RUNX2 and WWOX genes as molecular biomarkers and candidates for targeted therapy in Egyptian patients with primary conventional osteosarcoma

Background: The conventional osteosarcoma (OS) is the commonest primary malignant, bone tumor with complex genomic profiles and poor survival. Runt-related transcription factor 2 (RUNX2) and WW domain containing oxidoreductase (WWOX) genes are implicated in normal osteogenesis as well as in the development of primary conventional OS. Methods: We retrospectively assessed protein and RNA expression of the RUNX2 and WWOX genes by quantitative real time PCR (qPCR) and immunohistochemistry (IHC) in 80 cases of primary OS and 20 normal control (NC) subjects. Proteins and RNA expression levels of both genes were correlated to clinico-pathological features of the patients, progression free and overall survival (PFS& OS) rates. Results: In OS, RUNX2 protein was detected in 72/80 (90%) cases compared to 4/20 (20%) NC samples (p. < 0.001) and RUNX2-RNA was up regulated (up to 103.2 folds) in 60/80 (75%) (p = 0.01). WWOX protein and RNA (up to 7.2 folds) were detected in all NC samples but in 24/80 (30%) and 20/80 (20%) OS cases; respectively (p. < 0.001 for each). The concordance between the RNA and protein expressions for RUNX2 and WWOX was significantly high (X_trend

Naltrexone attenuates endoplasmic reticulum stress induced hepatic injury in mice.

Endoplasmic reticulum (ER) stress provides abnormalities in insulin action, inflammatory responses, lipoprotein B100 degradation and hepatic lipogenesis. Excess accumulation of triglyceride in hepatocytes may also lead to disorders such as non-alcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Opioid peptides are involved in triglyceride and cholesterol dysregulation, inflammation and cell death. In this study, we evaluated Naltrexone effects on ER stress induced liver injury. To do so, C57/BL6 mice received saline, DMSO and Naltrexone, as control groups. ER stress was induced by tunicamycin (TM) injection. Naltrexone was given before TM administration. Liver blood flow and biochemical serum analysis were measured. Histopathological evaluations, TNF-α measurement and Real-time RT-PCR were also performed. TM challenge provokes steatosis, cellular ballooning and lobular inflammation which significantly reduced in Naltrexone treated animals. ALT, AST and TNF-α increased in the TM group and improved in the Naltrexone plus TM group. Triglyceride and cholesterol levels decreased in TM treated mice with no increase in Naltrexone treated animals. In the Naltrexone plus TM group, gene expression of Bax/Bcl-2 ratio and caspase3 significantly lowered compared with the TM group. In this study, we found that Naltrexone had a notable alleviating role in ER stress induced steatosis and liver injury.

Hepatitis C virus and other risk factors in hepatocellular carcinoma.

UNLABELLED: Hepatocellular carcinoma (HCC) increased in Egypt in the past years, becoming the most common cancer among men. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are the known primary risk factors for HCC. This study describes the viral profile of HCC in a predominantly rural area in Egypt. We included 148 HCC cases and 148 controls from the Tanta Cancer Center and the Gharbiah Cancer Society in the Nile delta region. Serological (ELISA) and molecular (PCR) analysis for HBV and HCV infection were performed on plasma samples from each subject. Epidemiologic, environmental, and medical histories were collected by interviewing of subjects. Around 90.5% of cases and controls were from rural areas. HCV infection was high in both cases and controls (89.2% and 49.3%, for cases and controls respectively by serology). HCV was the most important HCC risk factor [OR 9.7 (95% CI: 3.3-28.0, P <0.01)], and HBV infection showed marginal tendency of increased risk [OR 5.4 (95% CI: 0.9-31.8, P <0.06)]. Ever worked in farming [OR 2.8 (95% CI: 1.1-7.2, P <0.03)] and history of cirrhosis [OR 3.6 (95% CI: 1.6-8.1, P <0.01)] or blood transfusion [OR 4.2 (95% CI: 0.99-17.8, P <0.05)] were also associated with increased HCC risk. This study in a predominantly rural area in Egypt supports previous reports from other parts of Egypt that HCV infection is the primary HCC risk factor in Egypt. Further understanding of the relationship between infection and other risk factors in the development of HCC could lead to targeted interventions for at-risk individuals. KEYWORDS: hepatocellular carcinoma; hepatitis; rural; risk factors; Egypt.

