Patient-Reported Outcomes in OlympiA: A Phase III, Randomized, Placebo-Controlled Trial of Adjuvant Olaparib in gBRCA1/2 Mutations and High-Risk Human Epidermal Growth Factor Receptor 2-Negative Early Breast Cancer.

PURPOSE: The OlympiA randomized phase III trial compared 1 year of olaparib (OL) or placebo (PL) as adjuvant therapy in patients with germline BRCA1/2, high-risk human epidermal growth factor receptor 2-negative early breast cancer after completing (neo)adjuvant chemotherapy ([N]ACT), surgery, and radiotherapy. The patient-reported outcome primary hypothesis was that OL-treated patients may experience greater fatigue during treatment. METHODS: Data were collected before random assignment, and at 6, 12, 18, and 24 months. The primary end point was fatigue, measured with the Functional Assessment of Chronic Illness Therapy-Fatigue scale. Secondary end points, assessed with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, Core 30 item, included nausea and vomiting (NV), diarrhea, and multiple functional domains. Scores were compared between treatment groups using mixed model for repeated measures. Two-sided P values <.05 were statistically significant for the primary end point. All secondary end points were descriptive. RESULTS: One thousand five hundred and thirty-eight patients (NACT: 746, ACT: 792) contributed to the analysis. Fatigue severity was statistically significantly greater for OL versus PL, but not clinically meaningfully different by prespecified criteria (≥3 points) at 6 months (diff OL v PL: NACT: -1.3 [95% CI, -2.4 to -0.2]; P = .022; ACT: -1.3 [95% CI, -2.3 to -0.2]; P = .017) and 12 months (NACT: -1.6 [95% CI, -2.8 to -0.3]; P = .017; ACT: -1.3 [95% CI, -2.4 to -0.2]; P = .025). There were no significant differences in fatigue severity between treatment groups at 18 and 24 months. NV severity was worse in patients treated with OL compared with PL at 6 months (NACT: 6.0 [95% CI, 4.1 to 8.0]; ACT: 5.3 [95% CI, 3.4 to 7.2]) and 12 months (NACT: 6.4 [95% CI, 4.4 to 8.3]; ACT: 4.5 [95% CI, 2.8 to 6.1]). During treatment, there were some clinically meaningful differences between groups for other symptoms but not for function subscales or global health status. CONCLUSION: Treatment-emergent symptoms from OL were limited, generally resolving after treatment ended. OL- and PL-treated patients had similar functional scores, slowly improving during the 24 months after (N)ACT and there was no clinically meaningful persistence of fatigue severity in OL-treated patients.

Physical Activity and Mammographic Density in Japanese Women.

BACKGROUND: Dense breast is one of the strong risk factors for breast cancer among women. While it has been established that physical activity is associated with decreased risk for breast cancer, results have been inconsistent in terms of mammographic density. Thus, we examined physical activity in relation to mammographic density among Japanese women in Tokyo. METHODS: We used 123,026 records from 33,698 Japanese women without a history of breast cancer who got mammograms at St. Luke's International Hospital in Tokyo, Japan from 2004 to 2019. Mammographic density was classified according to the Breast Imaging Reporting and Data System (BI-RADS), and women self-reported their physical activity level over the past year. ORs were estimated using logistic generalized estimating equations after adjusting for age, body mass index, menopausal status, parity, family history of breast or ovarian cancer, hormone therapy use, smoking status, alcohol consumption, and year. RESULTS: We observed inverse associations of physical activity with dense breasts. Adjusted ORs were 0.96 (95% confidence interval: 0.91-1.00) for women with physical exercise for 1-2 days per week, 0.94 (0.88-0.99) for those with physical exercise for 3-5 days per week, and 0.91 (0.84-0.99) for those with daily physical exercise when compared with those reported seldom physical exercise. CONCLUSIONS: Higher levels of physical activity may be associated with decreased mammographic density levels in Japanese women. IMPACT: Increasing physical activity may serve as a reasonable intervention to reduce mammographic density, and thereby, to mitigate the risk of breast cancer in Asian women.

Post-traumatic growth and cancer-related communication among adolescents having mothers with breast cancer.

