1. Department of General and Digestive Surgery, University Hospital Príncipe de Asturias, 28805 Madrid, Spain.
2. Departamento de Cirugia, Ciencias Medicas y Sociales. Faculty of Medicine and Health Sciences, University of Alcalá, 28801 Alcalá de Henares, Spain.
3. Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, 28801 Alcalá de Henares, Spain.
4. Ramón y Cajal Institute of Sanitary Research (IRYCIS), University Hospital Príncipe de Asturias, 28034 Madrid, Spain.
5. Department of General and Digestive Surgery. Surgical Nurse. University Hospital Príncipe de Asturias, 28805 Madrid, Spain.
6. Immune System Diseases-Rheumatology and Internal Medicine Service, University Hospital Príncipe de Asturias, (CIBEREHD), 28806 Alcalá de Henares, Spain.
Objective: The location of the primary tumor in colorectal cancer (CRC) could be a prognostic factor related to survival. However, its usefulness has not been sufficiently analyzed. The results in patients with tumors in initial stages are very limited, and there are descriptive parameters of survival that have not been analyzed in detail. In this study, the relationship between primary tumor location and survival in CRC patients was analyzed.
Materials And Methods: This was a retrospective observational study. All patients treated consecutively for CRC between January 2005 and December 2019 in the same hospital center were included. Overall survival (OS), cancer-related survival (CRS), time to recurrence (TTR), relapse-free survival (RFS) and postrecurrence survival (PRS) were analyzed, and the results were classified by tumor stage. The results were compared among patients with right colon (RS), left colon (LS) and rectal tumors.
Results: In the entire cohort, patients with RS tumors had lower OS and lower CRS at 60 months after diagnosis than did patients with LS or rectal tumors. In the regression analysis, the localization of the primary tumor was an independent prognostic indicator for OS and CRS. Analysis by tumor stage showed that patients with RS stage III tumors had lower OS and lower CRS at 60 months than did patients with LS and rectal tumors (42%, 59% and 53%, respectively, p = 0.006; and 48%, 63% and 57%, respectively, p = 0.025). Additionally, patients with RS Stage IV tumors had lower OS and lower CRS at 36 months than did patients with LS and rectal tumors (9%, 24%, 24%, respectively, p < 0.001; and 10%, 24% and 24%, respectively, p < 0.001). No differences were found in TTR and RFS among patients with stage I and II RS, LS, and rectal tumors. In contrast, patients with stage RS III tumors had significantly poorer PRS (9% for RS tumors, 13% for LS tumors, and 22% for rectal tumors) (p < 0.001).
Conclusion: The location of the primary tumor in patients with CRC is related to survival. The effect of laterality is more marked in patients with stage III and IV tumors. Patients with RS tumors had lower OS and CRS due to the lower survival of patients with stage IV RS tumors and lower PRS for patients with stage III tumors.
Keywords: colorectal cancer, survival, tumor recurrence, overall survival, time to recurrence, cancer-related survival, relapse-free survival