Global summit on mammographic screening

Optimizing breast cancer diagnosis with photoacoustic imaging: An analysis of intratumoral and peritumoral radiomics

Background

The differentiation between benign and malignant breast tumors extends beyond morphological structures to encompass functional alterations within the nodules. The combination of photoacoustic (PA) imaging and radiomics unveils functional insights and intricate details that are imperceptible to the naked eye.

Purpose

This study aims to assess the efficacy of PA imaging in breast cancer radiomics, focusing on the impact of peritumoral region size on radiomic model accuracy.

Materials and methods

From January 2022 to November 2023, data were collected from 358 patients with breast nodules, diagnosed via PA/US examination and classified as BI-RADS 3-5. The study used the largest lesion dimension in PA images to define the region of interest, expanded by 2 mm, 5 mm, and 8 mm, for extracting radiomic features. Techniques from statistics and machine learning were applied for feature selection, and logistic regression classifiers were used to build radiomic models. These models integrated both intratumoral and peritumoral data, with logistic regressions identifying key predictive features.

Results

The developed nomogram, combining 5 mm peritumoral data with intratumoral and clinical features, showed superior diagnostic performance, achieving an AUC of 0.950 in the training cohort and 0.899 in validation. This model outperformed those based solely on clinical features or other radiomic methods, with the 5 mm peritumoral region proving most effective in identifying malignant nodules.

Conclusion

This research demonstrates the significant potential of PA imaging in breast cancer radiomics, especially the advantage of integrating 5 mm peritumoral with intratumoral features. This approach not only surpasses models based on clinical data but also underscores the importance of comprehensive radiomic analysis in accurately characterizing breast nodules.

Assessment of Oxygen Saturation in Breast Lesions Using Photoacoustic Imaging: Correlation With Benign and Malignant Disease

BACKGROUND

Hypoxia is a hallmark of breast cancer (BC). Photoacoustic (PA) imaging, based on the use of laser-generated ultrasound (US), can detect oxygen saturation (So2) in the tissues of breast lesion patients.

PURPOSE

To measure the oxygenation status of tissue in and on both sides of the lesion in breast lesion participants using a multimodal Photoacoustic/ultrasound (PA/US) imaging system and to determine the correlation between So2 measured by PA imaging and benign or malignant disease.

MATERIALS AND METHODS

Multimodal PA/US imaging and gray-scale US (GSUS) of breast lesion was performed in consecutive breast lesion participants imaged in the US Outpatient Clinic between 2022 and 2023. Dual-wavelength PA imaging was used to measure the So2 value inside the lesion and on both sides of the tissue, and to distinguish benign from malignant lesions based on the So2 value. The ability of So2 to distinguish benign from malignant breast lesions was evaluated by the receiver operating characteristic curve (ROC) and the De-Long test.

RESULTS

A total of 120 breast lesion participants (median age, 42.5 years) were included in the study. The malignant lesions exhibited lower So2 levels compared to benign lesions (malignant: 71.30%; benign: 83.81%; P < .01). Moreover, PA/US imaging demonstrates superior diagnostic results compared to GSUS, with an area under the curve (AUC) of 0.89 versus 0.70, sensitivity of 89.58% versus 85.42%, and specificity of 86.11% versus 55.56% at the So2 cut-off value of 78.85 (P < .001). The false positive rate in GSUS reduced by 30.75%, and the false negative rate diminished by 4.16% with PA /US diagnosis. Finally, the So2 on both sides tissues of malignant lesions are lower than that of benign lesions (P < .01).

CONCLUSION

PA imaging allows for the assessment of So2 within the lesions of breast lesion patients, thereby facilitating a superior distinction between benign and malignant lesions.

Photoacoustic imaging of breast cancer: a mini review of system design and image features

Breast cancer is one of the leading causes for cancer related deaths in women, and early detection is extremely important to improve survival rates. Currently, x-ray mammogram is the only modality for mass screening of asymptomatic women. However, it has decreased sensitivity in radiographically dense breasts, which is also associated with a higher risk for breast cancer. Photoacoustic (PA) imaging is an emerging modality that enables deep tissue imaging of optical contrast at ultrasonically defined spatial resolution, which is much higher than that can be achieved in purely optical imaging modalities. Because of high optical absorption from hemoglobin molecules, PA imaging can map out hemo distribution and dynamics in breast tissue and identify malignant lesions based on tumor associated angiogenesis and hypoxia. We review various PA breast imaging systems proposed over the past few years and summarize the PA features of breast cancer identified in these systems.

