Clinical significance of L-type amino acid transporter 1 expression as a prognostic marker and potential of new targeting therapy in biliary tract cancer.

BACKGROUND: The expression of L-type amino acid transporter 1 (LAT1) has been described to play essential roles in tumor cell growth and survival. However, it remains unclear about the clinicopathological significance of LAT1 expression in biliary tract cancer. This study was conducted to determine biological significance of LAT1 expression and investigate whether LAT1 could be a prognostic biomarker for biliary tract cancer. METHODS: A total of 139 consecutive patients with resected pathologic stage I-IV biliary tract adenocarcinoma were retrospectively reviewed. Tumor specimens were stained by immunohistochemistry for LAT1, Ki-67, microvessel density determined by CD34, and p53; and prognosis of patients was correlated. Biological significance of LAT1 expression was investigated by in vitro and in vivo experiments with LAT inhibitor, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH) using cholangiocarcinoma cell line. RESULTS: In total patients, high LAT1 expressions were recognized in 64.0%. The expression of LAT1 was closely correlated with lymphatic metastases, cell proliferation and angiogenesis, and was a significant indicator for predicting poor outcome after surgery. LAT1 expression was a significant independent predictor by multivariate analysis. Both in vitro and in vivo preliminary experiments indicated that BCH significantly suppressed growth of the tumor and yielded an additive therapeutic efficacy to gemcitabine and 5-FU. CONCLUSIONS: High expression of LAT1 is a promising pathological marker to predict the outcome in patients with biliary tract adenocarcinoma. Inhibition of LAT1 may be an effective targeted therapy for this distressing disease.

Prognostic significance of global grading system of Gleason score in patients with prostate cancer with bone metastasis.

OBJECTIVE: To investigate the influence of the revised Gleason grading system (GGS, revised at a consensus conference organized by the International Society of Urological Pathology in 2005) on prediction of prognosis for patients with prostate cancer with bone metastasis. PATIENTS AND METHODS: Prostatic needle biopsy specimens from 113 patients with prostate cancer with bone metastasis were scored using the conventional GGS (CGGS), modified global GGS (MGGGS), and modified highest GGS (MHGGS). The patients were divided into two groups (Gleason score < or = 7 and > or = 8) using each grading system. Prostate-specific antigen failure-free survival after hormone therapy (HT) was estimated retrospectively. The Cox proportional hazard method was used for univariate and multivariate analysis. RESULTS: Patients with a Gleason score of < or = 7 had a significantly longer remission than patients with a score of > or = 8 according to each GGS. However, the better prognosis patients were detected more precisely by the CGGS and MGGGS than the MHGGS. Multivariate analysis showed that the CGGS and MGGGS were significant prognostic indicators for the outcome of HT after adjustment for other prognostic factors. CONCLUSIONS: These results suggest that the CGGS and MGGGS are more useful than the MHGGS as prognostic indicators for HT. Further evaluation in larger series is needed to define its clinical usefulness.

MALT type lymphoma demonstrating prominent plasma cell differentiation resembling fibrous variant of Hashimoto's thyroiditis: a three case report.

Fibrous variant of Hashimoto's thyroiditis (HT) is characterized by marked fibrous replacement of one third or more of the thyroid parenchyma. We present here three cases of mucosa associated lymphoid tissue (MALT) type lymphoma demonstrating prominent plasma cell differentiation resembling fibrous variant of HT. Histologically, thyroid structures were disturbed by a diffuse and focally nodular infiltration by mature plasma cells and cells with plasma cell differentiation against a background of prominent hyalinosis. In addition, scattered centrocyte-like (CCL) cells and lymphoepithelial lesions were observed in all three lesions. A portion of the resected specimens in all three cases exhibited HT. However, immunohistochemical study demonstrated that the plasma cells and CCL-cells of these three lesions had monotypic intracytoplasmic kappa light chain. Moreover, these three lesions demonstrated a clonal band on polymerase chain reaction assay for the immunoglobulin heavy chain gene. To avoid underdiagnosis, we emphasize that careful attention should be paid to these immunological features as well as to morphological findings.

Adrenal Ewing's Sarcoma in an Elderly Man.

Ewing's sarcoma usually arises in the bones of children and adolescents. We herein report a 74-year-old man with Ewing's sarcoma in the adrenal gland. The diagnosis was confirmed by a genetic test, pathological studies, and several imaging studies. He already had multiple liver metastases when he was transferred to our hospital and died on the 37th day. The diagnosis was further confirmed by autopsy studies. Adrenal Ewing's sarcoma is very rare, and our patient was older than other reported cases. Ewing's sarcoma should be considered even in elderly patients with adrenal tumors.

Primary omental gastrointestinal stromal tumor (GIST).