PURPOSE: This study aimed to clarify the characteristics of post-traumatic growth (PTG) among adolescents having mothers diagnosed with breast cancer and the relationship between PTG and cancer-related communication with breast cancer survivors. METHODS: A cross-sectional study was conducted using anonymous self-report questionnaires with breast cancer survivors and adolescent children. PTG in adolescents was measured using the Japanese version of the revised PTG Inventory for Children (PTGI-C-R-J). Furthermore, hierarchical multiple regression analysis was implemented. To evaluate the impact of cancer-related communication on each subscale, the total score of cancer-related communication was switched with other subscales individually within the constructed model. RESULTS: A total of 97 breast cancer survivors and their adolescent children were included. The mean scores of the total PTGI-C-R-J and subscale scores for "personal strength," "new possibilities," "relating to others," "appreciation of life," and "spiritual change" were 9.0, 1.7, 1.8, 2.3, 2.4, and 0.9, respectively. The connection between PTG and cancer-related communication was partially clarified. The PTGI-C-R-J score was higher when adolescents shared more information regarding breast cancer with their mothers and lower when adolescents expressed more negative feelings toward their mothers. Communication regarding relationships with mothers was not correlated with PTG. CONCLUSIONS: Of all PTG domains, "relating to others" and "appreciation of life" were comparatively higher in adolescents. Health professionals should support breast cancer survivors to ensure that they convey appropriate information regarding their treatment plans and side effects to their adolescent children. Health professionals should help adolescent children express their negative feelings calmly and clearly.

[Treatment Strategy for HER2 Positive and HER2 Low Breast Cancer].

Human epidermal growth factor receptor 2(HER2)positive breast cancer has been regarded as a poor prognosis breast cancer, but since the development of trastuzumab and various anti-HER2 drugs, the prognosis has significantly improved. Also, combining anti-HER2 drugs with chemotherapy as preoperative treatment, shows high ratings of pathological complete response(pCR). In terms of breast cancer, pCR is a prognosis predictive factor. As a result, in perioperative treatment for HER2 positive breast cancer, residual disease-guided approach which means to select postoperative treatment according to the response to preoperative chemotherapy has become the main stream. Furthermore, trastuzumab deruxtecan, which had been covered by insurance only for HER2 positive metastatic or recurrent breast cancer, was newly reimbursed for breast cancer with low HER2 expression at the end of March 2023, and the future movement is attracting attention.

Radiation-induced angiosarcoma of the breast: individual participant meta-analysis of Japanese population.

BACKGROUND: Radiation-induced angiosarcoma (RIAS) of the breast is a very rare and poor prognostic disease. According to previous studies, the efficacy of chemotherapy for RIAS is still controversial. However, no study has assessed the prognosis of RIAS and the prognostic impact of preoperative or postoperative chemotherapy in Japanese patients. Our study aimed to assess them in Japanese people using publication data with our three patients. METHODS: Thirty-nine patients diagnosed with RIAS, including 36 patients from 34 published case series, and three patients from our hospital were used for analysis. Disease-free survival (DFS), distant disease-free survival (DDFS), and overall survival (OS) were assessed. RESULTS: Among the 39 patients, 36 patients (92.3%) underwent surgery. The median DFS and OS periods were 14 months (range 1-75 months) and 23 months (range 4-84 months), respectively. Chemotherapy with taxane-based regimen was administered in 13 cases (33.2%) pre- or post-operatively. DFS was significantly improved with chemotherapy in addition to surgery (p = 0.037). However, addition of chemotherapy to surgery did not improve DDFS (p = 0.09) and OS (p = 0.878). In multivariate analysis, age ≥ 70 years was an independent but poor prognostic factor of DFS. Additionally, a lack of chemotherapy showed a trend to be associated with worse DFS. There was no independent variable contributing to DDFS and OS. CONCLUSIONS: Chemotherapy may have reduced the recurrence rate of RIAS in Japanese patients but did not improve OS. Further data are needed to confirm the efficacy and proper regimen of chemotherapy.

Oncofertility-related psycho-educational therapy for young adult patients with breast cancer and their partners: Randomized controlled trial.

