Ovarian cancer at young age: the contribution of mismatch-repair defects in a population-based series of epithelial ovarian cancer before age 40

At least one of ten patients with ovarian cancer is estimated to develop their tumor because of heredity with the breast and ovarian cancer syndrome due to mutations in the BRCA1 and BRCA2 genes and hereditary nonpolyposis colorectal cancer (HNPCC) being the major genetic causes. Cancer at young age is a hallmark of heredity, and ovarian cancers associated with HNPCC have been demonstrated to develop at a particularly early age. We used the Swedish Cancer Registry to identify a population-based series of 98 invasive epithelial ovarian cancers that developed before 40 years. Mucinous and endometrioid cancers were overrepresented and were diagnosed in 27% and 16% of the tumors, respectively. Immunostaining using antibodies against MLH1, PMS2, MSH2, and MSH6 was used to assess the mismatch-repair status and revealed loss of expression of MLH1/PMS2 in two cases, loss of MSH2/MSH6 in one case, and loss of MSH6 only in three tumors. A microsatellite instability-high phenotype was verified in five of six tumors. Based on the identified mutations and family history of cancer, several of these individuals are likely to be affected by HNPCC. We conclude that although the causes of the vast majority of epithelial ovarian cancer at young age are unknown, HNPCC should be considered because of the high risk of metachronous colorectal cancer in the individual and the possibility of preventing additional cancers in the family through control programs.     

Mismatch repair deficiency in ovarian cancer — Molecular characteristics and clinical implications

DNA mismatch repair (MMR) deficiency is associated with increased risk of developing several types of cancer and is the most common cause of hereditary ovarian cancer after BRCA1 and BRCA2 mutations. While there has been extensive investigation of MMR deficiency in colorectal cancer, MMR in ovarian cancer is relatively under-investigated. This review summarizes the mechanism of MMR, the ways in which MMR deficiency can promote carcinogenesis in general and then assesses the available studies regarding MMR deficiency in ovarian cancers with specific emphasis on implications for disease incidence and therapy. The incidence of germline MMR gene mutations in ovarian cancer is only 2% but other mechanisms of gene inactivation mean that loss of expression of one of the seven main genes (MSH2, MSH3, MSH6, MLH1, MLH3, PMS1 and PMS2) occurs in up to 29% of cases. Both mutational and expression data suggest that MMR deficiency is more common in non-serous ovarian cancer. Some studies suggest an improved survival for patients with MMR deficiency compared to historical controls but these do not account for the preponderance of non-serous tumors. A number of in vitro studies have suggested that MMR deficiency is a cause of platinum resistance. To date this has not been categorically demonstrated in the clinic. Larger studies that account for stage of presentation and immunohistochemical subtype are required to assess the effect of MMR deficiency on survival and chemosensitivity. Investigation of MMR related synthetic lethality in colorectal cancer has identified dihydrofolate reductase, DNA polymerase β and DNA polymerase γ and PTEN-induced putative kinase 1 as synthetic lethal to certain MMR defects by causing accumulation of oxidative DNA damage. These synthetic lethal targets require tested and others should be sought within the context of MMR deficient ovarian cancer in an attempt to provide novel therapeutic strategies for these patients.     

林奇综合征相关子宫内膜癌研究进展

林奇综合征（lynch syndrome,LS）是一种常染色体显性遗传病,既往称为遗传性非息肉病性结直肠癌（hereditary nonpolyposis colorectal cancer,HNPCC）,是由DNA错配修复（mismatch repair,MMR）基因MLH1、MSH2、MSH6和PMS2的胚系突变引起。LS患者有多种癌变倾向、发病低龄化及家族易感性,可同时或异时发生结直肠癌、子宫内膜癌（endometrial cancer,EC）、卵巢癌、胃癌和乳腺癌等,女性患者中EC与之最为密切,目前我国对于LS相关EC（LS-EC）认识尚不足,并未形成完整的诊疗标准或指南。为提高对LS-EC的认识,综述LS-EC的分子机制、临床病理特征、筛查及诊断、临床治疗手段、预防等。     

