Better contralateral breast cancer risk estimation and alternative options to contralateral prophylactic mastectomy

Outcomes from low-risk ductal carcinoma in situ: a systematic review and meta-analysis

PURPOSE

The current standard of treatment for ductal carcinoma in situ (DCIS) is surgery with or without adjuvant radiotherapy. With a growing debate about overdiagnosis and overtreatment of low-risk DCIS, active surveillance is being explored in several ongoing trials. We conducted a systematic review and meta-analysis to evaluate the recurrence of low-risk DCIS under various treatment approaches.

METHODS

PubMed, Embase, Web of Science, and Cochrane were searched for studies reporting ipsilateral breast tumour event (IBTE), contralateral breast cancer (CBC), and breast cancer-specific survival (BCSS) rates at 5 and 10 years in low-risk DCIS. The primary outcome was invasive IBTE (iIBTE) defined as invasive progression in the ipsilateral breast.

RESULTS

Thirty three eligible studies were identified, involving 47,696 women with low-risk DCIS. The pooled 5-year and 10-year iIBTE rates were 3.3% (95% confidence interval [CI]: 1.3, 8.1) and 5.9% (95% CI: 3.8, 9.0), respectively. The iIBTE rates were significantly lower in patients who underwent surgery compared to those who did not, at 5 years (3.5% vs. 9.0%, P = 0.003) and 10 years (6.4% vs. 22.7%, P = 0.008). Similarly, the 10-year BCSS rate was higher in the surgery group (96.0% vs. 99.6%, P = 0.010). In patients treated with breast-conserving surgery, additional radiotherapy significantly reduced IBTE risk, but not total-CBC risk.

CONCLUSION

This review showed a lower risk of progression and better survival in women who received surgery and additional RT for low-risk DCIS. However, our findings were primarily based on observational studies, and should be confirmed with the results from the ongoing trials.

Age-Related Incidence and Peak Occurrence of Contralateral Breast Cancer

Importance

Young patients with breast cancer have higher risk for developing contralateral breast cancer (CBC) and have epidemiologic characteristics different from those of older patients.

Objective

To examine the incidence and peak occurrence of CBC according to age at primary breast cancer (PBC) surgery.

Design, Setting, and Participants

This cohort study included patients who were diagnosed with and underwent surgery for unilateral nonmetastatic breast cancer at Asan Medical Center, Korea, between January 1, 1999, and December 31, 2013, with follow-up through December 31, 2018. Data were analyzed from December 1, 2021, through April 30, 2023. Patients were divided into 2 groups according to their age at surgery for PBC: younger (≤35 years) vs older (>35 years).

Main Outcomes and Measures

The main outcomes were cumulative incidence and hazard rate of CBC in the entire study population and in subgroups divided by cancer subtype, categorized according to hormone receptor (HR) and ERBB2 status.

Results

A total of 16 251 female patients with stage 0 to III breast cancer were analyzed; all patients were Korean. The mean (SD) age was 48.61 (10.06) years; 1318 patients (8.11%) were in the younger group, and 14 933 (91.89%) were in the older group. Median follow-up was 107 months (IQR, 79-145 months). Compared with the older group, the younger group had significantly higher incidence of CBC (10-year cumulative incidence, 7.1% vs 2.9%; P < .001) and higher risk (hazard ratio, 2.10; 95% CI, 1.62-2.74) of developing CBC. The hazard rate, which indicates risk for developing CBC at a certain time frame, differed according to the subtype of primary cancer. In patients with the HR+/ERBB2- subtype, the risk increased continuously in both age groups. In patients with the triple negative subtype, the risk increased until approximately 10 years and then decreased in both age groups. Meanwhile, in the HR-/ERBB2+ subtype, risk peaked earlier, especially in the younger group (1.7 years since first surgery in the younger group and 4.8 years in the older group).

Conclusions and Relevance

In this cohort study, patients aged 35 years or younger with breast cancer had a higher risk of developing CBC than older patients. Moreover, young patients with the HR-/ERBB2+ subtype tended to have a shorter interval for developing CBC. These findings might be useful in guiding treatment decisions, such as contralateral prophylactic mastectomy.