BACKGROUND: A couples' psycho-educational program called Oncofertility! Psycho-Education and Couple Enrichment (O!PEACE) therapy was created and its effect when provided before cancer treatment was examined. METHODS: This multicenter randomized controlled trial with nonmasking, parallel two-group comparison enrolled women aged 20 to 39 years with early-stage breast cancer and their partners. They were randomly assigned to receive O!PEACE (37 couples) or usual care (37 couples). Primary end points were cancer-related posttraumatic stress symptoms, symptoms of depression, and anxiety. Secondary end points were stress-coping strategies, resilience, and marital relationship. RESULTS: Women receiving psycho-educational therapy had significantly reduced Impact of Event Scale-revised version for Japanese scores (p = .011, ηp 2  =  = .089). For patients with Impact of Event Scale-revised version for Japanese scores at baseline ≥18.27, O!PEACE therapy improved these scores when compared with usual care (U = 172.80, p = .027, r = 0.258). A >5-point reduction was present in 59.3% and 30% of women in the O!PEACE therapy and usual-care groups, respectively. For partners, O!PEACE therapy significantly improved stress-coping strategies (95% CI, -0.60 to -0.05; p = .018, ηp 2  =  = .074) and escape-avoidance marital communication (95% CI, -0.33 to -0.08; p = .001, ηp 2  = .136). O!PEACE therapy significantly improved the partners' support (95% CI, 0.10-0.50; p = .001, ηp 2  = .127), the rate of receiving fertility preservation consultations, and knowledge levels. CONCLUSIONS: O!PEACE therapy before cancer treatment can improve posttraumatic stress symptoms, stress-coping behavior, and marital relationships. Larger sample sizes and longer term follow-up are required. PLAIN LANGUAGE SUMMARY: A psycho-educational program, the Oncofertility! Psycho-Education and Couple Enrichment (O!PEACE) therapy program was developed and evaluated for women diagnosed with breast cancer and their partners. A multicenter randomized controlled trial showed that the O!PEACE psycho-educational therapy, with only two precancer treatment sessions, can reduce cancer-related posttraumatic stress symptoms and improve oncofertility knowledge and marital relationships in young adult patients with breast cancer. The therapy could also improve stress-coping strategies in marital communications with their partners. Couples may use O!PEACE psycho-educational therapy to consider fertility preservation and improve their psychosocial aspects.

Adjuvant olaparib in the subset of patients from Japan with BRCA1- or BRCA2-mutated high-risk early breast cancer from the phase 3 OlympiA trial.

BACKGROUND: The efficacy and safety of olaparib compared with placebo in the subset of patients from Japan in the phase 3 OlympiA trial (NCT02032823) are reported here and contextualized with reference to the global OlympiA population. METHODS: Patients with germline BRCA1 and/or BRCA2 pathogenic variants and HER2-negative, high-risk early breast cancer who had received neoadjuvant or adjuvant chemotherapy and completed local treatment were eligible. Patients were randomized 1:1 to receive olaparib or placebo for 1 year. PRIMARY ENDPOINT: invasive disease-free survival (IDFS). Secondary endpoints: distant disease-free survival (DDFS), overall survival (OS), and safety. Data are reported from the first pre-specified interim analysis (data cut-off [DCO] March 27, 2020) and the second, event driven, pre-specified interim analysis of OS (DCO July 12, 2021) in patients from Japan. RESULTS: 140 patients were randomized in Japan (olaparib, n = 64; placebo, n = 76). At the first pre-specified interim analysis (median follow-up: 2.9 years), hazard ratios (HRs) for adjuvant olaparib compared with placebo were 0.5 for IDFS (95% confidence interval [CI] 0.18-1.24) and 0.41 for DDFS (95% CI 0.11-1.16). At the second pre-specified interim analysis of OS, three deaths occurred in the olaparib group versus six deaths in the placebo group (HR, 0.62 [95% CI 0.13-2.36]). Findings were consistent with those for the global population. No new safety signals were observed. CONCLUSIONS: While this analysis in a Japanese subset of patients was not powered to detect population-related treatment differences, efficacy and safety analysis results were consistent with the global OlympiA population, suggesting the findings from the global study are generalizable to clinical practice in Japan.

Clinicopathological and ultrasound characteristics of breast cancer in BRCA1 and BRCA2 mutation carriers.

