Explaining the Better Prognosis of Screening-Exposed Breast Cancers: Influence of Tumor Characteristics and Treatment

Recovery of the breast screening programme following pandemic-related delays: Should we focus on round length or uptake?

OBJECTIVES

The NHS Breast Screening programme is recovering from the hiatus in screening in 2020 due to the COVID-19 pandemic. Currently, open rather than timed invitations are issued, which leads to lower uptake but more rapid coverage of the eligible population by invitation and therefore closer adherence to a round length of 3 years. We aimed to estimate the likely effect on numbers of cancers detected at incident screens of a range of round lengths and uptake rates.

METHODS

We assumed exponential distributions of time to incidence of preclinical screen-detectable cancer and of time to progression thereafter to symptomatic clinical disease. We derived numerical values of these, along with screening sensitivity, from published research results and statistics from the NHS Breast Screening programme. These were used to calculate numbers of cancers detected at incident screens at ages 51-70 by round length and uptake rates.

RESULTS

We found that in a homogeneous population of cancers, a 4-year round length with uptake of 62%, as observed with timed appointments in London before the pandemic, would result in 295 cancers screen detected per 10,000 invited, compared to 222 cancers with a 3-year round and uptake of 46%, as observed in London during the recovery period. Similar results were found when we posited two populations, one of rapidly progressing and one of slowly progressing cancers.

CONCLUSIONS

It may be more productive in terms of early detection to focus on uptake rather than round length in the programme's recovery from the pandemic.

Impact of Barrett oesophagus diagnoses and endoscopies on oesophageal cancer survival in the UK: A cohort study

BACKGROUND

Current guidelines recommend endoscopic surveillance for Barrett oesophagus (BE), but the value of surveillance is still debated. Using a combination of primary care, secondary care and cancer registry datasets, we examined the impact of a prior BE diagnosis, clinical and risk factors on survival from oesophageal cancer and adenocarcinoma.

METHODS

Retrospective cohort study of patients aged 50 and above diagnosed with malignant oesophageal cancer between 1993 and 2014 using Clinical Practice Research Datalink (CPRD). All prior BE diagnoses and endoscopies were identified from CPRD and Hospital Episode Statistics. Histology information was obtained from linked cancer registry data. We used flexible parametric models to estimate excess hazard ratios (EHRs) for relative survival. We simulated the potential impact of lead-time by adding random lead-times from a variety of distributions to all those with prior BE.

RESULTS

Among our oesophageal cancer (n = 7503) and adenocarcinoma (n = 1476) cohorts only small percentages, 3.4% and 5.3%, respectively, had a prior BE diagnosis. Two-year relative survival was better among patients with BE: 48.0% (95% CI 41.9-54.9) compared to 25.2% (24.3-26.2) without. Patients with BE had a better prognosis (EHR = 0.53, 0.41-0.68). Survival was higher even if patients with BE had fewer than two endoscopies (50.0%; 43.6-57.3). A survival benefit was still observed after lead-time adjustment, with a 20% absolute difference in 2-year survival using a 5 year mean sojourn time.

CONCLUSIONS

Patients with a prior BE diagnosis had a survival advantage. This was not fully explained by surveillance endoscopies.

Beneficial Effect of Consecutive Screening Mammography Examinations on Mortality from Breast Cancer: A Prospective Study

Background Previously, the risk of death from breast cancer was analyzed for women participating versus those not participating in the last screening examination before breast cancer diagnosis. Consecutive attendance patterns may further refine estimates. Purpose To estimate the effect of participation in successive mammographic screening examinations on breast cancer mortality. Materials and Methods Participation data for Swedish women eligible for screening mammography in nine counties from 1992 to 2016 were linked with data from registries and regional cancer centers for breast cancer diagnosis, cause, and date of death (Uppsala University ethics committee registration number: 2017/147). Incidence-based breast cancer mortality was calculated by whether the women had participated in the most recent screening examination prior to diagnosis only (intermittent participants), the penultimate screening examination only (lapsed participants), both examinations (serial participants), or neither examination (serial nonparticipants). Rates were analyzed with Poisson regression. We also analyzed incidence of breast cancers proving fatal within 10 years. Results Data were available for a total average population of 549 091 women (average age, 58.9 years ± 6.7 [standard deviation]). The numbers of participants in the four groups were as follows: serial participants, 392 135; intermittent participants, 41 746; lapsed participants, 30 945; and serial nonparticipants, 84 265. Serial participants had a 49% lower risk of breast cancer mortality (relative risk [RR], 0.51; 95% CI: 0.48, 0.55; P < .001) and a 50% lower risk of death from breast cancer within 10 years of diagnosis (RR, 0.50; 95% CI: 0.46, 0.55; P < .001) than serial nonparticipants. Lapsed and intermittent participants had a smaller reduction. Serial participants had significantly lower risk of both outcomes than lapsed or intermittent participants. Analyses correcting for potential biases made little difference to the results. Conclusion Women participating in the last two breast cancer screening examinations prior to breast cancer diagnosis had the largest reduction in breast cancer death. Missing either one of the last two examinations conferred a significantly higher risk. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Stephen A. Feig in this issue.

