Reduction in rate of node metastases with breast screening: consistency of association with tumor size

Bahcesehir long-term population-based screening compared to National Breast Cancer Registry Data: effectiveness of screening in an emerging country

PURPOSE

We aimed to show the effects of long-term screening on clinical, pathologic, and survival outcomes in patients with screen-detected breast cancer and compare these findings with breast cancer patients registered in the National Breast Cancer Registry Data (NBCRD).

METHODS

Women aged 40-69 years, living in Bahcesehir county, Istanbul, Turkey, were screened every 2 years using bilateral mammography. The Bahcesehir National Breast Cancer Registry Data (BMSP) data were collected during a 10-year screening period (five rounds of screening). BMSP data were compared with the NBCRD regarding age, cancer stage, types of surgery, tumor size, lymph node status, molecular subtypes, and survival rates.

RESULTS

During the 10-year screening period, 8758 women were screened with 22621 mammograms. Breast cancer was detected in 130 patients; 51 (39.2%) were aged 40-49 years. The comparison of breast cancer patients in the two programs revealed that BMSP patients had earlier stages, higher breast-conserving surgery rates, smaller tumor size, more frequent negative axillary nodal status, lower histologic grade, and higher ductal carcinoma in situ rates than NBCRD patients (p = 0.001, for all).

CONCLUSION

These results indicate the feasibility of successful population-based screening in middle-income countries.

Rate of Re-excision after Breast-conserving Surgery for Invasive Lobular Carcinoma

Invasive lobular carcinoma (ILC) accounts for approximately 5 to 20 per cent of all breast cancers and is often multicentric. Despite pre- and intraoperative assessments to achieve negative margins, ILC is reported to be associated with higher rates of positive margin. This cross-sectional study examined patients with breast cancer treated at our institution from 2000 to 2010. The objective was to investigate the rate of re-excision resulting from positive or close margin (1 mm or less) in patients who underwent breast-conserving surgery (BCS) for ILC compared with invasive ductal carcinoma (IDC) and ductal carcinoma in situ (DCIS). Of the 836 patients treated, 416 patients underwent BCS. The rate of re-excision after BCS for ILC was 35.1 versus 17.7 per cent for IDC and 20.0 per cent for DCIS ( P = 0.04). Re-excisions were more often performed for positive margin in patients with ILC (11 of 37 [29.7%]) versus IDC (36 of 334 [10.8%]) and DCIS (five of 45 [11.1%];( P = 0.004). In this single-institution review, BCS for ILC had significantly higher rates of re-excision as a result of positive margins when compared with IDC and DCIS. Tumor size greater than 2 cm and lymph node involvement were identified as factors associated with positive surgical margin in ILC. The higher possibility of positive margins and the need for additional procedures should be discussed with patients undergoing BCS for ILC.

Mammography screening reduces rates of advanced and fatal breast cancers: Results in 549,091 women

BACKGROUND

It is of paramount importance to evaluate the impact of participation in organized mammography service screening independently from changes in breast cancer treatment. This can be done by measuring the incidence of fatal breast cancer, which is based on the date of diagnosis and not on the date of death.

METHODS

Among 549,091 women, covering approximately 30% of the Swedish screening-eligible population, the authors calculated the incidence rates of 2473 breast cancers that were fatal within 10 years after diagnosis and the incidence rates of 9737 advanced breast cancers. Data regarding each breast cancer diagnosis and the cause and date of death of each breast cancer case were gathered from national Swedish registries. Tumor characteristics were collected from regional cancer centers. Aggregated data concerning invitation and participation were provided by Sectra Medical Systems AB. Incidence rates were analyzed using Poisson regression.

RESULTS

Women who participated in mammography screening had a statistically significant 41% reduction in their risk of dying of breast cancer within 10 years (relative risk, 0.59; 95% CI, 0.51-0.68 [P < .001]) and a 25% reduction in the rate of advanced breast cancers (relative risk, 0.75; 95% CI, 0.66-0.84 [P < .001]).

CONCLUSIONS

Substantial reductions in the incidence rate of breast cancers that were fatal within 10 years after diagnosis and in the advanced breast cancer rate were found in this contemporaneous comparison of women participating versus those not participating in screening. These benefits appeared to be independent of recent changes in treatment regimens.

Systematic reviews as a 'lens of evidence': Determinants of benefits and harms of breast cancer screening

This systematic review, stimulated by inconsistency in secondary evidence, reports the benefits and harms of breast cancer (BC) screening and their determinants according to systematic reviews. A systematic search, which identified 9,976 abstracts, led to the inclusion of 58 reviews. BC mortality reduction with screening mammography was 15-25% in trials and 28-56% in observational studies in all age groups, and the risk of stage III+ cancers was reduced for women older than 49 years. Overdiagnosis due to mammography was 1-60% in trials and 1-12% in studies with a low risk of bias, and cumulative false-positive rates were lower with biennial than annual screening (3-17% vs 0.01-41%). There is no consistency in the reviews' conclusions about the magnitude of BC mortality reduction among women younger than 50 years or older than 69 years, or determinants of benefits and harms of mammography, including the type of mammography (digital vs screen-film), the number of views and the screening interval. Similarly, there was no solid evidence on determinants of benefits and harms or BC mortality reduction with screening by ultrasonography or clinical breast examination (sensitivity ranges, 54-84% and 47-69%, respectively), and strong evidence of unfavourable benefit-to-harm ratio with breast self-examination. The reviews' conclusions were not dependent on the quality of the reviews or publication date. Systematic reviews on mammography screening, mainly from high-income countries, systematically disagree on the interpretation of the benefit-to-harm ratio. Future reviews are unlikely to clarify the discrepancies unless new original studies are published.

