NSC30049 inhibits Chk1 pathway in 5-FU-resistant CRC bulk and stem cell populations.

The 5-fluorouracil (5-FU) treatment induces DNA damage and stalling of DNA replication forks. These stalled replication forks then collapse to form one sided double-strand breaks, leading to apoptosis. However, colorectal cancer (CRC) stem cells rapidly repair the stalled/collapsed replication forks and overcome treatment effects. Recent evidence suggests a critical role of checkpoint kinase 1 (Chk1) in preventing the replicative stress. Therefore, Chk1 kinase has been a target for developing mono or combination therapeutic agents. In the present study, we have identified a novel orphan molecule NSC30049 (NSC49L) that is effective alone, and in combination potentiates 5-FU-mediated growth inhibition of CRC heterogeneous bulk and FOLFOX-resistant cell lines in culture with minimal effect on normal colonic epithelial cells. It also inhibits the sphere forming activity of CRC stem cells, and decreases the expression levels of mRNAs of CRC stem cell marker genes. Results showed that NSC49L induces 5-FU-mediated S-phase cell cycle arrest due to increased load of DNA damage and increased γ-H2AX staining as a mechanism of cytotoxicity. The pharmacokinetic analysis showed a higher bioavailability of this compound, however, with a short plasma half-life. The drug is highly tolerated by animals with no pathological aberrations. Furthermore, NSC49L showed very potent activity in a HDTX model of CRC stem cell tumors either alone or in combination with 5-FU. Thus, NSC49L as a single agent or combined with 5-FU can be developed as a therapeutic agent by targeting the Chk1 pathway in 5-FU-resistant CRC heterogeneous bulk and CRC stem cell populations.

Discordant HER2 expression and response to neoadjuvant chemoradiotherapy in esophagogastric adenocarcinoma.

BACKGROUND: Targeting human epidermal growth factor receptor 2 (HER2) with trastuzumab in metastatic esophagogastric adenocarcinoma (EGA) improves survival. The impact of HER2 inhibition in combination with chemoradiotherapy (CRT) in early stage EGA is under investigation. This study analyzed the pattern of HER2 overexpression in matched-pair tumor samples of patients who underwent neoadjuvant CRT followed by surgery. METHODS: All patients with EGA who underwent standard neoadjuvant CRT followed by esophagectomy at the University of Florida were included. Demographics, risk factors, tumor features, and outcome data were analyzed. Descriptive statistics, Chi-square exact test, uni- and multivariate analyses, and Kaplan Meier method were used. HER2 expression determined by immunohistochemical (IHC) was scored as negative (0, 1+), indeterminate (2+) or positive (3+). RESULTS: Among 49 sequential patients (41 M/8 F) with matched-pair tumor samples, 9/49 patients (18%) had pathologic complete response (pCR), 10/49 had near pCR or not enough tumor (NET) to examine in the post- treatment samples. Patients with initial HER2 negativity demonstrated conversion to HER2 positivity after neoadjuvant CRT (7/30 cases; 23%). Baseline HER2 overexpression was more common in lower stage/node negative patients (67% in stages I, IIA vs. 33% in stages IIB, III) and did not correlate with treatment response or survival. CONCLUSIONS: Although limited by a relatively small sample size, our study failed to demonstrate that baseline HER2 protein over-expression in EGA predicts response to standard CRT. However, our data suggested that HER2 was up regulated by CRT resulting in unreliable concordance between pre-treatment (pre-tx) and post-treatment (post-tx) samples. Pre-therapy HER2 expression may not reliably reflect the HER2 status of persistent or recurrent disease.

EGFR family and cMet expression profiles and prognostic significance in esophagogastric adenocarcinoma.

