Optimizing the colorectal cancer screening programme using faecal immunochemical test (FIT) in Flanders, Belgium from the “interval cancer” perspective

Background Interval cancer (IC) is a critical issue in colorectal cancer (CRC) screening. We identified factors associated with ICs after faecal immunochemical test (FIT) screening and explored the impact of lowering FIT cut-off or shortening screening interval on FIT-ICs in Flanders. Methods FIT participants diagnosed with a CRC during 2013–2018 were included. Factors associated with FIT-ICs were identified using logistic regression. Distributions of FIT results among FIT-ICs were examined. Results In total, 10,122 screen-detected CRCs and 1534 FIT-ICs were included (FIT-IC proportion of 13%). FIT-ICs occurred more frequently in women (OR 1.58 [95% CI 1.41–1.76]) and ages 70–74 (OR 1.35 [1.14–1.59]). FIT-ICs were more often right-sided (OR 3.53 [2.98–4.20]), advanced stage (stage IV: OR 7.15 [5.76–8.88]), and high grade (poorly/undifferentiated: OR 2.57 [2.08–3.18]). The majority (83–92%) of FIT-ICs would still be missed if FIT cut-off was lowered from 15 to 10 µg Hb/g or screening interval was shortened from 2 to 1 year. Conclusions FIT-ICs were more common in women, older age, right-sided location, advanced stage and high grade. In Flanders, lowering FIT cut-off (to 10 µg Hb/g) or shortening screening interval (to 1 year) would have a minimal impact on FIT-ICs.

Comparison of Mammography Artificial Intelligence Algorithms for 5-year Breast Cancer Risk Prediction

PURPOSE: To examine the ability of 5 artificial intelligence (AI)-based computer vision algorithms, most trained to detect visible breast cancer on mammograms, to predict future risk relative to the Breast Cancer Surveillance Consortium clinical risk prediction model (BCSC v2). PATIENTS AND METHODS: In this case-cohort study, women who had a screening mammogram in 2016 at Kaiser Permanente Northern California with no evidence of cancer on final imaging assessment were followed through September 2021. Women with prior breast cancer or a known highly penetrant gene mutation were excluded. From the 329,814 total eligible women, a random subcohort of 13,881 women (4.2%) were selected, of whom 197 had incident cancer. All 4,475 additional incident cancers were also included. Continuous AI-predicted scores were generated from the index 2016 mammogram. Risk estimates were generated with the Kaplan-Meier method and time-varying area under the curve [AUC(t)]. RESULTS: For incident cancers at 0-1 year (interval cancer risk), BCSC demonstrated an AUC(t) of 0.62 (95% CI, 0.58-0.66), and the AI algorithms had AUC(t)s ranging from 0.66-0.71, all significantly higher than BCSC (P < .05). For incident cancers at 1 to 5 years (5-year future cancer risk), BCSC demonstrated an AUC(t) of 0.61 (95% CI, 0.60-0.62), and the AI algorithms had AUC(t)s ranging from 0.63 to 0.67, all significantly higher than BCSC. Combined BCSC and AI models demonstrated AUC(t)s for interval cancer risk of 0.67-0.73 and for 5-year future cancer risk of 0.66-0.68. CONCLUSION: The AI mammography algorithms we evaluated had significantly higher discrimination than the BCSC clinical risk model for interval and 5-year future cancer risk. Combined AI and BCSC models had slightly higher discrimination than AI alone.

Association of Regular Endoscopic Screening with Interval Gastric Cancer Incidence in the National Cancer Screening Program

Although regular endoscopic screening may help in early detection of gastric cancer, interval cancer remains a problem in the screening program. This study evaluated the association between regular endoscopic screening and interval cancer detection in the Korean National Cancer Screening Program (KNCSP). We defined three groups (regularly, irregularly, and not screened) according to the screening interval, and the trends in the interval cancer rate (ICR) between the groups were tested using the Cochran–Armitage test. The influence of regular endoscopic screening on the risk of interval cancer was evaluated using multivariable logistic regression. Among the 11,642,410 participants who underwent endoscopy, the overall ICR was 0.36 per 1000 negative screenings. The ICR of the not screened group (0.41) was the highest among the three groups and the risk of interval cancer in this group was 1.68 times higher (p < 0.001) than that in the regularly screened group. Women in their 40s who had regular screening with no history of intestinal metaplasia and gastric polyps would have the lowest probability of having interval cancer (0.005%). Regular participation in endoscopic screening programs for reducing the risk of interval cancer may help to improve the quality of screening programs.

