***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The purpose of this study was to assess the prognostic significance of the detection of circulating melanoma cells by reverse transcriptase-PCR in long-term clinical ly disease-free melanoma patients . Patients with melanoma who were free of clinical relapse for at least 6 months after primary tumor diagnosis were included and prospect ively followed . Tyrosinase mRNA in peripheral blood from these patients was assayed by reverse transcriptase-PCR at the time of their inclusion in the study . One hundred six blood sample s from 57 melanoma patients were analyzed . The median time between melanoma diagnosis and inclusion in the study was 24 months ( range , 7 - 51 months ) . The median follow-up time calculated from the time of inclusion in the study was 27 months ( range , 11 - 36 months ) . Tyrosinase mRNA in blood was detected in 10 ( 17.5 % ) of 57 patients : 2 ( 18 % ) of 11 stage I patients , 6 ( 19 % ) of 33 stage II patients , and 2 ( 15 % ) of 13 stage III patients . Actuarial 2-year DFS was 89 % for the tyrosinase-negative patients versus 30 % for the positive patients ( P = 0.003 ) . Actuarial 2-year OS was 97 % for the tyrosinase-negative patients versus 72 % for the positive patients ( P = 0.001 ) . Tyrosinase mRNA could be detected in the blood of a proportion of long-term disease-free melanoma patients , regardless of their initial clinical stage . The presence of late circulating melanoma cells in this selected group of clinical ly disease-free patients was significantly associated with a subsequent high risk of relapse and death PURPOSE Patients with American Joint Committee on Cancer ( AJCC ) stage III melanoma are at high risk of recurrence and death . We hypothesized that a multiple-marker reverse transcriptase polymerase chain reaction ( MM-RT-PCR ) blood assay could predict , early in the course of therapy , those patients destined to experience treatment failure with a melanoma vaccine ( MV ) previously shown to improve survival in a phase II clinical trial . PATIENTS AND METHODS After complete surgical resection , prospect ively collected cryopreserved peripheral-blood lymphocyte specimens ( n = 90 ) from the serial bleeds of 30 patients with AJCC stage III melanoma were studied by MM-RT-PCR , using the markers tyrosinase , melanoma antigen recognized by T cells-1 ( MART-1 ) , and universal melanoma antigen gene-A ( uMAG-A ) . All patients were enrolled in a phase II MV trial during the period of blood draws , and were selected for this study in a blinded fashion . Median duration of clinical follow-up was 74 months for the 13 survivors and 11 months for the 17 nonsurvivors . RESULTS The presence of at least one melanoma-specific RT-PCR marker was associated with an increased risk of disease recurrence ( risk rate , 3.12 ; P = .02 ) and decreased risk of survival ( relative rate , 2.62 ; P = .0496 ) by multivariate analysis . CONCLUSION MM-RT-PCR of the blood provided early prediction of subsequent disease recurrence and death in clinical ly disease-free AJCC stage III melanoma patients enrolled in a MV phase II trial . On the basis of the results of this pilot study , the MM-RT-PCR blood assay should be considered as a clinical ly important monitoring tool for assessing patient response to adjuvant therapy , and in the surveillance of clinical ly disease-free patients for the earliest signs of recurrence Purpose : Inconsistent reports on the detection of melanoma cells in peripheral blood by reverse transcriptase-PCR ( RT-PCR ) have result ed in uncertainty on the prognostic value of circulating melanoma cells . Experimental Design : We developed real-time RT-PCR assays for quantitation of tyrosinase , MelanA/MART1 , and gp100 and for porphobilinogen deaminase housekeeping gene . Melanoma tissue ( n = 18 ) , peripheral blood sample s from healthy donors ( n = 21 ) , and patients with cutaneous ( n = 122 ) and uveal ( n = 64 ) melanoma from our institution were analyzed . For quality control , an additional 251 sample s from ongoing multicenter studies were compared with in-house sample s. Results : Tyrosinase was not detected in healthy donor blood sample s. For the two other markers , cutoff values had to be defined to distinct patient sample s from controls . Patients with stage IV uveal and cutaneous melanoma  expressed all three markers more frequently and at higher levels in peripheral blood as compared with earlier stages . The variation of expression was 4 logs and