MIB-1 Staining Research Articles

Correlation of MIB-1 staining index and 201Tl-SPECT retention index in preoperative evaluation of malignancy of brain tumors

MIB-1 staining provides a useful index of the malignancy of brain tumors. However, because of the difficulty of evaluating malignancy based on the preoperative imaging findings, we investigated the correlation between the (201)Tl-SPECT retention index (RI) and MIB-1 staining index (MIB-1 SI) to determine the usefulness of RI for preoperative evaluation of the malignancy of brain tumors. The subjects of this study were 47 patients who underwent tumor removal surgery at our hospital in 2006 and 2007. The tumors consisted of 16 intraaxial tumors (all gliomas: 9 glioblastomas, 2 anaplastic astrocytomas, 2 anaplastic oligoastrocytomas, 1 oligodendroglioma, and 2 ependymomas), 8 other malignant brain tumors, and 23 extraaxial tumors (10 meningiomas, 7 pituitary adenomas, and 6 schwannomas). The mean RI and mean MIB-1 SI of the intraaxial tumors were 0.628% and 32.0%, respectively, and after MIB-1 SI was converted to the natural logarithm (log MIB-1 SI), Pearson's coefficient for the correlation between them was significant (r = 0.752, P < 0.001). The mean RI and mean MIB-1 SI of the extraaxial tumors were 0.377% and 3.01%, respectively, and after MIB-1 SI was converted to log MIB-1 SI, Pearson's coefficient for the correlation between them was significant (r = 0.803, P < 0.001). Thus, the MIB-1 SI values of highly malignant intraaxial tumors was strongly correlated with their RI values, and the (201)Tl-SPECT RI values were useful as an index of malignancy. RI values may also be useful for evaluating apparently benign extraaxial tumors for possible malignancy.

Prognostic value of WT1 protein expression level and MIB-1 staining index as predictor of response to WT1 immunotherapy in glioblastoma patients

The use of Wilms' tumor 1 (WT1) immunotherapy is considered to be an innovative approach for the treatment of malignant gliomas. Because of its novelty, tools that can accurately predict response to this therapy are still lacking. In this article, we investigated the role of WT1 protein expression level (score 1-4) and MIB-1 staining index in predicting survival outcome after therapy in patients with recurrent or progressive glioblastoma multiforme. Tumor samples from 37 patients enrolled in a phase II clinical trial on WT1 immunotherapy were immunohistochemically analyzed for WT1 levels and MIB-1 index. Results showed that median progression-free survival (PFS) was longer in the WT1 high expression group (score 3 and 4) compared with that of the low expression group (score 1 and 2) (20.0 weeks vs. 8.0 weeks; P = 0.022), and that the median overall survival (OS) was likewise longer in the former compared to the latter group (54.4 weeks vs. 28.4 weeks; P = 0.035). Furthermore, within the WT1 high expression group, tumors with intermediate staining intensity (WT1 score 3) have both the longest median PFS and OS, 24.4 weeks and 69.4 weeks, respectively. On the other hand, no significant correlation was noted between MIB-1 staining index and survival. In conclusion, our study has shown that WT1 protein expression level, not MIB-1 staining index, can be used as a prognostic marker to foretell outcome after immunotherapy, and that patients whose tumors have intermediate WT1 expression have the best survival outcome.

Mitogenic cardiomyopathy: A lethal neonatal familial dilated cardiomyopathy characterized by myocyte hyperplasia and proliferation

Pediatric cardiomyopathies are a heterogenous group of conditions of which dilated cardiomyopathies are the most common clinicomorphologic subtype. However, the etiology and pathogenesis of many cases of dilated cardiomyopathies remain unknown. We describe a series of 5 cases of a rare but clinically and histologically distinctive dilated cardiomyopathy that was uniformly lethal in early infancy. The 5 cases include 2 pairs of siblings. There was parental consanguinity in 1 of the 2 pairs of siblings. Death occurred in early infancy (range, 22-67 days; mean, 42 days) after a short history of general lethargy, decreased feeding, respiratory distress, or cyanosis. There was no specific birth or early neonatal problems. Autopsy revealed congestive cardiac failure and enlarged, dilated hearts with ventricular dilatation more pronounced than atrial dilatation, and endocardial fibroelastosis. Histology showed prominent hypertrophic nuclear changes of cardiac myofibers and markedly increased myocyte mitotic activity including occasional atypical mitoses. Immunohistochemical staining for Mib1 showed a markedly increased proliferative index of 10% to 20%. Ancillary investigations, including molecular studies, did not reveal a primary cause for the cardiomyopathies. This distinctive dilated cardiomyopathy characterized by unusual histologic features of myocyte nuclear hypertrophy and marked mitotic activity is lethal in early infancy. Its occurrence in 2 pairs of siblings suggests familial inheritance. Although the underlying molecular pathogenesis remains to be elucidated, it is important to recognize this distinctive entity for purposes of genetic counseling.