Translating genomic risk into an early detection strategy for sarcoma

Sarcomas have a strong genetic etiology, and the study of families affected by sarcomas has informed much of what we now understand of modern cancer biology. The recent emergence of powerful genetic technologies has led to astonishing reductions in costs and increased throughput. In the clinic, these technologies are revealing a previously unappreciated and rich landscape of genetic cancer risk. In addition to both known and new cancer risk mutations, genomic tools are cataloguing complex and polygenic risk patterns, collectively explaining between 15-25% of apparently sporadic sarcoma cases. The impact on clinical management is exemplified by Li-Fraumeni Syndrome, the most penetrant sarcoma syndrome. Whole body magnetic resonance imaging can identify surgically resectable cancers in up to one in ten individuals with Li-Fraumeni Syndrome. Taken together, parallel developments in genomics, therapeutics and imaging technologies will drive closer engagement between genetics and multidisciplinary care of the sarcoma patient in the 21st century.

Optical assessment of mammographic breast density by a 12-wavelength vs a continuous-spectrum optical spectroscopy device

A 12-laser-wavelength, fixed source-detector position, cup-based optical breast spectroscopy (OBS) device was developed for use in large-scale, multicenter trials as a mammographic breast density (MBD) quantification and breast cancer (BC) risk prescreening tool. In this study, the device was evaluated in comparison with a spectrometer-based device used in previous studies. The devices were compared on their ability to predict mammographic percent density (MPD) and to identify women with high MBD from optical spectra. OBS measurements were made on 60 women, (age 29-73), using both devices. Recent mammograms were collected for all women and MPD quantified from the mammograms. Principal components (PCs) analysis was performed on both sets of OBS spectra, and multivariate logistic regression analysis of the resulting PC scores was used to identify women with high MBD. Both devices are able to identify high MBD with very high sensitivity and specificity. Partial least-squares regression of the spectra was used to predict MPD. Both devices show a strong correlation between OBS-predicted MPD and MPD read from mammograms, however, the correlation is stronger for the continuous-spectrum device (r = 0.74, P = .001) than for the 12-wavelength device (r = 0.62, P = .004). Improvements to the cup-based device to reduce detector saturation should improve the prediction of MPD from the spectra.

A multi-wavelength, laser-based optical spectroscopy device for breast density and breast cancer risk pre-screening

Optical Breast Spectroscopy (OBS) has been shown to predict mammographic breast density, a strong breast cancer risk factor. OBS is a low-cost technique applicable at any age. OBS information may be useful for personalizing breast cancer screening programs based on risk to improve consensus on and adherence to screening guidelines. To facilitate the use of OBS in population-wide studies, a research prototype OBS device was modified to make it portable and cheaper and to require less operator interaction. Two major changes were made: (1) the broadband light source was replaced with a laser module with 13 individual wavelengths turned on sequentially, enabling the use of photodiode detectors instead of a spectrometer, and (2) the light sources and detectors were placed in fixed positions within 4 sizes of cup, eliminating the need for placement by the operator. Wavelengths were selected using data from two previous studies. The reduction in spectral content did not significantly reduce the ability to distinguish between different risk groups. Positions for the light sources and detectors were chosen based on Monte Carlo simulations to match the optically interrogated volumes of the original device. Two light sources and six detectors per cup were used in the final design.

Relationship between the method of detection and prognostic factors for breast cancer in a community with a screening programme

Objectives

To analyse and compare the prognostic factors of breast cancer in the target population of our community-screening programme as a function of the method of detection and to analyse the differences in the prognostic factors as a function of the patient's age and the screening episode.

Setting

A Breast Cancer-Screening Programme (BCSP) in Northeast Spain.

Methods

Observational study of all primary malignant breast lesions diagnosed in a woman between 50 and 69 years of age between 18 October 1995 and 31 December 2002. The 16 centres that women from the target population might have attended were contacted.

Results

A total of 225 (37.2%) of the lesions included were diagnosed through the BCSP, 59 (9.7%) interval cancers were detected, and 321 (53.1%) were detected through other circuits. Node involvement was significantly lower in the lesions detected at screening (32%) in comparison to the interval cancers (41.8%) and those detected through other circuits (47.5%). A significantly larger percentage of the interval tumours (28.6%) and the lesions diagnosed outside the BCSP (22.1%) scored 5.4 on the Nottingham Prognostic Index (NPI) than those diagnosed within the programme (10.9%). The relation between the NPI and the detection method was only statistically significant in the 65-69-year-old age group. The NPI score of the tumours detected by the BCSP showed a statistically significant association with age.

Conclusion

This analysis has shown notable differences in some prognostic factors for breast cancer according to the method of detection. Association between age and the a priori prognosis of the malignant lesions arises.

Screening for breast cancer with mammography

BACKGROUND

A variety of estimates of the benefits and harms of mammographic screening for breast cancer have been published and national policies vary.

OBJECTIVES

To assess the effect of screening for breast cancer with mammography on mortality and morbidity.

SEARCH STRATEGY

We searched PubMed (November 2008).

SELECTION CRITERIA

Randomised trials comparing mammographic screening with no mammographic screening.

