 gene is responsible for the occurrence of a small but significant proportion of familial breast cancer patients.

Presence of homozygous KIT exon 11 mutations is strongly associated with malignant clinical behavior in gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of gastrointestinal tract. GISTs range from benign indolent neoplasms to highly malignant sarcomas. Gain-of-function mutations of tyrosine kinase receptors, KIT or PDGFRA, have been identified in most GISTs. In this study, we report 36 GIST patients whose tumors had homozygous KIT exon 11 mutations detected by direct sequencing of PCR products. Loss of heterozygosity in KIT locus and other chromosome 4 loci were documented in majority of these tumors. However, fluorescence in situ hybridization with KIT locus-specific probe and chromosome 4 centromeric enumeration probe showed no evidence of KIT hemizygosity in a majority of analyzed cases. These findings are consistent with duplication of chromosome 4 with KIT mutant allele. Homozygous KIT exon 11 mutations were found in 33 primary tumors and 7 metastatic lesions. In two cases, shift from heterozygosity to homozygosity was documented during tumor progression being present in metastases, but not in primary tumors. Among primary GISTs, there were 16 gastric, 18 intestinal and 2 from unknown locations. An average primary tumor size was 12 cm and average mitotic activity 32/50 HPFs. Out of 32 tumors 29 (90.6%) with complete clinicopathologic data were diagnosed as sarcomas with more than 50% risk of metastatic disease, and 26 of 29 patients with follow-up had metastases or died of disease. An average survival time among pre-imatinib patients, who died of the disease was 33.4 months. Based on these findings, we conclude that presence of homozygous KIT exon 11 mutations is associated with malignant course of disease and should be considered an adverse prognostic marker in GISTs.

The 3020insC allele of NOD2 predisposes to early-onset breast cancer

The NOD2 gene has been associated with susceptibility to Crohn’s disease, and more recently with carcinoma of the colon as well. NOD2 is involved in the inflammatory response and the activation of the NFkB pathway. The range of cancer types associated with NOD2 has not been well studied. The 3020insC allele results in a truncated NOD2 protein and is present in approximately 7% of the population. We studied a possible association between the 3020insC allele of the NOD2 gene and breast cancer using 462 cases and 1910 controls from Poland. Patients were diagnosed with invasive breast cancer at are of two Szczecin regional hospitals between 2002 and 2004. Pathology specimens were reviewed for histological subtype and for the presence of ductal carcinoma in situ (DCIS). Overall there was no association between breast cancer and NOD2 (OR=1.1; p=0.76), but significant associations were observed between the presence of the allele and early-onset breast cancer (OR=1.9; p=0.01) and between the allele and ductal breast cancer with an in situ component (OR=2.2; p=0.006).

Comparison of genomic abnormalities between BRCAX and sporadic breast cancers studied by comparative genomic hybridization

Very little is known about the chromosomal regions harbouring genes involved in initiation and progression of BRCAX‐associated breast cancers. We applied comparative genomic hybridization (CGH) to identify the most frequent genomic imbalances in 18 BRCAX hereditary breast cancers and compared them to chromosomal aberrations detected in a group of 27 sporadic breast cancers. The aberrations observed most frequently in BRCAX tumours were gains of 8q (83%), 19q (67%), 19p (61%), 20q (61%), 1q (56%), 17q (56%) and losses of 8p (56%), 11q (44%) and 13q (33%). The sporadic cases most frequently showed gains of 1q (67%), 8q (48%), 17q (37%), 16p (33%), 19q (33%) and losses of 11q (26%), 8p (22%) and 16q (19%). Losses of 8p and gains 8q, 19 as well as gains of 20q (with respect to ductal tumours only) were detected significantly more often in BRCAX than in sporadic breast cancers. Analysis of 8p‐losses and 8q‐gains showed that these aberrations are early events in the tumorigenesis of BRCAX tumors. The findings of this report indicate similarities between BRCAX and BRCA2 tumours, possibly suggesting a common pathway of disease. These findings need confirmation by more extensive studies because only a limited number of cases were analysed and there are relatively few reports published.

Germline 657del5 mutation in the NBS1 gene in patients with malignant melanoma of the skin.

In this study we determined in what proportion of consecutive malignant melanoma (MM) cases the 657del5 mutation of exon 6 of the NBS1 gene can be detected and whether it is associated with the occurrence of MM. Two groups of patients were studied: a series of 80 consecutive patients with histologically confirmed MM of the skin diagnosed in the city of Szczecin, Poland, and a series of 530 consecutive individuals selected at random by family doctors from the city of Szczecin. Molecular examination included an allele-specific polymerase chain reaction assay for the NBS1 founder mutation (657del5), genomic sequencing, loss of heterozygosity analysis using CA-repeat microsatellite markers, and haplotype analysis. The NBS1 founder mutation was detected in two of the 80 (2.5%) MM cases and in three of the 530 individuals (0.6%) from the general population. The difference was not statistically significant. However, examination of tumorous DNA from the patients with MM and NBS1 mutation revealed loss of heterozygosity in both cases. Haplotype analysis revealed that allellic loss affects wild-type alleles. Breast cancer was found in second-degree relatives of both MM probands with NBS1 mutations. One of these probands was simultaneously affected with breast cancer. It seems that the 657del5 mutation of exon 6 of NBS1 gene may be responsible for the occurrence of a small proportion of MM patients, characterized by the occurrence of breast cancer among their relatives.

