Systematic review: surveillance for breast cancer in women treated with chest radiation for childhood, adolescent, or young adult cancer

Identification and management of patients at increased risk for breast cancer

Breast cancer is the most diagnosed invasive cancer in the United States, with 1 in 8 people assigned female at birth (AFAB) being affected.1 It is imperative that health care practitioners remain current and well-versed in identifying individuals at high risk for developing breast cancer. This article outlines an approach for obstetrics/gynecology practitioners to identify high-risk patients and to counsel on appropriate breast cancer screening, prevention, and risk-reduction options.

Paradoxes of breast cancer incidence and mortality in two corners of Europe

BACKGROUND

Breast cancer incidence is rising globally, while mortality rates show a geographical heterogenous pattern. Early detection and treatment have been proven to have a profound impact on breast cancer prognosis. The aim of his study was to compare breast cancer incidence, mortality, and survival rates in two contrasting corners of Europe, Sweden and Crete, to better understand cancer determinants with focus on disease burden and sociocultural factors.

METHODS

Breast cancer data from Sweden and Crete was derived from registries. Incidence and mortality were expressed as Age-Standardized Incidence Rates (ASIR), Age-Standardized Mortality Rates (ASMR).

FINDINGS

Breast cancer incidence has for decades risen in Sweden and on Crete. In 2019, ASIR was 217.5 in Sweden and 58.9 on Crete, (p < 0.001). Mortality rates showed opposite trends. ASMR in Sweden was reduced from 25.5 to 16.8 (2005-2019) while on Crete, ASMR increased from 22.1 to 25.3. A successive rise in survival rate in Sweden with a 5-year survival rate of 92% since 2015, but a converse development on Crete with 85% 5-year survival rate the same year.

INTERPRETATION

The incidence of breast cancer is slowly rising in both studied regions, but mortality increases on Crete in contrast to Sweden with sinking mortality rates. The interpretation of these findings is that differences in health care systems and health policies including differences in early detection like screening programs and early treatment, as well as sociocultural factors in the two countries might play an important role on the differences found in breast cancer burden.

Recent Trends in Screening Breast MRI

OBJECTIVE

The objective of this study was to assess trends in screening breast MRI utilization among privately insured women in the U.S. from 2007 to 2017.

METHODS

The utilization of screening breast MRI among women aged 25-64 years from January 1, 2007, to December 31, 2017, was obtained using the MarketScan Commercial Database. We used Current Procedural Terminology codes to exclude breast MRI exams performed in women with a new breast cancer diagnosis and in women imaged to assess response to neoadjuvant therapy in the preceding 90 days. During the 11-year study, 351 763 study-eligible women underwent 488 852 MRI scans.

RESULTS

An overall 55.0% increase in screening breast MRI utilization was observed over the study period, with a steadily increasing trend. The greatest annual increase in percent utilization was from 2007 to 2008 at 16.6%. The highest utilization rate was in 2017, in which 0.4% of women aged 25-64 years underwent screening breast MRI. Of the women who underwent screening MRI with sufficient follow-up, 76.5% underwent only one examination during the study period.

CONCLUSION

Utilization of screening breast MRI has increased steadily in the past decade to a peak of 0.4% of adult women. However, an estimated 9% of U.S. women are eligible for high-risk breast MRI screening; thus, utilization falls short of optimal compliance. Further studies to evaluate the barriers to screening compliance may help optimize utilization.

Adverse outcome pathways for ionizing radiation and breast cancer involve direct and indirect DNA damage, oxidative stress, inflammation, genomic instability, and interaction with hormonal regulation of the breast

