Miki Kushima

p53 mutations and overexpression affect prognosis of ovarian endometrioid cancer but not clear cell cancer

OBJECTIVE Although ovarian clear cell adenocarcinoma (OCCA) and ovarian endometrioid adenocarcinoma (EC) are considered to be closely related to endometriosis, the mechanisms of carcinogenesis of these two malignancies and malignant transformation of endometriosis are unclear. In this study, we examined the biology of OCCA and EC by performing large-scale analysis of K-ras activation and p53 mutation and overexpression in these malignancies. The results were subsequently analyzed for correlation with the clinicopathologic data. METHODS In the present study of OCCA and EC, we obtained clinicopathological data and analyzed frequency of mutations and overexpression of K-ras and p53. DNA was extracted from formalin-fixed, paraffin-embedded tissue, and target sequences were amplified in vitro by polymerase chain reaction. The DNA was analyzed for K-ras and p53 mutations by testing for single-strand conformation polymorphisms and by direct sequencing. Immunohistochemical staining was performed using p53 monoclonal antibody. Univariate analysis was performed using the Kaplan-Meier algorithm, and differences in survival were analyzed using the log rank test. The prognostic significance of the studied variables for survival was assessed using multivariate analysis with Cox regression analysis. RESULTS K-ras mutation was detected in 16.2% (6/37) of OCCA patients and 3.7% (1/27) of EC patients. No evidence of p53 mutation was detected in OCCA patients, but p53 mutation was detected in 63.0% of EC patients; these findings are consistent with the results of p53 immunohistochemistry. No statistical significance was observed for K-ras mutation in OCCA or EC. In EC patients, the absence of endometriosis and p53 overexpression was associated with a poorer survival. In OCCA patients tubulocystic and papillary histotype as well as stage II correlated with a worse survival. CONCLUSIONS p53 mutation, which was found in 63% of EC tumors, is an independent prognostic factor for EC patients. However, no p53 mutation was found in OCCA tumors. K-ras mutations did not affect survival of OCCA or EC patients.

K-ras mutation may promote carcinogenesis of endometriosis leading to ovarian clear cell carcinoma

Endometriosis shares some features characteristic of malignancy; however, it remains unclear whether endometriosis is a precursor to malignant disease. The objective is to determine the genetic relationship between endometriosis and ovarian clear cell carcinoma (OCCA). Among 37 Japanese patients with OCCA who underwent primary surgery at Showa University Hospital between 1987 and 1999, K-ras mutations were detected in 6. Three of these patients had ectopic endometrial tissue adjacent to the site of carcinoma. These cases demonstrated areas of endometriosis and areas of OCCA bordered by atypical endometriosis. We retrieved cells from regions of endometriosis and atypical endometriosis, as well as OCCA cells, by laser microdissection in each case. K-ras mutations were analyzed in each specimen dissected. DNA analysis of each region revealed that K-ras mutations were detectable in OCCA but not in endometriosis or atypical endometriosis. It is thought that a number of genetic alterations are involved in malignant transformation. It is possible that K-ras mutations are associated with malignant transformation of atypical endometriosis into OCCA, although further research is needed to define this mechanism.

Primary small cell carcinoma of the stomach.

Abstract  We report on an 80‐year‐old man with primary gastric small cell carcinoma (SmCC). He was admitted to hospital with hematemesis. An upper gastrointestinal examination revealed an irregularly ulcerated tumor, 60 mm in diameter, on the lesser curvature of the stomach body extending to the cardia. An endoscopic biopsy revealed a solid proliferation of intermediate‐sized tumor cells with hyperchromatic nuclei and scanty cytoplasm. Immunohistochemically, the neoplastic cells were positive for neuron‐specific enolase and chromogranin A, but negative for carcinoembryonic antigen. No tumor was detected on examination of the chest. Therefore, primary gastric SmCC was diagnosed preoperatively. To date, only 38 cases of primary gastric SmCC, including our case, have been reported. By using endoscopic biopsy, approximately two‐thirds of cases have been diagnosed incorrectly. In the reported cases of gastric SmCC, the endoscopic findings frequently indicated a submucosal tumor. Gastric SmCC is clinically aggressive and has an extremely poor prognosis, even when discovered at an early stage. Most patients with gastric SmCC die within 1 year of diagnosis. Although a standard treatment for gastric SmCC has not been established, intensive chemotherapy should be considered to promote long‐term survival. We believe that careful examination, including immunohistochemical investigation, is necessary for determining the therapeutic strategy whenever gastric SmCC is suspected during endoscopy.

