Efecto de la localización del tumor primario y del estadio tumoral sobre el patrón de recurrencia y la supervivencia en el cáncer de colon

Supervised by:
  1. Fernando Noguerales Fraguas Director

Defence university: Universidad de Alcalá

Fecha de defensa: 21 September 2023

  1. Pedro Cascales Sánchez Chair
  2. Francisca García-Moreno Nisa Secretary
  3. José Andrés García Marín Committee member

Type: Thesis


Introduction: Colorectal cancer (CRC) is a pathology with high incidence, prevalence, and mortality worldwide. In Spain, colorrectal cancer ranked first in incidence, third in prevalence (after breast cancer and prostate cancer), and second in mortality (after lung cancer) in the latest data recorded in 2020. Traditionally, CRC was considered as a single entity, but nowadays it is recognized that colon cancer has its own characteristics that separate in from rectal cancer. The embryonic development of the Right Colon (cecum, ascending colon and 2/3 proximal transverse colon) is different from that or the Left Colon (1/3 distal transverse colon, descending colon and sigmoid) and the Rectum. Additionally, epidemiology, genetic defects and oncogesis differ in each of them, as well as multiple aspects of clinical, diagnosis and treatment, causing their neoplasms to have different characteristics that evolve and behave differently. Currently, Right Colon Cancer (RCC), Left Colon Cancer (LCC) and Rectal Cancer (RC) tend to be considered as three independent entities. However, the location of the primary tumor as a risk factor for survival remains a subject of debate. It is not clear whether it should be considered a factor that has an independent effect of survival and/or recurrence. This debate is due to differences in the results of studies published in the scientific literature. This controversy is influenced by the lack of homogeneity in the publications so far, as some studies include only one tumor stage, others do not differentiate patients by stages, and most do not include the three locations separately in their analyses. We believe that these conditions act as biases, as they do not allow for appropriate comparisons. We believe that there is no solid published scientific information to consider the location of the primary tumor as an independent risk factor. We think this justifies the differences in survival found between the three entities in published research and motivates the conduct of this study. Hypothesis: There are differences in the recurrence frequency and survival in CRC between primary tumors located in Right Colon, Left Colon and Rectum. These behavioral differences provide valuable prognostic information about survival and the likelihood of recurrence. Objectives: The objective of this study is to analyze the relationship between Primary Tumor Location and recurrence and survival patterns in patients with CRC, as well as to detail the effects of this relationship on each TNM tumor stage.