BACKGROUND: Targeted therapy with anti-human epidermal growth factor receptor-2 (HER2) monoclonal antibody in patients with HER2 overexpressed esophagogastric adenocarcinoma (EGA) improves survival; however, the effect is transient due to the development of resistance. Some studies suggest that cMet overexpression provides cross talk for epidermal growth factor receptor (EGFR) and HER2 inhibition. We sought to characterize the expression profile of the EGFR family and cMet receptors in untreated, resected EGA. METHODS: This retrospective analysis included all sequential patients with esophageal or gastroesophageal junction (GEJ) adenocarcinoma who underwent primary resection, without neoadjuvant therapy or HER2 inhibition, with adequate tissue, at the University of Florida from 2001 to 2011. Central blinded immunohistochemistry (IHC) was performed on tumor specimens with EGFR, HER2, HER3, HER4 and cMet expression scored as low (0, 1+) or high (2+, 3+). Demographic and tumor characteristics were compared using Fisher exact test. Kaplan-Meier curves and univariate analysis compared survival among different receptors. RESULTS: Total 52 patients were included in the study with median age 66 years. High expression of EGFR (73%), HER2 (40%), HER3 (75%), HER4 (35%) and cMet (69%) was detected among the study group. HER3 and HER4 co-expression was found in 18 (35%) cases. Pan expression of all four EGFR family members with cMet was noted in only 17% of cases. On univariate analysis, tumor stage and depth correlated with survival, while cMet + HER3 +/- EGFR receptor co-expression trended towards a worse survival. CONCLUSIONS: EGFR family and cMet are frequently co-expressed in treatment naïve resected EGA or GEJ tumors. Although our data do not significantly show receptor status as a prognostic factor, the co-expression profiles support for further investigation to improve targeting of this signal transduction axis.

Clinical, morphologic, and immunophenotypic characteristics of ampullary carcinomas with an emphasis on SMAD4 expression.

BACKGROUND: The purpose of our study was to examine the relationship between clinicopathologic variables and morphologic subtypes in ampullary carcinoma, with an emphasis on the expression of SMAD4 tumor suppressor gene. METHODS: Sixty-three cases of ampullary carcinomas resected between 2000-2011 were included in this study. Clinical characteristics and outcome data were recorded. Tumors were classified as pancreatobiliary or intestinal type based on morphology, and immunohistochemical (IHC) studies for cytokeratin 7 (CK7), cytokeratin 20 (CK20), cytokeratin 17 (CK17), and SMAD4 were performed. RESULTS: Forty-nine percent of the ampullary tumors were pancreatobiliary, 29% were intestinal, and 22% were other variants. Tumors with pancreatobiliary morphology showed worse overall survival than those with intestinal morphology or other variants (P=0.03). A trend for higher stage, recurrence and less survival was seen in cases with negative SMAD4 expression. In multivariate analysis, age group (≤60 vs. >60 years) and expression of CK17 were the most prognostic of survival. CONCLUSIONS: Ampullary tumors with pancreatobiliary morphology have a worse overall survival, while negative SMAD4 expression is associated with a trend of less survival.

Interobserver variability of mitotic index and utility of PHH3 for risk stratification in gastrointestinal stromal tumors.

OBJECTIVES: Accurate grading of gastrointestinal stromal tumors (GISTs), based on mitotic index, can be problematic. METHODS: In this study, we compared interobserver variability in detecting mitosis on H&E with PHH3 immunohistochemistry (IHC). In addition, we examined the correlation between H&E mitosis and Ki-67 and the association of PHH3 and Ki-67 with overall survival. Four pathologists independently reviewed 50 GIST cases. RESULTS: Intraclass correlation coefficients showed good interobserver variability for mitotic counts on both H&E (0.918; 95% confidence interval [CI], 0.874-0.950) and PHH3 IHC (0.923; 95% CI, 0.882-0.953). Nineteen (38%) cases were graded higher and five (10%) cases were downgraded by at least one observer using PHH3 compared with H&E. Using receiver operating characteristic curve analysis, a PHH3 cutoff of seven or more mitoses was associated with worse overall survival (P = .028). Ki-67 showed poor correlation with H&E mitotic counts and overall survival (P = .077). CONCLUSIONS: PHH3 may thus be a valuable adjunct for risk stratification in GISTs.

Laryngeal actinomycosis in an immunocompromised patient.

Actinomycosis of the larynx represents an unusual presentation for a common bacterium comprising the oral and oropharyngeal florae. There are few cases reported in the literature of laryngeal actinomycosis occurring primarily in the immunocompromised population. Here, we present a case in a 74-year-old man that occurred in the setting of neutropenia as a result of chemotherapy. Once the diagnosis was made with biopsy of the larynx, the infection was resolved after a prolonged course of penicillin-based therapy.