MSH2 splice site mutation and endometrial cancer

Hereditary nonpolyposis colorectal cancer (HNPCC) is an inherited syndrome of cancer susceptibility caused by germ line mutations of genes participating in mismatch repair (MMR). Carriers of MMR gene mutations have an increased risk of colorectal cancers and cancer of other organs. Tumors of the endometrium represent the most frequent extracolonic malignancies in HNPCC. It has been suggested that women harboring MMR gene mutations have a higher risk of endometrial cancer than of colon cancer. Here, we describe an HNPCC patient with early-onset endometrial cancer and a strong familial history of endometrial tumors who harbored a germ line MSH2 splice site mutation (IVS9_2A>G). This mutation was responsible for abnormal messenger RNA processing, leading to the introduction of a premature stop signal and to the expression of a truncated MSH2 protein. In addition, the same mutation was associated with loss of MSH2 protein expression, high microsatellite instability, and PTEN inactivation. Although a direct relationship between the endometrial cancer susceptibility and the MSH2 mutation we found cannot be established, our observations, consistent with the work of other authors, suggest the involvement of germ line MSH2 abnormalities in endometrial tumor development and support the case for endometrial cancer screening in women from HNPCC families.     

Atypical clustering of gynecologic malignancies: A family study including molecular analysis of candidate genes

OBJECTIVE: We set out to determine whether hereditary nonpolyposis colorectal cancer (HNPCC) was responsible for cancer susceptibility in a family with gynecologic malignancies in three consecutive generations. METHODS: A detailed family history study, including review of medical records, was undertaken. Tumor DNAs from affected family members were evaluated for microsatellite instability (MSI). Linkage between cancer susceptibility and the candidate DNA mismatch repair genes MLH1, MSH2, MSH3, and MSH6 (GTBP) was investigated. MLH1 and MSH2 protein expression was evaluated by immunohistochemistry and MSH2 was investigated for mutation. RESULTS: Four gynecologic malignancies in the core family were confirmed. MSI was seen in six of seven cancers studied. The only MSI-negative tumor was an ovarian cancer from the proband's maternal grandmother, which arose at the age of 92. Haplotype analysis using chromosome 2p markers implicated the MSH2 gene in this family's cancer susceptibility. MSH2 protein expression was absent in an MSI-positive colon cancer from an affected family member. CONCLUSIONS: The inability to exclude linkage of MSH2 with the disease susceptibility, the presence of the MSI phenotype in cancers from family members sharing the same region of chromosome 2p, and the lack of immunodetectable MSH2 point to MSH2-associated HNPCC as a cause for this family's cancer susceptibility. Continued efforts to increase awareness of the heritability of endometrial cancer should improve our understanding of the disease, with resultant improved surveillance strategies, recommendations for surgical and chemoprophylaxis, and identification of patients at risk for malignancy as a result of HNPCC.     

Hereditary ovarian cancer. The role of BRCA1 gene dysfunction in response to chemotherapy

Hereditary ovarian cancer is often believed to be as a distinct disease. It is diagnosed earlier than its sporadic type; serous subtypes and more advanced stages are usually observed. Mutations of genes like BRCA1, BRCA2, MMR (MLH1, MSH2, PMS1, PMS2) are strictly associated with the heredity of ovarian and also breast cancer. Systematic controls and specific procedures to lower the risk of those tumors are required for mutation carriers. Most authors emphasize better prognosis for patients with inherited type of ovarian cancer when comparing to sporadic one. It probably results from dysfunction of BRCA1 gene, inducing better response to platinum-based cytostatic drugs. This phenomenon, called "BRCAness profile", is also observed in non-hereditary ovarian cancers and it arises from somatic mutation or hypermetylation of BRCA1 promoter. Thus, the process of DNA repair is defective. Currently new groups of drugs using the BRCA1 dysfunctions are being introduced into clinical practice.     

Society of Gynecologic Oncologists Education Committee statement on risk assessment for inherited gynecologic cancer predispositions