The impact of mammography screening programmes on incidence of advanced breast cancer in Europe: a literature review

Background

Observational studies have reported conflicting results on the impact of mammography service screening programmes on the advanced breast cancer rate (ABCR), a correlation that was firmly established in randomized controlled trials. We reviewed and summarized studies of the effect of service screening programmes in the European Union on ABCR and discussed their limitations.

Methods

The PubMed database was searched for English language studies published between 01-01-2000 and 01–06-2018. After inspection of titles and abstracts, 220 of the 8644 potentially eligible papers were considered relevant. Their abstracts were reviewed by groups of two authors using predefined criteria. Fifty studies were selected for full paper review, and 22 of these were eligible. A theoretical framework for their review was developed. Review was performed using a ten-point checklist of the methodological caveats in the analysis of studies of ABCR and a standardised assessment form designed to extract quantitative and qualitative information.

Results

Most of the evaluable studies support a reduction in ABCR following the introduction of screening. However, all studies were challenged by issues of design and analysis which could at least potentially cause bias, and showed considerable variation in the estimated effect. Problems were observed in duration of follow-up time, availability of reliable reference ABCR, definition of advanced stage, temporal variation in the proportion of unknown-stage cancers, and statistical approach.

Conclusions

We conclude that much of the current controversy on the impact of service screening programmes on ABCR is due to observational data that were gathered and/or analysed with methodological approaches which could not capture stage effects in full. Future research on this important early indicator of screening effectiveness should focus on establishing consensus in the correct methodology.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4666-1) contains supplementary material, which is available to authorized users.

Risk of non-sentinel node metastases in patients with symptomatic cancers compared to screen-detected breast cancers

BACKGROUND

Symptomatic breast cancers may be more aggressive as compared to screen-detected breast cancers. This could favor axillary lymph node dissection (ALND) in patients with symptomatic breast cancer and positive sentinel nodes.

METHOD

We identified 955 patients registered in the Danish Breast Cancer Cooperative Group (DBCG) Database in 2008 - 2010 with micrometastases (773) or isolated tumor cells (ITC) (182) in the sentinel node. Patients were cross-checked in the Danish Quality Database of Mammography Screening and 481 patients were identified as screen-detected cancers. The remaining 474 patients were considered as having symptomatic cancers. Multivariate analyses of the risk of non-sentinel node metastases were performed including known risk factors for non-sentinel node metastases as well as method of detection.

RESULTS

18% of the patients had metastases in non-sentinel nodes. This was evenly distributed between patients with symptomatic and screen-detected cancers; 18.5% vs 17.5% (OR 1.07; 95% CI 0.77-1.49; p = 0.69). In patients with micrometastases 21% had non-sentinel node metastases in the group with symptomatic cancers compared to 19% of patients with screen-detected cancers. This difference was not significant (OR 1.16; 95% CI 0.81-1.65, p = 0.43). Neither the multivariate analysis showed an increased risk of non-sentinel node metastases in patients with symptomatic cancers compared to screen-detected cancers (OR 1.12, CI 0.77-1.62, p = 0.55). In patients with ITCs 8% of patients with symptomatic cancers had non-sentinel node metastases compared to 13% of patients with screen-detected cancers. This difference was not significant (OR 0.58; 95% CI 0.22-1.54, p = 0.27). In the multivariate analysis, the risk of non-sentinel node metastases was still not significantly increased in patients with symptomatic cancers compared to screen-detected cancers (OR 0.45; 95% CI 0.16-1.27, p = 0.13).

CONCLUSION

We did not find any clinically relevant difference in the risk of non-sentinel node metastases between patients with symptomatic and screen-detected cancers with micrometastases or ITC in the sentinel node.

Performance indicators evaluation of the population-based breast cancer screening programme in Northern Portugal using the European Guidelines

OBJECTIVE

To evaluate the first 10 years of operation of the population-based breast cancer screening programme implemented in the Northern Region of Portugal, using selected recommended standard performance indicators.

METHODS

Data from women aged 50-69 screened with two-view mammography, biennially, in the period 2000-2009, were included. Main performance indicators were compared with the recommended levels of the European Guidelines.

