Applicability of the FDA-approved Immunohistochemical Panel for Identification of MMRd Phenotype in Uterine Endometrioid Carcinoma.

Recently, the US Food and Drug Administration (FDA) approved the Ventana MMR RxDx Panel as the first immunohistochemical companion diagnostic test for identification of tumors with mismatch repair (MMR) status. The aim of this study was to investigate the accuracy of this test in comparison with polymerase chain reaction (PCR)-based microsatellite instability (MSI) analysis. We assessed the MMR/MSI concordance rate in 140 cases of endometrioid carcinoma. MMR status was evaluated by immunohistochemistry (MMR-IHC), and MSI status was evaluated by PCR-based analysis (MSI-PCR). Potential molecular mechanisms responsible for MSH6 staining variations were also analyzed. Immunohistochemistry showed that 34 tumors (24.3%) were MMRd; these included 26 with combined MLH1/PMS2 loss, 2 with combined MSH2/MSH6 loss, and 6 with isolated MSH6 loss. Heterogeneous MSH6 loss was found in 10 tumors and was recognized only in tumors with combined MLH1/PMS2 loss. Eight of 10 tumors with heterogeneous MSH6 loss harbored MSH6 C8 tract instability, suggesting a secondary somatic event after MLH1/PMS2 loss. MSI-PCR revealed that 102 tumors were MSS, 4 were MSI-low, and 34 were MSI-high. Consequently, MMR-IHC and MSI-PCR showed perfect concordance (kappa=0.080, P <0.0001). However, 10 of the 34 MSI-high tumors, including the 6 tumors with isolated MSH6 loss, showed only minimal microsatellite shift by MSI-PCR, which may have been erroneously interpreted as MSS or MSI-low. On the basis of these findings, we consider that the FDA-approved immunohistochemical panel can detect MMR variations consistently and is more accurate than MSI-PCR for determining the applicability of immune checkpoint inhibitors for treatment of endometrioid carcinomas.

Glassy cell carcinoma of the cervix: cytologic features and expression of estrogen receptor, progesterone receptor and Her2/neu protein.

OBJECTIVE: To analyze the cytologic features, estrogen and progesterone receptors, and Her2/neu protein in glassy cell carcinoma (GCC) of the cervix. STUDY DESIGN: Cases were analyzed using various parameters, including age at presentation, stage, treatment and clinical course. Between 1990 and 2003, patients with primary cervical carcinomas were treated and cytopathologic analyses performed. Tests for estrogen receptor (ER), progesterone receptor (PR) and Her2/neu protein were performed on paraffin sections. RESULTS: GCC of the cervix is composed of large cells with abundant chromatin, which gives them their characteristic glassy appearance. Eleven cases were identified as GCC. One case (9.1%) was correctly diagnosed from the cervicovaginal smear. Among the GCC cases, ER, PR and Her2/neu were positive in 2 (18.1%), 1 (9.1%) and 5 (45.4%) cases, respectively. CONCLUSION: Cytology of GCC reveals characteristic features that differ from those of other carcinomas of the cervix. GCC has unique cytologic characteristics and causes diagnostic confusion, possibly leading to incorrect diagnoses. The reason for such low diagnostic precision in cytology might be due to the lack of differentiation and low frequency of this tumor. Our results, demonstrating Her2/ neu overexpression, may correlate with more aggressive behavior and a worse clinical outcome.

Expression of transcription factor E2F-1 in pancreatic ductal carcinoma: an immunohistochemical study.

E2F-1 is a transcriptional factor that mediates cell cycle progression from G1 to S phase, thereby influencing tumor progression. However, only a few clinicopathologic studies have been carried out using surgically removed specimens for defining its role in tumor biology. Therefore, we studied the expression of this cell cycle regulator on surgical specimens at the immunohistochemical level, and examined its possible relationship with proliferative index, assessed by analysis of MIB-1 expression, and clinicopathologic factors in pancreatic ductal carcinomas. E2F-1 and MIB-1 were immunostained on 54 surgically removed specimens, and nuclear reactivity was evaluated. The percentage of E2F-1 positive cells (E2F-1 PI) ranged from 3.8% to 71.4%. We found a statistically significant correlation between E2F-1 PI and the histologic grade of tumor differentiation (p = 0.0133), i.e. E2F-1 PI was higher in less-differentiated carcinomas. Furthermore, there was a positive correlation between E2F-1 PI and the percentage of MIB-1 PI (r = 0.763; p < 0.0001). The patients with higher E2F-1 PI (E2F-1 PI > or = 38.0 = median) showed a significantly shorter disease-associated survival time in R0 resection cases (n = 49, p = 0.015). The present analysis seems to support the theory that E2F-1 is upregulated in cell cycle, and its expression reflects the effector function of G1/S progression as far as pancreatic ductal carcinoma is concerned.

Expression of p21/WAF-1, status of apoptosis and p53 mutation in esophageal squamous cell carcinoma with HPV infection.

Human papilloma virus (HPV) is regarded as a causative carcinogenic agent in anogenital squamous cell carcinoma (SCC), but there is controversy about its etiologic role in esophageal SCC (ESCC). In this study, we attempted to clarify whether HPV infection plays a crucial role in the development of ESCC by analysis of multiple factors. These included: detection of HPV DNA; evaluation of immunohistochemical assays for HPV-related cell cycle regulators and apoptosis by the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling method; and genetic analysis of the p53 gene. Twenty of the 48 ESCC examined (42%) were found to be positive for the HPV genome by polymerase chain reaction. They comprised 16 cases with the HPV16 subtype, three with the HPV18 subtype, and one with both HPV16 and 18. Immunohistochemical analysis revealed that the expression of p21/WAF-1 was significantly decreased in HPV-positive cases (chi2 = 9.2614; P = 0.0023). Furthermore, the 10 apoptosis-negative (< or =10%) cases of HPV-positive SCC were almost exclusively p21/WAF-1-negative (chi2 = 12.1406; P = 0.0005), indicating the significance of the relationship between HPV infection and the phenotype that is expected from HPV-induced inhibition of p53. Although 14 cases possessed missense and deletion mutations of the p53 gene (of which four mutations were found in HPV-positive ESCC), no accumulation of the mutation was defined in the phenotype, suggesting that distinct mutation processes might be involved in HPV-negative and -positive ESCC. The data provide significant support for the hypothesis that HPV infection may play a crucial role in the oncogenesis of some ESCC.