Knowledge about established breast carcinogens can support improved and modernized toxicological testing methods by identifying key mechanistic events. Ionizing radiation (IR) increases the risk of breast cancer, especially for women and for exposure at younger ages, and evidence overall supports a linear dose-response relationship. We used the Adverse Outcome Pathway (AOP) framework to outline and evaluate the evidence linking ionizing radiation with breast cancer from molecular initiating events to the adverse outcome through intermediate key events, creating a qualitative AOP. We identified key events based on review articles, searched PubMed for recent literature on key events and IR, and identified additional papers using references. We manually curated publications and evaluated data quality. Ionizing radiation directly and indirectly causes DNA damage and increases production of reactive oxygen and nitrogen species (RONS). RONS lead to DNA damage and epigenetic changes leading to mutations and genomic instability (GI). Proliferation amplifies the effects of DNA damage and mutations leading to the AO of breast cancer. Separately, RONS and DNA damage also increase inflammation. Inflammation contributes to direct and indirect effects (effects in cells not directly reached by IR) via positive feedback to RONS and DNA damage, and separately increases proliferation and breast cancer through pro-carcinogenic effects on cells and tissue. For example, gene expression changes alter inflammatory mediators, resulting in improved survival and growth of cancer cells and a more hospitable tissue environment. All of these events overlap at multiple points with events characteristic of "background" induction of breast carcinogenesis, including hormone-responsive proliferation, oxidative activity, and DNA damage. These overlaps make the breast particularly susceptible to ionizing radiation and reinforce that these biological activities are important characteristics of carcinogens. Agents that increase these biological processes should be considered potential breast carcinogens, and predictive methods are needed to identify chemicals that increase these processes. Techniques are available to measure RONS, DNA damage and mutation, cell proliferation, and some inflammatory proteins or processes. Improved assays are needed to measure GI and chronic inflammation, as well as the interaction with hormonally driven development and proliferation. Several methods measure diverse epigenetic changes, but it is not clear which changes are relevant to breast cancer. In addition, most toxicological assays are not conducted in mammary tissue, and so it is a priority to evaluate if results from other tissues are generalizable to breast, or to conduct assays in breast tissue. Developing and applying these assays to identify exposures of concern will facilitate efforts to reduce subsequent breast cancer risk.

Clinical Practice Recommendations Based on an Updated Review of Breast Cancer Risk Among Women Treated for Childhood Cancer

Breast cancer is the most common secondary malignancy among women treated for childhood cancer. This review highlights interacting etiologies contributing to development of secondary breast cancer to complement guidelines for surveillance and survivorship care and make recommendations for clinical practice. Treatment exposures determine Children's Oncology Group breast cancer surveillance guidelines; those treated with cumulative doses ≥20 Gy chest irradiation should undergo annual magnetic resonance imaging and mammography after age 25 years or 8 years after exposure, whichever comes last. Recent investigations suggest that those treated with cumulative doses ≥10 Gy in fields affecting breast tissue, specifically whole lung, should be counseled for similar surveillance. Childhood sarcoma and leukemia survivors treated with anthracyclines and/or alkylating agents without radiation have increased risk for breast cancer and may require enhanced surveillance. Multigene testing and/or genomic evaluation for predisposition among certain childhood cancer subtypes may prove to be beneficial in identifying those at greatest risk. Pediatric oncology nurses who incorporate this information into survivorship care planning discussions/documents and clinical research endeavors may help reduce breast cancer-related morbidity/mortality for this at-risk population.

New exposure biomarkers as tools for breast cancer epidemiology, biomonitoring, and prevention: a systematic approach based on animal evidence

BACKGROUND

Exposure to chemicals that cause rodent mammary gland tumors is common, but few studies have evaluated potential breast cancer risks of these chemicals in humans.

OBJECTIVE

The goal of this review was to identify and bring together the needed tools to facilitate the measurement of biomarkers of exposure to potential breast carcinogens in breast cancer studies and biomonitoring.

METHODS

We conducted a structured literature search to identify measurement methods for exposure biomarkers for 102 chemicals that cause rodent mammary tumors. To evaluate concordance, we compared human and animal evidence for agents identified as plausibly linked to breast cancer in major reviews. To facilitate future application of exposure biomarkers, we compiled information about relevant cohort studies.

RESULTS

Exposure biomarkers have been developed for nearly three-quarters of these rodent mammary carcinogens. Analytical methods have been published for 73 of the chemicals. Some of the remaining chemicals could be measured using modified versions of existing methods for related chemicals. In humans, biomarkers of exposure have been measured for 62 chemicals, and for 45 in a nonoccupationally exposed population. The Centers for Disease Control and Prevention has measured 23 in the U.S. population. Seventy-five of the rodent mammary carcinogens fall into 17 groups, based on exposure potential, carcinogenicity, and structural similarity. Carcinogenicity in humans and rodents is generally consistent, although comparisons are limited because few agents have been studied in humans. We identified 44 cohort studies, with a total of > 3.5 million women enrolled, that have recorded breast cancer incidence and stored biological samples.

