Interval Cancer in Population-Based Colorectal Screening Programmes: Incidence and Characteristics of Tumours.

The objective of this study is to evaluate interval cancer (IC) in colorectal cancer (CRC) screening, which is CRC diagnosed in an individual after having received a negative faecal occult blood test and before the next invitation to participate in screening. A follow-up study was conducted on a cohort of participants in the first three screening rounds of four colorectal cancer screening programmes in Spain, n = 664,993. A total of 321 ICs and 2120 screen-detected cancers (SCs) were found. The IC and SC rates were calculated for each guaiac (gFOBT) or immunochemical (FIT) test. A Cox regression model was used to estimate the hazard ratios (HR) of IC risk factors. A nested case-control study was carried out to compare IC and SC tumour characteristics. The IC rate was 1.16‱ with the gFOBT and 0.35‱ with the FIT. Men and people aged 60-69 showed an increased probability of IC (HR = 1.81 and HR = 1.95, respectively). There was a decreased probability of IC in individuals who regularly participated in screening, HR = 0.62 (0.47-0.82). IC risk gradually rose as the amount of Hb detected in the FIT increased. IC tumours were in more advanced stages and of a larger size than SC tumours, and they were mostly located in the cecum. These results may play a key role in future strategies for screening programmes, reducing IC incidence.

Optimal cut-off value for detecting colorectal cancer with fecal immunochemical tests according to age and sex.

In the fecal immunological test, a suitable cut-off value may be selected to classify results as either positive or negative. Our aim is to estimate the optimal cut-off value for detecting colorectal cancer in different age and sex groups. This is a multicentric retrospective cohort study of participants in CRC screening programs with FIT between 2006 and 2012. A total of 545,505 participations were analyzed. Cancers diagnosed outside of the program were identified after a negative test result (IC_test) up until 2014. The Wilcoxon test was used to compare fecal hemoglobin levels. ROC curves were used to identify the optimal cut-off value for each age and sex group. Screening program results were estimated for different cut-off values. The results show that the Hb concentration was higher in colorectal cancer (average = 179.6µg/g) vs. false positives (average = 55.2µg/g), in IC_test (average = 3.1µg/g) vs. true negatives (average = 0µg/g), and in men (average = 166.2µg/g) vs. women (average = 140.2µg/g) with colorectal cancer. The optimal cut-off values for women were 18.3µg/g (50-59y) and 14.6µg/g (60-69y), and 16.8µg/g (50-59y) and 19.9µg/g (60-69y) for men. Using different cut-off values for each age and sex group lead to a decrease in the IC_test rate compared to the 20µg/g cut-off value (from 0.40‰ to 0.37‰) and an increase in the false positive rate (from 6.45% to 6.99%). Moreover, test sensitivity improved (90.7%), especially in men and women aged 50-59y (89.4%; 90%) and women aged 60-69y (90.2%). In conclusion, the optimal cut-off value varies for different sex and age groups and the use of an optimal cut-off value for each group improves sensitivity and leads to a small decrease in IC_tests, but also to a larger increase in false positives.

Factors that Influence Treatment Delay for Patients with Breast Cancer.

INTRODUCTION: The diagnosis or treatment of breast cancer is sometimes delayed. A lengthy delay may have a negative psychological impact on patients. The aim of our study was to evaluate the sociodemographic, clinical and pathological factors associated with delay in the provision of surgical treatment for localised breast cancer, in a prospective cohort of patients. METHODS: This observational, prospective, multicentre study was conducted in ten hospitals belonging to the Spanish national public health system, located in four Autonomous Communities (regions). The study included 1236 patients, diagnosed through a screening programme or found to be symptomatic, between April 2013 and May 2015. The study variables analysed included each patient's personal history, care situation, tumour history and data on the surgical intervention, pathological anatomy, hospital admission and follow-up. Treatment delay was defined as more than 30 days elapsed between biopsy and surgery. RESULTS: Over half of the study population experienced surgical treatment delay. This delay was greater for patients with no formal education and among widows, persons not requiring assistance for usual activities, those experiencing anxiety or depression, those who had a high BMI or an above-average number of comorbidities, those who were symptomatic, who did not receive NMR spectroscopy, who presented a histology other than infiltrating ductal carcinoma or who had poorly differentiated carcinomas. CONCLUSIONS: Certain sociodemographic and clinical variables are associated with surgical treatment delay. This study identifies factors that influence surgical delays, highlighting the importance of preventing these factors and of raising awareness among the population at risk and among health personnel.

Risk factors for severe complications of colonoscopy in screening programs.

