Hiroshi Yano

No Association of Mouse Mammary Tumor Virus-Related Retrovirus With Japanese Cases of Breast Cancer

Mouse mammary tumor virus (MMTV) is the causative agent of breast tumors in mice. Recently, DNA sequences homologous or closely related to MMTV env gene have been specifically detected in breast cancer tissue from significant numbers of American, Australian, and Tunisian women, suggesting a viral etiology for at least a part of human breast cancer. However, the viral sequences have not been detected from any of breast cancer samples in several subsequent studies. Thus, whether MMTV‐related retrovirus is a causative agent of human breast cancer remains controversial. To demonstrate if MMTV‐related retrovirus is involved in Japanese cases of breast cancer, breast tissue specimens from 46 breast cancer patients and 3 patients with benign mammary tumors were investigated. Extensive analysis using PCR and Southern blot hybridization, however, could not detect the MMTV env gene‐like sequence in any of the samples tested as well as in MCF7 cells that has previously been described as a positive control. Thus, MMTV itself or MMTV‐related retrovirus is not associated with breast carcinogenesis in Japanese women, and it is unclear whether this conclusion is merely a reflection of regional differences in its epidemics. J. Med. Virol. 80:1447–1451, 2008.

Immunohistochemical analysis of tumor biological factors in hepatocellular carcinoma: relationship to clinicopathological factors and prognosis after hepatic resection.

BackgroundThe relationship between patient prognosis and various tumor biological factors has been reported previously, and prognostic factors of tumor biology may improve predictions of prognosis after hepatectomy for hepatocellular carcinoma (HCC) and may contribute to a new staging classification. This study was designed to provide an immunohistochemical analysis of tumor biological factors in patients who underwent hepatectomy for HCC.MethodsFactors analyzed included p53 overexpression, microvessel counts, proliferating cell nuclear antigen, and expression of nm23. We examined 81 HCCs from patients with chronic liver diseases.ResultsIn patients who underwent chemoembolization before surgery, or those a who had confluent multinodular tumor, p53 expression tended to be higher than in patients without chemoembolization (33% vs 11%) or those with a simple nodular tumor (28% vs 10%), but the difference was not statistically significant (P = 0.051 and P = 0.092, respectively). A lower tumor microvessel count and negative nm23 expression were significantly associated with poor disease-free survival by univariate analysis (P ≪ 0.01 and P ≪ 0.05, respectively). A lower tumor microvessel count was found to be a significant prognostic factor for disease-free and overall survivals (risk ratios, 2.44 and 3.13, respectively; P ≪ 0.05), in addition to tumor size, vascular invasion, and longterm ascites, by Cox’s multivariate analysis.ConclusionsTumor microvessel count appears to be a useful prognostic marker for predicting HCC recurrence and patient survival.

Dedifferentiation of human primary thyrocytes into multilineage progenitor cells without gene introduction.

While identification and isolation of adult stem cells have potentially important implications, recent reports regarding dedifferentiation/reprogramming from differentiated cells have provided another clue to gain insight into source of tissue stem/progenitor cells. In this study, we developed a novel culture system to obtain dedifferentiated progenitor cells from normal human thyroid tissues. After enzymatic digestion, primary thyrocytes, expressing thyroglobulin, vimentin and cytokeratin-18, were cultured in a serum-free medium called SAGM. Although the vast majority of cells died, a small proportion (∼0.5%) survived and proliferated. During initial cell expansion, thyroglobulin/cytokeratin-18 expression was gradually declined in the proliferating cells. Moreover, sorted cells expressing thyroid peroxidase gave rise to proliferating clones in SAGM. These data suggest that those cells are derived from thyroid follicular cells or at least thyroid-committed cells. The SAGM-grown cells did not express any thyroid-specific genes. However, after four-week incubation with FBS and TSH, cytokeratin-18, thyroglobulin, TSH receptor, PAX8 and TTF1 expressions re-emerged. Moreover, surprisingly, the cells were capable of differentiating into neuronal or adipogenic lineage depending on differentiating conditions. In summary, we have developed a novel system to generate multilineage progenitor cells from normal human thyroid tissues. This seems to be achieved by dedifferentiation of thyroid follicular cells. The presently described culture system may be useful for regenerative medicine, but the primary importance will be as a tool to elucidate the mechanisms of thyroid diseases.