CONCLUSIONS

Exposure measurement methods and cohort study resources are available to expand biomonitoring and epidemiology related to breast cancer etiology and prevention.

Environmental exposures and mammary gland development: state of the science, public health implications, and research recommendations

OBJECTIVES

Perturbations in mammary gland (MG) development may increase risk for later adverse effects, including lactation impairment, gynecomastia (in males), and breast cancer. Animal studies indicate that exposure to hormonally active agents leads to this type of developmental effect and related later life susceptibilities. In this review we describe current science, public health issues, and research recommendations for evaluating MG development.

DATA SOURCES

The Mammary Gland Evaluation and Risk Assessment Workshop was convened in Oakland, California, USA, 16-17 November 2009, to integrate the expertise and perspectives of scientists, risk assessors, and public health advocates. Interviews were conducted with 18 experts, and seven laboratories conducted an MG slide evaluation exercise. Workshop participants discussed effects of gestational and early life exposures to hormonally active agents on MG development, the relationship of these developmental effects to lactation and cancer, the relative sensitivity of MG and other developmental end points, the relevance of animal models to humans, and methods for evaluating MG effects.

SYNTHESIS

Normal MG development and MG carcinogenesis demonstrate temporal, morphological, and mechanistic similarities among test animal species and humans. Diverse chemicals, including many not considered primarily estrogenic, alter MG development in rodents. Inconsistent reporting methods hinder comparison across studies, and relationships between altered development and effects on lactation or carcinogenesis are still being defined. In some studies, altered MG development is the most sensitive endocrine end point.

CONCLUSIONS

Early life environmental exposures can alter MG development, disrupt lactation, and increase susceptibility to breast cancer. Assessment of MG development should be incorporated in chemical test guidelines and risk assessment.

Screening and surveillance for second malignant neoplasms in adult survivors of childhood cancer: a report from the childhood cancer survivor study

BACKGROUND

Survivors of childhood cancer may develop a second malignant neoplasm during adulthood and therefore require regular surveillance.

OBJECTIVE

To examine adherence to population cancer screening guidelines by survivors at average risk for a second malignant neoplasm and adherence to cancer surveillance guidelines by survivors at high risk for a second malignant neoplasm.

DESIGN

Retrospective cohort study.

SETTING

The Childhood Cancer Survivor Study (CCSS), a 26-center study of long-term survivors of childhood cancer that was diagnosed between 1970 and 1986.

PATIENTS

4329 male and 4018 female survivors of childhood cancer who completed a CCSS questionnaire assessing screening and surveillance for new cases of cancer.

MEASUREMENTS

Patient-reported receipt and timing of mammography, Papanicolaou smear, colonoscopy, or skin examination was categorized as adherent to the U.S. Preventive Services Task Force guidelines for survivors at average risk for breast or cervical cancer or the Children's Oncology Group guidelines for survivors at high risk for breast, colorectal, or skin cancer as a result of cancer therapy.

RESULTS

In average-risk female survivors, 2743 of 3392 (80.9%) reported having a Papanicolaou smear within the recommended period, and 140 of 209 (67.0%) reported mammography within the recommended period. In high-risk survivors, rates of recommended mammography among women were only 241 of 522 (46.2%) and the rates of colonoscopy and complete skin examinations among both sexes were 91 of 794 (11.5%) and 1290 of 4850 (26.6%), respectively.

LIMITATIONS

Data were self-reported. Participants in the CCSS are a selected group of survivors, and their adherence may not be representative of all survivors of childhood cancer.

CONCLUSION

Female survivors at average risk for a second malignant neoplasm show reasonable rates of screening for cervical and breast cancer. However, surveillance for new cases of cancer is very low in survivors at the highest risk for colon, breast, or skin cancer, suggesting that survivors and their physicians need education about their risks and recommended surveillance.

PRIMARY FUNDING SOURCE

The National Cancer Institute, National Institutes of Health, and the American Lebanese Syrian Associated Charities.