Expression of insulin-like growth factor-II, matrix metalloproteinases, and their tissue inhibitors as predictive markers in the peripheral blood of HCC patients.

BACKGROUND/AIM: Elevated relative expression of insulin-like growth factor-II (IGF-II) was observed in hepatocellular carcinoma (HCC) liver tissues with a role in neovascularization and associated with poor prognosis. IGF-II is influenced by the proteolytic cleavage of IGF-binding protein 3 and by matrix metalloproteinases (MMP), which are further regulated by their tissue inhibitors tissue inhibitor of metalloprotienase-1 (TIMP-1). Our aim is to study new molecular markers for HCC. PATIENTS/METHODS: RNA was extracted from the peripheral blood for evaluating the relative expression of IGF-II, MMP-9, and TIMP-1 in correlation with clinical staging of 39 HCC patients and 15 healthy controls using TaqMan real-time PCR. RESULTS: The relative expression of IGF-II and MMP-9 mRNA were significantly elevated in HCC patients compared with healthy controls; P-value <0.0001 for both. There was a significant correlation between MMP-9 and different HCC stages. On the other hand, TIMP-1 was significantly down-regulated in HCC patients; P = 0.0003 with the elevation of the IGF-II/TIMP-1 ratio. Significant correlation between TIMP-1 and HCC Stage III and Stage IV was found; P-value = 0.0138. CONCLUSION: These results highlight the importance of profiling the expression of IGF-II, MMP-9, and TIMP-1 in the peripheral blood as prognostic molecular biomarkers in HCC.

Immunomodulators, sFas and Fas-L as potential noninvasive predictors of IFN treatment in patients with HCV genotype-4.

Recent studies have indicated that cytokines can be used as markers for disease progression in hepatitis C virus (HCV)-infected patients, therefore this study was conducted to determine the influence of pegylated IFN vs standard IFN on interleukin-2 receptor (IL-2R), IL-6R, IL-8, TNFR-I, TNFR-II, sFas, and sFas-L in Egyptian patients with chronic hepatitis C genotype 4, as no previous studies have been performed on this genotype. We also aim at establishing a possible relationship between these cytokines and the response to INF to determine whether they can be used as noninvasive markers for the response to INF therapy and as monitors for the outcome of treatment. Thirty-eight patients with chronic HCV hepatitis were investigated for the serum levels of the previously mentioned cytokines in a randomized opened controlled trial (22 patients treated with pegylated IFN and 16 patients treated with standard IFN). Cytokine levels were measured by ELISA at 0, 1 and 12 months of IFN therapy. There was marked increase in the serum levels of IL-2R and IL-6R in nonresponders to pegylated interferon, IL-8, TNFR-I and II were significantly higher in nonresponders to standard interferon but were also high in responders of pegylated interferon. sFas and sFas-L showed high levels among responders to pegylated interferon but the standard interferon was again less effective in this regard. Serum levels of TNFR-II, sFas and sFas-L have the potential to be used as serological markers for response to pegylated IFN therapy, and IL-8 is a predictor for nonresponse. Moreover, TNFR-I and II have the potential to be used as markers of response to standard IFN treatment. The persistent correlation between sFas and TNFR-II may elaborate the possible role of pegylated IFN in the induction of apoptosis as a possible new mechanism of viral clearance during treatment with pegylated interferon treatment.

[Thoracic soft tissue uptake on a bone scintigraphy. 2 cases]. / Fixations extra-osseuses thoraciques en scintigraphie du squelette. A propos de 2 cas.

Accumulation of bone seeking radiopharmaceuticals in soft tissue of the chest has many causes. We report two cases of 99m-Tc-HMDP uptake respectively in the lung, in a patient with localized amyloidosis, and on diaphragmatic metastasis of a PNET. Mechanisms of such uptake are discussed.

Epstein-Barr viral infection in extranodal lymphoma of the head and neck: correlation with prognosis and response to treatment.