Women with germline mutations in the cancer susceptibility genes, BRCA1 or BRCA2, associated with Hereditary Breast/Ovarian Cancer syndrome, have up to an 85% lifetime risk of breast cancer and up to a 46% lifetime risk ovarian cancer. Similarly, women with mutations in the DNA mismatch repair genes, MLH1, MSH2 or MSH6, associated with the Lynch/Hereditary Non-Polyposis Colorectal Cancer (HNPCC) syndrome, have up to a 40-60% lifetime risk of both endometrial and colorectal cancer as well as a 9-12% lifetime risk of ovarian cancer. Genetic risk assessment enables physicians to provide individualized evaluation of the likelihood of having one of these gynecologic cancer predisposition syndromes, as well the opportunity to provide tailored screening and prevention strategies such as surveillance, chemoprevention, and prophylactic surgery that may reduce the morbidity and mortality associated with these syndromes. Hereditary cancer risk assessment is a process that includes assessment of risk, education and counseling conducted by a provider with expertise in cancer genetics, and may include genetic testing after appropriate consent is obtained. This commentary provides guidance on identification of patients who may benefit from hereditary cancer risk assessment for Hereditary Breast/Ovarian Cancer and the Lynch/Hereditary Non-Polyposis Colorectal Cancer syndrome.     

Occult endometrial cancer and decision making for prophylactic hysterectomy in hereditary nonpolyposis colorectal cancer patients

BACKGROUND AND OBJECTIVE: Hereditary nonpolyposis colorectal cancer (HNPCC) is the most frequent form of hereditary colorectal cancer. In addition to the high lifetime risk for colorectal cancer in mutation carriers, there is also a remarkably increased risk for endometrial cancer (EC). METHODS: In this retrospective study, clinical and molecular approach to the individual decision making as to whether or not to perform a prophylactic hysterectomy in a subset of HNPCC patients is discussed. 147 female patients meeting at least one criterion of the Bethesda guidelines were included in this analysis between 1995 and 2003. After clinical and genetic counseling, patients gave informed written consent and microsatellite analysis, immunohistochemistry and sequencing of the mismatch repair genes MLH1, MSH2 and MSH6 was performed. RESULTS: 11 of the analyzed patients had a personal history of EC and had undergone previous hysterectomy at ages 26 to 62 years. Prophylactic hysterectomy with oophorectomy was considered in postmenopausal women meeting the Amsterdam criteria and/or carrying a disease causing mismatch repair gene mutation who were operated on because of diagnosed colorectal cancer in our center for hereditary cancer. This procedure was performed in 4 patients. None of them had shown any symptoms of a gynecologic malignancy. Preoperative gynecological examination showed no evidence for EC or ovarian cancer in these patients. Postoperative histological examination showed EC stage T1b N0 M0 in 2 patients. CONCLUSIONS: Since the efficiency of gynecological surveillance is uncertain, prophylactic hysterectomy could be an option for a subset of HNPCC patients and mutation carriers.     

Hereditary risk of women's cancers

The characterization of specific genes responsible for the hereditary risk of common cancers has enabled the development of clinical tests designed to identify at-risk individuals and to significantly improve the clinical outcome of such individuals. Two of the most important syndromes associated with a hereditary risk of cancer in women are hereditary breast and ovarian cancer, resulting from the BRCA1 and BRCA2 genes, and hereditary non-polyposis colorectal cancer, caused primarily by the MLH1 and MSH2 genes. As testing for the hereditary risk of breast, ovarian, endometrial and colorectal cancer enters the clinical mainstream, physicians responsible for the health care of women are increasingly required to assess and provide guidance to healthy patients with a strong family history, cancer survivors who may be at risk of a second cancer and women who discover that a family member carries a specific mutation identified through genetic testing. Obstetricians and gynaecologists must therefore become familiar with the principles of assessing the family history for specific hereditary cancer syndromes, with the appropriate use of tests to confirm such syndromes and with the management options for women who have inherited a greatly increased risk of cancer.     

Advances in the understanding of risk factors for ovarian cancer

The identification of risk factors for ovarian cancer is central to the goal of preventing deaths from this disease. Reproductive and hormonal history clearly modulate the risk of ovarian cancer. Continuous ovulation associated with nulliparity increases the likelihood of ovarian malignancy. Protective factors include conditions that suspend ovulation, such as pregnancy, lactation and oral contraceptive use. Hereditary syndromes account for 10% of ovarian cancer cases. The breast ovarian cancer syndrome is caused by mutations in the BRCA1 and BRCA2 genes and is associated with an 11-40% risk of developing ovarian cancer. The hereditary nonpolyposis colorectal cancer syndrome (HNPCC, or Lynch II) is caused by mutations in DNA mismatch repair genes and carries a 12% risk of ovarian cancer. Due to a lack of adequate screening techniques, women with BRCA1, BRCA2 or HNPCC mutations should consider prophylactic removal of the ovaries and fallopian tubes when childbearing is complete. Genetic polymorphisms are hereditary genetic variations that may act in concert with other genetic, hormonal or environmental factors to potentiate the risk of ovarian cancer. Finally, ovarian cancer risk is altered by environmental and behavioral factors. Further study of the risk factors for ovarian cancer is needed to develop effective preventive strategies.     