PURPOSE: BRCA1 and BRCA2 tumors exhibit different characteristics. This study aimed to assess and compare the ultrasound findings and pathologic features of BRCA1 and BRCA2 breast cancers. To our knowledge, this is the first study to examine the mass formation, vascularity, and elasticity in breast cancers of BRCA-positive Japanese women. METHODS: We identified patients with breast cancer harboring BRCA1 or BRCA2 mutations. After excluding patients who underwent chemotherapy or surgery before the ultrasound, we evaluated 89 cancers in BRCA1-positive and 83 in BRCA2-positive patients. The ultrasound images were reviewed by three radiologists in consensus. Imaging features, including vascularity and elasticity, were assessed. Pathological data, including tumor subtypes, were reviewed. RESULTS: Significant differences in tumor morphology, peripheral features, posterior echoes, echogenic foci, and vascularity were observed between BRCA1 and BRCA2 tumors. BRCA1 breast cancers tended to be posteriorly accentuating and hypervascular. In contrast, BRCA2 tumors were less likely to form masses. In cases where a tumor formed a mass, it tended to show posterior attenuation, indistinct margins, and echogenic foci. In pathological comparisons, BRCA1 cancers tended to be triple-negative subtypes. In contrast, BRCA2 cancers tended to be luminal or luminal-human epidermal growth factor receptor 2 subtypes. CONCLUSION: In the surveillance of BRCA mutation carriers, radiologists should be aware that the morphological differences between tumors are quite different between BRCA1 and BRCA2 patients.

Copy number alteration is an independent prognostic biomarker in triple-negative breast cancer patients.

BACKGROUND: Next-generation sequencing (NGS) has enabled comprehensive genomic profiling to identify gene alterations that play important roles in cancer biology. However, the clinical significance of these genomic alterations in triple-negative breast cancer (TNBC) patients has not yet been fully elucidated. The aim of this study was to clarify the clinical significance of genomic profiling data, including copy number alterations (CNA) and tumor mutation burden (TMB), in TNBC patients. METHODS: A total of 47 patients with Stage I-III TNBC with genomic profiling of 435 known cancer genes by NGS were enrolled in this study. Disease-free survival (DFS) and overall survival (OS) were evaluated for their association to gene profiling data. RESULTS: CNA-high patients showed significantly worse DFS and OS than CNA-low patients (p = 0.0009, p = 0.0041, respectively). TMB was not associated with DFS or OS in TNBC patients. Patients with TP53 alterations showed a tendency of worse DFS (p = 0.0953) and significantly worse OS (p = 0.0338) compared with patients without TP53 alterations. Multivariable analysis including CNA and other clinicopathological parameters revealed that CNA was an independent prognostic factor for DFS (p = 0.0104) and OS (p = 0.0306). Finally, multivariable analysis also revealed the combination of CNA-high and TP53 alterations is an independent prognostic factor for DFS (p = 0.0005) and OS (p = 0.0023). CONCLUSIONS: We revealed that CNA, but not TMB, is significantly associated with DFS and OS in TNBC patients. The combination of CNA-high and TP53 alterations may be a promising biomarker that can inform beyond standard clinicopathologic factors to identify a subgroup of TNBC patients with significantly worse prognosis.

Clinicopathological and imaging features of ductal carcinoma in situ in BRCA1/2 mutation carriers.

BACKGROUND: BRCA1/2-associated invasive breast cancer has been extensively studied. However, there are few reports of ductal carcinoma in situ (DCIS). OBJECTIVE: This study aimed to investigate the clinicopathological and imaging findings of DCIS in patients with BRCA1/2 mutations. METHODS: This was a single-institution, retrospective study. We identified patients diagnosed with DCIS with BRCA mutations between September 2003 and December 2020. Clinicopathological data and mammography (MG), magnetic resonance imaging (MRI), and ultrasound (US) findings were reviewed. RESULTS: We identified 30 cancers in 28 patients; 7 (25.0%) patients had BRCA1 mutations, and 21 (75.0%) had BRCA2 mutations. The median patient age was 42 years. Screening was the most common reason for the detection of DCIS (50.0%), followed by occult cancer diagnosed by pathological examination after risk-reducing mastectomy (26.7%). The nuclear grade was most often 1 (46.7%), and 93.3% were estrogen and/or progesterone receptor positive. The detection rates of MG, MRI, and US were 64.3%, 72.0%, and 64.0%, respectively. The most common imaging findings were calcification (100%) on MG, non-mass enhancement (88.9%) on MRI, and hypoechoic area (75.0%) on US. CONCLUSION: BRCA-associated DCIS was more strongly associated with BRCA2, and imaging features were similar to those of sporadic DCIS. Our results are helpful in informing surveillance strategies based on genotypes in women with BRCA mutations.