Interval cancer audit and disclosure in cervical screening programmes: An international survey

Background Legal cases involving the National Cervical Screening Programme in Ireland following non-disclosure of an interval cervical cancer audit prompted this first international comparative survey of interval cervical cancer audit. Methods A survey of 22 international population-based cervical screening programmes was conducted, to determine if they undertook audit of invasive cervical cancers. Those countries/regions that perform reviews were asked (i) how the audit was undertaken, including how the reviews were performed and how they controlled for retrospective bias, (ii) how women are informed of the audit process and how their consent is obtained, and (iii) how audit results were disclosed to patients. Results Seventeen countries/regions invited completed the survey (77%); 65% (11/17) have an audit process for interval cervical cancers. Five perform individual patient reviews; three perform programme-wide review, with calculation of interval cancer detection rates; one routinely performs programme-wide review with calculation of interval cancer detection rates and offers individual reviews, and one routinely performs local hospital-level reviews. In the remaining country/region, hospital laboratories audit cancers, with a national audit process for all cervical cancers. Varying methodologies for retrospective cytology review were employed; four include control samples, with a ratio varying from 1:1 to 1:2. Three conduct a blinded review. Most countries/regions do not discuss interval cancer audit with participants and 3/11 (27.3%) inform women when a cervical cancer audit takes place. Disclosure is limited and variable. Conclusion The responses suggest that there is no consistent approach to audit of interval cervical cancers or to disclosure of audit results.

Validation of a new fully automated software for 2D digital mammographic breast density evaluation in predicting breast cancer risk

We compared accuracy for breast cancer (BC) risk stratification of a new fully automated system (DenSeeMammo—DSM) for breast density (BD) assessment to a non-inferiority threshold based on radiologists’ visual assessment. Pooled analysis was performed on 14,267 2D mammograms collected from women aged 48–55 years who underwent BC screening within three studies: RETomo, Florence study and PROCAS. BD was expressed through clinical Breast Imaging Reporting and Data System (BI-RADS) density classification. Women in BI-RADS D category had a 2.6 (95% CI 1.5–4.4) and a 3.6 (95% CI 1.4–9.3) times higher risk of incident and interval cancer, respectively, than women in the two lowest BD categories. The ability of DSM to predict risk of incident cancer was non-inferior to radiologists’ visual assessment as both point estimate and lower bound of 95% CI (AUC 0.589; 95% CI 0.580–0.597) were above the predefined visual assessment threshold (AUC 0.571). AUC for interval (AUC 0.631; 95% CI 0.623–0.639) cancers was even higher. BD assessed with new fully automated method is positively associated with BC risk and is not inferior to radiologists’ visual assessment. It is an even stronger marker of interval cancer, confirming an appreciable masking effect of BD that reduces mammography sensitivity.

EP.TU.660The rate of interval colorectal cancer within 5 years of a negative colonoscopy at a district general hospital

Aims Interval colorectal cancer is defined as cancer that has developed within a short interval of a diagnostic test that did not detect a cancer. Many authors define this interval as five years, though more complex definitions of interval cancer have been proposed. Our aim was to determine what percentage of colorectal cancers diagnosed at our hospital had a negative colonoscopy within the 5 years prior to their diagnosis. Methods We obtained details of all colorectal cancers diagnosed between 2017-2019 at our department. We then surveyed the endoscopy system to detect the patients who had a negative colonoscopy within the 5 years prior to their diagnosis, to calculate what percentage of cancers diagnosed within that period were interval cancers. Results Between 2017-2019, 539 patients were diagnosed with colorectal cancer. Age at diagnosis varied widely from 21 to 107, and 310 (57.5%) of patients were male. Seventeen patients had a negative colonoscopy within 5 years (though two of these were planned repeat procedures within a few months of the index ‘negative’ colonoscopy). We can therefore calculate the rate of interval cancer at 3.1% between 2017-2019. Conclusions The aetiology of interval colorectal cancer has been attributed to patient/tumour factors (right colon and female sex) and technical factors (adenoma detection and caecal intubation rate). Though the rate of interval cancer at our department seems pleasingly low compared to the literature, we plan to investigate the risk factors that might be at play: are biological factors to blame or can our endoscopy service be improved?