Mucosal thickening in allergic and idiopathic rhinitis mucosa and its probable mechanism

Rhinitis is a prevalent condition characterized by nasal mucosal irritation. Conflicting studies suggest that the mucosa of patients with allergic and nonallergic rhinitis undergoes thickening. To investigate mucosal epithelial thickening in allergic and idiopathic rhinitis and to determine if the mechanism is a consequence of altered proliferation or apoptosis. Interactive image analysis was performed on histologic sections of inferior nasal turbinate tissue to measure epithelial thickness in 3 patient groups. Patients with allergic rhinitis (n = 15), patients with idiopathic rhinitis (n = 15), and a healthy control group (n = 10) were compared. Immunohistochemical and morphometric analyses were used to quantify cell proliferation (Mib-1), apoptosis (terminal uridine nick end labeling technique), and the antiapoptotic factor Bcl-2. Idiopathic epithelium was found to be significantly thickened compared with healthy epithelium (P = .04). Epithelial thickening occurred in some allergic patients, but the findings did not reach statistical significance (P = .22). No statistically significant difference in proliferation as evidenced by Mib-1 staining was seen among the 3 patient groups. Allergic mucosa differed statistically significantly to that of patients with idiopathic rhinitis (P = .01) and healthy controls (P = .005) in showing increased Bcl-2 staining, suggesting reduced apoptosis. Allergic epithelium shows significantly decreased apoptosis, which might explain the increased epithelial thickening seen in some study participants. This mechanism does not, however, appear to explain the significantly increased thickening seen in the idiopathic epithelium. Furthermore, both allergic and nonallergic epithelium showed regional thinning and thickening possibly involving an inflammatory infiltrate.

Uterine Smooth Muscle Tumors of Uncertain Malignant Potential (STUMP):

The current World Health Organization classification indicates that a uterine smooth muscle tumor that cannot be histologically diagnosed as unequivocally benign or malignant should be termed "smooth muscle tumor of uncertain malignant potential" (STUMP). STUMPs represent a heterogeneous group of rare tumors that have been the subject of only a few published studies, some of which lack detailed clinicopathologic details and/or follow-up data. More recently, it has been suggested that immunohistochemical staining may be helpful in the diagnosis of STUMPs. The clinicopathologic features of 16 cases of STUMP that exhibited usual smooth muscle differentiation, diagnosed between 1992 and 2006 from 11 hospitals, were studied and classified into 4 subgroups using terminology and criteria described by Stanford investigators. Immunohistochemical stains for p16, p53, MIB1 (ki-67), and estrogen and progesterone receptors were performed. The results were compared with those in the literature. The tumors were classified as follows: 6 as "atypical leiomyoma with limited experience", 7 as "smooth muscle tumor of low malignant potential", 2 as "atypical leiomyoma, low risk of recurrence," and 1 as "mitotically active leiomyoma, limited experience." Follow-up was 21 to 192 months (mean, 80.8 and median, 51.5). Only 2 tumors recurred, at 15 and 51 months, respectively; both were atypical leiomyoma with limited experience (multifocal moderate-to-severe atypia, no tumor cell necrosis, and mitotic counts of 4 and 5 mitotic figures /10 high-power fields, respectively). Both tumors had areas that were indistinguishable from benign leiomyoma and both had diffuse immunoreactivity for p16 and p53. Six other tumors that had focal staining for these markers all had a benign outcome. Both patients with recurrence were alive at last follow-up (at 40 and 74 mo). All the other patients were alive and disease-free. This and other studies suggest that uterine tumors classified as STUMPs using criteria proposed by Stanford investigators are usually clinically benign but should be considered tumors of low malignant potential because they can occasionally recur, in some cases, years after hysterectomy. After a mean follow-up of 80.8 months, only 2 of 16 tumors in this study recurred. Both of the latter tumors fulfilled the criteria for atypical leiomyoma with limited experience. Notably, the 2 recurrent tumors were the only ones that were strongly immunoreactive for p16 and p53, supporting earlier observations that these markers may be helpful in the prediction of the behavior of STUMPs. Patients diagnosed with STUMPs should receive long-term surveillance.