Prognostic effect of subsequent childbirth after the diagnosis of breast cancer using propensity score matching analysis.

BACKGROUND: Among younger patients, one of the important concerns is whether they can give birth safely. Although previous studies have investigated this topic, many aspects remain unclear owing to potential biases. We aimed to evaluate the prognostic effect of subsequent childbirth after the diagnosis using propensity score matching. METHODS: A single-center retrospective cohort study was conducted. This study included patients aged ≤ 45 years, diagnosed with breast cancer between 2005 and 2014. Patients with and without subsequent childbirth were assigned to the childbirth and non-childbirth cohorts, respectively. Relapse-free survival (RFS) and overall survival (OS) of the childbirth cohort were compared with those of the non-childbirth cohort. The covariates in the propensity score model included age, tumor size, node status, number of preceding childbirths before the diagnosis, estrogen receptor, and human epidermal growth factor receptor 2 status. RESULTS: 104 patients with childbirth and 2250 without childbirth were assigned to the respective cohorts. At a median follow-up of 82 months, the childbirth cohort showed a significantly longer RFS than the non-childbirth cohort (HR = 0.469 [0.221-0.992]; p = 0.047). There was no significant difference in the OS (HR = 0.208 [0.029-1.494]; p = 0.119). After matching, subsequent childbirth was not significantly associated with RFS (HR = 0.436 [0.163-1.164], p = 0.098) and OS (HR = 0.372 [0.033-4.134], p = 0.402). CONCLUSIONS: Subsequent childbirth was not associated with an increased risk of relapse and mortality. It is important to make younger patients aware of these novel findings and aid them in their decision-making.

The location of unilateral axillary lymphadenopathy after COVID-19 vaccination compared with that of metastasis from breast cancer without vaccination.

PURPOSE: Unilateral axillary lymphadenopathy is known to occur after coronavirus disease (COVID-19) vaccination. Post-vaccination lymphadenopathy may mimic the metastatic lymph nodes in breast cancer, and it is challenging to distinguish between them. This study investigated whether the localization of axillary lymphadenopathy on magnetic resonance imaging (MRI) could be used to distinguish reactive lymphadenopathy after COVID-19 vaccines from metastatic nodes. MATERIALS AND METHODS: We retrospectively examined preoperative MRI images of 684 axillae in 342 patients who underwent breast cancer surgery from June to October 2021. Lymphadenopathy was defined as cortical thickening or short axis ≥ 5 mm. The axilla was divided into ventral and dorsal parts on the axial plane using a perpendicular line extending from the most anterior margin of the muscle group, including the deltoid, latissimus dorsi, or teres major muscles, relative to a line along the lateral chest wall. We recorded the presence or absence of axillary lymphadenopathy in each area and the number of visible lymph nodes. RESULTS: Of 80 axillae, 41 and 39 were included in the vaccine and metastasis groups, respectively. The median time from the last vaccination to MRI was 19 days in the vaccine group. The number of visible axillary lymph nodes was significantly higher in the vaccine group (median, 15 nodes) than in the metastasis group (7 nodes) (P < 0.001). Dorsal lymphadenopathy was observed in 16 (39.0%) and two (5.1%) axillae in the vaccine and metastasis groups, respectively (P < 0.001). If the presence of both ventral and dorsal lymphadenopathy is considered indicative of vaccine-induced reaction, this finding has a sensitivity of 34.1%, specificity of 97.4%, and positive and negative predictive values of 93.3％ and 58.5%, respectively. CONCLUSION: The presence of deep axillary lymphadenopathy may be an important factor for distinguishing post-vaccination lymphadenopathy from metastasis. The number of axillary lymph nodes may also help.