Long-term results of chest wall reconstruction with DualMesh

The aim of this study was to evaluate the clinical outcomes of chest wall reconstruction using a new, expanded polytetrafluoroethylene prosthesis, DualMesh. Between December 2005 and March 2010, chest wall reconstruction using 2-mm DualMesh was performed in 11 patients. The indication for resection was primary lung cancer in six patients, malignant mesothelioma in one patient, recurrent lung cancer in one patient, recurrent invasive thymoma in one patient, postirradiated osteomyelitis in one patient, and chondro-hamartoma in one patient. The mean observation period was 23 months, and four cases were observed for more than three years. There were no operative deaths and no wound infections. There were two postoperative complications: prolonged air leakage occurred in a patient with pulmonary emphysema who underwent right lower lobectomy, and slight paradoxical respiration occurred in the patient who underwent resection of the entire sternal body for osteomyelitis. Follow-up chest computed tomography was performed routinely. No dehiscence occurred in any cases. Chest wall reconstruction using DualMesh demonstrated acceptable durability and biocompatibility, even after long-term follow-up. DualMesh has the potential to become an ideal prosthesis for the bony chest wall as an alternative to conventional polytetrafluoroethylene or polypropylene grafts.

Chromosomal imbalances associated with acquired resistance to fluoropyrimidines in human colorectal cancer cells.

The chromosomal aberrations underlying the development of resistance to fluoropyrimidines have not yet been identified. To characterise the genomic changes that induce the development of resistance to fluoropyrimidines, we used comparative genomic hybridisation (CGH) to analyse and compare the parent DLD-1 human colorectal cancer cell line and two cell lines, DLD-1/5-FU and DLD-1/FdUrd, which were resistant to 5-fluorouracil (5-FU) and 5-fluoro-2-deoxyuridine (FdUrd), respectively. Both resistant cell lines showed a genetic aberration derived from the parental cell line DLD-1. Losses of 3p and 3q were also detected as additional genetic changes in the two resistant cell lines. Both resistant cell lines showed decreased orotate phosphoribosyltransferase (OPRT) activity, which is associated with the activity of the uridine monophosphate (UMP) synthase gene (3q13). These results suggested that the loss of 3q might be a genetic change responsible for the decreased OPRT activity and fluoropyrimidine cytotoxic response in cancer cells. Amplification of 18p11.2-p11.3 containing the thymidine synthase (TS) gene (18p11.32) was observed only in the DLD-1/FdUrd-resistant cell line, which overexpresses TS. These findings suggested that 18p amplification represents a genetic change associated with the overexpression of the TS protein. Our results indicate that chromosomal aberrations identified by CGH could explain, at least in part, acquired fluoropyrimidine resistance.

Efficacy and safety of eribulin as first- to third-line treatment in patients with advanced or metastatic breast cancer previously treated with anthracyclines and taxanes

OBJECTIVESnDespite the survival benefit and acceptable tolerability of eribulin for advanced/metastatic breast cancer (MBC) patients pretreated with anthracyclines and taxanes, there is limited evidence of the clinical benefit of early eribulin use. We investigated the efficacy and safety of first- to third-line eribulin use in patients with MBC.nnnMATERIALS AND METHODSnIn this phase II, open-label, single-arm study conducted at 14 sites in Kyushu, Japan, women with histologically confirmed human epidermal growth factor receptor 2-negative MBC were enrolled between December 1, 2011 and November 30, 2013 (Data cut-off: November 30, 2014). Objective response rate (ORR; primary endpoint), disease control rate (DCR), progression-free survival (PFS), duration of response (DOR), overall survival (OS), and safety were evaluated.nnnRESULTSnOf 53 recruited patients, 47 were enrolled. The ORR was 17.0% (95% confidence interval, 7.6-30.8), DCR was 66.0% (51.2-77.8), median PFS was 4.9 months (3.5-7.0), DOR was 6.6 months (1.9-14.3), and median OS was 17.4 months (10.1-not evaluable). The common grade 3/4 adverse events were neutropenia (25 patients; 53.2%), leucopenia (16 patients; 42.1%) and febrile neutropenia (4 patients; 8.5%). Toxicity did not increase during the long-term treatment. Subgroup analysis indicated that first-line treatment led to higher ORR and prolonged PFS and OS than second-/third-line treatment and that incidence of adverse events in patients of second-/third-line treatment was not higher than that in patients of first-line treatment.nnnCONCLUSIONnEribulin exhibited efficacy and manageable tolerability in Japanese women with pretreated MBC in first- to third-line use. (ID: UMIN000007121).