correlated with tumor load and serum lactate dehydrogenase . In 2 of 3 uveal melanoma patients , detection of circulating tumor cells preceded the development of liver metastases . The diagnostic sensitivity was optimal in blood sample s containing > 0.1pg/μl porphobilinogen deaminase ( 95.7 % of in-house sample s and 57.4 % of multicenter sample s ) . Conclusions : Real-time RT-PCR is able to quantitatively define the quality of a sample and provides quantitative data for melanoma markers . Disparities in the results of previous studies may be attributable to undetected differences in sample quality . The prognostic relevance of this assay is currently under evaluation in several prospect i ve r and omized trials The aim of this study is to define the relationship between the tyrosinase expression in the peripheral blood and the clinical course of the disease in stage III disease-free melanoma patients after radical lymph node dissection .  RT – PCR techniques were used to identify tyrosinase mRNA in 110 patients ; a total of 542 blood sample s were investigated . In all , 54 patients ( 49 % ) showed at least one positive result ; 13 patients ( 11.8 % ) showed baseline positive results : six became negative thereafter , whereas seven showed follow-up positive results until disease progression occurred . One or more positive determinations were found during follow-up in 41 patients with negative baseline tyrosinase . No correlation was found between baseline results and the relapse rate or disease-free survival ( DFS ) , whereas a significant correlation was found between positive tyrosinase results and disease recurrence during follow-up . In fact , 72.9 % of positive patients relapsed , but only 19.3 % of negative cases did so . The median interval between the positive results and the clinical demonstration of the relapse was 1.9 months ( range 1–6.6 ) . Disease-free survival multivariate analysis selected , as independent variables , Breslow thickness ( P=0.05 ) , lymph node involvement according to the AJCC classification ( P=0.05 ) and tyrosinase expression ( P=0.0001 ) . In conclusion ,  RT – PCR tyrosinase mRNA expression is a reliable and reproducible marker associated with a high risk of melanoma progression and we encourage its clinical use in routine follow-up The clinical value of the reverse transcription polymerase chain reaction ( RT-PCR ) assay for tyrosinase in peripheral blood of melanoma patients is still under debate . A total of 212 blood sample s from 212 melanoma patients in all clinical stages ( AJCC ) were examined . Erythrocytes were lysed prior to RNA extraction by phenol precipitation from 2.7 ml of blood . cDNA for tyrosinase PCR was synthesized using r and om hexamers . Positive tyrosinase RT-PCR results were obtained in 11 % of 106 stage I patients , 18 % of 56 stage II patients , 31 % of 26 stage III patients and 67 % of 24 stage IV patients . After a median follow-up of 36 months ( range 26–41 ) , stage III patients with positive RT-PCR for tyrosinase had a shortened disease-free interval as compared to negative patients ( P < 0.01 ) . In stage IV patients , median overall survival was 8 months in case of a positive RT-PCR in contrast to 12 months in case of a negative test . While univariate analysis showed sex and primary tumour location associated with positive RT-PCR , multiple regression analysis revealed clinical stage and detection of tyrosinase transcripts in peripheral blood as best prognostic factors . Hazard ratios for disease-free survival were 19.7 ( confidence interval ( CI ) 8.53–45.5 , P = 0.0001 ) for metastatic vs primary disease and 2.96 ( Cl 1.49–5.89 , P = 0.002 ) for positive vs negative tyrosinase RT-PCR . The corresponding hazard ratios for overall survival were 97.0 ( Cl 12.7–741 , P = 0.0001 ) and 4.33 ( Cl 1.69–11.1 , P = 0.002 ) . Our results emphasize the importance of tyrosinase RT-PCR testing in peripheral blood . © 2000 Cancer Research BACKGROUND Circulating melanocytes can be detected in peripheral blood of patients with malignant melanoma by means of tyrosinase messenger RNA amplification . In this study we especially examined peripheral blood from patients with stage II melanoma before and after lymph node dissection for the detection of these circulating melanoma cells . Indeed the presence of regional nodal metastasis is one of the most important prognostic factors in patients with cutaneous melanoma . PATIENTS AND METHODS Blood sample s were collected from 20 normal patients , 42 patients