Publicação
Survival Analysis in Stage II Colon Carcinoma
| dc.contributor.author | Oliveira, Ana Raquel da Silva | |
| dc.contributor.institution | Faculty of Sciences | |
| dc.contributor.supervisor | Domingues, Tiago Miguel Dias | |
| dc.contributor.supervisor | Coelho, José Luís Passos | |
| dc.date.accessioned | 2026-02-13T13:15:02Z | |
| dc.date.available | 2026-02-13T13:15:02Z | |
| dc.date.issued | 2025 | |
| dc.description | Trabalho de projeto de mestrado, Bioestatística , 2025, Universidade de Lisboa, Faculdade de Ciências | |
| dc.description.abstract | Colon cancer is one of the most common cancers affecting both man and women worldwide. Stage II colon cancer primary curative treatment is surgical tumor resection, but disease recurrence may occur due to the presence of micro-metastases at the time of surgery. The goal of post-operative, or adjuvant, chemotherapy, is to eradicate such metastases and increase cure rate. It is not clear which patients in stage II disease benefit the most from adjuvant treatment, and since chemotherapy has related toxicity, it should only be given when beneficial. This was a retrospective cohort study conducted in a population of 295 patients from two hospitals, with stage II colon cancer who underwent curative surgery between 2012 and 2018. Follow-up data was updated until March 2025. The aim of this study was to perform a survival analysis in this population, understand which variables have a higher impact in overall (OS) and disease-free survival (DFS) and which variables are more relevant for these endpoints in patients who underwent adjuvant chemotherapy. After a descriptive analysis of the study population, non-parametric methods were used to estimate survival functions for high-risk variables. Cox regression models were built to understand the influence of variables in DFS and OS, given the presence of other variables. Variable selection was done through stepwise procedure based on AIC and also lasso procedure after data imputation. Model diagnostics was performed with Schoenfeld residuals and proportional hazards assumption did not hold under the Cox model. Thus, parametric accelerated failure time models were also fitted and analysed. In summary, there was a clear benefit in OS and DFS for patients who underwent adjuvant treatment and variables that had a higher significant effect in these endpoints were mostly variables that represent high-risk features. The findings in this study are in line with published literature. | en |
| dc.format | application/pdf | |
| dc.identifier.tid | 204173000 | |
| dc.identifier.uri | http://hdl.handle.net/10400.5/117069 | |
| dc.language.iso | eng | |
| dc.subject | Adjuvant treatment | |
| dc.subject | Colon cancer | |
| dc.subject | Cox model | |
| dc.subject | High risk | |
| dc.subject | Survival analysis | |
| dc.title | Survival Analysis in Stage II Colon Carcinoma | en |
| dc.type | master thesis | |
| dspace.entity.type | Publication | |
| rcaap.rights | openAccess |
Ficheiros
Principais
1 - 1 de 1
A carregar...
- Nome:
- TM_Ana_Raquel_Oliveira.pdf
- Tamanho:
- 12.28 MB
- Formato:
- Adobe Portable Document Format