Breast secretory carcinoma: a clinicopathologic study of four cases

Objective: To explore the clinicopathologic features of secretory carcinoma of breast (SCB). Methods: Four cases of SCB were analyzed by light microscopy, histochemistry, immunohistochemistry and electron microscopy. The clinical data were also analyzed. Special staining of periodic acid-Schiff reaction with diastase pretreatment, immunohistochemical staining of ER, PR, HER-2, p53, MIB-1, S-100, p63, CK8/18 and EMA by En Vision method were performed. Results: Solid, cribriform, tubular, or papillary architecture may be seen. Tumor forms cystic spaces filled with abundant pale pink secretory material, positive with diastase resistant periodic acid-Schiff (PAS-DR) stains. Tumor cells were small with bland nuclei and abundant pale, eosinophilic cytoplasm, rare mitotic activity and necrosis. Immunohistochemically, tumor cells were positive for CK8/18, EMA, negative for S-100, p63 and variable partially positive for p53, ER, PR, HER-2 and MIB-1. Under electron microscopy, the tumor cells possessed numerous membrane-bound secretory vacuoles in cytoplasm lined by microvilli. Con- clusion: SCB is a rare, low-malignant neoplasm. SCB have pathology, clinical picture, treatment, follow-up, immunohisto- chemical and genetic features that distinguish them from invasive ductal carcinomas of the usual type.

Malignant solitary fibrous tumour of the orbit

We aimed to report a case of orbital solitary fibrous tumour (SFT) in a child and to review the relevant literature. We describe an SFT in a 13-year-old boy with a 1-month history of painless proptosis in the left eye. Magnetic resonance imaging revealed a well circumscribed mass filling most of the left intraconal orbit. The lesion was excised and histopathological examination revealed a malignant SFT. Postoperative follow-up for 18 months was uneventful. Malignant SFT of the orbit should be included in the differential diagnosis of paediatric orbital tumours. Complete surgical excision remains the preferred method of management and the longterm prognosis is guarded.

The impact of Skp2 overexpression on recurrence-free survival following radical prostatectomy

Background In several human cancers, overexpression of Skp2 (S-phase kinase associated protein 2), which targets p27 for degradation, portends a poorer prognosis. We examined whether Skp2 overexpression is associated with recurrence following radical prostatectomy (RP) for prostate cancer. Methods Immunohistochemical staining for Skp2, p27, and MIB-1 was performed on 109 men with node-negative prostate cancer surgically managed from 1985 –1996. Associations between the stains were tested and Cox regression was used to determine the association between Skp2 expression and time to biochemical recurrence following RP. Results The 12 tumors (11%) with Skp2 overexpression all had correspondingly low p27 expression ( P = 0.006), and a similar inverse Skp2/p27 relationship was seen in vitro in LNCap cells. Skp2 overexpression in tissue was associated with higher Gleason score ( P = 0.002), more advanced pathological stage ( P = 0.01), and higher MIB-1 index ( P = 0.03), but a more favorable PSA profile ( P = 0.04). Five men received a TURP. Among 104 who received RP, median follow-up was 67 months (range: 0.2 –218). After adjusting for PSA, pathologic stage, and Gleason score, Skp2 overexpression remained significantly associated with a shorter time to biochemical recurrence (adjusted hazard ratio 4.8 (95% C.I. 1.6 –14, P = 0.004)). The median time to recurrence with high vs. low Skp2 was 4 vs. 54 months. Conclusions Skp2 overexpression was seen in a significant minority of surgically-managed men and was independently associated with a higher risk of recurrence, raising the possibility that Skp2 could be useful as a prognostic biomarker and as a potential molecular target for novel systemic agents in prostate cancer.

Medulloblastomas: a correlative study of MIB-1 proliferation index along with expression of c-Myc, ERBB2, and anti-apoptotic proteins along with histological typing and clinical outcome