DATA COLLECTION AND ANALYSIS

Both authors independently extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Eight eligible trials were identified. We excluded a biased trial and included 600,000 women in the analyses. Three trials with adequate randomisation did not show a significant reduction in breast cancer mortality at 13 years (relative risk (RR) 0.90, 95% confidence interval (CI) 0.79 to 1.02); four trials with suboptimal randomisation showed a significant reduction in breast cancer mortality with an RR of 0.75 (95% CI 0.67 to 0.83). The RR for all seven trials combined was 0.81 (95% CI 0.74 to 0.87). We found that breast cancer mortality was an unreliable outcome that was biased in favour of screening, mainly because of differential misclassification of cause of death. The trials with adequate randomisation did not find an effect of screening on cancer mortality, including breast cancer, after 10 years (RR 1.02, 95% CI 0.95 to 1.10) or on all-cause mortality after 13 years (RR 0.99, 95% CI 0.95 to 1.03).Numbers of lumpectomies and mastectomies were significantly larger in the screened groups (RR 1.31, 95% CI 1.22 to 1.42) for the two adequately randomised trials that measured this outcome; the use of radiotherapy was similarly increased.

AUTHORS' CONCLUSIONS

Screening is likely to reduce breast cancer mortality. As the effect was lowest in the adequately randomised trials, a reasonable estimate is a 15% reduction corresponding to an absolute risk reduction of 0.05%. Screening led to 30% overdiagnosis and overtreatment, or an absolute risk increase of 0.5%. This means that for every 2000 women invited for screening throughout 10 years, one will have her life prolonged and 10 healthy women, who would not have been diagnosed if there had not been screening, will be treated unnecessarily. Furthermore, more than 200 women will experience important psychological distress for many months because of false positive findings. It is thus not clear whether screening does more good than harm. To help ensure that the women are fully informed of both benefits and harms before they decide whether or not to attend screening, we have written an evidence-based leaflet for lay people that is available in several languages on www.cochrane.dk.

Screening for breast cancer with mammography

BACKGROUND

A variety of estimates of the benefits and harms of mammographic screening for breast cancer have been published and national policies vary.

OBJECTIVES

To assess the effect of screening for breast cancer with mammography on mortality and morbidity.

SEARCH STRATEGY

We searched PubMed (November 2008).

SELECTION CRITERIA

Randomised trials comparing mammographic screening with no mammographic screening.

DATA COLLECTION AND ANALYSIS

Both authors independently extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Eight eligible trials were identified. We excluded a biased trial and included 600,000 women in the analyses. Three trials with adequate randomisation did not show a significant reduction in breast cancer mortality at 13 years (relative risk (RR) 0.90, 95% confidence interval (CI) 0.79 to 1.02); four trials with suboptimal randomisation showed a significant reduction in breast cancer mortality with an RR of 0.75 (95% CI 0.67 to 0.83). The RR for all seven trials combined was 0.81 (95% CI 0.74 to 0.87). We found that breast cancer mortality was an unreliable outcome that was biased in favour of screening, mainly because of differential misclassification of cause of death. The trials with adequate randomisation did not find an effect of screening on cancer mortality, including breast cancer, after 10 years (RR 1.02, 95% CI 0.95 to 1.10) or on all-cause mortality after 13 years (RR 0.99, 95% CI 0.95 to 1.03).Numbers of lumpectomies and mastectomies were significantly larger in the screened groups (RR 1.31, 95% CI 1.22 to 1.42) for the two adequately randomised trials that measured this outcome; the use of radiotherapy was similarly increased.

AUTHORS' CONCLUSIONS

Screening is likely to reduce breast cancer mortality. As the effect was lowest in the adequately randomised trials, a reasonable estimate is a 15% reduction corresponding to an absolute risk reduction of 0.05%. Screening led to 30% overdiagnosis and overtreatment, or an absolute risk increase of 0.5%. This means that for every 2000 women invited for screening throughout 10 years, one will have her life prolonged and 10 healthy women, who would not have been diagnosed if there had not been screening, will be treated unnecessarily. Furthermore, more than 200 women will experience important psychological distress for many months because of false positive findings. It is thus not clear whether screening does more good than harm. To help ensure that the women are fully informed of both benefits and harms before they decide whether or not to attend screening, we have written an evidence-based leaflet for lay people that is available in several languages on www.cochrane.dk.

