Breast cancer risk assessment and risk distribution in 3,491 Slovenian women invited for screening at the age of 50; a population-based cross-sectional study.

BACKGROUND: The evidence shows that risk-based strategy could be implemented to avoid unnecessary harm in mammography screening for breast cancer (BC) using age-only criterium. Our study aimed at identifying the uptake of Slovenian women to the BC risk assessment invitation and assessing the number of screening mammographies in case of risk-based screening. PATIENTS AND METHODS: A cross-sectional population-based study enrolled 11,898 women at the age of 50, invited to BC screening. The data on BC risk factors, including breast density from the first 3,491 study responders was collected and BC risk was assessed using the Tyrer-Cuzick algorithm (version 8) to classify women into risk groups (low, population, moderately increased, and high risk group). The number of screening mammographies according to risk stratification was simulated. RESULTS: 57% (6,785) of women returned BC risk questionnaires. When stratifying 3,491 women into risk groups, 34.0% were assessed with low, 62.2% with population, 3.4% with moderately increased, and 0.4% with high 10-year BC risk. In the case of potential personalised screening, the number of screening mammographies would drop by 38.6% compared to the current screening policy. CONCLUSIONS: The study uptake showed the feasibility of risk assessment when inviting women to regular BC screening. 3.8% of Slovenian women were recognised with higher than population 10-year BC risk. According to Slovenian BC guidelines they may be screened more often. Overall, personalised screening would decrease the number of screening mammographies in Slovenia. This information is to be considered when planning the pilot and assessing the feasibility of implementing population risk-based screening.

Uncertainty estimation for deep learning-based pectoral muscle segmentation via Monte Carlo dropout.

Objective. Deep Learning models are often susceptible to failures after deployment. Knowing when your model is producing inadequate predictions is crucial. In this work, we investigate the utility of Monte Carlo (MC) dropout and the efficacy of the proposed uncertainty metric (UM) for flagging of unacceptable pectoral muscle segmentations in mammograms.Approach. Segmentation of pectoral muscle was performed with modified ResNet18 convolutional neural network. MC dropout layers were kept unlocked at inference time. For each mammogram, 50 pectoral muscle segmentations were generated. The mean was used to produce the final segmentation and the standard deviation was applied for the estimation of uncertainty. From each pectoral muscle uncertainty map, the overall UM was calculated. To validate the UM, a correlation between the dice similarity coefficient (DSC) and UM was used. The UM was first validated in a training set (200 mammograms) and finally tested in an independent dataset (300 mammograms). ROC-AUC analysis was performed to test the discriminatory power of the proposed UM for flagging unacceptable segmentations.Main results. The introduction of dropout layers in the model improved segmentation performance (DSC = 0.95 ± 0.07 versus DSC = 0.93 ± 0.10). Strong anti-correlation (r= -0.76,p< 0.001) between the proposed UM and DSC was observed. A high AUC of 0.98 (97% specificity at 100% sensitivity) was obtained for the discrimination of unacceptable segmentations. Qualitative inspection by the radiologist revealed that images with high UM are difficult to segment.Significance. The use of MC dropout at inference time in combination with the proposed UM enables flagging of unacceptable pectoral muscle segmentations from mammograms with excellent discriminatory power.

Quality assured implementation of the Slovenian breast cancer screening programme.

SETTING: The organised, population-based breast cancer screening programme in Slovenia began providing biennial mammography screening for women aged 50-69 in 2008. The programme has taken a comprehensive approach to quality assurance as recommended by the European guidelines for quality assurance in breast cancer screening and diagnosis (4th edition), including centralized assessment, training and supervision, and proactive monitoring of performance indicators. This report describes the progress of implementation and rollout from 2003 through 2019. METHODS: The screening protocol and key quality assurance procedures initiated during the planning from 2003 and rollout from 2008 of the screening programme, including training of the professional staff, are described. The organisational structure, gradual geographical rollout, and coverage by invitation and examination are presented. RESULTS: The nationwide programme was up and running in all screening regions by the end of 2017, at which time the nationwide coverage by invitation and examination had reached 70% and 50%, respectively. Nationwide rollout of the population-based programme was complete by the end of 2019. By this time, coverage by invitation and examination had reached 98% and 76%, respectively. The participation rates consistently exceeded 70% from 2014 to 2019. CONCLUSIONS: The successful implementation of the screening programme can be attributed to an independent central management, external guidance, and strict adherence to quality assurance procedures, all of which contributed to increasing governmental and popular support. The benefits of quality assurance have influenced all aspects of breast care and have provided a successful model for multidisciplinary management of other diseases.

