Cure Mixture Models in Breast Cancer Survival Studies

Author(s):  
Nahida H. Gordon
2019 ◽  
Vol 24 (1) ◽  
pp. 261-273 ◽  
Author(s):  
Ruth Helena Pimenta Fujimoto ◽  
Rosalina Jorge Koifman ◽  
Ilce Ferreira da Silva

Abstract Breast cancer survival in Latin America countries is below Central European countries. Hospital-based breast cancer survival studies in western Amazon, Brazil, are lacking. This article aims to estimate hospital-based breast cancer survival in Rio Branco, Acre, and predictor factors. Hospital-based cohort study of all women diagnosed with breast cancer (2007-2012) was proceeded. Information were obtained from medical reports, and follow-up was until 2013. One-, 2- and 5- years breast cancer specific-survival were estimated by Kaplan-Meier method. Crude and adjusted Harzards Ratios (HR) were estimated by proportional Cox regression model. One-, 2-, and 5-year overall breast cancer survival were 95.5%, 83.7%, and 87.3% respectively. Surgery combined to radiotherapy significantly affected 1-, 2-, and 5-year survival (99%, 94%, and 90.6%, respectively) as compared to other treatments (77%,57.1%, and 37.5%, respectively). Comparing to surgery combined to radiotherapy treatment, surgery alone increased the risk of death, independently of age and stage (HR = 7.23;95%CI:2.29-22.83). In Rio Branco, Acre, 5-year breast cancer survival is similar to more developed areas in Brazil. Surgery combined to radiotherapy was independently associated to a lower risk of death as compared to surgery alone and other treatment.


Author(s):  
Suong N.T. Ngo ◽  
Desmond B. Williams

Background: The effect of cruciferous vegetable intake on breast cancer survival is controversial at present. Glucosinolates are the naturally occurring constituents found across the cruciferous vegetables. Isothiocyanates are produced from the hydrolysis of glucosinolates and this reaction is catalysed by the plant-derived enzyme myrosinase. The main isothiocyanates (ITCs) from cruciferous vegetables are sulforaphane, benzyl ITC, and phenethyl ITC, which had been intensively investigated over the last decade for their antibreast cancer effects. Objective: The aim of this article is to systematically review the evidence from all types of studies, which examined the protective effect of cruciferous vegetables and/or their isothiocyanate constituents on breast cancer. Methods: A systematic review was conducted in Pubmed, EMBASE, and the Cochrane Library from inception to 27 April 2020. Peerreviewed studies of all types (in vitro studies, animal studies, and human studies) were selected. Results: The systematic literature search identified 16 human studies, 4 animal studies, and 65 in vitro studies. The effect of cruciferous vegetables and/or their ITCs intake on breast cancer survival was found to be controversial and varied greatly across human studies. Most of these trials were observational studies conducted in specific regions, mainly in the US and China. Substantial evidence from in vitro and animal studies was obtained, which strongly supported the protective effect of sulforaphane and other ITCs against breast cancer. Evidence from in vitro studies showed sulforaphane and other ITCs reduced cancer cell viability and proliferation via multiple mechanisms and pathways. Isothiocyanates inhibited cell cycle, angiogenesis and epithelial mesenchymal transition, as well as induced apoptosis and altered the expression of phase II carcinogen detoxifying enzymes. These are the essential pathways which promote the growth and metastasis of breast cancer. Noticeably, benzyl ITC showed a significant inhibitory effect on breast cancer stem cells, a new dimension of chemoresistance in breast cancer treatment. Sulforaphane and other ITCs displayed anti-breast cancer effects at variable range of concentrations and benzyl isothiocyanate appeared to have a relatively smallest inhibitory concentration IC50. The mechanisms underlying the cancer protective effect of sulforaphane and other ITCs have also been highlighted in this article. Conclusion: Current preclinical evidence strongly supports the role of sulforaphane and other ITCs as potential therapeutic agents for breast cancer, either as adjunct therapy or combined therapy with current anti-breast cancer drugs, with sulforaphane appeared to display the greatest potential.


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