An association between mammographic breast density and fine particulate matter among postmenopausal women.

Increasing breast density is a risk factor for breast cancer. Geographic variations in breast density may be due to differences in lifestyle and diet, as well as environmental factors such as air pollution exposure. However, these environmental contributors have not been established. In this study, we evaluated an association between air pollution and mammographic breast density. The study population for this study was postmenopausal women who had undergone screening mammography at the Center for Preventive Medicine, St. Luke's International Hospital, from April 2004 to September 2018. Individual mammography results were obtained from electronic charts. The ambient air pollution (PM2.5) density of the locations of interest, namely, the patients' residential areas during the study period, was obtained. The mean PM2.5 exposure levels for 1, 3, 5, and 7 years were determined. A generalized estimating equations model was used to examine the association between air pollution density and dense breast. A total of 44,280 mammography results were included in this study, and 29,135 were classified in the non-dense breast group and 15,145 in the dense breast group. There was a 3% increase in the odds of having dense breasts after 1 year (OR = 1.027, 95% confidence interval (CI) 1.019-1.034) and 3 years of PM2.5 exposure (OR = 1.029, 95% CI 1.022-1.036). This further increased to 4% at 5-year exposure (OR = 1.044, 95% CI 1.037-1.052) and 5% at 7-year exposure (OR = 1.053, 95% CI 1.044-1.063). The risk for dense breasts increased if the factors of smoking, family history of breast and/or ovarian cancer, and history of childbirth were present.

A prospective analysis of two studies that used the 5-mm interval slices and 5-mm margin-free method for ipsilateral breast tumor recurrence after breast-conserving surgery without radiotherapy.

BACKGROUND: Breast-conserving surgery with radiotherapy is one of standard treatments for early breast cancer. However, it is regarded as an option to treat elderly patients with small hormone receptor-positive breast cancer with breast-conserving surgery and hormone therapy without radiotherapy. We conducted two sequential prospective studies to examine the feasibility of breast-conserving surgery without radiotherapy since 2002 and present the results. PATIENTS AND METHODS: Primary female breast cancer patients who fulfilled the strict eligibility criteria were prospectively enrolled in two sequential studies named WORTH 1 and 2. The surgical materials were sliced in 5-mm intervals and all slices were examined microscopically. Postoperative radiotherapy was not allowed, but tamoxifen or anastrozole was administered for 5 years. Ipsilateral breast tumor recurrence (IBTR)-free survival was the primary outcome. RESULTS: The data of the two studies were combined (N = 321). The median follow-up period for IBTR was 94 months (4-192 months). Only three patients were treated with adjuvant chemotherapy. The 5- and 10-year IBTR-free rates were 97.0% and 90.5%, respectively. The age at operation and PR status affected IBTR rates independently. When we calculated IBTR-free rates of patients who were 65 years of age or older at the time of surgery and had PR-positive tumors, the 5- and 10-year IBTR rates were both 98.4%. CONCLUSIONS:  Our "5-mm-thick slice and 5-mm free-margin" method may be effective to select patients who can be treated by breast-conserving surgery and hormone therapy without radiotherapy.

Association between mammographic breast composition and breast cancer risk among Japanese women: a retrospective cohort study.

BACKGROUND: Mammographic breast composition is associated with breast cancer risk. However, evidence in a Japanese cohort investigating this association is scarce. Thus, we aimed to compare breast cancer risk between women with and without dense breasts. METHODS: All Japanese women who underwent breast cancer screening at a tertiary care academic hospital-affiliated preventive center at least twice with known baseline mammographic breast composition were included in this study. A single-center retrospective cohort study was conducted among 24,863 women who had 125,566 screening opportunities between April 1, 2005, and March 31, 2015. All women were categorized into two groups based on their baseline breast composition: women with dense breasts (13,815) and women with non-dense breasts (11,048). We compared the demographic characteristics between the two groups. After calculating person-years, Cox proportional hazards analyses were performed to estimate the hazard ratio (HR) of developing breast cancer according to breast composition status. RESULTS: During the study period, 358 breast cancer cases were identified. The dense and non-dense groups differed significantly by age, body mass index, family history of breast cancer, physical activity, history of smoking and alcohol consumption, number of pregnancies, and number of deliveries. After adjusting for these factors, Cox proportional hazards analyses showed that women with dense breasts had a significantly higher HR for developing breast cancer than women without dense breasts. The association was even stronger in younger women (≤ 50 years old), but it did not achieve statistical significance in older women. CONCLUSION: Dense breasts at baseline are a risk factor for developing breast cancer in Japanese women. However, this association was only observed in women aged 50 years or younger at the time of entry into the screening program.