Choosing Mastectomy vs. Lumpectomy-With-Radiation: Experiences of Breast Cancer Survivors

Background

Annually about 280,000 women are diagnosed with breast cancer. Treatment options depend on age, comorbidities, tumor stage, grade, size, and other factors. Often, patients must decide between two surgical treatment options: mastectomy or lumpectomy-with-radiation herein simply called a lumpectomy. Since both offer similar survival outcomes, the choice ultimately is the patient’s. However, most rely on inputs from doctors, family, friends, personal research, and other actions. We believe decision-making processes for future patients will be aided if experiences of prior breast cancer survivors are known. This study’s aim is to provide such information.

Methods

Feedback from prior breast cancer survivors was obtained using a 19-question survey distributed online to multiple breast cancer support groups. It focused on issues relevant to choosing between the two surgical options including, post-surgical complications, breast reconstruction, chronic pain, cosmetics, and surgery-choice satisfaction.

Results

Respondents (N=1606) had a median age of 49 years (range 26 to 88 years) and had a median body mass index (BMI) of 26.6 Kg/m². There were 978 mastectomy patients (60.9%) and 628 lumpectomy patients (39.1%). With regard to post-surgical reconstruction, 64.2% of mastectomy respondents and 13.5% of lumpectomy respondents decided to undergo breast cancer reconstruction following breast cancer surgery. Almost all (99.8%) of lumpectomy respondents had radiation side-effects; with skin irritation and thickening and chest wall tenderness being the most common. Among mastectomy patients, 94.3% had one or more complications; loss-or-changes in nipple or breast sensation, uneven breasts, chest wall tenderness, and breast swelling were the most common complications. Post-surgical pain lasting six months or more was experienced by a smaller percentage of mastectomy vs. lumpectomy patients (64.1% vs. 78%, p <0.00001). Mastectomy patients were also less likely to have pain that was persistent and present up to the time of the survey (35.4% vs. 46.0%, p=0.0002). With respect to cosmetic outcomes, mastectomy patients vs. lumpectomy patients were less likely to be either satisfied or very satisfied (52.2% vs. 62.7%, p=0.00004). Overall satisfaction of surgical treatment was 70.9% for mastectomy patients and 68.6% for lumpectomy patients.

Conclusion

Based on the experiences of these breast cancer survivors, mastectomy is associated with less chronic pain frequency and lower incidence of post-surgical side effects compared to lumpectomy. However, mastectomy is associated with lower cosmetic satisfaction. Breast cancer survivors that underwent a lumpectomy, reported being more satisfied with cosmetic outcomes but almost all reported radiation side-effects with skin thickening listed as the most common. Lumpectomy was also associated with higher chronic pain frequency compared to mastectomy.

The overall surgical treatment satisfaction reported by mastectomy and lumpectomy respondents was similar. The composite findings will provide information that will aid future breast cancer patients in making a decision between having a mastectomy or a lumpectomy.

The risk of contralateral breast cancer: a SEER-based analysis

BACKGROUND

We sought to estimate the annual risk and 25-year cumulative risk of contralateral breast cancer among women with stage 0-III unilateral breast cancer.

METHODS

We identified 812,851 women with unilateral breast cancer diagnosed between 1990 and 2015 in the SEER database and followed them for contralateral breast cancer for up to 25 years. Women with a known bilateral mastectomy were excluded. We calculated the annual risk of contralateral breast cancer by age at diagnosis, by time since diagnosis and by current age. We compared risks by ductal carcinoma in situ (DCIS) versus invasive disease, by race and by oestrogen receptor (ER) status of the first cancer.

RESULTS

There were 25,958 cases of contralateral invasive breast cancer diagnosed (3.2% of all patients). The annual risk of contralateral breast cancer over the 25-year follow-up period was 0.37% and the 25-year actuarial risk of contralateral invasive breast cancer was 9.9%. The annual risk varied to a small degree by age of diagnosis, by time elapsed since diagnosis and by current age. The 25-year actuarial risk was similar for DCIS and invasive breast cancer patients (10.1 versus 9.9%). The 25-year actuarial risk was higher for black women (12.7%) than for white women (9.7%) and was lower for women with ER-positive breast cancer (9.5%) than for women with ER-negative breast cancer (11.2%).

CONCLUSIONS

Women with unilateral breast cancer experience an annual risk of contralateral breast cancer ~0.4% per year, which persists over the 25-year follow-up period.

Longitudinal Study of Psychosocial Outcomes Following Surgery in Women with Unilateral Nonhereditary Breast Cancer

INTRODUCTION

Rates of bilateral mastectomy are rising in women with unilateral, nonhereditary breast cancer. We aim to characterize how psychosocial outcomes evolve after breast cancer surgery.