AIMS: To determine the prevalence of Epstein-Barr virus (EBV) infection in primary extranodal lymphoma of the head and neck (PELHN) in immunocompetent patients. PELHN represents 16.18% of all lymphoma diagnosed at the National Cancer Institute, Cairo. Although EBV infection is highly associated with lymphoma in immunocompromised patients, the situation in immunocompetent patients is still unclear. MATERIAL AND METHODS: The study included 50 PELHN (11 cases in the nose and paranasal sinuses, 11 in the nasopharynx, 13 in the tonsils, seven in the oropharynx and eight in the oral cavity), five reactive lymph nodes, 15 normal nasopharyngeal tissue and 25 throat washes of healthy subjects from Egypt. Cases and controls were assessed for the presence of EBV by polymerase chain reaction (PCR) and in situ hybridization techniques, the presence of 30 base pair deletion of the LMP-1 (del-LMP1) gene and for the expression of p53, Ki67, bcl-2 and Bax by immunohistochemistry. This was also correlated with the clinical outcome of patients. RESULTS: EBV was detected in 90% and 70% of the cases using EBER in situ hybridization and PCR, respectively. All cases of nasal type lymphoma were positive for EBV. del-LMP1 gene was detected in 24/35 of EBV+ cases (68.6%), whereas 11 cases had wild-type variant either alone or mixed with del-LMP1. There was a significant difference in the frequency of del-LMP1 between lymphoma and normal tissues. Overexpression of Ki67, p53 and bcl-2 was detected in 78.1%, 62.5% and 20% of cases, whereas loss of Bax was detected in 18% of the cases. Multivariate analysis showed that only p53 overexpression, del-LMP1 variant and advanced disease stage are independent prognostic factors. CONCLUSION: EBV infection is frequent in PELHN in Egypt. Possible pathogenic mechanisms involve deregulation of p53 and enhanced proliferation (as detected by high Ki67 index). The presence of del-LMP1 variants, p53 overexpression and advanced disease stage are poor prognostic factors associated with reduced survival and poor response to therapy.

Human papilloma virus infection and overexpression of p53 protein in bilharzial bladder cancer.

AIMS AND BACKGROUND: An association between human papilloma virus (HPV) and bladder cancer has been reported. However, the role of HPV in bilharzial bladder cancer and its prevalence have not yet been clarified. STUDY DESIGN: We investigated 50 cases for HPV types 16/18 by in situ hybridization. Also, p53 protein expression by immunohistochemistry was evaluated in 41 of the 50 cases, with correlation of these factors to clinicopathologic parameters and tumor relapse after primary treatment. RESULTS: HPV was detected in 46% of Egyptian bladder carcinomas (23/50 cases). Positivity was 47.8% for squamous cell carcinoma and 36.4% for transitional cell carcinoma. There was a possible viral-bilharzial association as 52.8% of Bilharzial cases, whereas only 12.5% of non-Bilharzial cases were HPV positive (P <0.05). P53 protein was found in 19/41 (46.3%) cases. There was a concordance between HPV and p53 in 58.5% of cases. Neither factor was related to tumor recurrence after primary treatment. CONCLUSIONS: HPV may thus be implicated in the etiology of bilharzial bladder cancer, but a definite causal relationship remains to be demonstrated. HPV together with p53 alterations work in synergy to accelerate the carcinogenic process, as there was concordance in the results of both parameters in 24/41 (58.5%) cases.

Hepatitis C virus genotyping versus serotyping in Egyptian patients.

BACKGROUND: The RNA genome of hepatitis C virus (HCV) displays extensive sequence variation. In this study, serotyping and genotyping techniques were applied to assess this variability by comparing the performance of the serotyping assay with a panel of well-characterized HCV strains isolated from chronic active hepatitis (CAH) patients. PATIENTS AND METHODS: 60 serum samples from CAH patients were analyzed. All isolates were genotyped by a line probe assay and the results of genotyping and serotyping were evaluated. RESULTS: The overall sensitivity of the serotyping and genotyping techniques was 81.16% with a concordance of 73.3%. Type 4 was detected in 73.3% of cases and it was highly heterogeneous. CONCLUSION: Type 4 HCV is the most prevalent type in Egyptian CAH patients and there is a high concordance between the results of serotyping and genotyping techniques.

Allelic instability as a predictor of survival in Egyptian breast cancer patients.

