The COVID-19 pandemic was declared by the World Health Organization (WHO) on 11 March 2020 [1]. The first case of COVID-19 in Portugal was reported on 2 March 2020. By May 2023, 5.4 million cases of COVID-19 had been confirmed, along with 25.9 thousand deaths [2].

The strategies implemented to control the virus dissemination posed a challenge to healthcare systems, with cancellations and delays in elective and non-urgent procedures [3], [4]. A systematic review of the literature allowed to identify a decrease in the use of health resources by 1/3 during the pandemic [5]. Further, medical appointments were reduced by 42 %, hospitalizations by 28 %, diagnostic tests by 31 %, and therapeutic interventions by 30 % [5].

There was a drop in the healthcare provision services of the Portuguese National Health Service (NHS), with a reduction in the number of consultations, both in primary and in hospital health care, a decrease in the number of elective surgeries and a slowdown in disease screening programs [6]. It is expected that the provision in oncology care has been negatively affected by the pandemic in Portugal, as in other countries. In the United States of America (USA) there was a reduction in cancer screenings, along with an increase in cancer mortality [7]. An increase in cancer deaths is expected in Canada until 2030 due to the decrease in oncology care activities during the pandemic [8].

This study aims to evaluate the impact of the COVID-19 pandemic on the oncological screening programs carried out in the Portuguese NHS, and to estimate consequences on breast, cervical, and colorectal cancer morbidity and mortality.