ABSTRACT
Odds ratio (OR) and relative risk (RR) are the most commonly used statistical indicators for the estimation of the association between exposure and outcome. In the cohort study with rare outcomes, the estimated OR approximately equals RR, but RR seems more interpretable. The study aims to explore the difference between OR and RR estimated by different multivariate analyses to provide reference for the selection of more appropriate multivariate regression methods and reporting indicators for estimating the association between exposure and rare outcome in cohort studies. This case study used the data from China birth cohort study. Modes of conception and congenital disabilities were regarded as exposure and outcome, respectively. Maternal age, family history of congenital disabilities with clear evidence were included as covariates. Logistic regression, log-binomial regression, and Poisson regression were used to estimate the OR and RR, respectively. Then, OR, RR, and their 95%CI estimated by three regression models were compared. The OR estimated by logistic regression was approximately equal to the RR estimated by log-binomial regression or Poisson regression. However, the RR estimated by log-binomial regression or Poisson regression was closer to 1.00, with a narrower 95%CI. Log-binomial regression or Poisson regression might have non convergence or over dispersion problems. It is recommended to report the RR obtained by log-binomial regression or Poisson regression in the cohort study with rare outcomes if applicable.
ABSTRACT
We aimed to study radiomics approach based on biparametric magnetic resonance imaging (MRI) for determining significant residual cancer after androgen deprivation therapy (ADT). Ninety-two post-ADT prostate cancer patients underwent MRI before prostatectomy (62 with significant residual disease and 30 with complete response or minimum residual disease [CR/MRD]). Totally, 100 significant residual, 52 CR/MRD lesions, and 70 benign tissues were selected according to pathology. First, 381 radiomics features were extracted from T2-weighted imaging, diffusion-weighted imaging, and apparent diffusion coefficient (ADC) maps. Optimal features were selected using a support vector machine with a recursive feature elimination algorithm (SVM-RFE). Then, ADC values of significant residual, CR/MRD lesions, and benign tissues were compared by one-way analysis of variance. Logistic regression was used to construct models with SVM features to differentiate between each pair of tissues. Third, the efficiencies of ADC value and radiomics models for differentiating the three tissues were assessed by area under receiver operating characteristic curve (AUC). The ADC value (mean ± standard deviation [s.d.]) of significant residual lesions ([1.10 ± 0.02] × 10-3 mm2 s-1) was significantly lower than that of CR/MRD ([1.17 ± 0.02] × 10-3 mm2 s-1), which was significantly lower than that of benign tissues ([1.30 ± 0.02] × 10-3 mm2 s-1; both P < 0.05). The SVM feature models were comparable to ADC value in distinguishing CR/MRD from benign tissue (AUC: 0.766 vs 0.792) and distinguishing residual from benign tissue (AUC: 0.825 vs 0.835) (both P > 0.05), but superior to ADC value in differentiating significant residual from CR/MRD (AUC: 0.748 vs 0.558; P = 0.041). Radiomics approach with biparametric MRI could promote the detection of significant residual prostate cancer after ADT.
Subject(s)
Male , Humans , Prostatic Neoplasms/drug therapy , Androgen Antagonists/therapeutic use , Androgens , Neoplasm, Residual , Retrospective Studies , Magnetic Resonance Imaging/methods , Diffusion Magnetic Resonance Imaging/methodsABSTRACT
Objective:To investigate the quality of 5-year medical undergraduates in China,analyze the influ-ence factors and put forward relevant policy suggestions. Method:By stratified random sampling,there are 24 medi-cal colleges or universities in northeastern, eastern, central, southern and southwestern China were included. Ac-cording to access the official websites,the enrollment data of 5-year medical undergraduates were collected. Result:The percentile of medical students'average score in entrance examination was around 33.46% ~56.32% in the first batch. There are significant difference among areas about the quality of medical undergradnates. Conclusion:At pres-ent,the quality of the 5-year medical undergraduates is good. Because high quality students unwilling to apply for clinical medicine,the quality of students declined. For this question,the suggestions are to improve enrollment sta-tus,school finical support,medical environment and doctors' welfare.
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Objective To analyze the imaging findings in MiT family translocation renal cell carcinoma (RCC) for the better understanding on the rare tumor combined with its clinicopathological features.Methods Fifteen patients with MiT family translocation RCC were analyzed retrospectively including 14 cases of Xp11.2 RCC and 1 case of t(6;11) RCC.Tumor location,size,capsule sign,hemorrhage,cystic change,calcification,density,signal features and enhancement pattern were evaluated.Results Four men and ten women aged from 14 to 42 years old (mean age of 26 years old) were diagnosed as Xp1 1.2 RCC.Most of the tumors (n =12) were located in renal medulla and most of the tumors (n =11) were 4 cm or more in diameter.There were 8 cases with hemorrhage.They were always well-defined (n =11) and all heterogeneous.Additionally,we could find calcification (a half of the number) typically distributed on CT.The tumor density was grater on plain CT (n =8) and the signal intensive was slightly high on T1WI (n-6) and low or slightly low on T2WI (n =9) than renal cortex.All of the cases were slightly or moderately persistent enhancement on DCE CT and MRI.The imaging features of the male patient with t(6;11)RCC was similar with Xp11.2 RCC apart from the diameter of 16 cm.Conclusions MiT family translocation RCC should be considered when a young patient presents with a relatively huge and well-defined renal tumor with an obviously heterogeneous features,annular calcification and persistent enhancement.It is difficult to distinguish Xp11.2 RCC and t(6,11) RCC,but size maybe play a hinting role in discriminate them.
ABSTRACT
<p><b>OBJECTIVE</b>To retrospectively analyze the clinical value of diffusion-weighted MR imaging in the detection of prostate cancer in suspected patients.</p><p><b>METHODS</b>Between January 2009 and December 2010, the 551 patients suspected as prostate cancer underwent prostate biopsy. Patients in group A were accepted to a transrectal ultrasound (TRUS) guided transrectal prostate biopsy (n = 410), while patients in group B were accepted to a diffusion weighted imaging (DWI) and TRUS jointly guided transrectal prostate biopsy (n = 141). The two groups were divided into 4 subgroups by prostate specific antigen (PSA) < 10 µg/L, 10 µg/L ≤ PSA < 20 µg/L, 20 µg/L ≤ PSA < 50 µg/L and PSA ≥ 50 µg/L. Then, the diagnostic rates of prostate biopsy guided by combination of DWI and TRUS with only TRUS were compared.</p><p><b>RESULTS</b>The diagnostic rate of patients with PSA < 10 µg/L, 10 µg/L ≤ PSA < 20 µg/L, 20 µg/L ≤ PSA < 50 µg/L and PSA ≥ 50 µg/L were 12.1%, 31.1%, 48.0%, 91.2% in group A, and 23.7%, 35.5%, 66.7%, 96.3% in group B, respectively. In the patients with PSA less than 10 µg/L, there were significant differences in diagnostic rate between the two biopsy techniques (χ(2) = 4.405, P < 0.05).</p><p><b>CONCLUSION</b>The combination of DWI and TRUS showed the potential to guide biopsy to cancer foci in patients suspected as prostate cancer. For patients with PSA < 10 µg/L, a DWI and TRUS jointly guided transrectal prostate biopsy was recommended.</p>