This work was designed with the purpose of determining whether the presence of allelic imbalances (AI) such as microsatellite instability (MSI) and loss of heterozygosity (LOH) in chromosomes 2, 11, 13, and 17 in primary breast cancer could be used as prognostic indicators of patient survival. The DNA from breast cancers removed from 29 patients who were followed-up for up to five years was analyzed for MSI and LOH using a panel of 24 markers located at chromosome 2 (TPO, D2S131, D2S144, D2S171, D2S177, D2S119, D2S123, D2S147 and D2S136), chromosome 11 (C-RAS, Int-2, D11S940, D11S912), chromosome 13 (D13S289, D13S260, D13S267, D13S218, D13S263, D13S155, and D13S162), and chromosome 17 (D17S513, TP53, D17S855, and D17S785). The frequency of AI in the markers studied ranged from 30-55%, being highest for D11S912, D2S171, TP53 and D17S855. Univariate analysis showed association between overall survival rate and AI in 9 out of the 24 markers tested. Five of them were located at the area of the mismatch repair gene (MMR)-2 gene, two at 11p, one at 13q and one at 17p. Using multivariate analysis, it was observed that only pathological and clinical stage (defined as stage II or not) and AI at D2S171, D11S912, or D17STP53 generated significant predictive models for survival.

Microsatellite instability during the immortalization and transformation of human breast epithelial cells in vitro.

The objective of this study was to determine whether microsatellite instability (MSI) and loss of heterozygosity (LOH) are involved in the immortalization of human breast epithelial cells (HBECs) in vitro and in the early stages of their transformation by benzo[a]pyrene (BP) and 7,12-dimethylbenz[a]anthracene (DMBA). We performed a genome-wide analysis of a total of 466 microsatellite DNA polymorphism loci along the X chromosome and the 22 pairs of human autosomes. MSI was found in the immortalized MCF-10F cells at the following loci: D11S1392 (on chromosome 11p13) and D17S849 (at 17p13.3), D17S796 (at 17p13.1), D17S513 (at 17p13.1), TP53 (at 17p13.1), D17S786 (at 17p13.1), and D17S520 (at 17p12) on chromosome 17. The BP-transformed cells exhibited MSI in the same loci and also in locus D11S912 (at 11q25). The more transformed BP1E cells also exhibited MSI on chromosome 13q12-13 at D13S260 and D13S289, markers known to flank the breast cancer susceptibility gene BRCA2. In the DMBA-transformed D3 and D3-1 cells, MSI was observed at the locus D13S260 in addition to the previously reported locus D16S285 (at 16q12.1). No LOH was observed on any of the chromosomes tested in these cells. These observations led us to conclude that the immortalization and transformation of HBECs may involve defects in mechanisms responsible for the cell's genomic stability, such as DNA replication and DNA mismatch repair.

Biological and molecular basis of human breast cancer.

Human breast cancer remains the most common malignancy in the American women. The ultimate cure of this disease relies on a better understanding of the mechanisms underlying the initiation and progression of this disease. The neoplastic transformation of HBEC in vitro represents a successful model for obtaining knowledge on the molecular and biological alterations that may contribute to the tumorigenic mechanisms. We have presented here a current understanding of chemically transformed HBEC in the following aspects: 1. Factors affecting the transformation of HBEC such as genetic predisposition and differentiation status and prior immortalization; 2. New targets for studying the mechanism of cell immortalization such as alterations in telomerase activity and differential expression of cell cycle dependent genes as well as others recently isolated through differential cloning such as H-ferritin, and a calcium binding protein; 3. Epigenetic and genetic mechanisms underlying cell transformation; 4. The association of microsatellite instability in specific loci on chromosomes 11, 13, and 16 with the progression of cell transformation; and 5. The application of microcell mediated chromosome transfer technique as an approach to testing the functional role of specific genes whose dysregulation or loss of function may contribute to the ultimate cell transformation. Further efforts in this cell system will be directed to determine the roles of identified molecular changes as well as the mapping/cloning of tumor suppressor or senescence genes such as those that may reside on chromosomes 11 or 17.

Tissue and serum c-erbB-2 and tissue EGFR in breast carcinoma: three years follow-up.