BACKGROUND: We report herein a rare case of primary omental gastrointestinal stromal tumor (GIST). CASE PRESENTATION: A 65 year-old man was referred to our hospital with a huge abdominal mass occupying the entire left upper abdomen as shown by sonography. On computed tomography (CT), this appeared as a heterogeneous low-density mass with faint enhancement. Abdominal angiography revealed that the right gastroepiploic artery supplied the tumor. With such an indication of gastric GIST, liposarcoma, leiomyosarcoma or mesothelioma laparotomy was performed and revealed that this large mass measured 20 x 17 x 6 cm, arising from the greater omentum. It was completely resected. Histopathologically, it was composed of proliferating spindle and epithelioid cells with an interlacing bundle pattern. Immunohistochemically, the tumor was positive for myeloid stem cell antigen (CD34), weakly positive for c-KIT (CD117) and slightly positive for neuron-specific enolase (NSE), but negative for cytokeratin (CK), alpha-smooth muscle actin (SMA) and S-100 protein. A mutation was identified in the platelet-derived growth factor alpha (PDGFRA) juxtamembrane domain (exon 12, codon561) and the tumor was diagnosed as an omental GIST. The postoperative course was uneventful. The patient is treated by Glevec(R) and is alive well with no sign of relapse. CONCLUSION: Our case demonstrated a weak immunohistochemical expression of c-kit (CD117) and a point mutation in PDGFRA exon 12 resulting in an Asp for Val561 substitution. Imatinib therapy as an adjuvant to complete resection has been carried out safely. Because of the rarity of primary omental GISTs, it is inevitable to analyze accumulating data from case reports for a better and more detailed understanding of primary omental GISTs.

Complete resection of a huge pancreatic undifferentiated carcinoma with osteoclast-like giant cells.

Pancreatic undifferentiated carcinoma with osteoclast-like giant cells (PUC-OGC) is a rare neoplasm. We report a case of rapidly advancing PUC-OGC. A 54-year-old man had elevated tumor marker levels. Abdominal computed tomography showed a cystic mass in the body and tail of the pancreas, which infiltrated adjacent organs. The tumor exhibited rapid growth (doubling time: 39 days) but no metastases. We diagnosed PUC-OGC clinically and excised the pancreatic body and tail along with the spleen, left kidney, adrenal gland, and transverse colon. Pathological diagnosis showed histology consistent with PUC-OGC and a negative margin without nodal involvement despite the tumor being 28 cm in maximum diameter and having invaded the left kidney. The patient survived a year with a recurrence of liver metastasis after the initial surgery due to the partial hepatectomy and chemotherapy. Complete resection might be a good strategy to cure PUC-OGC in this case.

Combined small cell carcinoma of the sinonasal tract associated with syndrome of inappropriate secretion of antidiuretic hormone: A case report.

Combined small cell carcinoma (SmCC) and squamous cell carcinoma (SqCC) is a rare malignant neoplasm in the head and neck. This study presents the first reported case of combined SmCC and SqCC originating from the sinonasal tract accompanied by syndrome of inappropriate secretion of antidiuretic hormone (SIADH). An 80-year-old female presented with a four-week history of right nasal discharge, nasal obstruction and left neck swelling. Imaging studies revealed a tumorous lesion in the maxillary sinus encroaching upon the right nasal cavity and left cervical lymph node (LN) swelling. An incisional biopsy carried out from the right maxillary sinus and LNs resulted in a diagnosis of combined SmCC with SqCC, staged as T4aN2cM0. Clinical examination revealed a sustained increase of antidiuretic hormone, hyponatremia with urinary sodium increase, and serum hypo-osmosis, resulting in SIADH. Water restriction to <1,000 ml/day was effective in improving sodium and osmotic imbalance. Curative treatment for the tumor was not prescribed due to the poor condition of the patient. Palliative treatment was administered and the patient succumbed to cachexia five months after histological diagnosis. The presence of SIADH may have marked implications for the treatment and prognosis of this disease.

L-type amino acid transporter 1 expression is highly correlated with Gleason score in prostate cancer.

Upregulation of L-type amino acid transporter 1 (LAT1), a member of the system L amino acid transporter family, may be detected by immunohistochemical methods. Immunoreactive LAT1 expression in prostate cancer is considered to be a promising biomarker for high-grade malignancy. However, the mutual association between LAT1 and Gleason score, the most fixed indicator for grading the malignancy of prostate cancers, remains to be elucidated. The aim of this study was to clarify the correlations between LAT1 and other factors in prostate cancer, including the Gleason score. We evaluated 54 cases of primary prostate cancer, surgically resected without any neoadjuvant therapies and performed immunohistochemistry for LAT1, Ki-67, CD34 and vascular endothelial growth factor on the tissue sections. The Gleason score as well as the age, pathological stage (pStage) of prostate cancer and serum concentration of prostate-specific antigen (PSA) of each case were also assessed. Statistical analysis for the correlations between LAT1 expression and Gleason score and each of the other characteristics studied was performed. As a result, a strong significant correlation between immuno-reactive LAT1 expression and Gleason score was identified (P<0.01). We concluded that immunoreactive LAT1 expression in tissue sections of prostate cancer may be useful as a biomarker for high-grade malignancy.

