A Combinatory Approach for Selecting Prognostic Genes in Microarray Studies of Tumour Survivals

Different from significant gene expression analysis which looks for genes that are differentially regulated, feature selection in the microarray-based prognostic gene expression analysis aims at finding a subset of marker genes that are not only differentially expressed but also informative for prediction. Unfortunately feature selection in literature of microarray study is predominated by the simple heuristic univariate gene filter paradigm that selects differentially expressed genes according to their statistical significances. We introduce a combinatory feature selection strategy that integrates differential gene expression analysis with the Gram-Schmidt process to identify prognostic genes that are both statistically significant and highly informative for predicting tumour survival outcomes. Empirical application to leukemia and ovarian cancer survival data through-within- and cross-study validations shows that the feature space can be largely reduced while achieving improved testing performances

Vaginal vault recurrences of endometrial cancer in non-irradiated patients — Radiotherapy or surgery

Background: The treatment of locally recurrent endometrial cancer is based on limited evidence. The standard treatment is radiotherapy (RT) which is effective for local control and the effect has been documented in prospective studies. Investigations of surgical treatment (ST) of recurrences are few and limited to previously irradiated patients or patients with advanced disease. Investigation of surgical treatment for isolated vaginal vault recurrence is practically nonexistent. The aim of this study is to evaluate the efficacy of RT and ST in a non-irradiated group with recurrent endometrial cancer limited to the vaginal vault. Methods: Patients treated for recurrent endometrial cancer at Odense University Hospital, Denmark between 2003 and 2012 were identified, n = 118. Thirty-three patients had an isolated vaginal vault recurrence and were treated with either RT, ST or both. Re-recurrence rates and survival rates were calculated at 2 year follow-up using Fishers exact test. Results: Twenty-six patients were treated with RT, 5 with ST, 2 with both. The mean (SD) follow-up-time was 4.4 years (2.99) (RT) and 3.9 years (0.90) (ST). Two year re-recurrence rates were 40% (RT) (95 CI 9.2–48%) and 0% (ST) (95 CI 0–60%). Two-year survival rates were 83% (RT) (95 CI 71–100%) and 100% (ST) (95 CI 40–100%) ST had one re-recurrence at 2.3 years. Conclusion: This study indicates that ST is an appropriate treatment for locally recurrent endometrial cancer. Our study involves a limited number of patients and is made retrospectively, therefore prospective and ideally randomized trials evaluating both survival and complications are warranted