Medulloblastoma (MB) is the most common pediatric brain tumor. It is however rare in adults. The genetic and protein expression profile of medulloblastoma is complex, which is worthwhile in terms of prognostication and development or selection of targeted therapy. The aims and objectives to correlate the MIB-1 proliferation index and protein expression profiles of c-Myc, ERBB2, and anti-apoptotic proteins (Bcl2 and Bcl-xL) in tumor cells with histological subtypes and clinical outcome. In 50 cases, histopathological subtyping was done, and protein expression profiling by immunohistochemical technique was performed by stains for MIB-1, Bcl2, Bcl-xL, c-Myc, and ERBB2 in 30 cases. The findings were correlated with histological types and patient's average follow-up data. Histological subtypes were similar to that described in literatures. The average expression of Bcl2, Bcl-xL, MIB-1, c-Myc, and ERBB2 were as follows: 50.38%, 38.18%, 59.03%, 46.16%, and 59.62%, respectively. Bcl2 expression showed statistically significant correlation with progress-free survival (PFS) [p = 0.046], while ERBB2 and MIB-1 showed a trend of higher expression in progressive disease. The protein expression pattern did not correlate with histological subtypes. Though Bcl-2, ERBB2, and MIB-1 LI came out to be potential markers of aggressive behavior, c-Myc did not correlate with PFS in MB.

Human immunodeficiency virus–associated precursor T-lymphoblastic leukemia/lymphoblastic lymphoma: report of a case and review of the literature

We describe a case of human immunodeficiency virus-associated T-lymphoblastic leukemia/lymphoblastic lymphoma in a 43-year-old Italian man with a history of human immunodeficiency virus infection lasting 9 years. Immunoperoxidase stains showed that neoplastic cells were positive for CD3, TdT, CD45, CD10, CD1a, CD2, CD7, CD5, and CD43 (focal). The proliferation rate was approximately 70%, assessed by Ki-67/MIB-1 staining. Flow cytometry of the marrow aspirate revealed an intermediate/cortical T-lymphoblastic phenotype: negative for surface CD3 and positive for cytoplasmic CD3, CD1a, TdT, CD2, CD7, CD5, and CD8, with partial coexpression of dimCD4. Analysis of T-cell receptor gamma polymerase chain reaction products showed clonality. T-lymphoblastic leukemia/lymphoblastic lymphoma is a very rare occurrence in the clinical setting of human immunodeficiency virus infection. It is not listed in the World Health Organization classification of lymphomas associated with human immunodeficiency virus infection. Only 4 cases of human immunodeficiency virus-associated T-lymphoblastic leukemia/lymphoblastic lymphoma are reported in the current medical literature.

A study of proliferative markers and tumor suppressor gene proteins in different grades of ependymomas

Ependymomas are CNS tumors that originate from the spinal canal and walls of the ventricular system. Considerable controversy continues to exist with regard to their prognostic factors; age and extent of resection are the only statistically significant prognostic factors yet identified. The authors report a retrospective study of a homogenous population of 119 patients harbouring ependymomas between 1991 and 2002. All clinico-radiological and follow-up data were analyzed and a pathologic review was performed by two pathologists. Immunohistochemical staining for MIB-1, Topo IIalpha, p53 and MDM2 was performed. Histopathologic grades show relationship with MIB1 and Topo IIalpha labelling indices and cut-off values of 5% can differentiate between anaplastic and lower grades. p53 and MDM2 proteins expression are not common in ependymomas; however, they are seen in higher grades only and may be involved in the tumor progression.

Transitional Cell Metaplasia of Fallopian Tube Fimbriae

Germline mutations in the hereditary breast/ovary carcinoma genes BRCA1 or BRCA2 confer increased lifetime risk for ovarian, fallopian tube, and primary peritoneal carcinoma. This risk can be minimized by prophylactic surgery. Risk-reducing salpingo-oophorectomy (RRSO) provides 2 potential benefits: long-term cancer risk reduction and immediate detection of occult early carcinoma, which frequently arises in the tubal fimbriae. Recognition of occult early tubal carcinoma is challenging because it is often microscopic in size and can be confined to the fimbrial epithelium without invasion. Transitional cell metaplasia is a benign epithelial alteration that is a common finding in the serosa of the tube but is underrecognized in the tubal fimbriae, where it may mimic tubal intraepithelial carcinoma. The aim of this study was to define the incidence, morphology, immunophenotype, and distribution of transitional cell metaplasia of the fimbriae in RRSO specimens from 96 women with BRCA germline mutations and to compare these features to those of tubal intraepithelial carcinoma in this cohort. RRSO specimens from an additional 30 women at increased risk for ovarian cancer based on strong family history were also studied, along with RRSO from 1 patient with Lynch syndrome, and 1 patient with PTEN mutation. Transitional cell metaplasia of the fimbriae was present in 26% of all RRSO specimens. It was commonly multifocal (67%), with involvement of the tip, edges, or base of the fimbrial plicae. Average size of a metaplastic focus was 1.3 mm (range: 0.1 to 10 mm). None of the metaplastic foci expressed p53 by immunohistochemistry nor was there increased staining for the proliferation marker MIB-1. Occult early carcinoma was detected in 6/128 RRSO specimens. Median tumor size was 2.7 mm (range: 1 to 11 mm). All expressed p53 and showed markedly increased MIB-1 staining. The key criteria distinguishing transitional cell metaplasia from tubal intraepithelial carcinoma were uniform cell size and shape, normal nucleus:cytoplasm ratios, lack of nuclear atypia, presence of nuclear grooves, lack of mitoses, and absence of p53 expression or increased staining for MIB-1. No particular clinical variables (BRCA 1 vs. BRCA 2 mutation, parity, personal history of breast cancer, prior abdomino-pelvic surgery, or intraoperative findings) or benign pathologic alterations in the RRSO specimens were associated with the presence of transitional cell metaplasia of the fimbriae. None of the patients with this finding developed peritoneal carcinoma during follow-up ranging from 1 month to 9 years. This study demonstrates that transitional cell metaplasia of the fimbriae is a common benign finding in RRSO specimens that should not be confused with the much less common finding of tubal intraepithelial carcinoma.

