Background: Electronic health records are becoming an increasingly valuable resource for epidemiology but their data quality needs to be quantified. We aimed to validate twenty-five types of incident cancer cases in the Information System for Research in Primary Care (SIDIAP) in Catalonia with the population-based cancer registries of Girona and Tarragona as the gold-standard. Methods: We calculated the sensitivity, positive predictive values (PPV), and the time-difference between the date of diagnosis entered into the SIDIAP and into the registries. We added hospital discharge cancer diagnoses to the SIDIAP to assess sensitivity changes. Results: We identified 27,046 incident cancer diagnoses in the SIDIAP from 2009–2015 among the 949,841 residents of Girona and Tarragona. The cancer types with the highest sensitivity were breast (89%, 95% CI: 88–90%), colorectal (81%, 95% CI: 80–82%), and prostate (81%, 95% CI: 80–83%). Trachea, bronchus and lung cancers had the highest PPV (76%, 95% CI: 74%-78%) followed by stomach (72%, 95% CI: 68–75%) and pancreas (71%, 95% CI: 67–75%). Most cancer diagnoses were reported with less than three months of difference between the SIDIAP and the registries. More cases were registered first in the registries than in the SIDIAP. By adding cancer diagnoses based on hospital discharge data, sensitivity increased for all cancers, especially for gallbladder and biliary tract for which the sensitivity increased by 21%. Conclusion: The SIDIAP includes 76% of the cancer diagnoses in the cancer registries but includes a considerable number of cases that are not in the registries. The SIDIAP reports most of the cancer diagnoses within a three-month period difference from the date of diagnosis in the cancer registries. Our results support the use of the SIDIAP cancer diagnoses for epidemiological research when cancer is the outcome of interest. We recommend adding hospital discharge data to the SIDIAP to increase data quality, particularly for less frequent cancer types.

To describe colorectal cancer (CRC) mortality trends during 1985–2004 and to estimate CRC mortality projections for the period 2005–2019 in Spain. A Bayesian age-period-cohort analysis has been carried out to investigate the effect of the age, period, and birth cohort on CRC mortality in Spain. Mortality projections until 2019 were based on the age-period-cohort model. During 1985–1994, CRC mortality increased in both sexes (3.9% yearly in men and 1.5% in women). After 1995, CRC mortality increased in men (1.6%) and leveled off in women (−0.6%). Colon cancer mortality increased for the whole period in men, this increase being lower in the second decade (1985–1994: 5.0%; 1995–2004: 1.8%). In women, colon cancer mortality increased in the first decade (2.8%) and leveled off during the second decade (−0.1%). Rectal cancer mortality increased in men (1.2%) and decreased in women (−1.1%) during the whole study period. Projections showed an increase in the number of CRC deaths in men older than 60 years and a level off in women. Although mass screening for CRC in Spain has not been available, the favorable recent changes in CRC mortality trends observed after 1995 could be related to progress in diagnosis and treatment. The projected number of deaths could be used as reference scenario for assessing future impact of new treatments as well as the potential impact of future population-based screening when introduced.

This study aimed to estimate potential undetected cancers over the first 2 years of the COVID-19 pandemic in Catalonia. Cancer incidence was compared between pre-pandemic (2019) and pandemic (March 2020-January 2022) periods in the Catalan Pathology Registry (CPR) according to sex, age, and tumor site. The correlation between cancer diagnosis and COVID-19 health care workload was also evaluated by means of the Pearson's correlation coefficient (R). The expected incident cancers (E) during the pandemic were estimated by applying 2019 CPR cancer incidence specific rates by sex and 5-year age groups to the 2020 and 2021 Catalan population pyramids. CPR incident cancers were considered observed (O). Standardized incidence ratios (SIR) and 95% confidence intervals (CIs) were calculated using the O/E ratio. After two pandemic years, cancer diagnosis decreased by 12% (SIR 0.88, 95% CI 0.87-0.89), or ∼7700 undetected cancers (13 000 with nonmelanoma skin cancer). Without nonmelanoma skin cancer, 72% of the cancer underdiagnosis was generated in 2020. Diagnoses decreased more in men (whole pandemic −14%; 2020 −21%; 2021 −8%) than in women (−9%, −19%, −3%, respectively), dropping significantly overall in all pandemic waves but the fifth (first −37%, second −16%, third −8%, fourth −6%, fifth −2%, sixth −6%), and across all adult age groups. In the first wave, CPR cancer diagnosis was inversely correlated with COVID-19 caseload in primary care (R −0.91, 95% CI −0.97 to −0.75) and occupancy in conventional hospital wards (R −0.91, 95% CI −0.99 to −0.48) and intensive care (R −0.91, 95% CI 95% −0.98 to −0.70). Our study evaluated the overall pandemic impact on cancer diagnosis on a large scale and with minimal selection bias, showing that as of February 2022, cancer detection in Catalonia had not yet recovered to pre-pandemic levels. Pending cancer incidence data from population-based cancer registries, early CPR data could inform the development of Spanish cancer control plans.

Breast cancer (BC) is the most frequent cancer in women, accounting for 28% of all tumors among women in Catalonia (Spain). Mastectomy has been replaced over time by breast-conserving surgery (BCS) although not as rapidly as might be expected. The aim of this study was to assess the evolution of surgical procedures in incident BC cases in Catalonia between 2005 and 2011, and to analyze variations based on patient and hospital characteristics. We processed data from the Catalonian Health Service’s Acute Hospital Discharge database (HDD) using ASEDAT software (Analysis, Selection and Extraction of Tumor Data) to identify all invasive BC incident cases according to the codes 174.0-174.9 of the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) that were attended for the one-year periods in 2005, 2008 and 2011. Patients were classified according to surgical procedures (BCS vs mastectomy, and immediate vs delayed reconstruction), and results were compared among periods according to age, stage, comorbidity and hospital level. BC surgical procedures were performed in more than 80% of patients. Surgical cases showed a significant increasing trend in the proportion of women aged 50–69 years, more advanced disease stages, higher comorbidity and they were attended in hospitals of less complexity level throughout the study period. Similar pattern was found for patients treated with BCS, which increased significantly from 67.9% in 2005 to 74.0% in 2011. Simple lymph node removal increased significantly (from 48.8% to 71.4% and from 63.6% to 67.8% for 2005 and 2011 in conservative and radical surgery, respectively). A slightly increase in the proportion of mastectomized young women (from 28% in 2005 to 34% in 2011) was detected, due to multiple factors. About 22% of women underwent post-mastectomy breast reconstruction, this being mostly immediate. The use of HDD linked to the ASEDAT allowed us to evaluate BC surgical treatment in Catalonia. A consolidating increasing trend of BCS was observed in women aged 50–69 years, which corresponds with the pattern in most European countries. Among the mastectomized patients, immediate breast reconstructions have risen significantly over the period 2005–2011.

Analysing the observed differences for incidence or mortality of a particular disease between two different situations (such as time points, geographical areas, gender or other social characteristics) can be useful both for scientific or administrative purposes. From an epidemiological and public health point of view, it is of great interest to assess the effect of demographic factors in these observed differences in order to elucidate the effect of the risk of developing a disease or dying from it. The method proposed by Bashir and Estève, which splits the observed variation into three components: risk, population structure and population size is a common choice at practice.