Hereditary breast and ovarian cancer: what the primary care physician should know

In recent years, testing for cancer susceptibility genes has entered the clinical setting. The practicing physician needs to be familiar with this evolving area of medicine to be able to counsel and/or refer high-risk patients such as those with a strong personal or family history of cancer. The following is a review of the clinically pertinent information regarding hereditary breast and ovarian cancers resulting from mutations in BRCA genes. A special emphasis is placed on the different options available for BRCA mutation carriers, because many interventions have already proven to be highly efficacious. The increased risk of cancer seen in hereditary nonpolyposis colorectal cancer (HNPCC) is not part of this review but is mentioned briefly.     

Microsatellite instability and hMLH1 and hMSH2 gene expression in Taiwanese hereditary nonpolyposis colorectal cancer.

BACKGROUND AND PURPOSE: The mutation rate of hMSH2 and hMLH1 (20%) in Taiwanese hereditary nonpolyposis colorectal cancer (HNPCC) is lower than that reported in other countries. This study aimed to examine the microsatellite instability (MSI) status and gene expression pattern of Taiwanese HNPCC in an effort to establish correlation between these data and results of prior genetic screening. METHODS: The "Bethesda markers" were used for the MSI analysis. Tumor and neighboring tissues were obtained from 10-mm sections of neutral formalin-fixed, paraffin-embedded, hematoxylin and eosin-stained specimens with a PixCell laser-capture microdissector. Four-mm sections were used for the immunohistochemical analysis by avidin-biotin complex method and final coloring with diaminobenzidine. A pathologist performed scoring of the pathological specimens twice, using a double-blinded methodology. Thirteen tissue blocks from 8 HNPCC families (Amsterdam's criteria) were included in this study. RESULTS: Although the majority of the HNPCC tissues displayed a MSI-high phenotype (10/13, 76.9%), lack of expression of MSH2 and MLH1 was infrequent. Furthermore, only 1 germ-line mutation was detected in the peripheral blood leukocytes of the patients whose tumors had lost protein expression of MSH2 or MLH1. CONCLUSIONS: Our results indicate that the pathogenesis of Taiwanese HNPCC is different from that in other countries. Rather than immunohistochemical analysis, MSI status, and genetic screening, clinical history remains a reliable method for diagnosis of HNPCC in Taiwanese the population.     

Genetic testing for gynaecological cancer

The traditional family-history approach to genetic testing involves taking a detailed three generation family-history from both sides of the family, ethnicity, type of cancer, age of onset and death. Testing for BRCA1/BRCA2 mutations is offered at a ≥10% combined BRCA1/BRCA2 probability. Risk models such as the Manchester scoring system, BOADICEA and BRCAPRO can be used to calculate BRCA1/BRCA2 probability. High-risk women identified should be referred to a regional genetics service for genetic counselling and testing. The Amsterdam-Criteria-2 have been traditionally used to identify Lynch syndrome (caused by a mismatch repair gene (MLH1/MSH2/MSH6/PMS2) mutation). Molecular (immunohistochemistry and Microsatellite instability) analysis of tumour tissue is now established as an initial step, with genetic testing undertaken for protein deficient or MSI unstable tumours. This is offered for those fulfilling Bethesda criteria and recently for all colorectal cancer cases <60 years. BRCA1/BRCA2 testing is recommended for all non-mucinous invasive epithelial ovarian cancers irrespective of family-history (10–20% have a BRCA1/BRCA2 mutation). This is being undertaken by non-genetics clinicians. A population-based approach to genetic testing identifies 50% more carriers at risk. It has been extensively investigated in the Ashkenazi-Jewish population and found to be extremely cost-effective in this community. This is expected to lead to change in guidelines in the future.     