PATIENTS AND METHODS

We performed a prospective cohort study of women with unilateral, sporadic stage 0-III breast cancer at University Health Network in Toronto, Canada between 2014 and 2017. Women completed validated psychosocial questionnaires (BREAST-Q, Impact of Event Scale, Hospital Anxiety & Depression Scale) preoperatively, and at 6 and 12 months following surgery. Change in psychosocial scores was assessed between surgical groups using linear mixed models, controlling for age, stage, and adjuvant treatments. P < .05 were significant.

RESULTS

A total of 475 women underwent unilateral lumpectomy (42.5%), unilateral mastectomy (38.3%), and bilateral mastectomy (19.2%). There was a significant interaction (P < .0001) between procedure and time for breast satisfaction, psychosocial and physical well-being. Women having unilateral lumpectomy had higher breast satisfaction and psychosocial well-being scores at 6 and 12 months after surgery compared with either unilateral or bilateral mastectomy, with no difference between the latter two groups. Physical well-being declined in all groups over time; scores were not better in women having bilateral mastectomy. While sexual well-being scores remained stable in the unilateral lumpectomy group, scores declined similarly in both unilateral and bilateral mastectomy groups over time. Cancer-related distress, anxiety, and depression scores declined significantly after surgery, regardless of surgical procedure (P < .001).

CONCLUSIONS

Psychosocial outcomes are not improved with contralateral prophylactic mastectomy in women with unilateral breast cancer. Our data may inform women considering contralateral prophylactic mastectomy.

Breast Reconstruction with a Lateral Breast Free Flap: A New Application of Breast-sharing

Supplemental Digital Content is available in the text.

Breast reconstruction using contralateral autologous tissue, also known as breast sharing, is a viable option previously described in the literature, whereby flaps based on perforators of the internal mammary artery (internal mammary artery pedicle) are used. We report a postoncological breast reconstruction case using a microvascular flap taken from the lateral pole of the contralateral breast. We highlight the importance of preserving the medial pole of the donor breast for improving cosmesis, avoiding symmastia, and preserving the intermammary sulcus, as a difference with flaps based on the internal mammary artery pedicle flaps. Breast sensation could be recovered by neurotization of the lateral intercostal nerve, which may be included in the contralateral breast flap to be transferred. Contralateral breast free flaps could be an alternative to reconstruct the breast in selected patients. Oncological risk factors are discussed. Advances in genetic testing and tumor cell biology could help us to select the accurate candidates for this reconstructive technique.

Preventive drug therapy and contralateral breast cancer: summary of the evidence of clinical trials and observational studies

Background: Breast cancer patients have a lifelong 2-4-fold increased risk of developing a second primary tumor in the contralateral breast compared with the risk for a first primary breast cancer in the general female population. Prevention of contralateral breast cancer (CBC) has received increased attention during recent decades. Here, we summarize and discuss the available literature on drug preventive therapy and CBC.Results: The endocrine-targetting drugs, tamoxifen and aromatase inhibitors are used as standard adjuvant treatment for estrogen receptor (ER)-positive breast cancer. Both are associated with relative risk reductions of CBC of up to 50%, but incur serious side effects. Several prescription drugs originally developed for other purposes, including bisphosphonates, statins, non-steroidal anti-inflammatory drugs, metformin, anti-hypertensives and retinoids, have shown anti-cancer activity in preclinical models. However, results of observational studies on CBC are sparse and inconsistent, with only statins demonstrating promise as preventive agents and a potential treatment option for ER-negative breast cancer patients.Conclusion: Future studies are needed to assess the effect of statins in risk reduction and to identify other drugs with chemopreventive potential against CBC. Eventually, efforts must be directed towards identifying those breast cancer patients likely to benefit most from specific preventive therapies.

Genetic ablation of mammary ducts through foxa1 prevents breast cancer occurrence

Risk reducing mastectomy is the only surgical approach for the prevention of breast cancer in women with deleterious genetic mutations or in those deemed to be at extremely high risk. However, up to 10.5% of these women still developed breast cancer. Thus, developing new strategies for complete prevention of breast cancer is imperative. Mammary ducts were ablated by mammary-specific ablation of forkhead box protein A1 (Foxa1). Mammary tumorigenesis was induced in control and mammary-specific Foxa1 knockout mice using carcinogens. No mammary tumors were observed in these knockout mice compared to four types of breast tumors induced in control mice. We present a promising novel strategy for the prevention of breast cancer by genetic ablation of mammary ducts via targeting Foxa1.