Total thyroidectomy versus thyroid lobectomy for papillary thyroid cancer: Comparative analysis after propensity score matching: A multicenter study

BACKGROUNDnIn patients with papillary thyroid carcinoma (PTC), the role of total thyroidectomy (TT) versus that of thyroid lobectomy (TL) has been controversial.nnnMETHODSnThis retrospective study was approved by our institutional review board, and the requirement to obtain informed consent was waived. In total, 173 patients with 1- to 5-cm stage cN0 and cM0 PTC tumors treated by curative surgery from 1994 to 2008 were evaluated. Clinicopathologic features and adverse events were compared between patients who underwent TT and those who underwent TL. After adjustment for differences in baseline clinicopathologic factors using propensity score matching, we compared recurrence-free survival (RFS) and OS.nnnRESULTSnTL was performed in 120 patients and TT in 53 patients. Patients who underwent TT were older; had larger tumors; more frequently had nodal metastasis, multifocal tumors, and extracapsular invasion; and more frequently underwent radioactive iodine ablation than patients who underwent TL. Hypocalcemia requiring medication and recurrent laryngeal nerve paralysis were more frequent in TT than TL. The 10-year RFS and OS of all patients were 93.3% and 96.7%, respectively. There was no significant difference in RFS (90.6% vs 93.0% in TT and TL groups, respectively) or OS (96.2% vs 96.9% in TT and TL groups, respectively) according to the extent of surgical resection after propensity score matching.nnnCONCLUSIONnEquivalent prognoses were observed for patients with 1- to 5-cm stage cN0 and cM0 PTC tumors treated by TL or TT after propensity score matching. Adverse events occurred less frequently in patients who underwent TL than TT.

Novel diagnostic procedure for determining metastasis to sentinel lymph nodes in breast cancer using a semi-dry dot-blot method

We developed an easy, quick and cost‐effective detection method for lymph node metastasis called the semi‐dry dot‐blot (SDB) method, which visualizes the presence of cancer cells with washing of sectioned lymph nodes by anti‐pancytokeratin antibody, modifying dot‐blot technology. We evaluated the validity and efficacy of the SDB method for the diagnosis of lymph node metastasis in a clinical setting (Trial 1). To evaluate the validity of the SDB method in clinical specimens, 180 dissected lymph nodes from 29 cases, including breast, gastric and colorectal cancer, were examined. Each lymph node was sliced at the maximum diameter and the sensitivity, specificity and accuracy of the SDB method were determined and compared with the final pathology report. Metastasis was detected in 32 lymph nodes (17.8%), and the sensitivity, specificity and accuracy of the SDB method were 100, 98.0 and 98.3%, respectively (Trial 2). To evaluate the efficacy of the SDB method in sentinel lymph node (SLN) biopsy, 174 SLNs from 100 cases of clinically node‐negative breast cancer were analyzed. Each SLN was longitudinally sliced at 2‐mm intervals and the sensitivity, specificity, accuracy and time required for the SDB method were determined and compared with the intraoperative pathology report. Metastasis was detected in 15 SLNs (8.6%), and the sensitivity, specificity, accuracy and mean required time of the SDB method were 93.3, 96.9, 96.6 and 43.3 min, respectively. The SDB method is a novel and reliable modality for the intraoperative diagnosis of SLN metastasis.

Intracystic Papillary Carcinoma of Breast Harbors Significant Genomic Alteration Compared with Intracystic Papilloma: Genome-wide Copy Number and LOH Analysis Using High-Density Single-Nucleotide Polymorphism Microarrays

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Detection of p53 gene mutations by nonisotopic RNase cleavage assay as a predictor of poor prognosis in colorectal cancers.

The present study was undertaken to evaluate p53 gene mutation as a prognostic factor in patients with colorectal cancer. Nonisotopic RNase cleavage assay (NIRCA), recently used for detecting gene mutations, was employed to detect p53 gene mutations in this study. In 15 samples of colorectal tumors, NIRCA was confirmed to be simple, accurate, and thus useful for clinical use, compared with polymerase chain reaction single-strand conformational polymorphism (PCR-SSCP). In another group of 79 cases of colorectal cancer analyzed for p53 gene mutation by using NIRCA, mutations were detected in 58 of 79 (73.4%) cases. Multivariate Cox proportional-hazards analysis showed that p53 gene mutation was a significant prognostic factor in patients with colorectal cancer. Our results showed that NIRCA is a simple and sensitive method, and thus useful for genetic screening of colorectal cancer. Furthermore, our results showed that p53 gene mutation is an independent predictor of poor prognosis in colorectal cancers.