Lynch syndrome in women less than 50 years of age with endometrial cancer

OBJECTIVE: To estimate the frequency of mismatch repair deficiencies associated with hereditary nonpolyposis colorectal cancer, or Lynch syndrome, in women less than age 50 with endometrial cancer. METHODS: Consecutive patients less than age 50 diagnosed with endometrial adenocarcinoma were identified. Available pathologic specimens were freshly sliced, and protein expression for MLH1, MSH2, MSH6, and PMS2 was evaluated by immunohistochemistry. Slides were scored on a semiquantitative method with complete absence of any of the four proteins suggesting a deficiency. All results were confirmed by microsatellite instability testing. RESULTS: Sixty-one pathology specimens were analyzed. Twenty-one (34%) of the tumors had absence of staining of at least one of the four mismatch repair proteins determined by immunohistochemistry and confirmed by microsatellite instability testing. Obese patients were less likely than nonobese patients to have a mismatch repair deficiency (21% versus 59%, respectively). Non-obese patients had a relative risk for a mismatch repair deficiency of 5.5 (95% confidence interval 1.6-19.1; P=.01). CONCLUSION: Many women diagnosed with endometrial cancer before age 50 will have a mismatch repair deficiency discovered by immunohistochemistry and microsatellite instability testing. A number of young women diagnosed with endometrial cancer will require further genetic testing for mismatch repair mutations. LEVEL OF EVIDENCE: III.     

Women with breast and uterine cancer are more likely to harbor germline mutations than women with breast or uterine cancer alone: A case for expanded gene testing

ObjectiveWe explored the germline mutation spectrum and prevalence among 1650 women with breast and uterine cancer (BUC) who underwent multi-gene hereditary cancer panel testing at a single commercial laboratory.MethodsThe combined frequency of mutations in 23 BC and/or UC genes was compared between BUC cases and control groups with (1) no personal cancer history; (2) BC only; and (3) UC only using logistic regression.ResultsFourteen percent (n = 231) of BUC cases tested positive for mutations in BC and/or UC genes and were significantly more likely to test positive than individuals with BC only (P < 0.001), UC only (P < 0.01), or unaffected controls (P < 0.001). Analysis of gene-specific mutation frequencies revealed that MSH6, CHEK2, BRCA1, BRCA2, ATM, PMS2, PALB2 and MSH2 were most frequently mutated among BUC cases. Compared to BC only, BRCA1, MLH1, MSH2, MSH6, PMS2 and PTEN mutations were more frequent among BUC; however, only ATM mutations were more frequent among BUC compared to UC only. All of the more commonly mutated genes have published management guidelines to guide clinical care. Of patients with a single mutation in a gene with established testing criteria (n = 152), only 81.6% met their respective criteria, and 65.8% met criteria for multiple syndromes.ConclusionsWomen with BUC are more likely to carry hereditary cancer gene mutations than women with breast or uterine cancer alone, potentially warranting expanded genetic testing for these women. Most mutations found via multi-gene panel testing in women with BUC have accompanying published management guidelines and significant implications for clinical care.     

Ovarian cancer linked to Lynch syndrome typically presents as early-onset, non-serous epithelial tumors

Objective

Heredity is a major cause of ovarian cancer and during recent years the contribution from germline mismatch repair (MMR) gene mutations linked to Lynch syndrome has gradually been recognized.

Methods

We characterized clinical features, tumor morphology and mismatch repair defects in all ovarian cancers identified in Swedish and Danish Lynch syndrome families.

Results

In total, 63 epithelial ovarian cancers developed at mean 48 (range 30-79) years of age with 47% being early stage (FIGO stage I). Histologically, endometrioid (35%) and clear cell (17%) tumors were overrepresented. The underlying MMR gene mutations in these families affected MSH2 in 49%, MSH6 in 33% and MLH1 in 17%. Immunohistochemical loss of the corresponding MMR protein was demonstrated in 33/36 (92%) tumors analyzed.

Conclusion

The combined data from our cohorts demonstrate that ovarian cancer associated with Lynch syndrome typically presents at young age as early-stage, non-serous tumors, which implicates that a family history of colorectal and endometrial cancer should be specifically considered in such cases.     

Identifying and managing hereditary risk of breast and ovarian cancer

In the past, all women with a family history of breast or ovarian cancer were considered to be at increased risk of cancer themselves. The discovery of BRCA1 and BRCA2 demonstrated that susceptibility to breast and ovarian cancer can be inherited by women as a single-gene autosomal dominant disorder. For such women, evaluation of family history is an important screening tool to identify the possibility of hereditary cancer risk but only genetic testing can provide definitive, individualized risk assessment. Women who have inherited mutations in BRCA1 or BRCA2 now have several medical management options to address their increased risk of cancer. A well-educated community of health care providers and patients can use hereditary risk assessment, including genetic testing, to improve health care.     

