Breast Cancer Society Registry Database Research Articles

189P Characteristics and prognosis of breast cancer patients who have experienced hormone replacement therapy: From the Korean Breast Cancer Society Registry database

Hormone replacement therapy (HRT) is a risk factor for breast cancer (BC). The characteristics and prognosis of HRT-related BC are not well known. We have evaluated the characteristics and prognosis of BC in a cohort of Korea patients who have experienced HRT.

Clinical significance of HER2 status in T1bN0 breast cancer: a nationwide study from the Korean Breast Cancer Society.

The prognosis of patients with node-negative T1b tumors according to human epidermal growth factor receptor 2 (HER2) status is not known. This group of patients has not been studied in the available randomized trials. The objective of this study was to evaluate the survival of patients in a monoethnic group diagnosed with T1b lymph node-negative breast cancer depending on HER2 status. We analyzed 3110 patients with T1bN0M0 breast cancer whose data were deposited into the Korean Breast Cancer Society Registry database between 2000 and 2009. Overall survival (OS) and breast cancer-specific survival (BCSS) were compared according to HER2 status. Among all patients, 494 (15.9%) had HER2-positive breast cancer. At a mean follow-up of 93months, 108 deaths and 86 breast cancer-specific deaths were noted among all patients. There was no significant difference in OS between the HER2-negative and HER2-positive groups (p = 0.103). The same result was observed for BCSS. However, in the subgroup of estrogen receptor (ER)-positive women, HER2-negative patients had a better BCSS prognosis than HER2-positive patients (p = 0.025). Multivariate analysis also indicated a significant difference in BCSS in the ER-positive subgroup (HR 2.60; 95% CI 1.15-5.87; p = 0.021). This study analyzed a large nationwide and monoethnic cohort and found a significant difference only in BCSS in the ER-positive subgroup according to HER2 status. Anti-HER2 therapy may be considered in HER2-positive and ER-positive patients with small, node-negative breast cancer.

Characteristics and prognosis of 17 special histologic subtypes of invasive breast cancers according to World Health Organization classification: comparative analysis to invasive carcinoma of no special type.

Breast cancer is a heterogeneous disease with various histopathologic subtypes. Except for invasive carcinoma of no special type (NST), other subtypes are rare with limited data. The purpose of this study was to analyze the characteristics and prognosis of special histopathologic subtypes of breast cancer compared to NST. A total of 136,140 patients were analyzed using the Korean Breast Cancer Society Registry database between January 1996 and March 2019. The clinicopathologic features and survival outcomes of special type breast carcinoma were compared with those of NST. The prevalence of special subtypes other than NST was 13.7% (n = 18,633). Compared to NST, patients with lobular, medullary, metaplastic, and micropapillary carcinoma had larger tumors (p < 0.001). Patients with mucinous, tubular, medullary, metaplastic, and cribriform carcinoma presented with less node metastasis (p < 0.001), contrary to patients with micropapillary carcinoma. Patients with lobular, mucinous, tubular, papillary, and cribriform carcinoma presented as luminal A subtype much more often (p < 0.001). Micropapillary carcinoma included more luminal B subtype (p < 0.001). Typically, medullary and metaplastic carcinoma included more triple-negative subtypes (p < 0.001). In survival analysis, only medullary (Hazard Ratio (HzR) 0.542, 95% CI 0.345 to 0.852, p = 0.008) and metaplastic carcinoma (HzR 1.655, 95% CI 1.317 to 2.080, p < 0.001) showed significantly different overall survival from NST by multivariate analysis. Breast cancer had distinct clinicopathologic features according to histopathologic subtype. However, special types of breast cancer had similar survival outcomes compared to NST when adjusting for other prognostic factors, except for metaplastic carcinoma and medullary carcinoma.

11P - The prognosis of rare histopathologic subtype of breast cancer

BackgroundBreast cancer is a heterogeneous disease with various histopathologic subtypes. As the prevalence of special types of breast cancer other than invasive carcinoma of no special type (NST) is low, limited data about the clinical behavior and prognosis according to the histologic types were documented with discordant results. The purpose of this study was to analyze the characteristics and the prognosis of rare histopathologic subtype of breast cancer compared with NST and to understand better for proper management. MethodsA total of 133,969 patients were analyzed in this study among the patients who were registered in the Korean Breast Cancer Society Registry database between January 1996 and March 2019 in Korea. ResultsThe prevalence of special types of breast cancer other than NST was 13.7% (n = 18,633). The patients with lobular, mucinous, tubular, papillary, and cribriform carcinoma presented as luminal A subtype much more than NST (77.6%, 74.6%, 77.2%, 57.4%, and 78.1% vs 47.5%, respectively, p < 0.001). A micropapillary carcinoma included more luminal B subtype with even high K-67 expression or positive HER2 than NST (40.9% vs 29.5%, p < 0.001). Typically, medullary and metaplastic carcinoma included more triple negative breast cancer (44.8% and 64.8% vs 13.5%, p < 0.001) than NST. In survival analysis, lobular (HR 0.879, p = 0.029), mucinous (HR 0.529, p < 0.001), tubular (HR 0.781, p < 0.001), papillary (HR 0.728, p < 0.001), medullary (HR 0.500, p < 0.001), and cribriform carcinoma (HR 0.291, p = 0.001) showed better overall survival than NST, and metaplastic carcinoma (HR 1.995, p < 0.001) showed worse outcome significantly. However, after adjusting for age, stage, molecular subtypes, grade, and lymphovascular invasion, only metaplastic carcinoma showed different overall (HR 1.762, p < 0.001) and breast cancer-specific survival (HR 1.685, p = 0.012) from NST. ConclusionsIn conclusion, invasive breast cancer had specific clinical and pathologic features according to the histopathologic subtype. However, special types of breast cancer other than NST have similar survival outcomes compared to NST when adjusting for other prognostic factors, except for metaplastic carcinoma. Editorial acknowledgementThis research was supported by the Korean Breast Cancer Society. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