RESULTS

A total of 202,039 screening examinations were performed, 71,731 (35.5%) in the initial screening and 130,308 (64.5%) in the subsequent screening. Coverage rate by examination reached 74.3% of the target population, in the last period evaluated. Recall rates were 8.1% and 2.4% and cancer detection rates were 4.4/1000 and 2.9/1000 respectively, for initial and subsequent screenings. The breast cancer detection rate, expressed as a multiple of the background expected incidence was 3.1 in initial screen and 2.2 in subsequent screen. The incidence of invasive interval cancers met the desirable recommended levels both the first and second years since last screening examination, in the initial and subsequent screenings. Invasive tumours <15mm were 50.4% and 53.8% of the invasive cancers detected in initial and subsequent screenings. Less favourable size, grading and biomarkers expression were found in interval cancers compared to screen-detected cancers.

CONCLUSIONS

Breast cancer screening programme in the Northern Region of Portugal was well accepted by the population. Most of the performance indicators were consistent with the desirable levels of the European Guidelines, which indicate an effective screening programme. Future research should verify the consistency of some of these results by using updated information from a larger population.

Complexities and challenges in the pathologic assessment of size (T) of invasive breast carcinoma

Size (the "T" in the TNM System) of invasive breast carcinoma is a proven independent prognostic factor; however, its accurate determination can be challenging. The purpose of this review is to discuss the complexities inherent in determining "T"-including those encountered in the clinical measurement ("cT", ie, physical and radiologic assessment) as well as pathologic determination (pT) of invasive breast carcinomas. Pathologic estimation of tumor size, macroscopic, as well as microscopic, can be problematic due to the complexity of multiple situations, seeming confusion regarding staging guidelines, and interobserver variation in interpretation. Additional problematic scenarios in determination of "T" include those incurred in excisions performed after the performance of needle core biopsies, and in cases wherein there are multiple foci of invasive carcinoma, as well as in carcinomas status post-neoadjuvant chemotherapy. It can also be difficult to determine "T" in certain types of invasive carcinoma, particularly those of the lobular type. In this communication, some of the complexities and challenges in determing "T" are discussed, and modest suggestions are offered to assist in optimizing such assessments.

Type of breast cancer diagnosis, screening, and survival

INTRODUCTION

Breast cancer screening is known to reduce mortality. In the present study, we analyzed the prevalence of breast cancers detected through screening, before and after introduction of an organized screening, and we evaluated the overall survival of these patients in comparison with women with an extrascreening imaging-detected breast cancer or those with palpable breast cancers.

MATERIALS AND METHODS

We collected data about all women who underwent a breast operation for cancer in our department between 2001 and 2008, focusing on type of tumor diagnosis, tumor characteristics, therapies administered, and patient outcome in terms of overall survival, and recurrences. Data was analyzed by R (version 2.15.2), and P < .05 was considered significant.

RESULTS

Among the 2070 cases of invasive breast cancer we considered, 157 were detected by regional mammographic screening (group A), 843 by extrascreening breast imaging (group B: 507 by mammography and 336 by ultrasound), and 1070 by extrascreening breast objective examination (group C). The 5-year overall survival in groups A, B, and C were, respectively, 99% (95% CI, 98%-100%), 98% (95% CI, 97%-99%), and 91% (95% CI, 90%-93%), with a significant difference between the first 2 groups and the third (P < .05) and a trend between groups A and B (P = .081).

CONCLUSION

The diagnosis of invasive breast cancer with screening in our population resulted in a survival gain at 5 years from the diagnosis, but a longer follow-up is necessary to confirm this data.

Impact of familial risk and mammography screening on prognostic indicators of breast disease among women from the Ontario site of the Breast Cancer Family Registry

Although several studies have found screen-detected cancers in women with familial breast cancer risk have favorable prognostic features compared with symptomatic cancers, the impact of level of familial risk is unknown. A cohort of 899 first-degree female relatives of cases of breast cancer from the Ontario site of the Breast Cancer Family Registry was followed for 2 years. Logistic regression analyses compared diagnoses of breast cancer or benign breast disease (BBD) between women at high (n = 258, 28.7 %) versus low/moderate (n = 641, 71.3 %) familial risk. Similar analyses compared prognostic features of invasive cancers and BBD by level of familial risk and mammography screening status. Among 899 women, 44 (4.9 %) were diagnosed with invasive breast cancer and/or ductal carcinoma in situ, and 56 (6.2 %) with BBD. Women with high familial risk were significantly more likely to be diagnosed with breast cancer [odds ratio (OR) = 2.84, 95 % confidence interval (CI) 1.50-5.38] than low/moderate risk women, particularly if diagnosed at age ≥50 (OR = 2.99, 95 % CI 1.37-6.56) or screened with mammography (OR = 3.33, 95 % CI 1.54-7.18). High risk women were more likely to be diagnosed with BBD (OR = 1.94, 95 % CI 1.03-3.66). Level of familial risk was not associated with prognostic features. Cancers among unscreened women were larger (OR = 9.72, 95 % CI 1.01-93.61) and diagnosed at stage II or above (OR = 7.80, 95 % CI 1.18-51.50) compared with screen-detected cancers. Screening mammography may be effective for women with a first-degree family history of breast cancer, irrespective of level of familial risk.