Functional and histological changes in rat femoral arteries by HIFU exposure

This study was an investigation of arterial contractility in response to high-intensity focused ultrasound (HIFU) and of histologic changes to the artery with various intensities of HIFU. We constructed a prototype HIFU transducer in combination with an imaging probe that provides color Doppler imaging and Doppler velocimetry. HIFU was applied through the skin to deep femoral arteries in left thighs of Sprague-Dawley rats; color images of the blood flow were used to aim the HIFU beam. Peak intensities used were 530, 1080, 2750 and 4300 W/cm2. The duration of each HIFU exposure was 5 s. HIFU was applied to five focal spots of each leg. These focal spots were aligned with a spacing of 1.0 mm so as to form a line across the artery. Blood flow occlusion was accomplished by HIFU at an intensity of 4300 W/cm2, but the flow continued with the lower intensities. Peak systolic velocities (PSVs) of blood flow as measured by Doppler velocimetry increased in the arteries to which HIFU had been applied at 1080 and 2750 W/cm2. The increase corresponded with HIFU intensity. Exposure to HIFU at 530 W/cm2 did not change the blood flow velocity. Histologic studies have demonstrated that exposure to HIFU at 2750 and 4300 W/cm2 leads to vacuolar degeneration and destruction of elastic fibers of the tunica media of the artery. Exposure at 1080 W/cm2 led to increased PSV, but did not induce histologic changes in the vessel wall. In conclusion, the response of the artery to HIFU varied with intensity. Vascular contraction without tissue degeneration occurred at low intensity; with increasing intensity, the tissue degeneration detectable in histology reduced the vascular diameter and, finally, at high intensity, the blood flow was occluded. Although these phenomena appeared to be mainly due to thermal effects, mechanical effects might have some role, particularly on vascular contraction.

Intrahepatic status of regulatory T cells in autoimmune liver diseases and chronic viral hepatitis

Aim:  Regulatory T cells (Tregs) maintain immunological tolerance and suppress autoreactive immune responses. We evaluated the intrahepatic status of Tregs in patients with autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), chronic hepatitis C (CH‐C), or chronic hepatitis B (CH‐B).

Disappearance of CD21-positive Follicular Dendritic Cells Preceding the Transformation of Follicular Lymphoma: Immunohistological Study of the Transformation Using CD21, p53, Ki-67, and P-glycoprotein

Some follicular lymphomas histologically transform into diffuse aggressive lymphomas, the prognosis of which is poor. There are, however, no reliable histological criteria for predicting which cases will later undergo such transformation. In low-grade B-cell lymphomas, follicular dendritic cells form dense mesh-like networks that contain accumulating neoplastic B-cells. These are rare in high-grade lymphomas. We immunohistochemically analyzed CD21-positive follicular dendritic cells in 32 follicular lymphomas, including 3 transformed lymphomas, in addition to immunohistological study using P-glycoprotein, p53, and Ki-67. We found that the mesh-like networks in follicles are more clearly defined in low-grade lymphomas than in high-grade lymphomas (p = 0.015). Neoplastic follicles in 2 transformed lymphomas lost the networks of follicular dendritic cells before transformation despite the existence of morphologically clear follicles. This differed from the non-transformed cases of the same cytological grades. Prognosis was statistically better for patients with low-grade tumor than for those with high-grade tumor (p = 0.026), and there was a trend toward poorer survival among CD21-negative cases (p = 0.186). P-glycoprotein, p53, and Ki-67 expressions did not provide sufficient information to predict the transformation of follicular lymphoma. The presence of CD21-positive follicular dendritic cells in neoplastic follicles might help predict the potential of follicular lymphoma to transform to diffuse large B-cell lymphoma.