Association of retroperitoneal fibrosis with malignancy and its outcomes

Introduction Retroperitoneal fibrosis (RPF) is characterized by a highly fibrotic retroperitoneal mass and encompasses the idiopathic form and secondary to malignancies. Because we have limited knowledge whether RPF is associated with malignancy, we aimed to investigate the relationship between RPF and malignancy and to compare the characteristics and prognosis of cancers among patients with RPF. Methods Medical records of 111 patients diagnosed as having RPF were reviewed and 38 cases of cancer, confirmed by biopsy, were identified. Standardized incidence ratios (SIRs) were calculated for cancers and stratified according to cancer type and RPF-cancer diagnosis interval. Cancer characteristics and outcomes were compared between RPF-cancer diagnosis intervals. Results The average age at RPF diagnosis was 59.2 ± 15.0 years, and 69.4% of the patients were male. The cancer SIRs in patients with RPF relative to age- and sex-matched individuals in the general population was 2.2 (1.6–3.1). SIRs of renal pelvis cancer and multiple myeloma were significantly higher than in the general population. When stratified by RPF-cancer intervals, the SIR for cancer was 9.9 within 1 year of RPF diagnosis, while no significant increase in the SIR was found after 1 year from RPF diagnosis. Cancer stage was more advanced at the time of diagnosis in patients within a 1-year interval for RPF than those with cancer within a >5-year interval, with a correspondingly increased mortality in the former patients. Conclusions RPF was significantly associated with malignancy, particularly those diagnosed within 1 year of RPF diagnosis. Cancer stages at diagnosis were more advanced and the mortality rate was higher in patients within a 1-year interval between RPF and cancer diagnosis than in those with a >5-year interval between diagnoses.

Diagnostic accuracy of a novel artificial intelligence system for adenoma detection in daily practice: a prospective non-randomized comparative study

Background and Aims: Adenoma detection rate (ADR) varies significantly between endoscopists with up to 26% adenoma miss rate (AMR). Artificial intelligence (AI) systems may improve endoscopic quality and reduce the rate of interval cancer. We evaluated the efficacy of an AI system in real time colonoscopy and its influence on the AMR and the ADR. Patients and methods: In this prospective non-randomized comparative study we analyzed 150 patients (age 65±14, 69 women, 81 men) undergoing diagnostic colonoscopy at a single endoscopy center in Germany from June to October 2020. Every patient was examined concurrently by an endoscopist and AI using two opposing screens. The AI system GI Genius (Medtronic), overseen by a second observer, was not visible to the endoscopist. AMR was the primary outcome. Both methods were compared by the McNemar Test. Results: There was no significant and no clinically relevant difference (p=0.754) in AMR between the AI system (6/197, 3.0%, 95%CI [1.1-6.5]) and routine colonoscopy (4/197, 2.0%, 95%CI [0.6-5.1]). The polyp miss rate of the AI system (14/311, 4.5%, 95%CI [2.5-7.4]) was not significantly different (p=0.720) from routine colonoscopy (17/311, 5.5%, 95%CI [3.2-8.6]). There was no significant difference (p=0.500) between the ADR with routine colonoscopy (78/150, 52.0%, 95%CI [43.7-60.2]) and the AI system (76/150, 50.7%, 95%CI [42.4-58.9]). Routine colonoscopy detected adenomas in two patients that were missed by the AI system. Conclusion: The AI system had a comparable performance to experienced endoscopists during real-time colonoscopy with similar high ADR (>50%).