Fat necrosis in free DIEAP flaps: incidence, risk, and predictor factors.

Fat necrosis within a deep inferior epigastric artery perforator flap reconstructed breast is considered a minor complication from reconstructive point of view, but one that can induce anxiety, inconvenience and concerns about cancer recurrence to the oncologist and the patient. A series of 100 consecutive unilateral deep inferior epigastric artery perforator flap breast reconstructions were reviewed to identify the institutional incidence as well as potential risk and predictor factors of fat necrosis. Examination revealed 37 reconstructed breasts with palpable firmnesses (described as clinical fat necrosis) and ultrasonography and mammography confirmed signs of fat necrosis in 30 reconstructed breasts. Flaps harvested on a single perforator, obese patients with body mass index > or = 30 and revision operations were all statistically significant predictors in our statistical model. Postoperative radiotherapy, a reconstructed breast volume over 500 mL and a pedicle raised on a single row of perforators were statistically significant only after univariate analysis and their statistical strength was lost after introducing them with multivariate model. This study helped us to further clarify criteria for selection of patients undergoing breast reconstruction with flaps from the abdomen.

Improvement of early detection of breast cancer through collaborative multi-country efforts: Observational clinical study.

AIM: The aim of this paper is to present baseline imaging data and the improvement that was achieved by the participating centers after applying practice-specific interventions that were identified during the course of a multicentric multinational research coordinated project. INTRODUCTION: The incidence and mortality rates from breast cancer are rising worldwide and particularly rapidly across the countries with limited resources. Due to lack of awareness and screening options it is usually detected at a later stage. Breast cancer screening programs and even clinical services on breast cancer have been neglected in such countries particularly due to lack of available equipment, funds, organizational structure and quality criteria. MATERIALS AND METHODS: A harmonized form was designed in order to facilitate uniformity of data collection. Baseline data such as type of equipment, number of exams, type and number of biopsy procedures, stage of cancer at detection were collected from 10 centers (9 countries: Bosnia-Herzegovina, Costa Rica, Egypt, India, North Macedonia, Pakistan, Slovenia, Turkey, Uganda) were collected. Local practices were evaluated for good practice and specific interventions such as training of professionals and quality assurance programs were identified. The centers were asked to recapture the data after a 2-year period to identify the impact of the interventions. RESULTS: The data showed increase in the number of training of relevant professionals, positive changes in the mammography practice and image guided interventions. All the centers achieved higher levels of success in the implementation of the quality assurance procedures. CONCLUSION: The study has encountered different levels of breast imaging practice in terms of expertise, financial and human resources, infrastructure and awareness. The most common challenges were the lack of appropriate quality assurance programs and lack of trained skilled personnel and lack of high-quality equipment. The project was able to create higher levels of breast cancer awareness, collaboration amongst participating centers and professionals. It also improved quality, capability and expertise in breast imaging particularly in centers involved diagnostic imaging.

Minimal risk of macrometastases in the non-sentinel axillary lymph nodes in breast cancer patients with micrometastatic sentinel lymph nodes and preoperatively ultrasonically uninvolved axillary lymph nodes.