A Clinical Decision Support Tool to Predict Cancer Risk for Commonly Tested Cancer-Related Germline Mutations

The rapid drop in the cost of DNA sequencing led to the availability of multi-gene panels, which test 25 or more cancer susceptibility genes for a low cost. Clinicians and genetic counselors need a tool to interpret results, understand risk of various cancers, and advise on a management strategy. This is challenging as there are multiple studies regarding each gene, and it is not possible for clinicians and genetic counselors to be aware of all publications, nor to appreciate the relative accuracy and importance of each. Through an extensive literature review, we have identified reliable studies and derived estimates of absolute risk. We have also developed a systematic mechanism and informatics tools for (1) data curation, (2) the evaluation of quality of studies, and (3) the statistical analysis necessary to obtain risk. We produced the risk prediction clinical decision support tool ASK2ME (All Syndromes Known to Man Evaluator). It provides absolute cancer risk predictions for various hereditary cancer susceptibility genes. These predictions are specific to patients' gene carrier status, age, and history of relevant prophylactic surgery. By allowing clinicians to enter patient information and receive patient-specific cancer risks, this tool aims to have a significant impact on the quality of precision cancer prevention and disease management activities relying on panel testing. It is important to note that this tool is dynamic and constantly being updated, and currently, some of its limitations include (1) for many gene-cancer associations risk estimates are based on one study rather than meta-analysis, (2) strong assumptions on prior cancers, (3) lack of uncertainty measures, and (4) risk estimates for a growing set of gene-cancer associations which are not always variant specific. All of these concerns are being addressed on an ongoing basis, aiming to make the tool even more accurate.

Chair Heterogeneity Index: Describing the dose heterogeneity inside the tumor volume where there is a boost volume

In this report, Chair Heterogeneity Index (CHI) was introduced to assess the dose heterogeneity inside the target with a boost volume. CHI was defined by dividing (V_Rx − V_Dl) by (V_Dm − V_Dh): V_Rx, V_Dl, V_Dm and V_Dh were four points selected from the target cumulative dose volume histogram curve. The effectiveness of CHI was validated by assessing the treatment plans for nasopharyngeal cancer (NPC, 12 cases), breast cancer after breast-conserving-surgery (BC, 10 cases), and stereotactic radiosurgery after whole brain irradiation (SRS, 9 cases). Our results indicate that both CHI and HI of the target can distinguish Volumetric Modulated Arc Therapy (VMAT) from Intensity Modulated Radiation Therapy (IMRT, p < 0.05) while the mean differences in CHI (NPC 1.16, BC 1.19 and SRS 3.3) were larger than those in HI (NPC 0.03, BC 0.02 and SRS 0.02). In addition, CHI of the combination volume (the target minus the boost) were statistically higher in VMAT than IMRT in all three kinds of cancer. In conclusion, CHI was effective in assessing the dose heterogeneity inside a target containing a boost volume.

Endocrine therapy and related issues in hormone receptor-positive early breast cancer: a roundtable discussion by the breast cancer therapy expert group (BCTEG)

Purpose

Management of breast cancer is a rapidly evolving field, and, although evidence-based guidelines are available for clinicians to provide direction on critical issues in patient care, clinicians often left to address these issues in the context of community practice situations with their patients. These include the patient’s comorbid conditions, actual versus perceived benefit of treatments, patient’s compliance as well as financial/reimbursement issues, and long-term tolerability of therapy.

Methods

A meeting of global oncology experts was convened in January 2017 with the belief that there is a gap in clinical practice guidance on several fundamental issues in breast cancer care, particularly in the community setting, where oncologists may encounter multiple tumor types. The goal was to discuss some of the most important questions in this area and provide some guidance for practicing oncologists.

Results

Topics addressed included risk of contralateral breast cancer recurrence in patients with estrogen receptor-positive early breast cancer who have undergone 5 years of adjuvant endocrine therapy, adverse events associated with endocrine therapy and their management, emergent data on adjuvant bisphosphonate therapy and its apparent benefit in reducing breast cancer recurrence, recent findings of extended adjuvant endocrine therapy trials, and the use of currently available genomic biomarker tests as a means of further informing treatment decisions.

Conclusions

A summary of the discussion on these topics and several ‘expert opinion statements’ are provided herein in an effort to convey the collective insights of the panel as it relates to current standard practice.