Amplification of erbB-1 and c-erbB-2 genes has been shown in human breast cancer. Expression of these protooncogenes results in production of epidermal growth factor receptor (EGFR) and c-erbB-2. Both are transmembrane receptors with tyrosine kinase activity. Recent data have indicated that the external domain of c-erbB-2 is shed into the culture supernatant of certain breast cancer cell lines and sera of breast cancer patients. A body of literature has shown that the overexpression of these receptors in malignant tissue and c-erbB-2 when shed into serum is associated with bad prognosis. In the present work, tissue EGFR and c-erbB-2 were determined in the membrane fractions of histopathologically verified malignant and normal tissues from the same breast of 94 patients. These values were also determined in 48 tissue specimens of benign mastopathies. Serum c-erbB-2 was quantified in breast cancer patients (n = 105), patients with benign breast disease (n = 48) and 30 apparently healthy women as controls. Patients were followed up by determination of serum c-erbB-2 for one year and clinically for three years to detect any distant metastasis or recurrence. The levels of tissue and serum c-erbB-2 and Estrogen receptors were significantly higher in the carcinomas and sera of breast cancer patients than benign breast diseases or normal controls. Follow-up, although short, of pre-operative serum c-erbB-2 showed a prognostic value (P = 0.007) better than that of tumor size (P = 0.04), EGFR (P = 0.18), nodal involvement (P = 0.25) and tissue c-erbB-2 (P = 0.85). The shedding of soluble fragments of c-erbB-2 into the serum seems to be a characteristic of the potentially malignant cell. The EGFR mean level, however, was significantly lower in malignant tissues than benign and normal ones. A new definition of EGFR status was developed. Accordingly, the recurrence of the disease was more frequent among patients with negative EGFR. The present work did not reveal any correlation between tissue, serum c-erbB-2 or EGFR on one hand and age, menopausal status, stage, histological type and grade of carcinomas and nodal involvement on the other hand. The present work showed an inverse correlation between estrogen receptor level and level of EGFR in malignant tissues.

Epidermal growth factor receptors: status and effect on breast cancer patients.

The predictive potential of Epidermal Growth Factor Receptor (EGFR) is still a matter of debate. EGFR was quantified biochemically using an enzyme immunoassays malignant and normal tissues from the same breast (n = 94) as well as benign mastopathies (n = 40). The mean level of EGFR in malignant tissues showed a significant decrease from the control and benign ones with a weak positive correlation existing between EGFR level in malignant and control tissue of the same breast. Statistically, no cut-off line could be drawn between malignant and non malignant tumors due to the large overlap in their values. On the contrary to reports on EGFR, when the patients were classified according to the relative changes in EGFR from malignant and adjacent tissue, patients with a relative EGFR decrease (negative EGFR) in malignant tissue showed the poorer prognosis in short term follow up. Mean EGFR values in malignant or normal tissue, or the difference between them, did not show any significant correlation with the age of the patients, menstrual status, clinical stage, type and grade of the carcinoma and lymph node involvement. The present work showed also an inverse correlation between EGFR and Estrogen Receptor (ER) level in the malignant tissues.

Diverse patterns of recognition of hepatitis C virus core and nonstructural antigens by antibodies present in Egyptian cancer patients and blood donors.

Serum samples from 429 cancer patients, 82 unpaid blood donors, and 74 paid blood donors were tested for hepatitis C virus (HCV) markers in two commercially available enzyme immunoassays (EIAs). A total of 229 of 429 (53.4%) cancer patients were positive by the two EIAs. A total of 34 of 156 (21.8%) of the blood donors were positive by the EIAs, with a higher prevalence among paid blood donors (20/74; 27%) compared with that among the unpaid blood donors (14 of 82; 17%). EIA-positive sera were tested for confirmation of the results in an immunoblot assay (LiaTek) in which reactivities to four synthetic peptides representing the HCV core protein and two synthetic peptides representing nonstructural proteins 4 and 5 were measured. Of 243 first and/or second EIA-positive samples from cancer patients, 188 (77.2%) were confirmed to be positive in the synthetic peptide immunoblot. A total of 33 of 35 (94.3%) blood donor samples were confirmed to be positive. A great diversity in reactivity patterns was seen. However, all sera from the group of paid blood donors were exclusively reactive to core peptides 1 and 2. A subset of LiaTek assay-positive samples were tested by the four-antigen RIBA-2 assay. The sera from the paid blood donors were all nonreactive. A subset of the LiaTek-positive sera was analyzed for the presence of the HCV genome by reverse transcriptase-PCR. Eleven of the 20 serum samples with reactivity to LiaTek core peptides 1 and 2 only were HCV reverse transcriptase-PCR positive, as were the majority of the sera with other reactivity patterns by the LiaTek assay. The results confirm the very high prevalence of HCV infection in Egypt. Furthermore, the results indicate that there is circulating in Egypt, particularly in the group of blood donors paid for their donation, an HCV variant which elicits an immune response that is not detected by the RIBA-2 assay.