IMAGe association: report of two cases in siblings with adrenal hypoplasia and review of the literature.

We report the postmortem findings of two siblings with gross and microscopic features consistent with IMAGe association (Intrauterine growth retardation, Metaphyseal dysplasia, Adrenal hypoplasia congenita, and Genital anomalies) with an emphasis on the histopathology of the adrenal gland in this rare syndrome. The first sibling was an 8-week old male diagnosed postnatally with primary adrenal insufficiency. There was no deletion of the DAX1 gene by FISH. Examination at autopsy revealed dysmorphic features including frontal bossing, epicanthal folds, flat philtrum, cryptorchidism, penile chordee, overriding fourth toe, and height and weight below 3rd percentile. Grossly, the adrenal glands were not identified; however, microscopic examination of the suprarenal soft tissue revealed a 3 mm focus of disorganized fetal adrenal cortex with distended "cytomegalic" cells with abundant pink eosinophilic cytoplasm, vesicular nuclei, and cytoplasmic vacuolization. A minute focus of permanent adult cortex was also seen, but no adrenal medulla was identified. An autopsy of the sibling, who died 12 years previously at day 9 of life, revealed dysmorphic facial features with cryptorchidism and a large phallus. The adrenal glands were grossly hypoplastic (11 mm). Histologically, the adrenal glands showed disorganized fetal cortex with cytomegalic cells, a larger amount of permanent adult cortex, and bizarre nuclei with numerous pseudoinclusions. While there is currently limited information regarding the histopathologic adrenal findings in IMAGe association, our small case series suggests overlapping features between X-linked recessive congenital adrenal hypoplasia (cytomegalic cells with lack of permanent adult cortex) and autosomal recessive congenital adrenal hypoplasia (diminished permanent adult cortex without cytomegalic cells).

Plexiform fibromyxoma: report of two pediatric cases and review of the literature.

Plexiform fibromyxoma is a distinctive mesenchymal neoplasm usually arising in the gastric antrum. We report 2 cases of this entity in pediatric patients, including the first case arising in the esophagus. The patients were a 16-year-old female who presented with chest pain and was found on computed tomographic scan to have a midesophageal mass at the level of the carina, and an 11-year-old female with a gastric mass. Both patients underwent surgical resection of their tumors, which histologically exhibited a plexiform growth pattern with multiple nodules in the muscularis propria and infiltrative borders. The nodules were composed of a rich myxoid stroma with bland uniform spindle cells, no mitoses or necrosis, and delicate blood vessels in the background. Immunohistochemical studies demonstrated that the tumor cells were immunoreactive with smooth muscle actin and not reactive with S-100, CD34, desmin, and c-kit (CD117). We report the first case of plexiform fibromyxoma originating in the esophagus, emphasize its occurrence in pediatric patients, and review the related literature.

Mullerian cysts of the posterior mediastinum: report of two cases and review of the literature.

Cystic lesions can be occasionally be found in the mediastinum, and typically include bronchogenic cysts, esophageal duplication cysts, and neuroenteric cysts. In 2005, Hattori described the first mediastinal cyst with Mullerian differentiation. Since that time, three other authors have described similar cysts occurring in the posterior mediastinum. Here we present two cases of patients with ciliated cysts with Mullerian differentiation with expression of estrogen receptor, progesterone receptor, PAX8 and Wilm's tumor 1, occurring in the posterior mediastinum and review the related literature.

Well-Differentiated Central Cartilage Tumors of Bone: An Overview.

Well-differentiated hyaline cartilage tumors are among the most common tumors encountered in the skeleton; their radiographic and pathologic classification and clinical management can be challenging. Pathologists find cartilage tumors difficult because their precise classification is as dependent on the clinical and radiographic findings as the histologic features; the distinction between benign and malignant cartilage neoplasms demands good communication and teamwork between pathologists, orthopedic surgeons, and radiologists. This review focuses on the necessary clinical, radiographic, and pathologic features that allow distinction between enchondroma and low-grade central chondrosarcoma and interpretation of lesions encountered in the enchondromatosis syndromes.