Consequences of universal MSI/IHC in screening ENDOMETRIAL cancer patients for lynch syndrome

Objective

Determine factors impacting the uptake of genetic counseling and results of genetic testing following universal tumor testing for Lynch syndrome in patients with endometrial cancer.

Methods

The study population consisted of two unselected cohorts of endometrial cancer patients, 408 identified retrospectively and 206 identified prospectively. Immunohistochemistry for mismatch repair protein expression and/or microsatellite instability analysis was performed on these tumors. MLH1 methylation analysis was performed on tumors with loss of MLH1 protein. Tumor studies were considered suggestive of Lynch Syndrome if they showed immunohistochemical loss of MSH2, MSH6 or PMS2, loss of MLH1 without MLH1 promoter methylation, and/or microsatellite instability. Participants with suggestive tumor studies were contacted and offered genetic counseling and testing.

Results

In the retrospective cohort, 11% had tumor studies suggestive of Lynch syndrome, and 42% was seen for genetic counseling. A germline mutation was detected in 40%, and one had a variant of uncertain significance. In the prospective cohort, 8.7% of patients had tumor testing suggestive of Lynch syndrome; 72% were seen for genetic counseling. Germline mutations were found in 40%, and one had a variant of uncertain significance. Common challenges included timing of re-contact, age, perceived lack of relevance, inability to travel and limited insurance coverage.

Conclusions

There are several barriers to genetic counseling and testing follow-up after universal tumor testing, and uninformative genetic test results present a management challenge. It is important to consider these limitations when implementing an approach to screening endometrial cancer patients for Lynch syndrome.     

Family history of gynaecological cancers

Women are presenting to primary and secondary care with concerns about a family history of ovarian and breast cancer, or ovarian, endometrial and bowel cancer. Although most ovarian and endometrial cancer is sporadic, about 5−10% is due to mutations in genes which predispose to breast/ovarian cancers, BRCA1 and BRCA2, and ovarian/endometrial and bowel cancer, the mismatch repair genes of hereditary non-polyposis colon cancer (HNPCC). This review considers different scenarios in women presenting with a family history of ovarian and endometrial cancer. It uses these family histories to illustrate the ways in which families at high risk of ovarian and endometrial cancer can be identified by pedigree analysis. There will be further discussion about these genes and the different management options available to families, including surveillance, chemoprevention and prophylactic surgery.     

Lynch Syndrome in patients with clear cell and endometrioid cancers of the ovary

Objective

Patients with Lynch Syndrome are at an increased risk for a variety of malignancies, including ovarian cancer. Ovarian cancers associated with Lynch Syndrome are predominantly clear cell or endometrioid in histology. Lynch Syndrome is characterized by germline mutations in mismatch repair (MMR) genes. The current study aims to assess the prevalence of loss of MMR expression in patients with endometrioid and clear cell ovarian carcinoma.

Methods

A retrospective review identified 90 patients with endometrioid and/or clear cell carcinomas. Slides made from tumor tissue microarray blocks were evaluated using immunohistochemical stains with antibodies against MLH1, PMS2, MSH2, and MSH6. Statistical analysis was performed.

Results

Seven of the 90 cases (7.8%) had loss of MMR expression. The mean age of patients with loss of MMR expression (47 years) was significantly younger than those with retained MMR expression (p = 0.014). Loss of MMR expression was present in 20% of patients under the age of 53 with clear cell or endometrioid cancers. Genetic studies found that 3 of the 5 patients with loss of MMR expression carried mutations consistent with Lynch Syndrome; acquired hypermethylation of MLH1 was noted in one patient. Six of 7 patients (86%) whose tumors lacked MMR expression had synchronous or metachronous primary malignancies, a significantly greater prevalence than those with retained MMR expression (p < 0.001).

Conclusion

Patients under the age of 53 with clear cell or endometrioid ovarian carcinomas are at a clinically significant risk for loss of MMR expression and Lynch Syndrome; routine screening with immunohistochemical staining should be considered.