Micrometastases in the sentinel lymph node (SLN) carry a considerable risk of macrometastases in the non-sentinel lymph nodes (NSLN), resulting in axillary lymph node dissection (ALND). Preoperative ultrasound (US) examination of the axillary lymph nodes combined with a fine-needle aspiration biopsy (FNAB) has been proved to discover metastases in the axillary lymph nodes. The aim of our study was to assess the risk of macrometastases in NSLN in patients with micrometastatic SLN after a preoperative US examination of the axillary lymph nodes. The study included 36 patients in whom, after preoperative axillary US, micrometastases in the SLN were revealed and ALND was subsequently performed. At final histopathology, no macrometastases were discovered in the NSLN. In four patients, additional micrometastases were discovered in the NSLN. In conclusion, the risk of macrometastases in the NSLN in patients with preoperatively ultrasonically uninvolved axillary lymph nodes is minimal.

Characterization of spatiotemporal changes for the classification of dynamic contrast-enhanced magnetic-resonance breast lesions.

OBJECTIVE: The early detection of breast cancer is one of the most important predictors in determining the prognosis for women with malignant tumours. Dynamic contrast-enhanced magnetic-resonance imaging (DCE-MRI) is an important imaging modality for detecting and interpreting the different breast lesions from a time sequence of images and has proved to be a very sensitive modality for breast-cancer diagnosis. However, DCE-MRI exhibits only a moderate specificity, thus leading to a high rate of false positives, resulting in unnecessary biopsies that are stressful and physically painful for the patient and lead to an increase in the cost of treatment. There is a strong medical need for a DCE-MRI computer-aided diagnosis tool that would offer a reliable support to the physician's decision providing a high level of sensitivity and specificity. METHODS: In our study we investigated the possibility of increasing differentiation between the malignant and the benign lesions with respect to the spatial variation of the temporal enhancements of three parametric maps, i.e., the initial enhancement (IE) map, the post-initial enhancement (PIE) map and the signal enhancement ratio (SER) map, by introducing additional methods along with the grey-level co-occurrence matrix, i.e., a second-order statistical method already applied for quantifying the spatiotemporal variations. We introduced the grey-level run-length matrix and the grey-level difference matrix, representing two additional, second-order statistical methods, and the circular Gabor as a frequency-domain-based method. Each of the additional methods is for the first time applied to the DCE-MRI data to differentiate between the malignant and the benign breast lesions. We applied the least-square minimum-distance classifier (LSMD), logistic regression and least-squares support vector machine (LS-SVM) classifiers on a total of 115 (78 malignant and 37 benign) breast DCE-MRI cases. The performances were evaluated using ten experiments of a ten-fold cross-validation. RESULTS: Our experimental analysis revealed the PIE map, together with the feature subset in which the discriminating ability of the co-occurrence features was increased by adding the newly introduced features, to be the most significant for differentiation between the malignant and the benign lesions. That diagnostic test - the aforementioned combination of parametric map and the feature subset achieved the sensitivity of 0.9193 which is statistically significantly higher compared to other diagnostic tests after ten-experiments of a ten-fold cross-validation and gave a statistically significantly higher specificity of 0.7819 for the fixed 95% sensitivity after the receiver operating characteristic (ROC) curve analysis. Combining the information from all the three parametric maps significantly increased the area under the ROC curve (AUC) of the aforementioned diagnostic test for the LSMD and logistic regression; however, not for the LS-SVM. The LSMD classifier yielded the highest area under the ROC curve when using the combined information, increasing the AUC from 0.9651 to 0.9755. CONCLUSION: Introducing new features to those of the grey-level co-occurrence matrix significantly increased the differentiation between the malignant and the benign breast lesions, thus resulting in a high sensitivity and improved specificity.

Outcome of MRI-guided vacuum-assisted breast biopsy - initial experience at Institute of Oncology Ljubljana, Slovenia.