with stage I melanoma and 23 patients with stage III melanoma . Twenty patients with stage II melanoma were tested 3 days before lymph node dissection and 2 à 8 weeks after . To identify circulating melanocytes , we used coupled reverse-transcription and polymerase chain reaction to target tyrosinase messenger RNA . RESULTS None of the 20 patients with stage II melanoma had detectable circulating melanocytes before lymph node dissection . By contrast , 7 of them became transiently PCR positive in the 8 weeks following surgery . We observed no evidence of correlation between the presence of circulating melanocytes after lymph node dissection and the risk of relapse within 6 months after surgery or the presence of capsule breaking or the number of involved lymph nodes . Sixty-nine percent of stage III patients and none of stage I patients were found to have circulating melanocytes . DISCUSSION Our study suggests that melanoma cells could circulate transiently after lymph node dissection . Confrontation of our results with literature data , despite important discrepancies related in part to sensibility technique , shows that the presence of circulating melanoma cells is correlated to the clinical stage . Prognostic value of these circulating cells need to be further assessed by prospect i ve studies with large number of patients and long follow-up PURPOSE Circulating melanoma cells can be detected in peripheral blood by means of tyrosinase mRNA amplification by reverse-transcriptase polymerase chain reaction ( RT-PCR ) . We conducted a prospect i ve study to evaluate the clinical significance of the presence of circulating neoplastic cells in the blood of patients with malignant melanoma ( MM ) . METHODS A sensitive RT-PCR assay was used to detect tyrosinase mRNA in the peripheral blood of patients with stages I to IV melanoma . Healthy subjects or patients with other malignancies were used as negative controls . RESULTS Ninety-one assessable patients were included in the study . There was a statistically significant association between RT-PCR positivity and clinical stage . Circulating melanoma cells were detected in 36 % of patients with localized disease ( stages I and II ) , in 45 % of patients with regional nodal involvement ( stage III ) , and in 94 % of patients with metastatic disease ( stage IV ) ( P < .001 ) . In stage II-III patients who were RT-PCR-positive for mRNA tyrosinase in blood , the recurrence rate and disease-free survival were significantly worse than patients who were RT-PCR-negative . In multivariate analysis , RT-PCR was an independent prognostic factor for recurrence in patients with nonmetastatic disease ( P = .002 ) . CONCLUSION The detection of circulating melanoma cells in peripheral blood by RT-PCR correlated with the clinical stage of patients with melanoma and was an independent prognostic factor for recurrence . Further studies are warranted to better assess the significance of this test in the evaluation of prognosis , early detection of relapse , and in monitoring the effectiveness of systemic therapy BACKGROUND AND DESIGN Polymerase chain reaction ( PCR ) detection of circulating tumor cells from malignant melanoma ( MM ) was recently described , but the prognostic value of this method in the treatment of patients with MM remained unclear . In the present prospect i ve study , blood sample s ( n = 193 ) were collected from 93 patients with MM : 10 stage I patients after primary tumor resection , 18 patients with regional lymph node metastases before node resection , 33 disease-free but high-risk patients ( previously treated for node metastases ) , and 32 patients with distant metastases . Circulating melanocytes were detected using a reverse transcriptase PCR method that analyzes tyrosinase gene expression . All patients were kept under regular surveillance . RESULTS The  PCR assay was always negative in normal individuals and in subjects with non-MM metastatic cancer , while it was positive in 16 of 32 patients with disseminated MM . Five of eight patients who were PCR-positive before node dissection vs one of 10 who were PCR-negative relapsed within  
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Furthermore , CTC positivity rates in early stages were higher and in the metastatic setting were lower than expected , which indicates an unsatisfactory accuracy of currently available CTC detection assays .
Our findings suggest that CTC might have a clinical ly valuable prognostic power in patients with melanoma .