Hiv-Associated Lymphoma

A 39-year-old man with AIDS experienced worsening shortness of breath, cytopenia, and fever and was admitted to Baylor University Medical Center. The patient also reported symptoms of anorexia, diarrhea, abdominal pain, and generalized body pain. The physical examination showed cachexia; a large perineal Kaposi sarcoma tumor, as well as scattered Kaposi sarcoma lesions on his face, neck, back, and chest; dependent edema in the legs and scrotum; a scrotal ulcer; and abdominal distension with ascites and tenderness. No lymphadenopathy or hepatosplenomegaly was noted. A lung infiltrate and right-sided pleural effusion were evident, and the possibility of parapneumonic effusion was considered. A complete blood count demonstrated leukopenia (white blood cell count, 500 K/uL), anemia (hemoglobin, 8.6 g/dL), and thrombocytopenia (platelet count, 19,000 K/uL), with a virtual absence of CD4+ cells (<1%). The absolute lymphocyte count was 288 cells/L. HIV-1 RNA quantification by polymerase chain reaction was <50. The patient's blood cultures were also positive for Streptococcus viridans. The source of the infection was believed to be the skin, in association with Kaposi sarcoma. The patient was treated with broad-spectrum antibiotics, and follow-up blood cultures showed resolution of the infection. The pleural effusion was drained and sent for cytologic evaluation. Results showed highly atypical, pleomorphic lymphoid cells (Figures ​(Figures11 and ​and22). Usual B and T cell markers (CD3, CD5, CD10, CD15, CD20, CD79a, PAX5) were negative, and activation markers (CD30 and MUM1) were positive in this tumor. CD138 showed a minimal to no staining pattern (although most PELs show a positive reaction). The tumor proliferation marker MIB-1 (Ki-67) showed strong positivity, with staining of 75% of cells (Figure ​(Figure33). The cells were positive for human herpesvirus 8 (HHV8) and Epstein-Barr virus (EBV) (Figure ​(Figure44). The EBV copy number in the pleural fluid was 105,000/mL. Figure 1 (a) Highly cellular smear with multiple aggregates of mononuclear cells (×10, hematoxylin and eosin stain [H&E]). (b) Note the pleomorphic nature of the cells (×20, H&E). (c) Some of the cells show plasma cytoid features ... Figure 2 High-power view (×40, H&E) of primary effusion lymphoma. Note the multinucleated tumor cell with prominent macronucleoli (arrow) in a background of highly atypical pleomorphic mononuclear cells. Figure 3 Immunohistochemistry results showed positive staining (×10) for (a) CD30, (b) MUM1, and (c) MIB1 (75%). Figure 4 (a) Primary effusion lymphoma with a distinct, strong positive reaction to HHV8 (×10). (b) Ebstein-Barr virus–encoded small RNAs (EBER) staining showed scattered, slightly positive cells (×10). Although the differential diagnosis based on the clinical findings would include pyothorax-associated lymphoma, Burkitt lymphoma, lymphomatous effusion of disseminated lymphoma, malignant melanoma, and pleomorphic non–small cell carcinoma, the absence of HHV8 in each of these lymphomas eliminated them from consideration. Primary effusion lymphoma (PEL) was diagnosed.