BACKGROUND: Like all breast imaging modalities MRI has limited specificity and the positive predictive value for lesions detected by MRI alone ranges between 15 and 50%. MRI guided procedures (needle biopsy, presurgical localisation) are mandatory for suspicious findings visible only at MRI, with potential influence on therapeutic decision. The aim of this retrospective study was to evaluate our initial clinical experience with MRI-guided vacuum-assisted breast biopsy as an alternative to surgical excision and to investigate the outcome of MRI-guided breast biopsy as a function of the MRI features of the lesions. PATIENTS AND METHODS.: In 14 women (median age 51 years) with 14 MRI-detected lesions, MRI-guided vacuum-assisted breast biopsy was performed. We evaluated the MRI findings that led to biopsy and we investigated the core and postoperative histology results and follow-up data. RESULTS: The biopsy was technically successful in 14 (93%) of 15 women. Of 14 biopsies in 14 women, core histology revealed 6 malignant (6/14, 43%), 6 benign (6/14, 43%) and 2 high-risk (2/14, 14%) lesions. Among the 6 cancer 3 were invasive and 3 were ductal carcinoma in situ (DCIS). The probability of malignancy in our experience was higher for non-mass lesion type and for washout and plateau kinetics. CONCLUSIONS: Our initial experience confirms that MRI-guided vacuum-assisted biopsy is fast, safe and accurate alternative to surgical biopsy for breast lesions detected at MRI only.

Low performance of the MSKCC nomogram in preoperatively ultrasonically negative axillary lymph node in breast cancer patients.

BACKGROUND AND OBJECTIVES: In order to predict the nonsentinel lymph node (NSLN) metastases in sentinel lymph node (SLN) positive patients a nomogram was created at the Memorial Sloan Kettering Cancer Centre (MSKCC). The aim of our study was to validate the MSKCC nomogram in patients grouped by the preoperative ultrasound (US) examination of the axillary lymph nodes. METHODS: The MSKCC nomogram was validated separately in three groups of patients: (US-0) only clinically preoperatively negative axillary lymph nodes (126 patients), (US-1) US negative axillary lymph nodes (109 patients), and (US-2) US suspicious but fine needle aspiration biopsy (FNAB) negative axillary lymph nodes (41 patients). RESULTS: The predicted probability underestimates the actual probability with the mean absolute error equal to 0.116 in the US-0 group (P = 0.003), and overestimates the actual probability (mean absolute error equal to 0.084) in US-1 group (P = 0.033) and US-2 group (mean absolute error is 0.110) (P = 0.275). CONCLUSION: We found that the MSKCC nomogram overestimates the probability of the NSLN metastases in breast cancer patients with (i) preoperatively US negative or (ii) US suspicious, but FNAB negative axillary lymph nodes. We also found that MSKCC nomogram has only limited value in patients with only clinically negative axillary lymph nodes.

Patients with preoperatively ultrasonically uninvolved axillary lymph nodes: a distinct subgroup of early breast cancer patients.

INTRODUCTION: Ultrasound (US) preoperative examination of the axillary lymph nodes combined with the fine needle aspiration biopsy (FNAB) is often used in order to reduce the number of sentinel lymph node (SLN) biopsy procedures in clinically node negative breast cancer patients. The pathohistological characteristics of the ultrasonically negative axillary lymph nodes in clinically negative axillary lymph nodes are not known. The aim of our study was to compare the pathohistological characteristics of ultrasonically uninvolved axillary lymph nodes (US group) versus clinically uninvolved axillary lymph nodes (non-US group) in SLN biopsy candidates. METHODS: We included 658 patients after SLN biopsy; 286 patients in the US group and 372 in the non-US group. The pathohistological characteristics of axillary lymph nodes were evaluated by univariate analysis and logistic regression. RESULTS: In the univariate analysis, the proportion of macrometastastic SLN, total number of metastatic lymph nodes per patient, proportion of nonsentinel lymph node (NSLN) metastases and proportion of NSLN macrometastases were found to be lower in the US group compared to the non-US group. In the logistic regression model, only US of the axilla (p=0.010; OR: 0.57) and tumor size were significant predictors for the presence of SLN macrometastases or macrometastatic NSLN (p<0.001; OR: 0.23). CONCLUSION: The patients with US negative axillary lymph nodes form a distinct subgroup of early breast cancer patients having a significantly lower tumor burden in the axillary lymph nodes compared to those with only clinically negative axillary lymph nodes.