Renal immature teratoma in a male adult: A case report and literature review.

RATIONALE: Teratomas commonly arise in the gonads, including ovary and testis. The kidney is one of the most rare regions of primary teratoma. To date, about 19 cases of renal teratoma have been reported, and only 3 articles have reported renal immature teratoma; however, all of them occur in infant or children. In the present study, we reported a renal inmature teratoma in a male adult. PATIENT CONCERNS: The present patient was a middle-aged man with aching pain in the left waist, and contrast-enhanced CT showed a lump in the left kidney with mild-to-moderate enhancement, and a low density small necrotic area was seen in the center. DIAGNOSIS, INTERVENTIONS, AND OUTCOMES: The patient underwent radical nephrectomy. Based on postsurgical histopathology, the final diagnosis of this case was renal immature teratoma. Postoperative chemotherapy was carried out, and the patient has been followed-up for 18 months without tumor recurrence. LESSONS: Adult renal immature teratoma is rare, and the diagnosis is mainly based on the pathological findings.

The prognostic value of microRNA-183 in human cancers: A meta-analysis.

BACKGROUND: Several studies have been conducted to explore the prognostic value of miR-183 in different types of cancer; however, their results were controversial. Therefore, the present meta-analysis was conducted to comprehensively evaluate the prognostic value of miR-183 expression level in cancer. METHODS: A comprehensive literature search was carried out by searching PubMed and EMBASE database between January 1966 and April 2017. Fixed effect and random effect models were used to evaluate the pooled hazard risk (HR) and the relevant 95% confidence intervals (CIs). Subgroup analyses and sensitivity analysis were also carried out. RESULTS: A total of 12 studies published between 2011 and 2017 were included in the present meta-analysis. The meta-analysis result indicated that there was a significant association between miR-183 expression level and overall survival (HR = 2.642; 95%CI: 2.152-3.245), and there was a significant association between miR-183 expression level and tumor progression (HR = 2.403; 95%CI: 1.267-4.559). In subgroup analysis, we found that high expression level was significantly associated with poor prognosis in most cancers (HR = 2.824, 95%CI: 2.092-3.813); however, low miR-183 level was significantly associated with poor prognosis in melanoma and pancreatic ductal adenocarcinoma (HR = 2.322, 95%CI: 1.337-4.031). CONCLUSIONS: The results of our meta-analysis indicated that the highly expressed miR-183 might predict poor survival of patients with most cancer types, whereas the downregulated miR-183 level might be associated with poor prognosis in patients with melanoma and pancreatic ductal adenocarcinoma.

Metformin therapy and prostate cancer risk: a meta-analysis of observational studies.

OBJECTIVE: Several observational studies have shown that metformin therapy may modify the risk of prostate cancer. We carried out a meta-analysis of relevant studies evaluating the effect of metformin therapy on prostate cancer risk. METHODS: We searched pubmed database (January 1966-February 2014) for case-control and cohort studies that assessed metformin therapy and prostate cancer risk. Two authors independently assessed eligibility and extracted data. Summary RRs was calculated using fixed-effects model or random-effects model. Heterogeneity among studies was examined using Q and I(2) statistics. RESULTS: We included six cohort studies and four case-control studies in the present meta-analysis, comprising 863,769 participants and 39,073 prostate cancer cases. The pooled RR of prostate cancer in relation to metformin therapy was 0.92 (95% CI: 0.84-1.02, P = 0.112). When we stratified the various studies by study type, we found that metformin therapy was associated with a significant reduced risk of prostate cancer among cohort studies (RR = 0.92, 95% CI [0.87, 0.96], P<0.001); however, no significant association was detected among case-control studies (RR = 0.95, 95% CI [0.78, 1.16], P = 0.632). There was also no indication of publication bias as suggested by Begg's test (P = 0.421) and Egger's test (P = 0.627). CONCLUSION: Our findings indicate that metformin therapy is not significantly associated with lower prostate cancer risk.

Vasectomy and the risk of prostate cancer: a meta-analysis of cohort studies.

BACKGROUND: The relationship of vasectomy to prostate cancer has great public health significance. However, the results of observational studies were conflicting. To determine whether vasectomy is associated with the risk of prostate cancer, we performed a meta-analysis of cohort studies. METHODS: A literature search was carried out using Pubmed, Embase, Cochrane Libraryl, and China National Knowledge Infrastructure (CNKI) between January 1966 and July 2013. Before meta-analysis, between-study heterogeneity and publication bias were assessed using adequate statistical tests. Fixed-effect and random-effect models were used to estimate summary relative risks (RR) and the corresponding 95% confidence intervals (CIs). Potential sources of heterogeneity were detected by meta-regression. Subgroup analyses and sensitivity analysis were also performed. RESULTS: A total of nine cohort studies contributed to the analysis. There was heterogeneity among the studies but no publication bias. Pooled results indicated that vasectomy was not associated with a significant increase of total prostate cancer risk (RR = 1.07, 95% CI [0.79, 1.46]). When stratified the various studies by geographic location, we found a significant association between vasectomy and increased PCa risk among studies conducted in the USA (RR = 1.54, 95% CI [1.23, 1.93]), however, there was no significant association between vasectomy and PCa risk among studies conducted in non-USA countries (RR = 0.74, 95% CI [0.50, 1.09]). Furthermore, sensitivity analysis confirmed the stability of the results. CONCLUSIONS: In conclusion, the present meta-analysis of cohort studies suggested that vasectomy was not associated with increased risk of prostate cancer. More in-depth studies are warranted to report more detailed results, including stratified results by age at vasectomy, tumor grade, and tumor stage.