Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sentinel lymph node dissection (SLND) as originally described by D.L. Morton et al. (Surg Oncol Clin North Am 1992;1:247-59), is currently being used at most tertiary institutions for staging patients with intermediate-level melanomas. Identification and subsequent surgical resection of occult metastasis before the development of clinical disease may improve survival in these patients. This study is a retrospective review of patients with intermediate melanomas treated by the senior author (P.S.D.). Isosulfan blue dye and a radioactive technetium-labeled dye were used to identify the sentinel node. Sentinel nodes were evaluated by routine hematoxylin and eosin staining, immunohistochemical staining for S-100 and HMB-45, and later in the study with multipanel reverse transcriptase-polymerase chain reaction analysis. All patients were followed closely. Fifty-seven patients with primary melanoma were evaluated between December 1995 and June 1998. Thirty-two patients underwent SLND; two patients underwent SLND on two separate drainage basins, for a total of 34 procedures. The median age was 49 years (range, 19-77). There were 11 females and 21 males. The locations of the primary melanoma were: head and neck, seven; extremity, 8; and trunk, 18; 1 patient had a dual primary melanoma at presentation. Clark's levels of invasion among the patients were level III, 5; and level IV, 27; median Breslow thickness was 1.4 mm (range, 0.45-3.8 mm). A sentinel node was not identified in four procedures (11.1%). Twenty-two nodes (73%) were negative by all methods, and eight (27%) were positive by at least one method. All positive patients underwent complete lymphadenectomy, and routine hematoxylin and eosin stains identified no additional positive nodes. Median follow-up was 21 months (6-36 months). Two patients developed recurrent disease. The other 30 patients remain disease free at last follow-up. SLND is a low-morbidity technique that accurately stages patients with intermediate-level melanoma. Early intervention with complete therapeutic lymphadenectomy and possible interferon therapy may improve the survival of patients with stage III melanoma. A complete discussion of the technique for SLND and an update of this data is presented.
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PMID:Sentinel lymphadenectomy for staging patients with intermediate-level melanoma. 1075

The presence of tyrosinase mRNA in the peripheral blood cells of melanoma patients has been recently studied as a possible marker of haematogenous dissemination. However, considerable variations in the rates of detection have been noted. We determined the presence of tyrosinase mRNA-positive circulating cells using reverse transcriptase-polymerase chain reaction (RT-PCR) in 35 patients with stage I melanoma, two patients with stage II melanoma and two patients with stage III melanoma. Among the patients with stage 1, 13 were tested before and after surgery (< 1 h). Twenty healthy subjects served as negative controls. Out of the melanoma patients, the tyrosinase gene was expressed in three of the 52 samples tested. Tyrosinase mRNA was present in the circulating cells of only one patient with stage I melanoma after intra-congenital naevi resection. However, two other stage I patients developed rapidly lethal metastasis within the following 6 months, despite the lack of detectable tyrosinase mRNA. None of stage II patients were positive for the tyrosinase transcripts, while both patients with stage III melanoma showed enzyme expression. Our results confirm those of previous studies, showing that a small proportion of stage I melanoma patients have tyrosinase-positive circulating cells. Moreover, the lack of tyrosinase mRNA detection in the blood does not necessarily exclude metastatic progression. Therefore, this study indicates that the detection of tyrosinase mRNA-positive circulating cells by RT-PCR is not a predictive biomarker of a metastasis risk in patients with stage I melanoma.
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PMID:The detection of tyrosinase mRNA in the peripheral blood of stage I melanoma patients is not of clinical relevance in predicting metastasis risk and survival. 1080 11

Last year the Melanoma Group of the European Organization for Research and Treatment of Cancer (EORTC-MG) completed accrual (1418 patients) for trial EORTC 18952, a three-arm phase III trial evaluating adjuvant therapy with two different intermediate doses of interferon (IFN) alfa-2b versus observation for stage IIB-III melanoma. About 25% of the patients entered the trial with tumor-positive sentinel nodes (SNs). Prognosis was significantly better in SN-positive patients than in patients with palpable regional node involvement (P < .00001). Subsequently the EORTC-MG embarked on two large phase III trials of adjuvant therapy based on the tumor status of the SN. In trial EORTC 18961 for stage II melanoma, GM2-KLH/QS-21 vaccination is compared with observation (1300 patients); in trial EORTC 18991 for stage III melanoma, 5-year treatment with pegylated interferon alfa-2b (PEG-Intron) is compared with observation (900 patients). Translational research projects will compare SN assessment by hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC), and reverse transcriptase-polymerase chain reaction (RT-PCR) to determine the relative accuracy of each method and its correlation to relapse and survival of patients with stage II melanoma. In stage III patients, a similar workup of the most proximal nonsentinel node in the full lymph-node dissection specimen will indicate the accuracy of each methodology to detect nodal metastasis beyond the SN and the prognostic significance thereof. These findings will be correlated to the results of sequential blood testing by RT-PCR and by tumor marker assays for S100, TA90, and angiostatin. In addition, tumor-positive and tumor-negative SNs will be assessed for activated cytotoxic T lymphocytes and downregulation of dendritic cell functions.
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PMID:The EORTC melanoma group translational research program on prognostic factors and ultrastaging in association with the adjuvant therapy trials in stage II and stage III melanoma. European Organization for Research and Treatment of Cancer. 1159 96

Management of cutaneous melanoma has changed after introduction in the clinical routine of sentinel lymph node biopsy (SLNB) for nodal staging. By defining the nodal basin status, SLNB provides a powerful prognostic information. Nevertheless, some debate still surrounds the accuracy of this procedure in terms of false-negative rate. Several large-scale studies have reported a relatively high false-negative rate (5.6%-21%), correctly defined as the proportion of false-negative results with respect to the total number of "actual" positive lymph nodes. In this review, we identified all the technical aspects that the nuclear medicine physician, the surgeon, and the pathologist should take into account to improve accuracy of the procedure and minimize the false-negative rate. In particular, SPECT/CT imaging detects more SLNs than those found by planar lymphoscintigraphy. Furthermore, the nuclear medicine community should reach a consensus on the radioactive counting rate threshold to better guide the surgeon in identifying the lymph nodes with the highest likelihood of housing metastases ("true biologic SLNs"). Analysis of the harvested SLNs by conventional techniques is also a further potential source for error. More accurate SLN analysis (eg, molecular analysis by reverse transcriptase-polymerase chain reaction) and more extensive SLN sampling identify more positive nodes, thus reducing the false-negative rate.The clinical factors identifying patients at higher-risk local recurrence after a negative SLNB include older age at diagnosis, deeper lesions, histological ulceration, and head-neck anatomic location of the primary lesion.The clinical impact of a false-negative SLNB on the prognosis of melanoma patients remains controversial, because the majority of studies have failed to demonstrate overall statistically significant disadvantage in melanoma-specific survival for false-negative SLNB patients compared with true-positive SLNB patients.When new more effective drugs will be available in the adjuvant setting for stage III melanoma patients, the implication of an accurate staging procedure for the sentinel lymph nodes will be crucial for both patients and clinicians. Standardization and accuracy of SLN identification, removal, and analysis are required.
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PMID:Sentinel lymph node mapping in melanoma: the issue of false-negative findings. 2456 92