Severe complications (SC) in colonoscopy represent the most important adverse effect of colorectal cancer screening programs (CRCSP). The objective is to evaluate the risk factors for SC in colonoscopy indicated after a positive fecal occult blood test in population-based CRCSP. The SC (n = 161) identified from 48,730 diagnostic colonoscopies performed in a cohort of all the women and men invited from 2000 to 2012 in 6 CRCSP in Spain. A total of 318 controls were selected, matched for age, sex and period when the colonoscopy was performed. Conditional logistic regression models were estimated. The analysis was performed separately in groups: immediate-SC (same day of the colonoscopy); late-SC (between 1 and 30 days after); perforation; and bleeding events. SC occurred in 3.30‰ of colonoscopies. Prior colon disease showed a higher risk of SC (OR = 4.87). Regular antiplatelet treatment conferred a higher risk of overall SC (OR = 2.80) and late-SC (OR = 9.26), as did regular anticoagulant therapy (OR = 3.47, OR = 7.36). A history of pelvic-surgery or abdominal-radiotherapy was a risk factor for overall SC (OR = 5.03), immediate-SC (OR = 8.49), late-SC (OR = 4.65) and perforation (OR = 21.59). A finding of adenoma or cancer also showed a higher risk of overall SC (OR = 8.71), immediate-SC (OR = 12.67), late-SC (OR = 4.08), perforation (OR = 4.69) and bleeding (OR = 17.02). The risk of SC doesn't vary depending on the type of preparation or type of anesthesia. Knowing the clinical history of patients such as regular previous medication and history of surgery or radiotherapy, as well as the severity of the findings during the colonoscopy process could help to focus prevention measures in order to minimize SC in CRCSP.

Factors influencing participation in colorectal cancer screening programs in Spain.

To analyze the sociodemographic and organizational factors influencing participation in population-based colorectal cancer screening programs (CRCSP) in Spain, a retrospective study was conducted in a cohort of people invited to participate in the first 3 screening rounds of 6 CRCSP from 2000 to 2012. Mixed logistic regression models were used to analyze the relationship between sociodemographic and organizational factors, such as the type of fecal occult blood test (FOBT) used and the FOBT delivery type. The analysis was performed separately in groups (Initial screening-first invitation, Subsequent invitation for previous never-responders, Subsequent invitation-regular, Subsequent invitation-irregular intervals). The results showed that, in the Initial screening-first invitation group, participation was higher in women than in men in all age groups (OR 1.05 in persons aged 50-59years and OR 1.12 in those aged 60-69years). Participation was also higher when no action was required to receive the FOBT kit, independently of the type of screening (Initial screening-first invitation [OR 2.24], Subsequent invitation for previous never-responders [OR 2.14], Subsequent invitation-regular [OR 2.03], Subsequent invitation-irregular intervals [OR 9.38]) and when quantitative rather than qualitative immunological FOBT (FIT) was offered (Initial screening-first invitation [OR 0.70], Subsequent invitation for previous never-responders [OR 0.12], Subsequent invitation-regular [OR 0.20]) or guaiac testing (Initial screening-first invitation [OR 0.81], Subsequent invitation for previous never-responders [OR 0.88], Subsequent invitation-regular [OR 0.73]). In conclusion, the results of this study show that screening participation could be enhanced by inclusion of the FOBT kit with the screening invitation and the use of the quantitative FIT.

Trends in detection of invasive cancer and ductal carcinoma in situ at biennial screening mammography in Spain: a retrospective cohort study.

BACKGROUND: Breast cancer incidence has decreased in the last decade, while the incidence of ductal carcinoma in situ (DCIS) has increased substantially in the western world. The phenomenon has been attributed to the widespread adaption of screening mammography. The aim of the study was to evaluate the temporal trends in the rates of screen detected invasive cancers and DCIS, and to compare the observed trends with respect to hormone replacement therapy (HRT) use along the same study period. METHODS: Retrospective cohort study of 1,564,080 women aged 45-69 years who underwent 4,705,681 screening mammograms from 1992 to 2006. Age-adjusted rates of screen detected invasive cancer, DCIS, and HRT use were calculated for first and subsequent screenings. Poisson regression was used to evaluate the existence of a change-point in trend, and to estimate the adjusted trends in screen detected invasive breast cancer and DCIS over the study period. RESULTS: The rates of screen detected invasive cancer per 100.000 screened women were 394.0 at first screening, and 229.9 at subsequent screen. The rates of screen detected DCIS per 100.000 screened women were 66.8 at first screen and 43.9 at subsequent screens. No evidence of a change point in trend in the rates of DCIS and invasive cancers over the study period were found. Screen detected DCIS increased at a steady 2.5% per year (95% CI: 1.3; 3.8), while invasive cancers were stable. CONCLUSION: Despite the observed decrease in breast cancer incidence in the population, the rates of screen detected invasive cancer remained stable during the study period. The proportion of DCIS among screen detected breast malignancies increased from 13% to 17% throughout the study period. The rates of screen detected invasive cancer and DCIS were independent of the decreasing trend in HRT use observed among screened women after 2002.