Hemangiopericytoma in the Lateral Ventricle -Case Report-

A 31-year-old female presented with a particularly rare hemangiopericytoma (HPC) in the right lateral ventricle manifesting as a 6-month history of visual disturbance and headache. Left hemianopsia and choked disc were identified by an ophthalmologist who referred her to us. Magnetic resonance imaging demonstrated a 5-cm homogeneously enhanced mass in the trigone of the right lateral ventricle. The tumor was totally removed by two stage surgery. The histological findings were consistent with HPC. HPC is very important to differentiate from meningioma and solitary fibrous tumors because HPC is more aggressive. The histological and immunochemical findings are important for the differential diagnosis. The present case showed no local recurrence or metastasis without radiation therapy for 4 years, indicating that radiation therapy is not absolutely imperative for patients with intraventricular HPC showing low MIB-1 staining index after total removal.

Sequential Chemotherapy Followed by High Dose Therapy and Autologous Stem Cell Rescue for Mantle Cell Lymphoma: Impact of MIB-1 on Outcome

Introduction: Optimal management of mantle cell lymphoma (MCL) remains undefined. However, recent data support the conclusion that upfront consolidation with high dose therapy with autologous stem cell rescue (HDT/ASCR) can improve the PFS (Dreyling, et al., 2005; Geisler, et al., 2008) and possibly OS (Geisler, et al. 2008). Based on gene expression profiling data, the proliferation signature has emerged as a critical determinant of prognosis in MCL (Rosenwald, et al., 2003). Immunohistochemical assessment of proliferation as estimated by MIB-1 (Ki-67) staining has been shown to predict outcome in patients with MCL treated with chemotherapy or immunochemotherapy. With conventional chemotherapy, the reported MIB-1 staining cutoff associated with poor prognosis reportedly varies from 10–30%. Since 1994 we have treated patients (pts) with MCL with sequential chemotherapy followed by HDT/ASCR. The current analysis is a retrospective review of our treatment program focused on the impact of upfront consolidation with HDT/ASCR on the prognostic significance of proliferation as measured by MIB-1 immunohistochemistry.Methods: Seventy-nine patients underwent upfront consolidation with HDT/ASCR for MCL. Fifty-two patients had evaluation of proliferation by MIB-1 immunohistochemistry. MIB-1 expression was estimated visually and assigned a percentage. Patients were binned into quintiles of MIB-1 expression: 0–20% (n=32, 61.5%); 21–40% (n=5, 9.6%); 41–60% (n=5, 9.6%); 61–80% (n=5, 9.6%); and 81–100% (n=5, 9.6%). Outcomes were analyzed by the method of Kaplan-Meier and comparisons were by log-rank.Results: The EFS and OS at 5 years was 65.1% and 61.4% respectively for the subset of patients with available MIB-1 staining (n=52); the outcomes for the entire group (n=79) did not differ from the subset. Outcomes (PFS, OS) were evaluated by MIB-1 quintile with successive cutoff values of 20%, 40%, 60% and 80%. MIB-1 cutoff values of 40% or less were not predictive of outcome. However, when the cutoff was 60% or 80%, both the PFS and OS were significantly worse for the high proliferation group. Nineteen percent of patients had a proliferation fraction of greater than 60%. For patients with MIB-1 staining of >60% the PFS was 4.2 years and was not reached for the group with staining ≤60% (p=0.004). Similarly, overall survival was significantly different, (p=0.031).Conclusions: These findings suggest that upfront consolidation with HDT/ASCR can partially overcome the adverse impact of proliferation on outcome and the adverse outcomes are seen in a subgroup of approximately 20% of patients with MIB-1 staining of greater than 60%.

Biomarker (ProExTM C, p16INK4A, and MiB-1) distinction of high-grade squamous intraepithelial lesion from its mimics

