Yong Chen

Shenzhen Second People's Hospital, Shen-ch’üan-shih, Zhejiang Sheng, China

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Publications (5)12.9 Total impact

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    ABSTRACT: To scrutinize the literature in order to analyze the efficacy and safety of Gamma knife surgery (GKS) for nonfunctioning pituitary adenomas (NFPAs) with volumetric classification. Electronic databases including MedLine, PubMed and Cochrane Central were searched. The literature relating to patients with NFPAs treated with GKS was collected. Eligible studies reported on the rate of tumor control (RTC), the rate of radiosurgery-induced optic neuropathy injury (RRIONI), the rate of radiosurgery-induced endocrinological deficits (RRIED), and other parameters. 17 studies met the criteria. According to the tumor volume, NFPAs were divided into three groups: the RTC of group I(93 patients) with tumor volumes less than 2 ml was 99%(95% CI:96-100%), the RRIONI was 1%(95% CI:0-4%), the RRIED was 1%(95% CI:0-4%). The RTC of group (301 patients) with volumes from 2 to 4 ml was 96%(95% CI:92-99%), the RRIONI was 0 (95% CI:0-2%) and RRIED was 7%(95% CI:2-14%). The RTC of group (531 patients) with volumes larger than 4 ml was 91%(95% CI:89-94%), the RRIONI was 2%(95% CI:0-5%) and the RRIED was 22%(95%CI:14-31%). There were significant differences in the RTC and in the RRIED among three groups (P<0.001), which showed that there were higher RRIED and lower RTC with the increase of tumor volume. NFPAs, according to the tumor volume classification, need stratification for GKS treatment. GKS is the optimal choice for group II NFPAs. Patients with residual tumor volume less then 4ml will benefit most from GKS treatment.
    European Journal of Endocrinology 07/2013; DOI:10.1530/EJE-13-0400 · 3.69 Impact Factor
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    ABSTRACT: Objective: Previous studies attempting to define the natural history of postoperative nonfunctioning pituitary adenomas (pNFPAs) were somewhat limited by selection bias and/or small numbers and/or lack of consistency among the study findings. The aim of this study was to scrutinize the literature in order to analyze the natural history of pNFPAs. Methods: Electronic database including MEDLINE, PubMed and Cochrane CENTRAL were searched. The literature relating to the patients with pNFPAs without postoperative radiotherapy and pharmacotherapy was collected. Eligible studies reported on the rate of tumor recurrence, the tumor growth-free survival rate (TGFSR) at 5 and 10 years, and/or the residual tumor volume doubling time (TVDT). Results: 19 studies met the criteria. The pNFPAs were divided into two groups: the pooled recurrence rate of group I without detectable residual tumor (371 patients) was 12% (95% CI 6-19%), the TGFSR at 5 and 10 years were 96% (95% CI 89-99%) and 82% (95% CI 65-94%), respectively. The pooled recurrence rate of group II with residual tumor (600 patients) was 46% (95% CI 36-56%), the TGFSR at 5 and 10 years were 56% (95% CI 41-71%) and 40% (95% CI 27-53%), respectively. The mean TVDT was 3.4 years (95% CI 2.4-4.5 years). Conclusions: pNFPAs, with or without detectable residual tumor, need stratification of treatment and radiological/endocrinological follow-up strategy. According to the TVDT, residual tumor regrowth is very slow, which permits an extensive and safe follow-up program for most patients.
    Neuroendocrinology 06/2012; 96(4). DOI:10.1159/000339823 · 4.93 Impact Factor
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    ABSTRACT: Dopamine receptor agonists (DAs) can reduce hormone release and tumor mass in the majority of prolactinomas, whereas such effects are controversial in clinically nonfunctioning pituitary adenomas (NFPAs). Whether expression of dopamine 2 receptor (D2R) is different in subgroups of NFPAs has not been fully elucidated. We assessed and compared D2R subtype (long: D2L and short: D2S) mRNA levels in subgroups of NFPAs by real-time reverse transcriptase polymerase chain reaction (RT-PCR). For both D2L and D2S mRNA, there were no significant differences among them. Only 21.6% of NFPAs showed relatively high D2R mRNA levels; furthermore, histopathological subtypes of those cases with relatively high D2R expression were gonadotropinomas and null-cell adenomas. These data suggest that DAs are effective only for a small proportion of NFPAs, and relatively high D2R expression may more possibly happen to a subset of gonadotropinomas and null-cell adenomas.
