Cancer survival in the northwestern of Sao ˜ Paulo State, Brazil: A population-based study

Background

Cancer is the world’s leading public health problem, and is among the four leading causes of premature death (before 70 years of age) in most countries. In the future, the cancer burden is expected to rise by approximately 30 million in 2040 (excluding non-melanoma skin cancer cases) compared to the 19 million estimated in 2020 [1] . The increase in cancer incidence and mortality is driven by aging, population growth, and changing distribution of risk factors, especially those associated with socioeconomic development. Therefore, it is expected that a rising cancer burden will occur mainly in middle-income countries [1] .

In Brazil, the Ministry of Health mandated the National Cancer Institute (INCA) to estimate the cancer burden in the country and reported that between 2023 and 2025, approximately 704,000 new cases of cancer will be diagnosed annually. Cancer is the second leading cause of death in many regions of Brazil after cardiovascular disease [2] . Despite advances in medical technology, there has been a steady increase in cancer incidence every year [3] . Prevention is essential; however, its implementation and adoption have been slow and insufficient in many countries, including Brazil. A double-edged strategy is needed to reduce cancer mortality, focusing on prevention to reduce cancer incidence and improving early detection and care to increase cancer survival [4] .

Since the mid-20th century, survival has improved at many cancer sites [5] . Survival estimates are becoming increasingly relevant as life expectancy among individuals diagnosed with cancer increases and cancer treatment continues to improve [6] . As cancer patients survive longer, there is a need to produce information on prognosis to assess the effectiveness of the health system [7] .

Population-based cancer registries (PBCRs) collect, store, process, and analyze data, thereby generating cancer burden information [89] . Population-based cancer survival can help guide national policies and ultimately improve the survival of the population by impacting the health system and treatment guidelines, ensuring equality and equity, and forming effective national cancer plans [10] .

Brazil has high-quality regional PBCRs (approximately 31) with an estimated coverage of approximately 20 % of the population. However, not all PBCRs can provide sufficiently robust follow-up data for survival analyses [11] . The PBCR of the Barretos Region (PBCR-Barretos) is managed by a reference institution in cancer care (Hospital de Cancer de Barretos, São Paulo, Brazil), and the institutional hospital-based cancer registry is the major notification source, which ensures data quality, especially for clinical staging and patient follow-up (status at last contact). Therefore, PBCR-Barretos being one of the few Brazilian PBCRs with the possibility of supplying survival data, this study aimed to provide long-term survival estimates among patients diagnosed with cancer in the region of Barretos (São Paulo State, Brazil).