Factors associated with the survival of colorectal cancer in Mexico.

Background/aims: Colorectal cancer (CRC) is a public health problem. In Mexico, there have been no recent studies conducted on survival in terms of this pathology or on the influence of prognostic factors. The study aims to determine the probability of survival in patients with CRC presence of low levels of schooling and a rural population, adjusted for clinical stage and type of treatment.

Methods: A retrospective study was conducted in a cohort of 305 patients with CRC treated at State Cancer Center, located in Veracruz-Mexico; the follow-up period of 60 months (2012-2016). The survival probability was calculated using the Kaplan-Meier estimator and the log-rank test with 95% confidence intervals (CIs). Prognostic factors were determined using hazard ratio (HR) multivariate Cox regression analysis.

Results: Overall survival was 40% at 60 months. Subjects in the age group ≥ 65 years had a low survival rate of 28% (P= 0.026) and an advanced clinical stage of 22% (P< 0.001). Of the patients with bone metastasis, none survived longer than 5 years (P= 0.008). With respect to the unfavorable prognostic factors identified in the multivariate analysis, a decreased level of schooling was associated with an HR of 7.6 (95% CI, 1.1-54.7), advanced clinical stage was associated with an HR of 2.1 (95% CI, 1.2-4.0), and the presence of metastasis had an HR of 1.8 (95% CI, 1.1-2.9).

Conclusions: Poor prognostic factors include an advanced clinical stage, the presence of metastasis and a low level of schooling. These findings confirm the importance of screening for early diagnosis, diminishing the barriers to accessing treatment and prospectively monitoring the population.