Analysis of the tumor characteristics in young age breast cancer patients using collaborative stage data of the Korea Central Cancer Registry

Custom target-sequencing in triple-negative and luminal breast cancer from young Brazilian patients

OBJECTIVES

To identify somatic mutations in tumors from young women with triple-negative or luminal breast cancer, through targeted sequencing and to explore the cancer driver potential of these gene variants.

METHODS

A customized gene panel was assembled based on data from previous sequencing studies of breast cancer from young women. Triple-negative and luminal tumors and paired blood samples from young breast cancer patients were sequenced, and identified gene variants were searched for their driver potential, in databases and literature. Additionally, the authors performed an exploratory analysis using large, curated databases to evaluate the frequency of somatic mutations in this gene panel in tumors stratified by age groups (every 10 years).

RESULTS

A total of 28 young women had their tumoral tissue and blood samples sequenced. Using a customized panel of 64 genes, the authors could detect cancer drivers in 11/12 (91.7 %) TNBC samples and 11/16 (68.7 %) luminal samples. Among TNBC patients, the most frequent cancer driver was TP53, followed by NF1, NOTCH1 and PTPN13. In luminal samples, PIK3CA and GATA3 were the main cancer drivers, and other drivers were GRHL2 and SMURF2. CACNA1E was involved in both TN and luminal BC. The exploratory analysis also indicated a role for SMURF2 in luminal BC development in young patients.

CONCLUSIONS

The data further indicates that some cancer drivers are more common in a specific breast cancer subtype from young patients, such as TP53 in TNBC and PIK3CA and GATA3 in luminal samples. These results also provide additional evidence that some genes not considered classical cancer-causing genes, such as CACNA1E, GRHL2 and SMURF2 might be cancer drivers in this age group.

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.

Survival After Development of Contralateral Breast Cancer in Korean Patients With Breast Cancer

Importance

Contralateral breast cancer (CBC) is the most frequently diagnosed primary cancer in patients with breast cancer. Although many studies have reported survival after the development of CBC, results have been inconsistent.

Objective

To investigate whether the development of CBC is associated with survival among patients with breast cancer.

Design, Setting, and Participants

This cohort study was conducted at the Asan Medical Center, Korea, among patients who were diagnosed with primary unilateral, nonmetastatic, stage 0 to III breast cancer between 1999 and 2013 and followed up through 2018. The median (IQR) follow-up was 107 (75-143) months. Patients were categorized into CBC and no-CBC groups by whether they developed CBC during the follow-up period. Data were analyzed from November 2021 to March 2023.

Exposure

Development of CBC.

Main outcomes and measures

Survival rates of CBC and no-CBC groups were compared using a time-dependent Cox proportional hazard model in the entire study population and in subgroup analyses by interval of CBC development and subtype of the primary breast cancer.

Results

Among 16 251 patients with breast cancer (all Asian, specifically Korean; mean [SD] age, 48.61 [10.06] years), 418 patients developed CBC. There was no significant difference in overall survival between CBC and no-CBC groups (hazard ratio, 1.166; 95% CI, 0.820-1.657). Patients who developed CBC within 1.5 years after the surgery of the primary breast cancer had a higher risk for overall death during the study period (hazard ratio, 2.014; 95% CI, 1.044-3.886), and those who developed CBC after 1.5 years showed no significant difference in survival compared with the no-CBC group. Patients with hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (ERBB2, formerly HER2)-negative breast cancer had a higher risk for overall death in the CBC group (hazard ratio, 1.882; 95% CI, 1.143-3.098) compared with the no-CBC group.

Conclusions and Relevance

This study found that development of CBC in patients with breast cancer was not associated with survival but that early development of CBC after diagnosis of the primary breast cancer or development of CBC in patients with HR-positive/ERBB2-negative breast cancer was associated with survival. These results may provide valuable information for patients seeking advice on opting for contralateral prophylactic mastectomy.