Topoisomerase IIα and minichromosome maintenance protein 2 are proteins associated with aberrant S-phase induction. The current study evaluated the performance of these biomarkers (ProEx™ C; TriPath Oncology, Burlington, NC) compared with p16INK4A and MiB-1 in distinguishing high-grade squamous intraepithelial lesions (HSILs) from HSIL mimics. We collected archival cervical biopsy, cone, and curettage specimens from 96 cases in which the differential diagnosis of HSIL vs reactive epithelial changes was considered. Hematoxylin- and eosin-stained slides were reviewed independently by three pathologists and scored for the presence or absence of SIL. Immunostains for ProEx C, p16, and MiB-1 were available for 95, 96, and 59 samples, respectively, and classified blinded to histological interpretation. Strong nuclear and cytoplasmic staining for p16 and staining for MiB-1 and ProEx C that extended beyond the lower one-third of the epithelium were scored as positive. χ2-tests and receiver operating characteristic analysis were conducted to statistically compare biomarker immunostaining performance against majority histological interpretation of SIL. Agreement between pathologists was also assessed by the κ-statistic. Inter-observer agreement ranged from fair to moderate (κ=0.37–0.57). All three biomarkers correlated strongly with the majority diagnosis of SIL (P<0.001). Positive staining for ProEx C, p16, and MiB-1 was observed in 87% (N=52/60), 84% (N=51/61), and 94% (34/36), respectively, of SIL and negative in 71% (N=25/35), 63% (N=22/35), and 52% (N=12/23), respectively, of majority diagnoses of NoSIL. The combination of p16/ProEx C predicted more SIL (92%, N=33/36) and NoSIL (61%, N=14/23) than p16 plus MiB-1 (94%, N=34/36 and 43%, N=10/23), although this difference was not statistically significant. ProEx C appears to provide an equivalent level of sensitivity and a higher level of specificity for HSIL alone or in conjunction with p16. Its principal value may be in providing a lower false positive rate for NoSIL relative to MiB-1.

Pineal parenchymal tumors – utility of immunohistochemical markers in prognostication

The pineal parenchymal tumors are rare, comprising 15-30% of all tumors of pineal region. Their histological classification alone has been found to be inadequate for prognostication. Hence, we correlated their immunohistochemical profile with the prognosis. A retrospective analysis of 33 pineal parenchymal tumors treated from 1990-2004 was performed. The histological features of the tumors were reviewed and immunohistochemical staining for neurofilament protein (NF), MIB-1, synaptophysin and GFAP were performed. Results were correlated with the patients' survival. The study comprised 6 pineocytomas (PC), 17 pineoblastomas (PB) and 10 pineal parenchymal tumors with intermediate differentiation (PPT-ID) which included 3 mixed PC/PB. The histological diagnosis was obtained from microsurgical biopsy/decompression, stereotactic or endoscopic biopsy. Adjuvant therapy was advised based on histology. All pineocytomas stained positive for NF. Most pineoblastomas (13/16) failed to show any immunoreactivity with NF. The mean MIB-1 labeling index in pineocytomas, PPT of ID and pineoblastomas were 1.58, 16.1 and 23.52 respectively (p < 0.001). All the tumors stained positive for synaptophysin, although the intensity of the staining varied. NF-positive tumors had a higher chance of disease-free state, irrespective of histological subgroup (p = 0.0036). The median disease-free survival in pineoblastomas with negative NF staining was 5 months, which was less than that of pineoblastomas with positive NF staining (32 months). Neurofilament immunoreactivity indicates better prognosis in pineal parenchymal tumors. The MIB-1 labeling index can be utilized as an additional tool to differentiate pineal parenchymal tumors into various subgroups.

Characterization of childhood precursor T‐lymphoblastic lymphoma by immunophenotyping and fluorescent in situ hybridization: A report from the Children's Oncology Group

T-lymphoblastic lymphoma (T-LBL) accounts for 25-30% of childhood non-Hodgkin's lymphoma and is closely related to T-lymphoblastic leukemia (T-ALL). Recently, we demonstrated distinct differences in gene expression between childhood T-LBL and T-ALL, but molecular pathogenesis and relevant protein expression patterns in T-LBL remain poorly understood. Children with T-LBL with disseminated disease were registered and treated on COG protocol 5971. Paraffin-embedded tumor tissue was obtained at diagnosis for immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) studies. We determined the pattern and intensity of staining for c-Myc, Skp2, Mib-1, p53, TCL-1, bcl-2, and bcl-6 proteins by IHC and c-Myc, p53, bcl-2, bcl-6, and TCR alpha/delta molecular alterations by FISH in 22 pediatric T-LBL cases. The majority of T-LBL samples expressed Mib-1 (59%) and c-Myc (77%) proteins in greater than 50% of the cells, but Skp2 (14%), p53 (14%), and bcl-2 (23%) expression was less common. FISH studies demonstrated 18% gains and 10% losses in c-Myc, 16% gains in p53, 12% gains and 6% losses in bcl-2, and 6% gains and 19% losses in bcl-6 with little direct correlation between the IHC and FISH studies. Childhood T-LBL is a highly proliferative tumor associated with enhanced expression of c-Myc protein, but without detectable c-Myc molecular alterations. FISH studies did not identify consistent etiologies of molecular dysregulation, and future studies with other molecular approaches may be required to elucidate the molecular pathogenesis of childhood T-LBL.

