**1. Introduction**

Neoplastic pathology is the second leading cause of mortality in adults in developed countries. The World Health Organization (WHO) as well as the Pan American Health Organization (PAHO) in their 2017 review, states that in 2015 cancer caused 8.8 million deaths worldwide. They stand out as the cancers with the highest number of deaths; lung cancer, hepatocarcinoma, colorectal cancer, gastric cancer, and breast cancer [1]. In Latin America, according to PAHO statistics, cancer is the second cause of death in the region, it is estimated that 2.8 million people are diagnosed each year and 1.3 million people die from this disease annually [1]. In about 50% of diagnosed cases, there is some degree of metastasis, this being responsible for more than 90% of cancer deaths. Surgical resection is the main treatment for malignant tumors, and in many cases; the only potentially curative treatment. Despite the constant development of new surgical techniques and both chemotherapy and radiotherapy treatments, the incidence of tumor recurrence has changed very little over time. This

suggests that there could be other important factors, some of them apparently linked to the surgical procedure, which may play a fundamental role in the progression of neoplastic pathology and the appearance of metastases. There is a growing interest in understanding these factors and the potential effect that anesthesia and its different techniques may have on them [2, 3].

Anesthetic drugs can induce changes in cell pathophysiology such as cell proliferation, angiogenesis, and apoptosis, and may be determinant in the progression of oncological disease in patients. This is why we are interested in identifying the main perioperative factors that play a role in tumor recurrence in cancer patients who undergo surgery; as well as evaluating which drugs may or may not be beneficial in the perioperative period [3–5].