A case-control study to evaluate the impact of the breast screening programme on mortality in England

BACKGROUND

Over the past 30 years since the implementation of the National Health Service Breast Screening Programme, improvements in diagnostic techniques and treatments have led to the need for an up-to-date evaluation of its benefit on risk of death from breast cancer. An initial pilot case-control study in London indicated that attending mammography screening led to a mortality reduction of 39%.

METHODS

Based on the same study protocol, an England-wide study was set up. Women aged 47-89 years who died of primary breast cancer in 2010 or 2011 were selected as cases (8288 cases). When possible, two controls were selected per case (15,202 controls) and were matched by date of birth and screening area.

RESULTS

Conditional logistic regressions showed a 38% reduction in breast cancer mortality after correcting for self-selection bias (OR 0.62, 95% CI 0.56-0.69) for women being screened at least once. Secondary analyses by age group, and time between last screen and breast cancer diagnosis were also performed.

CONCLUSIONS

According to this England-wide case-control study, mammography screening still plays an important role in lowering the risk of dying from breast cancer. Women aged 65 or over see a stronger and longer lasting benefit of screening compared to younger women.

Breast cancer distant recurrence lead time interval by detection method in an institutional cohort

BACKGROUND

Lead time, the interval between screen detection and when a disease would have become clinically evident, has been cited to explain longer survival times in mammography detected breast cancer cases (BC).

METHODS

An institutional retrospective cohort study of BC outcomes related to detection method (mammography (MamD) vs. patient (PtD)). Cases were first primary invasive stage I-III BC, age 40-74 years (n = 6603), 1999-2016. Survival time was divided into 1) distant disease-free interval (DDFI) and 2) distant disease-specific survival (DDSS) as two separate time interval outcomes. We measured statistical association between detection method and diagnostic, treatment and outcome variables using bivariate comparisons, Cox proportional hazards analyses and mean comparisons. Outcomes were distant recurrence (n = 422), DDFI and DDSS.

RESULTS

39% of cases were PtD (n = 2566) and 61% were MamD (n = 4037). MamD cases had a higher percentage of Stage I tumors [MamD 69% stage I vs. PtD 31%, p < .001]. Rate of distant recurrence was 11% among PtD BC cases (n = 289) vs. 3% of MamD (n = 133) (p < .001). Order of factor entry into the distant recurrence time interval (DDFI) model was 1) TNM stage (p < .001), 2) HR/HER2 status (p < .001), 3) histologic grade (p = .005) and 4) detection method (p < .001). Unadjusted PtD DDFI mean time was 4.34 years and MamD 5.52 years (p < .001), however when stratified by stage, the most significant factor relative to distant recurrence, there was no significant difference between PtD and MamD BC. Distant disease specific survival time did not differ by detection method.

CONCLUSION

We observed breast cancer distant disease-free interval to be primarily associated with stage at diagnosis and tumor characteristics with less contribution of detection method to the full model. Patient and mammography detected breast cancer mean lead time to distant recurrence differed significantly by detection method for all stages but not significantly within stage with no difference in time from distant recurrence to death. Lead time difference related to detection method appears to be present but may be less influential than other factors in distant disease-free and disease specific survival.

Evidence for reducing cancer-specific mortality due to screening for breast cancer in Europe: A systematic review

BACKGROUND

The aim of this study was to quantify the impact of organised mammography screening on breast cancer mortality across European regions. Therefore, a systematic review was performed including different types of studies from all European regions and stringently used clearly defined quality appraisal to summarise the best evidence.

METHODS

Six databases were searched including Embase, Medline and Web of Science from inception to March 2018. To identify all eligible studies which assessed the effect of organised screening on breast cancer mortality, two reviewers independently applied predefined inclusion and exclusion criteria. Original studies in English with a minimum follow-up of five years that were randomised controlled trials (RCTs) or observational studies were included. The Cochrane risk of bias instrument and the Newcastle-Ottawa Scale were used to assess the risk of bias.

RESULTS

Of the 5015 references initially retrieved, 60 were included in the final analysis. Those comprised 36 cohort studies, 17 case-control studies and 7 RCTs. None were from Eastern Europe. The quality of the included studies varied: Nineteen of these studies were of very good or good quality. Of those, the reduction in breast cancer mortality in attenders versus non-attenders ranged between 33% and 43% (Northern Europe), 43%-45% (Southern Europe) and 12%-58% (Western Europe). The estimates ranged between 4% and 31% in invited versus non-invited.

CONCLUSION

This systematic review provides evidence that organised screening reduces breast cancer mortality in all European regions where screening was implemented and monitored, while quantification is still lacking for Eastern Europe. The wide range of estimates indicates large differences in the evaluation designs between studies, rather than in the effectiveness of screening.