Osteoporosis Associated with Breast Cancer Treatments Based on Types of Hormonal Therapy: A Cross-Sectional Study Using Korean National Sample Data

Background and Objectives: This study aimed to investigate osteoporosis-related treatments and the overall anticancer drug treatment tendencies, with a focus on selective estrogen receptor modulators (SERMs) and aromatase inhibitors (AIs), in Korean patients with breast cancer from 2010 to 2019. Materials and Methods: Data were obtained from the Health Insurance Review and Assessment Service. Patients with breast cancer (International Classification of Diseases, 10th Revision code: C50) as a principal diagnosis at least once from 2010 to 2019 were included. Those with osteoporosis (M80, M81, or M82) as a principal or sub-diagnosis or those who received osteoporosis treatment at least once were categorized as the osteoporosis-related treatment group, and others as the non-osteoporosis-related treatment group. The trends of drug prescriptions and treatment costs in patient groups were evaluated using descriptive statistics. Results: Among all included patients, those aged 45-54 years (40.20%) without osteoporosis treatment and those aged 55-64 years (34.11%) with osteoporosis treatment were the most common. SERM was the most commonly prescribed anticancer drug (29.20%) in the entire patient group, followed by AIs (20.83%). Patients without osteoporosis treatment had the highest prescription rate of SERM (31.48%), and those with osteoporosis treatment had a higher prescription rate of AIs (34.28%). Additionally, SERM and AIs were prescribed most frequently before and after the age of 55 years, respectively, regardless of the presence of treatment. Conclusions: This study found that osteoporosis-related treatment and patient age were associated with anticancer drug prescriptions. The present findings would help clinicians and researchers in the clinical diagnosis and treatment of breast cancer.

Prediction of breast cancer using blood microbiome and identification of foods for breast cancer prevention

The incidence of breast cancer (BC) is increasing in South Korea, and diet is closely related to the high prevalence of BC. The microbiome directly reflects eating habits. In this study, a diagnostic algorithm was developed by analyzing the microbiome patterns of BC. Blood samples were collected from 96 patients with BC and 192 healthy controls. Bacterial extracellular vesicles (EVs) were collected from each blood sample, and next-generation sequencing (NGS) of bacterial EVs was performed. Microbiome analysis of patients with BC and healthy controls identified significantly higher bacterial abundances using EVs in each group and confirmed the receiver operating characteristic (ROC) curves. Using this algorithm, animal experiments were performed to determine which foods affect EV composition. Compared to BC and healthy controls, statistically significant bacterial EVs were selected from both groups, and a receiver operating characteristic (ROC) curve was drawn with a sensitivity of 96.4%, specificity of 100%, and accuracy of 99.6% based on the machine learning method. This algorithm is expected to be applicable to medical practice, such as in health checkup centers. In addition, the results obtained from animal experiments are expected to select and apply foods that have a positive effect on patients with BC.

Oncologic outcomes of immediate breast reconstruction in young women with breast cancer receiving neoadjuvant chemotherapy

BACKGROUND

Oncologic safety of postmastectomy breast reconstruction in young women with breast cancer is not well-defined, especially in the setting of neoadjuvant chemotherapy (NACT). We retrospectively compared the oncologic outcomes following nipple-sparing (NSM)/skin-sparing mastectomy (SSM) with immediate breast reconstruction (IBR) and conventional mastectomy (CM) alone in young breast cancer patients after NACT.

METHODS

A total of 1266 women with primary breast cancer who underwent NACT followed by total mastectomy with or without IBR were reviewed. Of these, only young patients (age ≤ 40 years at diagnosis) were included in the outcome analysis (n = 375). After propensity score-matching by clinical T and N stage, molecular subtype, response to NACT, and adjuvant radiotherapy status, 228 patients were 1:1 matched, comprising balanced IBR group (with NSM/SSM) and CM-alone group.

RESULTS

The 5-year locoregional recurrence-free, disease-free, distant metastasis (DM)-free, and breast cancer-specific survival (BCSS) rates for the entire cohort of young patients were 83.4%, 65.3%, 71.7%, and 85.4%, respectively. Locoregional recurrence rates between the matched groups were similar (14% vs. 15.8%; p = 0.710); however, IBR group had significantly lower DM rate (27.2% vs. 40.4%; p = 0.036) and breast cancer mortality (14.9% vs. 27.2%; p = 0.023) than CM-alone group. IBR group showed significantly improved 5-year DM-free survival (74.1% vs. 62.6%; p = 0.043) and BCSS (89.1% vs. 77.6%; p = 0.048) rates than CM-alone group.

CONCLUSIONS

Our results indicated that IBR with NSM/SSM does not negatively affect long-term oncologic outcomes compared to CM alone in young women with breast cancer receiving NACT.