Nipple aspirate fluid-A liquid biopsy for diagnosing breast health

Purpose

Nipple secretions are protein‐rich and a potential source of breast cancer biomarkers for breast cancer screening. Previous studies of specific proteins have shown limited correlation with clinicopathological features. Our aim, in this pilot study, was to investigate the intra‐ and interpatient protein composition of nipple secretions and the implications for their use as liquid biopsies.

Experimental design

Matched pairs of nipple discharge/nipple aspirate fluid (NAF, n = 15) were characterized for physicochemical properties and SDS‐PAGE. Four pairs were selected for semiquantitative proteomic profiling and trypsin‐digested peptides analyzed using 2D‐LC Orbitrap Fusion MS. The resulting data were subject to bioinformatics analysis and statistical evaluation for functional significance.

Results

A total of 1990 unique proteins were identified many of which are established cancer‐associated markers. Matched pairs shared the greatest similarity (average Pearson correlation coefficient of 0.94), but significant variations between individuals were observed.

Conclusions and clinical relevance

This was the most complete proteomic study of nipple discharge/nipple aspirate fluid to date providing a valuable source for biomarker discovery. The high level of milk proteins in healthy volunteer samples compared to the cancer patients was associated with galactorrhoea. Using matched pairs increased confidence in patient‐specific protein levels but changes relating to cancer stage require investigation of a larger cohort.

Association of Adjuvant Tamoxifen and Aromatase Inhibitor Therapy With Contralateral Breast Cancer Risk Among US Women With Breast Cancer in a General Community Setting

Importance

Within 10 years after breast cancer diagnosis, roughly 5% of patients develop contralateral breast cancer (CBC). Randomized trials have found that therapy including tamoxifen citrate and aromatase inhibitors (AIs) reduces CBC risk. But little is known about the magnitude and duration of protective associations within the context of real-world clinical management settings, where varying durations of and gaps in treatment are common.

Objective

To determine the association between adjuvant tamoxifen and AI therapy and CBC risk within a general community setting.

Design, Setting, and Participants

A retrospective cohort study of CBC risk among 7541 patients diagnosed with a first primary unilateral invasive breast cancer at Kaiser Permanente Institute for Health Research (Colorado) or Kaiser Permanente Northwest Center for Health Research (Oregon) between January 1, 1990, and December 31, 2008. Data were analyzed from 1 year after diagnosis of the first breast cancer through the earliest of the following events: CBC diagnosis, other second cancer diagnosis, death, last tumor registry follow-up, exit from the Kaiser Permanente health care plan, or end of study follow-up (December 31, 2010, for Oregon and December 31, 2011, for Colorado).

Exposures

Adjuvant tamoxifen use and AI therapy were treated as time-dependent exposures, assessed using electronic prescription records.

Main Outcomes and Measures

Incident CBC based on long-term systematic follow-up.

Results

Among 7541 women with invasive breast cancer, median age at initial breast cancer diagnosis was 60.6 years (age range, 24.9-84.9 years). Women were predominantly (92.9% [7009 of 7541]) of white race. During a median of 6.3 years (range, 1-20.9 years) of follow-up, 248 women developed CBC (45 in situ and 203 invasive). Contralateral breast cancer risk decreased significantly with increasing tamoxifen therapy duration. In current users, the relative risk (RR) per year of tamoxifen use was 0.76 (95% CI, 0.64-0.89), with an estimated 66% (RR, 0.34; 95% CI, 0.29-0.40) RR reduction for 4 years of use compared with nonusers. Risk reductions were slightly smaller for past users but were still significant at least 5 years after stopping tamoxifen therapy (RR per year of use, 0.85; 95% CI, 0.71-0.995). In addition, AI use without tamoxifen therapy was associated with reduced CBC risk (RR for AI users compared with nonusers, 0.48; 95% CI, 0.22-0.97). Risk reductions were most apparent among women whose primary and CBCs were estrogen receptor positive.

Conclusions and Relevance

Tamoxifen therapy was associated with reduced CBC risk during treatment and after its cessation, with risk progressively decreasing as tamoxifen therapy duration increased. Among those surviving at least 5 years, tamoxifen use for at least 4 years was estimated to prevent 3 CBCs per 100 women by 10 years after an estrogen receptor-positive first breast cancer, an absolute risk reduction that is consistent with findings from clinical trials. If adjuvant endocrine therapy is indicated for breast cancer treatment, these findings in concert with trial data suggest that women should be encouraged to complete the full course.