Adenocarcinoma arising from mature cystic teratoma of the ovary

An extremely rare adenocarcinoma arising from a mature cystic teratoma is reported. A 58‐year‐old woman underwent bilateral salpingo‐oophorectomy because of a tumor in each ovary. The right ovarian tumor (solid, 9.6 × 9.6 × 6.3 cm) was a benign thecoma. Histology revealed the left ovarian cystic tumor (multilocular, 6.4 × 4.8 × 2.8 cm) was a mature cystic teratoma containing skin, fatty tissue and respiratory epithelial tissue. In addition, there was a small focal adenocarcinomatous lesion contiguous to the teratomatous ciliated columnar epithelium without stromal invasion (so‐called adenocarcinoma in situ) that was suggestive of respiratory epithelium origin. However, goblet cells were present in the glandular structures of the lesion and immunohistochemical staining was segmentally strongly positive for CK20 and uniformly negative for CK7. These results suggested that the adenocarcinomatous lesion had a mucin secretory gastrointestinal phenotype. Further investigation and the collection of more cases is necessary to determine the origin and growth mechanism of adenocarcinoma arising from mature cystic teratoma of the ovary.

Tumor dimension and prognosis in surgically treated lung cancer: for intentional limited resection.

Tumors with a maximum dimension of 3 cm are categorized as T1, whereas those greater than 3 cm are T2 by TNM classification. Some physicians suggest that early-stage peripheral lung cancer should have a maximum tumor diameter of 2 cm and that limited surgery (segmentectomy without lymph node dissection) is acceptable for the patients. In this study, the relationship between the tumor dimension and prognosis was analyzed in 207 patients with surgically treated primary non–small-cell lung cancer (SCLC). The 5-year survival rate of those with tumors 3 cm or less and without lymph node (LN) metastases was 86%, which was significantly higher than that of those with tumors more than 3 cm and without hilar and mediastinal LN metastases (65%) (p < 0.05). However, 33% of the patients with tumors 3 cm or less had LN metastases, and the 5-year survival rate did not differ between those with tumors 3 cm or less (60%) and those with tumors more than 3 cm (54%). Twenty-eight percent of patients with tumors 2 cm or less had LN metastases, and the 5-year survival rate of the patients with tumors 2 cm or less was 62%. The 5-year survival rate of those with tumors 2 cm or less and without LN metastases was 88%. Forty-six patients with tumors 2 cm or less included 5 cases with an intrapulmonary metastasis in the same lobe (11%). In conclusion, a size of 3 cm is an appropriate boundary as the T factor. Because those with tumors 2 cm or less have a relatively high percentage of LN metastases, intraoperative frozen sections of LN should be considered for those undergoing limited surgery for primary non-SCLCs 2 cm or less. Intrapulmonary metastases also should be considered for those undergoing limited surgery even if the maximum dimension of the primary tumor is less than 2 cm.

Application of high-intensity focused ultrasound for umbilical artery occlusion in a rabbit model

To investigate the application of high‐intensity focused ultrasound (HIFU) for fetal umbilical artery blood flow occlusion in a rabbit model.

Study of p53 gene alteration as a biomarker to evaluate the malignant risk of Lugol-unstained lesion with non-dysplasia in the oesophagus

Mutations of the p53 gene are detected frequently in oesophageal dysplasia and cancer. It is unclear whether Lugol-unstained lesions (LULs) with non-dysplastic epithelium (NDE) are precursors of oesophageal squamous cell carcinoma (ESCC). To study the genetic alterations of NDE in the multistep process of oesophageal carcinogenesis, we determined the relationship between p53 mutations and LULs-NDE. Videoendoscopy with Lugol staining was performed prospectively in 542 oesophageal cancer-free subjects. Lugol-unstained lesions were detected in 103 subjects (19%). A total of 255 samples, including 152 LULs (NDE, 137; dysplasia, 15) and 103 paired samples of normal staining epithelium, were obtained from 103 subjects. After extraction of DNA and polymerase chain reaction analysis, direct sequencing method was applied to detect mutations of the p53 gene. The p53 mutation was detected in five of 137 samples with LULs-NDE (4%) and in five of 15 samples with dysplasia (33%). A hotspot mutation was found in 20% of LULs-NDE with p53 mutation and in 40% of dysplasia with p53 mutation. In contrast, no p53 mutations were found in 103 paired NDE samples with normal Lugol staining. In biopsy samples from oesophageal cancer-free individuals, the p53 missense mutations containing a hotspot mutation were found in NDE, which was identified as an LUL. These findings suggest that some LULs-NDE may represent the earliest state of oesophageal squamous cell carcinoma in Japanese individuals.