Anemia is a highly prevalent condition in the surgical population (1, 2). On the other hand, the oncology population is at higher risk of developing anemia due to specific treatments for the disease, such as chemotherapy and radiotherapy. Preoperative anemia has been associated with an increased risk of postoperative morbidity and even mortality (3). Despite this, the prevalence of preoperative anemia in the Chilean oncology population has not been quantified. To answer this question, a retrospective cohort study was designed between January and December 2022 to quantify the prevalence of anemia in the surgical population of the National Cancer Institute. In addition, the impact on morbidity and mortality at 30 days, 6 months, and 1 year will be evaluated. Statistical analysis will be performed using R. Studio Version 2023.09.1+494 (2023.09.1+494).

General Objective:

To quantify the prevalence of preoperative anemia in the National Cancer Institute's oncology surgical population and its impact on postoperative outcomes.

Specific Objectives:

1. To quantify the prevalence of preoperative anemia in the National Cancer Institute's oncology population.
2. To stratify the prevalence of preoperative anemia in the National Cancer Institute's oncology population by severity.
3. To assess 30-day, 6-month, and 1-year mortality in cancer patients with and without anemia in the National Cancer Institute's oncology population.

Inclusion Criteria:

• Patients over 18 years of age
• Oncologic surgery with curative intent

Exclusion Criteria:

• Emergency surgery
• Patients who received a preoperative transfusion
• Patients without a preoperative blood count

Consecutive patients operated at the National Cancer Institute will be included in a retrospective cohort study between January and December 2022.