Xenografts of primary human gynecological tumors grown under the renal capsule of NOD/SCID mice show genetic stability during serial transplantation and respond to cytotoxic chemotherapy

Objectives Human cancer tissue xenograft models may provide a more accurate reflection of tumor biology than cell lines. This study evaluates the genetic and phenotypic stability of primary human gynecological tumors grown as serially transplanted xenografts. The response to conventional chemotherapy and novel molecular targeted chemotherapy is assessed in one of the transplantable xenograft lines. Methods Fresh tumor was transplanted beneath the renal capsule of NOD/SCID mice. Transplantable tumor lines were derived from 5 tumors (4 ovarian carcinomas and 1 uterine sarcoma), and serially transplanted for 2-6 generations. Comparisons were made between primary tumor and corresponding transplantable xenografts by CGH array, immunohistochemistry, and BRCA mutation analysis. Transplantable xenografts created from known BRCA1 germline mutation carriers were analyzed for histopathologic response (tumor volume, apoptotic and mitotic indices) to combination carboplatin/paclitaxel and to PARP inhibitor (PJ34). Results Unsupervised hierarchical cluster analysis applied to a 287 feature CGH array demonstrated a low degree of intratumoral genetic variation in 4/5 cases, with greater degree of variation in the fifth case (clear cell ovarian carcinoma derived from an omental sample). Assessment of proliferation using MIB-1 staining was concordant between primary tumor and transplantable xenograft in all ovarian cancer cases. BRCA mutation analysis identified germline BRCA1 mutation for further testing and this xenograft showed a significant response to carboplatin/paclitaxel chemotherapy, including a decrease in tumor volume and proliferation but did not demonstrate a response to the poly (ADP-ribose) polymerase-1 inhibitor PJ34. Conclusions Xenografts derived from gynecologic tumors can be serially transplanted and grown under renal capsule of NOD/SCID mice with minimal genetic change. This model may be used to study progression of tumors, identify therapeutic targets, and test treatment modalities in tumors with well-characterized abnormalities in genes of fundamental importance in ovarian carcinogenesis, such as loss of BRCA1.

The association between overexpression of skp2 and the risk of recurrence following prostatectomy

11052 Background: Decreased expression of the cell cycle inhibitor p27 is associated with a poor prognosis in several human cancers. Skp2 is a substrate recognition unit specifically targeting p27 for degradation and may therefore represent a therapeutic target in cancers with low p27. We sought to determine whether Skp2 overexpression is associated with p27 suppression and an increased risk of recurrence among men with prostate cancer treated with prostatectomy. Methods: We identified 110 men who received a prostatectomy for non-metastatic, node-negative prostate cancer from 1985–1996. Immunohistochemistry (IHC) staining for Skp2, p27, and MIB-1 were performed on paraffin-embedded material. Stains were scored based on the percent of cells showing nuclear staining, averaged by counting 100 tumor cells in 5 different areas. A threshold of >30% was used for high p27 staining, and a threshold of ≥5% was used for high Skp2 and high MIB-1. The primary endpoint was time to prostate-specific antigen (PSA) failure. Results: Overall 12 tumors (11%) had high Skp2 expression. These 12 all had correspondingly low p27 expression (p=0.006, Chi-Square). 40% of tumors with high Skp2 also had high MIB-1 expression, while only 13% of tumors with low Skp2 had high MIB-1 (p=0.035). Skp2 overexpression was associated with higher Gleason score (p=0.001) and more advanced pathological T-category (p=0.004). Median follow-up from the time of surgery was 67 months (range: 0.2 to 218 months). On Cox multivariable analysis, Skp2 overexpression was associated with a significantly shorter time to PSA failure (adjusted hazard ratio 5.2 (95% C.I. 1.9–14, p=0.001) after adjusting for PSA, pathologic T-category, and prostatectomy Gleason score. The median time to PSA failure was 4 months among those with Skp2 overexpression compared to 54 months among those who did not overexpress Skp2. Conclusions: Skp2 overexpression was associated with low levels of p27, poor prognostic features, and increased risk of recurrence. These results support the concept of Skp2-mediated degradation of p27, suggest a possible role for Skp2 in tumor progression, and raise the possibility that Skp2 could be a potential therapeutic target, particularly for tumors which underexpress p27. No significant financial relationships to disclose.