    Neurological Sciences 07/2011; 33(2):275-9. DOI:10.1007/s10072-011-0701-6 · 1.50 Impact Factor
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    ABSTRACT: Invasive prolactinomas are more likely to be resistant to drug therapy but the mechanism of this is still unknown. The objective of this study was to analyze the different expression of ERmRNA and D2RmRNA isoforms in prolactinomas responsive and resistant to dopamine agonist (DA), and to discuss the correlation of such gene expression with tumor biological behavior. A prospective study of 20 consecutive patients who harbored prolactinomas was designed. Patients were classified as responsive (14 cases) or resistant (six cases) according to their clinical and biochemical response to bromocriptine. Tumor tissue samples were examined by means of QRT-PCR analysis. Median D2SmRNA expression in responsive patients was about 2.5-fold that in resistant ones (13.5 +/- 10.4 and 5.4 +/- 2.4, respectively, P = 0.09). No significant difference was found between D2LmRNA expression levels (P = 0.77). However, there was a significant difference between D2S/D2LmRNA ratios for responsive and resistant tumors (P = 0.012). A significant difference was not found between these two groups in levels of ERalphamRNA and ERbetamRNA expression (P = 0.20 and 0.06, respectively). D2SmRNA expression was significantly different for invasive and noninvasive tumors (6.2 +/- 3.6 vs. 17.0 +/- 11.2, respectively, P = 0.02). The D2S/D2L ratio is related to the responsiveness of prolactinomas to DA medication, in which D2SmRNA plays an important role. Lower expression of D2SmRNA in invasive tumor patients suggests that invasive prolactinomas may be more likely to be resistant to DA medication.
    Journal of Neuro-Oncology 08/2010; 99(1):25-32. DOI:10.1007/s11060-009-0107-y · 2.79 Impact Factor
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    ABSTRACT: To observe the postoperative residual non-functioning pituitary adenomas (PR-NFPAs) without postoperative radiotherapy and to analyze the natural history of PR-NFPAs' growth in order to provide a basis for selecting appropriate strategies of clinical treatment. We evaluated the natural history of 20 patients with PR-NFPAs who did not receive postoperative radiotherapy and drug therapy. Through MRI images, the residual tumor volumes of those patients were serially measured. We further calculated the monthly growth rate and the tumor volume doubling time (TVDT) and analyzed the correlations between the patient age, gender, volume of residual tumor, cavernous sinus (CS) invasion and TVDT. All patients received observation alone. Among which, 17 adenomas increased in volume and 3 remained unchanged during a follow-up period of 7 months to 17 years (mean 3.90 yr). The mean patient age was 41.8 years. As to 17 patients with tumor regrowth, the tumor volume at the beginning of MRI observation period was 4.73 cm(3) and tumor volume at the last MRI observation was 16.98 cm(3). During the mean 4-year follow-up period, the average monthly growth rate of PR-NFPAs was 7.87% and the mean TVDT was 724 days. Such factors as patient age, gender, volume of residual tumor and CS invasion did not affect the TVDT of PR-NFPAs. The tumor growth rate of PR-NFPAs is not significantly correlated with the patient gender, age, volume of residual tumor and CS invasion. In conjunctions with the volume of PR-NFPAs and the distance between residual adenoma and optic chiasm, we should take the TVDT into consideration and determine the appropriate and safe follow-up period.
    Zhonghua yi xue za zhi 03/2010; 90(9):597-600.