[Laparoscopy treatment of colon cancer: ducking is no fair play!].
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Colonic Neoplasms↗
Biomedical subjects
Andrew Kramar
Publications and source records attributed to Andrew Kramar.
[Increasing the quality of clinical trials in oncology: an important challenge].
The scientific literature publishes many articles reporting results of clinical trials. The criticisms which usually follow show the importance of the trial methodology in all of its aspects, since the results of these trials may have a strategic impact on the treatment of patients in the future. A clinical trial, no matter how many patients are included, will not have the anticipated impact if there are methodological biases. An inappropriate statistical analysis can always be redone, missing data can sometimes be retrieved, but a protocol not correctly followed or an inadequate strategy are fatal errors as far as the value of the conclusions of the trial are concerned. It is not ethical nowadays to start a clinical trial on humans if the results of the trials do not permit a conclusion because of methodological problems or inadequate resources. Each trial should thus be oriented in such a way so that each step is planned with an irreproachable quality by avoiding as much as possible methodological biases. The tendency today, which consists in adapting treatments more and more on an individual basis, will make it more difficult to undertake large simple clinical trials able to answer a simple question. Trials no longer escape the necessity to plan one or more interim analysis, since it is no longer ethical to continue to include patients without even thinking of looking at the results before the expected end of the trial, especially for severe adverse reactions.
Bias↗
Development and validation of a prognostic model to predict the length of survival in patients with carcinomas of an unknown primary site.
PURPOSE: To identify clinical and biologic variables with significant impact on survival in patients with carcinomas of an unknown primary site and to develop a simple prognostic model for the selection of patients in prospective clinical trials. PATIENTS AND METHODS: Univariate and multivariate prognostic factor analyses were conducted in a population of 150 unselected patients and led to the construction of two successive classification schemes. An external data set of 116 patients enrolled onto two prospective trials was used for validation. RESULTS: When studying clinical variables only, poor performance status (2 or 3) and presence of liver metastases were retained in the multivariate analysis. The first classification scheme consisted of three subgroups of patients with median survivals of 10.8, 6.0, and 2.4 months, according to the number of adverse prognostic factors. With the introduction of serum lactate dehydrogenase (LDH) levels in a further step, liver metastases were no longer significant. The second classification scheme therefore included poor performance status (relative risk [RR], 2.1) and elevated serum LDH level (RR, 2.1). Good-risk and poor-risk patients were identified, with median survivals of 11.7 months and 3.9 months, respectively (P <.0001). The 1-year survival rates were 45% and 11%, respectively. This second classification scheme was validated in an external data set: the median survival rates of patients assigned to the good-risk group and the poor-risk group were 12 months and 7 months, respectively (P =.0089). The 1-year survival rates were 53% and 23%, respectively. CONCLUSION: A simple prognostic model using performance status and serum LDH levels was developed and validated. It allows the assignment of patients into two subgroups with divergent outcome. Further prospective trials will be designed using this prognostic model.
Analysis of Variance↗
Progesterone receptor quantification as a strong prognostic determinant in postmenopausal breast cancer women under tamoxifen therapy.
There is now an emerging body of evidence that shows there is a relationship between the survival of breast cancer patients and the expression level of steroid receptors. The aim of this study was to determine the relationship existing between estrogen receptors (ER) and progesterone receptors (PR) cytosolic content and the prognosis of postmenopausal breast cancer women under tamoxifen therapy. Two hundred and nineteen postmenopausal patients, without neoadjuvant chemotherapy and treated postoperatively with tamoxifen for at least 2 years, were followed up in our Cancer Center. We used flexible regression modeling and log likelihood methods for determining optimum cut-off values for steroid receptors, which allows the separation of patients into significantly different categories in term of survival. For PR, 3 categories were defined (category 1: PR < 10, category 2: 10 < or = PR < 60 and category 3: PR > or = 60 fmol/mg P). Univariate analysis at 8 years indicated that significant differences in event-free survival (EFS) were found for tumor size (T) (p = 0.005), lymph node status (N) (p = 0.003), histological Scarff, Bloom and Richardson grade (p = 0.003), ER values divided into 5 categories (p = 0.02) and PR values divided into 3 categories (p = 1 x 10(-5)). Eight-year EFS rate for the 3 PR categories, adjusted for N, were 39, 66 and 81%, respectively. Multivariate Cox analysis indicated that only T, N and PR values were significant variables for EFS. Patients with PR values > or = 60 present significantly greater EFS rates than patients with PR < 60 (p < 0.001). Our results show that the PR level in ER positive postmenopausal women is a strong prognostic marker in postmenopausal breast cancer women under tamoxifen therapy.
Aged↗