Debridement of burn wounds with a surgical ultrasonic aspirator.

Ultrasonic ablation of tissue by the surgical ultrasonic aspirator (SUA) is an established technique in neurosurgery and hepatobiliary surgery. We report the first use of SUA in the debridement of burn wound in three patients. Our initial experience suggested that SUA allows meticulous wound debridement and cleansing with minimal bleeding and destruction of normal tissue and, therefore, is an extremely useful surgical instrument to add to the armamentarium of the burn surgeon.

[Destructive paraffinoma of the breast and thoracic wall caused by paraffin injection for mammary increase. Apropos of 3 cases with review of the literature]. / Paraffinomes destructifs des seins et de la paroi thoracique dus à l'injection de paraffine pour augmentation mammaire. A propos de trois cas et revue de la littérature.

The injection of a high viscosity fluids into the tissues for cosmetic body contouring has been practised in the last four decades in the East and South-East of Asia. The injection of liquid paraffin for mammary augmentation was widely practised by surgeons, physician and even non medical people. Unfortunately, most of these cases ended by having different varieties of paraffinoma as a complication of a foreign body reaction. We report three cases of a destructive form of these paraffinomas ulcerating into both breasts and the anterior chest wall. One case was treated by bilateral mastectomy, radical excision of the anterior chest wall soft tissue and reconstruction by a vertical Rectus Abdominus Myocutaneous Flap. The second case had bilateral mastectomy and followed up for facial paraffinomas. The third case was just followed for up regular wound care as surgery was not indicated due to advanced age, poor general condition and the family request.

Acute mass burns caused by o-chlorobenzylidene malononitrile (CS) tear gas.

The use of tear gas in controlling riots has been an accepted practice in many countries for the past four decades. In a recent event, a large quantity of tear-gas canisters were used during a situation of unrest in a Hong Kong Refugees' Detention Centre. We report 96 cases of acute burn injury as an unpredicted side effect of o-chlorobenzylidene malononitrile (CS) tear gas. There were 47 females and 49 males with an age ranging between < 1 to 51 years. These burns were categorized as minor burns, with the total body surface area (TBSA) ranging from 1 to 8 per cent with mean percentage of 3. Most of the patients sustained superficial or partial-skin thickness injuries. Only two patients were admitted to the Prince of Wales Hospital Burns Centre because of deeper burns; debridement and skin grafting was required in one of them. The mechanism of burn injury was due to the flame generated from the grenade explosion, direct contact between the hot canister and the victim's skin, and the effect of the chemical powder inside the canisters when it splashed onto the victim's body. We suggest that the noxious transient effects of tear gas are underestimated, furthermore varying cutaneous effects and deep burns may result from its uncontrolled use during riots. There is a continuing need to reassess the potential toxic effects of CS tear gas as a riot control agent and to debate whether its future use can be condoned under any circumstances.

P53 mutations in egyptian bladder-cancer.

Cancer of the bladder is a frequent malignancy in Egypt and other developing countries in which bladder infection with the parasite Schistosoma haematobium is common. Several epidemiological, histopathological and clinical characteristics of cancer of the Bilharzial bladder suggest that it is distinct from bladder cancer seen in industrialized countries. Little is known, however, about molecular aberrations in Egyptian bladder cancer. We studied the status of p53 in a series of 25 cases of Egyptian bladder cancer using immunohistochemistry to detect the p53 protein and SSCP/sequencing to identify mutations in the p53 gene. Ten of 25 (40%) tumor samples showed a mutation by SSCP/sequencing. Mutations were seen in both the squamous and transitional cell variants. The presence of mutations was associated with advanced stage of disease. Immunohistochemistry had a sensitivity of 70%, and a Specificity of 85% for detecting p53 mutations. Our data show that p53 mutations are a common event in Egyptian bladder cancer, and may be an indicator of advanced disease. Immunohistochemistry is both sensitive and specific for detecting p53 mutations in this tumor, and may be used to assess the prognostic value of p53 mutations in this disease.