220P - Prognosis of mastectomy with reconstruction after neoadjuvant chemotherapy: A nationwide study of the Korean Breast Cancer Society

BackgroundWe compared the prognosis of patients with breast cancer according to surgical options including mastectomy with reconstruction after neoadjuvant chemotherapy (NAC). We also assessed the association between prognosis and surgical options according to clinical stage and clinical response in patients with neoadjuvant chemotherapy. MethodsA total of 140,712 patients were enrolled in the Korean Breast Cancer Society Registry database between 2000 and 2014 in Korea. We compared the prognosis of three groups; 1) patients who underwent breast-conserving surgery (BCS), 2) patients who underwent mastectomy, and 3) patients who underwent mastectomy with reconstruction. ResultsOf all 6,634 patients who were treated with NAC, 1,745 patients underwent BCS, 1,459 patients underwent mastectomy, and 363 patients underwent mastectomy with reconstruction. In survival analysis, five-year survival rate (5YSR) of mastectomy with BR group was not inferior compare to other groups in clinical stage IIA and IIB. 5YSR of mastectomy with BR group was 100% and 90.0% clinical stage IIA and IIB, whereas 5YSR of mastectomy group was 97.2% and 86.2% (clinical stage IIA and IIB; P=0.033 and 0.023). In clinical stage IIIA and IIIB, there was no significant difference in 5YSR between mastectomy with BR group and other groups. However, women who underwent mastectomy with BR had a worse prognosis compare to BCS or mastectomy group in clinical stage IIIC. In univariate analysis by Cox regression method according to surgical methods, women who underwent mastectomy with BR had a worse prognosis compared to other groups in patients with clinical stage IIIC (HR 5.88; 95% CI 2.17-15.89; P < 0.001). In multivariate analysis, women who underwent mastectomy with reconstruction followed by NAC were associated with a worse prognosis in clinical stage IIIC. (HR 3.41; 95% CI 1.29-8.99; P=0.013). ConclusionsIn this study, women who underwent mastectomy with reconstruction followed by NAC were associated with a worse prognosis in the clinically advanced stage. This study suggests that reconstruction followed by NAC should be considered for appropriately selected patients. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

The prognostic significance of preoperative tumor marker (CEA, CA15-3) elevation in breast cancer patients: data from the Korean Breast Cancer Society Registry.

Tumor markers such as carcinoembryonic antigen (CEA) and cancer antigen 15-3 (CA15-3) are widely used for monitoring breast cancer. However, the prognostic efficacy of preoperative elevations of CEA and CA15-3 levels in breast cancer patients remains controversial. We retrospectively analyzed the clinicopathological parameters of 149,238 patients in the Korean Breast Cancer Society Registry Database who underwent surgery between January 2000 and December 2015. The patients with elevated CA15-3/CEA levels had worse overall survival (OS) than the patients with normal CA15-3/CEA levels. For the luminal A subtype, the CA15-3- and CEA-elevated group had a hazard ratio (HR) of 2.14 (95% CI 1.01-4.55). The CA15-3-elevated group had an HR of 2.38 (95% CI 1.58-3.58) and the CEA-elevated group had an HR of 1.79 (95% CI 1.20-2.68) compared to the normal group. For the luminal B subtype, the CA15-3- and CEA-elevated group had an HR of 3.99 (95% CI 2.23-7.16), whereas the CA15-3-elevated group had an HR of 2.38 (95% CI 1.58-3.58) and the CEA-elevated group had an HR of 1.79 (95% CI 1.20-2.68). For the HER2 subtype, elevated CEA level was the only independent prognostic factor. However, for the triple-negative breast cancer (TNBC) subtype, elevated preoperative CEA and CA15-3 levels were not significant prognostic factors for OS. Preoperative CEA and CA15-3 levels showed varying prognostic ability according to breast cancer subtype. Preoperative CA15-3 and CEA elevation are significant prognostic factors for luminal breast cancer, but they were not significant factors for TNBC.

