Tatsuya Takenouchi

Niigata Cancer Center Hospital, Niahi-niigata, Niigata, Japan

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Publications (7)15.85 Total impact

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    ABSTRACT: The importance of the genetic background of melanoma cells to the individual susceptibility to treatment has become apparent. In Caucasians, BRAF mutations are frequently detected in lesions on the skin of younger patients compared to NRAS and KIT mutations. However, clinical and pathological characteristics associated with BRAF, NRAS and KIT mutations have not been fully evaluated in East Asians. To clarify clinical and pathological characteristics associated with BRAF, NRAS and KIT mutations in Japanese melanoma patients. Clinical data were retrospectively collected from 11 hospitals in Japan. BRAF, NRAS and KIT mutations were evaluated with polymerase chain reaction and Sanger sequencing. The relationships between these gene mutations and pathological and clinical findings were analyzed. The number of cases examined were 171 (primary: 135, metastases: 11, paired: 25), and all were Japanese patients. The detection rates of BRAF, NRAS and KIT mutations were 30.4%, 12.3% and 12.9%, respectively. Compared with the wild type, the presence of BRAF mutations was significantly associated with younger age (median, 50.0 years vs. 70.0 years, p<0.001). BRAF mutation was frequently detected in the lesions of the scalp (80%; 4/5), trunk (72.0%; 18/25), extremities (56.7%; 17/30) and neck (44.4%; 4/9), and the least prevalent were the face (22.2%; 2/9), nail (12.5%; 3/24), palm or sole (8.9%; 4/45) and mucosa (0%). NRAS mutations were prevalent in the face (33.3%) and palm or sole (20.0%), and the median age of these patients was 70.5 years. A KIT mutation was observed in the nail apparatus (25%), palm or sole (15.6%) and mucosa (18.2%). The median age of the patients with a KIT mutation was 63.0 years. Heterogeneity of mutations between primary and metastatic lesions was detected in six of 25 cases (24%). Solar elastosis was identified in 12 of 71 cases (15.3%), among which four cases harbored BRAF(V600E) (2 cases), BRAF(V600K), NRAS(Q61K) or NRAS(Q61L), respectively. Some clinical characteristics associated with BRAF, NRAS and KIT mutations were observed in Japanese patients, and we observed both similarities to and differences from those of Caucasians. Our findings could provide useful information in efforts to clarify the tumor genesis of malignant melanomas. Copyright © 2015 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.
    Journal of dermatological science 07/2015; DOI:10.1016/j.jdermsci.2015.07.012 · 3.42 Impact Factor