The 3020insC Allele of NOD2 Predisposes to Cancers of Multiple Organs

The NOD2 gene has been associated with susceptibility to Crohns disease and individuals with Crohns disease are at increased risk for cancer at a number of organ sites. We studied the association between the 3020insC allele of the NOD2 gene and cancer among 2604 cancer patients and 1910 controls from Poland. Patients were diagnosed with one of twelve types of cancer in the Szczecin region between 1994 and 2004. Significant associations were found for colon cancer (OR = 1.8; 95% CI 1.2 to 2.6), for lung cancer (OR = 1.7; 95% CI = 1.1 to 2.5) and for ovarian cancer (OR = 1.6; 95% CI 1.1 to 2.3). In addition, a significant association was found for early-onset laryngeal cancer (OR = 2.9; 95% CI 1.4 to 6.2) and for breast cancer in the presence of DCIS (OR = 2.1 95% CI = 1.2 to 3.6). The NOD2 3020insC allele is relatively common (in Poland 7.3% of individuals) and may be responsible for an important fraction of cancer cases. We estimate that the lifetime cancer risk among carriers of this allele is 30% higher than that of individuals with two wild-type alleles.

Rarity of germline 1100delC mutation in CHK2 in patients with malignant melanoma of the skin.

In this study the proportion of sporadic and familial malignant melanoma (MM) cases harbouring 1100delC in CHK2 was determined to assess whether this mutation is associated with the occurrence of MM. Three groups of patients were studied: (i) 101 patients with histologically confirmed sporadic MM of the skin diagnosed in the city of Szczecin, Poland; (ii) 16 MM patients with a family history of MM in their first-degree relatives; and (iii) 1024 individuals selected at random by family doctors from the city of Szczecin. Molecular examination included an allele-specific oligonucleotide polymerase chain reaction assay for the CHK2 founder mutation (1100delC), genomic sequencing, loss of heterozygosity analysis using CA-repeat microsatellite markers, and haplotype analysis. The CHK2 founder mutation was detected in one out of 101 (1%) of the sporadic MM cases, in none of the 16 familial MMs, and in two of the 1024 individuals (0.2%) from the general population. The differences between the groups of patients were not statistically significant. The MM patient with a CHK2 founder mutation was a 56-year-old female with a history of brain tumours at age 33 and 40 years, sarcoma at 41 years and finally MM at 55 years. Examination of tumorous DNA isolated from the MM and the sarcoma from this patient revealed no loss of heterozygosity in either tumour. It seems that examination of sporadic or familial MM cases for the 1100delC germline mutation in CHK2 is not justified. To evaluate whether this CHK2 founder mutation is associated with MM in patients with LFS syndrome, more MM cases from LFS families should be examined.

Diagnosis of major tumor categories in fine-needle aspirates is more accurate when light microscopy is combined with intermediate filament typing. A study of 403 cases

Intermediate filament (IF) typing of tumor cells with monoclonal antibodies was applied to 403 fineneedle aspirates. In 271 cases specific cytologic diagnosis of tumor type was apparent from clinical data and light microscopic study alone. Intermediate filament typing confirmed the tumor type in 262 cases and changed an erroneous cytologic diagnosis of major tumor type in nine cases. In a second group of 132 difficult cases, where the tumor type could not be revealed with certainty, IF typing confirmed the cytologic suggestion of tumor type in 50 cases, changed it in nine cases, and helped resolve ambiguities in cytologic diagnosis in 59 cases. It did not help in 14 cases. Thus IF typing adds independent objective differentiation specific information to descriptive tumor typing currently used in aspiration cytologic study. When combined with the morphologic analysis of tumor cells and clinical information it can refine the cytologic diagnosis of major tumor types and prevent error.

Frequency and nature of hMSH6 germline mutations in Polish patients with colorectal, endometrial and ovarian cancers

To the Editor: It is estimated, that somewhere between 5% and 10% of human cancers are a result of a constitutional mutation in a single, highly penetrant gene (1). According to the literature, hMSH6 mutation carriers are affected most frequently by cancers of the colorectum, endometrium or ovaries and hMSH6 families often do not fulfill the HNPCC diagnostic criteria (2,3). Currently, there is no information about hMSH6 mutations in the Polish population, except for one reported alteration identified in a previous study (4). Three cancer types were investigated: colorectal cancers – CRC(489 cases), endometrial cancers – EC(153 cases) and ovarian cancers – OC(179 cases). Each of group was further stratified using the following criteria:

Pulmonary Benign Metastasizing Leiomyoma from the Uterine Leiomyoma: A Case Report

Summary Background Benign metastasizing leiomyoma (BML) is a rare condition described as multiple well-differentiated leiomyomas at sites distant from the uterus. Apart from lungs it has also been reported in lymph nodes, heart, brain, bone, skin, eye and spinal cord. We present a case of pulmonary benign metastasizing leiomyoma in a female patient admitted to our hospital with suspicion of left adnexal tumor. Case Report A 45-year-old woman was referred to our hospital with suspicion of left adnexal tumor. The control transvaginal ultrasound examination performed at admission to the Gynecological Department excluded adnexal neoplasm. However, a large amount of fluid within the Douglas pouch raised the oncological concern. The patient underwent myomectomy in 2005. In the same year she was diagnosed with multiple lung nodules and underwent pulmonary wedge resection with the diagnosis of pulmonary benign metastasizing leiomyoma being stated. The decision of reevaluation of the specimen, control CT and puncture of the Douglas pouch fluid was made. Computed tomography performed at the Department of Diagnostic Imaging and Interventional Radiology of the Pomeranian Medical University Hospital revealed multiple, bilateral nodules. The microscopic examination of the samples confirmed the initial diagnosis of benign metastasizing leiomyoma with no evidence of neoplastic cells within the fluid. Conclusions Pulmonary benign metastasizing leiomyoma is a rare entity. However, it should be always taken into consideration in women with a previous or coincident history of uterine leiomyoma, especially when no evidence of other malignancy is present.