Guideline implementation for breast healthcare in low- and middle-income countries: early detection resource allocation

A key determinant of breast cancer outcome in any population is the degree to which cancers are detected at early stages of disease. Populations in which cancers are detected at earlier stages have lower breast cancer mortality rates. The Breast Health Global Initiative (BHGI) held its third Global Summit in Budapest, Hungary in October 2007, bringing together internationally recognized experts to address the implementation of breast healthcare guidelines for early detection, diagnosis, and treatment in low- and middle-income countries (LMCs). A multidisciplinary panel of experts specifically addressed the implementation of BHGI guidelines for the early detection of disease as they related to resource allocation for public education and awareness, cancer detection methods, and evaluation goals. Public education and awareness are the key first steps, because early detection programs cannot be successful if the public is unaware of the value of early detection. The effectiveness and efficiency of screening modalities, including screening mammography, clinical breast examination (CBE), and breast self-examination, were reviewed in the context of resource availability and population-based need by the panel. Social and cultural barriers should be considered when early detection programs are being established, and the evaluation of early detection programs should include the use of well developed, methodologically sound process metrics to determine the effectiveness of program implementation. The approach and scope of any screening program will determine the success of any early detection program as measured by cancer stage at diagnosis and will drive the breadth of resource allocation needed for program implementation.

Screening for breast cancer with mammography

BACKGROUND

A variety of estimates of the benefits and harms of mammographic screening for breast cancer have been published and national policies vary.

OBJECTIVES

To assess the effect of screening for breast cancer with mammography on mortality and morbidity.

SEARCH STRATEGY

We searched PubMed (June 2005).

SELECTION CRITERIA

Randomised trials comparing mammographic screening with no mammographic screening.

DATA COLLECTION AND ANALYSIS

Both authors independently extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Seven completed and eligible trials involving half a million women were identified. We excluded a biased trial from analysis. Two trials with adequate randomisation did not show a significant reduction in breast cancer mortality, relative risk (RR) 0.93 (95% confidence interval 0.80 to 1.09) at 13 years; four trials with suboptimal randomisation showed a significant reduction in breast cancer mortality, RR 0.75 (0.67 to 0.83) (P = 0.02 for difference between the two estimates). RR for all six trials combined was 0.80 (0.73 to 0.88). The two trials with adequate randomisation did not find an effect of screening on cancer mortality, including breast cancer, RR 1.02 (0.95 to 1.10) after 10 years, or on all-cause mortality, RR 1.00 (0.96 to 1.04) after 13 years. We found that breast cancer mortality was an unreliable outcome that was biased in favour of screening, mainly because of differential misclassification of cause of death. Numbers of lumpectomies and mastectomies were significantly larger in the screened groups, RR 1.31 (1.22 to 1.42) for the two adequately randomised trials; the use of radiotherapy was similarly increased.

AUTHORS' CONCLUSIONS

Screening likely reduces breast cancer mortality. Based on all trials, the reduction is 20%, but as the effect is lower in the highest quality trials, a more reasonable estimate is a 15% relative risk reduction. Based on the risk level of women in these trials, the absolute risk reduction was 0.05%. Screening also leads to overdiagnosis and overtreatment, with an estimated 30% increase, or an absolute risk increase of 0.5%. This means that for every 2000 women invited for screening throughout 10 years, one will have her life prolonged. In addition, 10 healthy women, who would not have been diagnosed if there had not been screening, will be diagnosed as breast cancer patients and will be treated unnecessarily. It is thus not clear whether screening does more good than harm. Women invited to screening should be fully informed of both benefits and harms.

Breast cancer in limited-resource countries: early detection and access to care

Although incidence, mortality, and survival rates vary fourfold in the world's regions, in the world as a whole, the incidence of breast cancer is increasing, and in regions without early detection programs, mortality is also increasing. The growing burden of breast cancer in low-resource countries demands adaptive strategies that can improve on the too common pattern of disease presentation at a stage when prognosis is very poor. In January 2005, the Breast Health Global Initiative (BHGI) held its second summit in Bethesda, MD. The Early Detection and Access to Care Panel reaffirmed the core principle that a requirement at all resource levels is that women should be supported in seeking care and should have access to appropriate, affordable diagnostic tests and treatment. In terms of earlier diagnosis, the panel recommended that breast health awareness should be promoted to all women. Enhancements to basic facilities might include the following, in order of resources: effective training of relevant staff in clinical breast examination (CBE) both for symptomatic and asymptomatic women; opportunistic screening with CBE; demonstration projects or trials of organized screening using CBE or breast self-examination; and finally, feasibility studies of mammographic screening. Ideally, for complete evaluation, such projects require notification of deaths among breast cancer cases and staging of diagnosed tumors.

Issues in breast cancer screening

This paper will review the use of screening mammography in the United States, with an emphasis on its limitations as currently practiced. It will then emphasize several areas where breast cancer imaging practice can be improved, namely in reducing overtreatment of potentially nonlethal cancers, in monitoring the effectiveness of nonsurgical therapies, and in guiding noninvasive therapies. Any new modality that is to have an impact on breast cancer mortality must perform comparably to screening mammography to become widely utilized. While mammography is not perfect, it has set a high threshold that other modalities must reach before they will be widely utilized for screening or diagnosis.