Relationship Between Breast Density, Breast Cancer Subtypes, and Prognosis.

BACKGROUND: In the United States, Europe, and Asia, a consensus has been reached that there is a higher risk of breast cancer in high density breasts. However, there are some contrary reports that suggest the absence of an association between breast composition and breast cancer subtype; thus, there is conflicting evidence. The purpose of this study was to investigate trends in the incidence of breast cancer subtypes according to breast composition and analyze the survival rates in Japanese women. PATIENTS AND METHODS: Between 2007 and 2008, 1258 Japanese patients with invasive breast cancer who underwent mammography and obtained a pathological diagnosis in our institution were included in the study. We compared cancer subtypes with breast composition types (dense and non-dense breast), and classified them based on initial mammography findings. Information on 5- and 10-year survival rates was collected by chart review for patients with dense and nondense breasts. Statistical analysis was performed using the Pearson's chi-square test for breast composition and cancer subtype. The effect of breast composition on mortality was examined using a multivariate Cox proportional hazards model, and adjusted hazard ratios were calculated. RESULTS: No significant difference was found between breast cancer subtype and breast composition (P = .08). Five-year (log-rank test, P = .09) and 10-year (log-rank test, P = .31) survival rates were not significantly different between breast composition types. CONCLUSION: There was no significant association between breast composition and cancer subtypes. There was also no significant difference in the prognosis between patients with and without dense breasts.

Impact of childbirth history on dense breast in mammographic screening: a cross-sectional study.

BACKGROUND: The evaluation of breast density is important, because dense breast has been shown to be associated with increased risk of breast cancer and a greater risk of a false-negative diagnostic performance due to masking a tumor. Although the relationship between parity and dense breast is under investigation, conclusive evidence is lacking. We aimed to investigate whether parity affects breast density. METHODS: The study design is a cross-sectional study. The subjects are healthy Japanese women who underwent opportunistic mammographic screening at the center for preventive medicine at a single institution from January 2016 to December 2018. Clinical characteristics and lifestyle factors were obtained from questionnaires. Breast density was categorized into 4 groups, namely, almost entirely fatty dense, scattered fibroglandular dense, heterogeneously dense, and extremely dense, according to the Breast Imaging Reporting and Data System. Heterogeneously and extremely dense were considered collectively as dense breast. Multivariate logistic regression analysis was conducted to investigate the relationship between parity and dense breast among premenopausal and postmenopausal women separately. RESULTS: 7612 premenopausal and 9252 postmenopausal women were investigated. Dense breast was shown in 62.6% of nulliparity, 57.3% of single parity, 47.3% of two parity, 37.6% of more than two parity among premenopausal women, and in 41.6% of nulliparity, 31.1% of single parity, 19.3% of two parity, 10.1% of more than two parity among postmenopausal women. For premenopausal women, two parity, single parity and nulliparity showed a higher risk for dense breast with statistically significance (Odds Ratio (OR) adjusted for potential confounding factors: 1.458 (95% Confidence interval (CI); 1.123-1.894), 2.349 (95%CI; 1.801-3.064), 3.222 (95%CI; 2.500-4.151), respectively), compared with more than two parity. For postmenopausal women, two parity, single parity and nulliparity had a higher risk (OR: 1.849 (95%CI; 1.479-2.312), 3.023 (95%CI; 2.385-3.830), 4.954 (95%CI; 3.975-6.174), respectively) with statistically significance, compared with more than two parity. CONCLUSIONS: Parity showed an inverse trend of having dense breast among both premenopausal and postmenopausal women. In particular, nulliparous women need to recognize their higher risk of dense breast. In the future, the declining fertility rate may affect the prevalence of dense breast in the world.