Downregulated circulating microRNAs after surgery: potential noninvasive biomarkers for diagnosis and prognosis of early breast cancer

Success in curing breast cancer largely depends on the stage at diagnosis. Circulating microRNAs are becoming a promising noninvasive biomarker. We postulate that a postoperative decline in circulating microRNAs might have diagnostic and prognostic value. Applying high-throughput microarrays, we screened the dysregulated microRNAs in paired serum samples before and after surgery. The relative concentrations of putative markers between the early breast cancer and cancer-free groups were evaluated in the training set and verified in the validation set. Sensitivity, specificity, and receiver operating characteristic (ROC) curves were used to assess diagnostic value. Survival analysis was performed using Kaplan–Meier estimates and a Cox proportional hazards model. Five microRNAs significantly reduced after surgery were selected for the training set. We found that miR-130b-5p, miR-151a-5p, miR-206, and miR-222-3p were significantly higher in the breast cancer group. Each of the four microRNAs had potential diagnostic value. The combined four microRNAs (training set: area under the curve (AUC) 0.8457; validation set: AUC 0.9309) had better diagnostic value than each single microRNA. MiR-222-3p was an independent prognostic factor for disease-free survival (HR = 13.19; 95% CI, 1.06–163.59; P = 0.045). Patients with no fewer than three highly expressed miRNAs had shorter DFS than patients with 0–2 highly expressed miRNAs (HR = 2.293; 95% CI, 1.128–0.662; P = 0.022). Our findings indicate that postoperatively downregulated circulating miR-130b-5p, miR-151a-5p, miR-206, and miR-222-3p may be potential biomarkers for breast cancer diagnosis and prognosis.

Screening Patterns and Mortality Differences in Patients With Lung Cancer at an Urban Underserved Community

BACKGROUND

The landmark National Lung Screening Trial demonstrated significant reduction in lung cancer-related mortality. However, European lung cancer screening (LCS) trials have not confirmed such benefit. We examined LCS patterns and determined the impact of LCS-led diagnosis on the mortality of newly diagnosed patients with lung cancer in an underserved community.

PATIENTS AND METHODS

Medical records of patients diagnosed with primary lung cancer in 2013 through 2016 (n = 855) were reviewed for primary care provider (PCP) status and LCS eligibility and completion, determined using United States Preventative Services Task Force guidelines. Univariate analyses of patient characteristics were conducted between LCS-eligible patients based on screening completion. Survival analyses were conducted using Kaplan-Meier and multivariate Cox regression.

RESULTS

In 2013 through 2016, 175 patients with primary lung cancer had an established PCP and were eligible for LCS. Among them, 19% (33/175) completed screening prior to diagnosis. LCS completion was associated with younger age (P = .02), active smoking status (P < .01), earlier stage at time of diagnosis (P < .01), follow-up in-network cancer treatment (P = .03), and surgical management (P < .01). LCS-eligible patients who underwent screening had improved all-cause mortality compared with those not screened (P < .01). Multivariate regression showed surgery (hazard ratio, 0.31; P = .04) significantly affected mortality.

CONCLUSION

To our knowledge, this is the first study to assess LCS patterns and mortality differences on patients with screen-detected lung cancer in an urban underserved setting since the inception of United States Preventative Services Task Force guidelines. Patients with a LCS-led diagnosis had improved mortality, likely owing to cancer detection at earlier stages with curative treatment, which echoes the finding of prospective trials.

Short- and Long-Term (10-year) Results of an Organized, Population-Based Breast Cancer Screening Program: Comparative, Observational Study from Hungary

BACKGROUND

A nationwide breast cancer screening program was introduced in Hungary in the year 2002 for women aged 45-65 years to be performed biannually.

METHODS

To investigate and report the short-term and 10-year follow-up results, we analyzed our Breast Unit's prospectively led database of screened (Group A) and age-matched symptomatic (Group B) patients from 2002 to 2007. We compared the clinicopathologic features of tumors and the impact of screening on surgical treatment, as well as the overall (OS), disease-specific (DSS) and disease-free survival (DFS) of different groups.

RESULTS

Data from 208 screen-detected and 101 symptomatic patients between 45 and 65 years of age were examined. Screen-detected women were younger (54 vs. 58.5 years; p = 0.001) had significantly smaller tumors (15.5 vs. 17 mm; p = 0.044), and more breast-conserving surgery (68.8 vs. 59.4%; p = 0.032). Survival statistics were not statistically different at the median follow-up of 123 months; however, there was a trend toward improved DFS in Group A (82.7 vs. 74.3%; p = 0.074).

CONCLUSIONS

Our study showed a significant reduction in rates of mastectomy in the screen-detected group in the short term, which does not translate into better survival rates based on initial long-term data. In order to realize the real advantage of this newly enstated screening program, a longer period of investigation is needed.