Objective: To compare the opportunity in the start of treatment in patients with a diagnosis of gastric cancer, treated under the modality of prospective global payment contract (PGP) and under the modality of contract by event at the National Cancer Institute (INC) during the year 2019. Methods: This is a retrospective cohort observational analytical study. The target population were patients over 18 years of age who began the process of care for their diagnosis of gastric cancer at the INC between January 1 and December 31, 2019. Results: When conducting the review and analysis of the electronic medical records of the target population, it was observed that patients with severe associated comorbidities have a delay in the initiation of cancer treatment due to the execution of the prior control of the underlying pathologies; When performing the statistical analysis and the unadjusted and adjusted quantile regression (by age, sex and type of first therapy) of the data, excluding those with extreme values (above 2 SD, n= 14, and corresponding to the cases with comorbidity), for opportunities 1 (time elapsed in days since the ordering of the treatment and the start of this) and 2 (time elapsed in days since the definition of the treatment and the start of this), a shorter waiting time was evidenced (median in days) in the implementation of the first treatment in patients treated under the PGP contract modality compared with patients treated under contract by Event, the result of opportunity 2 being statistically significant (p= 0.007). For opportunity 3 (time elapsed in days from the first visit to the INC and the start of treatment), a longer waiting time (median in days) was obtained at the start of the first treatment in patients seen under the PGP modality compared to those attended under Event contract (p= 0.014). Conclusions: Differences were identified in the opportunities at the beginning of the first treatment of the population with gastric cancer treated under different contract modalities between the insurers and the INC by excluding the data with extreme values corresponding to cases with severe comorbidities, however, it is recommended for Future research, where possible, have patients who are cared for under the different contracting modalities and who live in Bogotá and outside the city in order to make a more accurate comparison of the results obtained, in addition to being able to have access to better information. quality in terms of sociodemographic factors of the population studied to establish possible causes that may also delay the start of cancer treatment.