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    ABSTRACT: Although extramammary Paget's disease (EMPD) mostly presents as intraepithelial carcinoma, we sometimes encounter patients with invasive EMPD (iEMPD) who have lymph node metastasis and may develop distant metastasis. Although sentinel lymph node biopsy (SLNB) is widely accepted for various cancers, there is no large study that has assessed its role in iEMPD. The main objective of this study is to assess the role of SLNB in patients with iEMPD. We retrospectively collected data on 151 iEMPD patients treated from 1998 to 2012 in 11 institutes in Japan. All 151 patients received curative surgery for their primary tumor and none of them had distant metastasis. SLNB was performed on the 107 patients without lymphadenopathy to determine their LN status. The 44 other patients with lymphadenopathy underwent one of the following procedures to determine their LN status: SLNB in 22 cases, immediate LN dissection in 21, and LN biopsy in 1. Compared to those without lymphadenopathy, patients with lymphadenopathy had advanced primary tumors (nodule in the primary tumor, thicker tumor, deeper invasion level, and lymphovascular invasion). The rate of LN metastasis in patients with lymphadenopathy was 80%, compared to 15% in patients without lymphadenopathy who underwent SLNB. Compared to those with negative SLN, patients with positive SLN had advanced primary tumors (nodule in the primary tumor, deeper invasion level, and lymphovascular invasion). Multivariate analysis revealed that dermal invasion (odds ratio 5.8, p=0.04) and lymphovascular invasion (odds ratio 18.0, p=0.0023) were independent factors associated with SLN positivity. Notably, there was no difference in survival between patients with or without SLN metastasis (p=0.71). On the other hand, patients with lymphadenopathy showed worse survival than those with positive SLN (p=0.045). Clinical lymphadenopathy was strongly correlated with pathological LN metastasis and also associated with worse survival than absence of lymphadenopathy. The rate of occult LN metastasis detected by SLNB was 15%. Survival was not affected by SLN status even when an advanced primary tumor was present in patients with positive SLN. Our results raise the possibility that SLNB and subsequent LN dissection improved the survival of patients with early stage lymphatic spread. Our study indicates that SLNB should be considered for iEMPD if lymphadenopathy is not apparent. Copyright © 2015 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.
    Journal of dermatological science 04/2015; 79(1). DOI:10.1016/j.jdermsci.2015.03.014 · 3.42 Impact Factor
  • Tatsuya Takenouchi · Sumiko Takatsuka ·
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    ABSTRACT: Conventional surgical excision (SE) is commonly used to treat patients with basal cell carcinoma (BCC). There have been few studies, however, evaluating the long-term prognosis of Japanese patients receiving SE for treatment of BCC. The purpose of this retrospective study is to determine the effectiveness of SE in accomplishing the long-term cure of patients with BCC. We enrolled 290 patients with primary BCC who underwent SE during 1998-2006. The prognosis of treated patients was subsequently investigated using data obtained through our hospital cancer registration section. In total, 205 patients (70.7%) were treated for BCC lesions located on the face. The mean tumor diameter of excised lesions was 12.8 mm. A majority of patients in the study (256 patients, 88.3%) had pigmented BCC. The mean surgical margin at SE was 3.8 mm. Two patients developed local recurrence during the postoperative course of 290 patients (mean duration, 80 months). One patient developed recurrent disease 21 months after surgery, and the other developed recurrence at 66 months after surgery. The 5- and 10-year cumulative recurrence rates were 0.4% and 0.8%, respectively. In conclusion, this study demonstrated that long-term high cure rates of BCC in Japanese patients may be achieved through conventional SE. A better prognosis was obtained in this study compared with similar studies reported previously in Caucasians. This may be related to the predominance of pigmented versus non-pigmented lesions in the Japanese population.
    The Journal of Dermatology 06/2013; 40(9). DOI:10.1111/1346-8138.12207 · 2.25 Impact Factor
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    ABSTRACT: Various microscopic classifications of metastatic sentinel lymph nodes (SLN) have been reported along with predictors of additional lymph node positivity and their correlations with the prognosis. The purpose of this study was to re-evaluate these classifications in the Japanese population. We selected the following three classifications, based on the procedural simplicity of the measurements: maximum diameter (maximum diameter of the largest tumor lesion in the SLN; <0.1, 0.1-1.0, >1.0 mm), invasion depth (depth of tumor invasion measured from the capsule in the SLN; SI ≤ 0.3 mm, SII >0.3 to ≤ 1.0 mm, SIII >1.0 mm), and microanatomic location (microanatomic location of the tumor deposits within the SLN; "subcapsular", "parenchymal", "combined", "multifocal", "extensive"). A retrospective study, using prescribed survey forms, was carried out. Among the 450 patients, including the 149 cases with SLN metastasis, an additional lymph node positivity rate of 0% could be predicted only in patients with a maximum diameter category of less than 0.1 mm. As compared with that in the SLN metastasis-negative cases, however, the prognosis was poorer in cases with SLN metastasis, even those with lesions falling under the maximum diameter category of less than 0.1 mm, invasion depth category of SI (≤ 0.3 mm) and microanatomic location category of subcapsular. The prognosis is particularly poor for the microanatomic location category of extensive, which should thus be regarded as a macrometastasis. A prospective study with standardized procedures, including pathological evaluation, is needed in order to confirm our conclusion.
    The Journal of Dermatology 09/2011; 39(2):130-7. DOI:10.1111/j.1346-8138.2011.01318.x · 2.25 Impact Factor
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    ABSTRACT: Patients with primary cutaneous melanoma underwent sentinel node (SN) mapping and biopsy at 25 facilities in Japan by the combination of radiocolloid with gamma probe and dye. Technetium-99m ((99m)Tc)-tin colloid, (99m)Tc-phytate, 2% patent blue violet (PBV) and 0.4% indigo carmine were used as tracers. In some hospitals, 0.5% fluorescent indocyanine green, which allows visualization of the SN with an infrared camera, was concomitantly used and examined. A total of 673 patients were enrolled, and 562 cases were eligible. The detection rates of SN were 95.5% (147/154) with the combination of tin colloid and PBV, 98.9% (368/372) with the combination of phytate and PBV, and 97.2% (35/36) with the combination of tin colloid or phytate and indigo carmine. SN was not detected in 12 cases by the combination method, and the primary tumor was in the head and neck in six of those 12 cases. In eight of 526 cases (1.5%), SN was detected by PBV but not by radiocolloid. There were 13 cases (2.5%) in which SN was detected by radiocolloid but not by PBV. In 18 of 36 cases (50%), SN was detected by radiocolloid but not by indigo carmine. Concomitantly used fluorescent indocyanine green detected SN in all of 67 cases. Interference with transcutaneous oximetry by PVB was observed in some cases, although it caused no clinical trouble. Allergic reactions were not reported with any of the tracers. (99m)Tc-tin colloid, (99m)Tc-phytate, PBV and indocyanine green are useful tracers for SN mapping.
    The Journal of Dermatology 09/2011; 39(4):336-8. DOI:10.1111/j.1346-8138.2011.01340.x · 2.25 Impact Factor
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    Tatsuya Takenouchi ·
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    ABSTRACT: Basal cell carcinoma (BCC) and seborrheic keratosis (SK) are representative pigmented skin tumors, and they are differentiated as non-melanocytic lesions in the two-step dermoscopy algorithm proposed by the Consensus Net Meeting on Dermoscopy. Because most BCC in Japanese patients are pigmented clinically, dermoscopy plays an important role in their differential diagnosis. The dermoscopic criteria for BCC include the lack of a pigment network and the presence of at least one positive feature for BCC, such as large blue-gray ovoid nests, multiple blue-gray globules, leaf-like areas, spoke wheel areas, arborizing vessels and ulceration. Whereas various dermoscopic features are seen in SK, comedo-like openings, milia-like cysts, and fissures and ridges are especially important features. It is necessary for clinicians to consider the pathological conditions causing the dermoscopic features of BCC and SK. In addition, the sensitivity and specificity of each feature should be taken into consideration to ensure an accurate dermoscopic diagnosis.
    The Journal of Dermatology 01/2011; 38(1):59-65. DOI:10.1111/j.1346-8138.2010.01093.x · 2.25 Impact Factor