A comparison of interobserver reproducibility of Gleason grading of prostatic carcinoma in Japan and the United States.

CONTEXT: Gleason grading is now the sole prostatic carcinoma grading system recommended by the World Health Organization. It is imperative that there be good interobserver reproducibility within this system worldwide. To our knowledge, there are no studies, using the same specimens, that compare the interobserver reproducibility of Gleason grading in Japan and the United States. OBJECTIVE: To compare the interobserver reproducibility of Gleason grading of prostatic carcinoma in Japan and the United States using, in Japan, images from the identical biopsy glass slides that were originally graded in the United States. DESIGN: Microsopic images from 37 needle biopsies of prostatic carcinoma were placed on CD-ROM and distributed to 14 Japanese pathologists for grading. These 14 physicians included 8 general pathologists and 6 pathologists with a special interest in urologic pathology. The needle biopsies had been previously reviewed so that a consensus diagnosis could be formed by a panel of urologic pathologists in the United States and Canada. Interobserver agreement with the consensus diagnoses was calculated by determining the overall kappa coefficient for the Japanese pathologists and then compared to the interobserver agreement among American general pathologists who had previously graded identical needle biopsies from which the CD-ROM images had been taken. RESULTS: The interobserver agreement with the consensus diagnoses for the 4 Gleason grading groups (Gleason grades 2-4, 5-6, 7, and 8-10) among the Japanese urologic pathologists in this series of cases was substantial (overall kappa = 0.68), and for the Japanese general pathologists, it was moderate (overall kappa = 0.49), similar to that reported in the earlier study of American general pathologists (overall kappa = 0.44). The major interobserver reproducibility problem for both Japanese and American general pathologists is undergrading. The major areas of undergrading are the underdiagnosis of Gleason scores 5-6 as Gleason scores 2-4, and the underdiagnosis of cribriform sheets and fragments of cribriform Gleason pattern 4 carcinoma as Gleason pattern 3. CONCLUSIONS: The interobserver reproducibility of the Gleason grading for this collection of specimens was similar among Japanese and American general pathologists. The overall kappa values for these generalists of 0.44 and 0.49 are only in the moderate (0.41-0.60) range of interobserver agreement when compared to 0.68, substantial (0.61-0.80) agreement, for Japanese urologic pathologists. Educational efforts to improve Gleason grading have been shown to be effective and are clearly warranted.

Immunohistochemical expression of 14-3-3 sigma protein in various histological subtypes of uterine cervical cancers.

14-3-3 sigma (sigma) has been a major G2/M checkpoint control gene and has demonstrated that its inactivation in various cancers occurs mostly by epigenetic hypermethylation, not by genetic change. In order to confirm 14-3-3sigma protein expression together with p16 and p53 in cervical cancers, immunohistochemistry was performed using various histological subtypes of cervical cancers and dysplasia. Strong and diffuse immunoreactivity for 14-3-3sigma was uniformly observed in all the cervical dysplasia (17/17) and squamous cell carcinomas (29/29) including human papillomavirus (HPV)-negative cases. Even in adenosquamous carcinomas and adenocarcinomas of the cervix, immunohistochemical expression of 14-3-3sigma was shown with relatively high frequency (13/15, 87% and 22/27, 81%). In the in situ hybridization study, mRNA of 14-3-3sigma was expressed in six of eight immunohistochemical-negative cases. Therefore, the undetectable expression of 14-3-3sigma protein in cervical cancers might, at least in part, be due to a proteolysis not epigenetic hypermethylation. It is of interest that cancers without 14-3-3sigma expression were predominantly those lacking HPV DNA, and that there were no cases with concomitant inactivation of 14-3-3sigma and p16 in the present study. These observations are consistent with the hypothesis that inactivation of either 14-3-3sigma or p16 has an effect equivalent to the expression of E6 and E7 oncoproteins of HPV.

Immunohistochemical demonstration of 14-3-3 sigma protein in normal human tissues and lung cancers, and the preponderance of its strong expression in epithelial cells of squamous cell lineage.

In order to confirm 14-3-3 sigma (sigma) protein distribution in human tissues, immunohistochemistry was performed using various paraffin-embedded human tissues. In normal human tissues, the strongest immunoreactivity for 14-3-3sigma protein was observed in squamous epithelia at various sites, followed by basal cells of the trachea, bronchus and basal or myoepithelial cells of various glands. Moderate to weak 14-3-3sigma immunoreactivity was seen in the epithelial cells of the alimentary tract, gall bladder, urinary tract and endometrium. In the lung, 14-3-3sigma immunoreactivity was also observed in hyperplastic type II alveolar cells and metaplastic squamous cells. Immunohistochemical study using non-small-cell lung cancers revealed that 14-3-3sigma immunoreactivity was stronger in squamous cell carcinomas than in adenocarcinomas. The present study revealed that 14-3-3sigma expression was exclusively present in various epithelial cells and had a tendency to be stronger in cells destined for squamous epithelium or differentiating toward squamous cells in human normal and neoplastic cells.