Clinical subtypes and prognosis in breast cancer according to parity: a nationwide study in Korean Breast Cancer Society.

We explored the association between parity and the risk of developing a specific subtype of breast cancer. We also assessed the association between parity and prognosis according to subtypes. A total of 158,189 patients were enrolled in the Korean Breast Cancer Society Registry database between 1996 and 2015 in Korea. The database provided information on sex, age, number of parity, surgical method, stage, histological findings, presence of biologic markers, adjuvant therapy, and date and cause of death. The patients with higher parity showed a higher ratio of triple-negative breast cancer (TNBC) and human epidermal growth factor receptor 2 (HER2) subtypes. In univariate analysis, women with TNBC who had more than three children had a worse prognosis compared to other groups (HR 1.83; 95% CI 1.34-2.49; P < 0.001). This association was also observed in women younger than 50years (HR 1.63; 95% CI 1.07-2.48; P = 0.021). In multivariate analysis stratified by subtypes, women who had more than three children were associated with a worse prognosis in TNBC in the total population (HR 1.53; 95% CI 1.11-2.12; P = 0.011). This association was also observed in patients younger than 50years of age (HR 1.53; 95% CI 1.09-2.61; P = 0.017). Women who had more than three children were more likely to develop hormone receptor-negative (HR-) subtypes. Women who had more than three children were associated with worse prognosis in patients younger than 50years of age and in patients with TNBC.

Differences in prognosis and efficacy of chemotherapy by p53 expression in triple-negative breast cancer.

TP53 mutation is the most common mutation in breast cancer, and it is considered a target marker of triple-negative breast cancer (TNBC). We investigated whether expression of p53 detected by immunochemical staining predicts the chemotherapy response of TNBC. A total of 11,393 TNBC patients who had between stage I and stage III enrolled in the Korean Breast Cancer Society Registry database from January 1, 2000 to December 31, 2015. There were 6,331 'p53-positive (+) TNBC' patients and 5062 'p53-negative (-) TNBC' patients. In univariate analysis, p53(+) TNBC had a worse prognosis than p53(-) TNBC in patients not receiving chemotherapy (P = 0.003). However, there was no difference in prognosis between p53(+) TNBC and p53(-) TNBC for patients receiving chemotherapy. In multivariate analysis adjusted for age and stage, the risk of p53(+) TNBC was 1.84 times higher than that of p53(-) TNBC in the non-chemotherapy group. However, there was no difference between p53(+) TNBC and p53(-) TNBC in patients receiving chemotherapy. In p53(+) TNBC, the risk was 0.6-fold lower when chemotherapy was administered than when chemotherapy was not administered. However, in p53(-) TNBC, there was no risk reduction effect by chemotherapy. The prognosis of p53(+) TNBC has worse than p53(-) TNBC, but the risk for survival was significantly reduced with chemotherapy. It suggests that p53(+) TNBC would be more sensitive to chemotherapy than p53(-) TNBC.

Clinical subtypes and prognosis of pregnancy-associated breast cancer: results from the Korean Breast Cancer Society Registry database.

We analyzed the clinicopathologic characteristics and prognosis of pregnancy-associated breast cancer (PABC) according to clinical subtypes to better understand the characteristics of PABC. A total of 83,792 female patients between the ages of 20 and 49 were enrolled in the Korean Breast Cancer Society Registry database from January 1, 1996 to December 31, 2015. 'PABC' is defined as breast cancer diagnosed during pregnancy or within 1year after delivery. Other patients were defined as 'non-PABC' patients. In non-PABC patients, luminal A subtype was the most common (50.2%). In PABC patients, TNBC was the most common (40.4%) subtype, while luminal A comprised 21.2% and HER2 subtype comprised 17.3%. There was a significant difference in overall survival (OS). In non-PABC patients, TNBC had the highest HR (HR 2.3, 95% CI 2.1-2.6). In PABC patients, the luminal B subtype (HR+ HER2-high Ki67) had the highest HR at 7.0 (95% CI 1.7-29.1). In multivariate analysis of OS by subtypes, PABC patients had significantly higher HR than non-PABC patients in the HER2 subtype (HR 2.0, 95% CI 1.1-3.7) and luminal B subtype (HR+ HER2-high Ki67) (HR 4.4, 95% CI 1.6-12.3). PABC showed different biologic features than non-PABC. PABC had a particularly poor prognosis in the luminal B (HR+ HER2-highKi67) and HER2 subtypes. To improve the prognosis of PABC, treatment should be considered according to subtype. Development of drugs that can be used during pregnancy is needed.

Trends in breast reconstruction: Implications for the National Health Insurance Service.

BackgroundBreast reconstruction has become more common as mastectomy has become more frequent. In Korea, the National Health Insurance Service (NHIS) began covering breast reconstruction in April 2015. This study aimed to investigate trends in mastectomy and breast reconstruction over the past 10 years and to evaluate the impact of NHIS coverage on breast reconstruction.MethodsNationwide data regarding mastectomy and breast reconstruction were collected from the Korean Breast Cancer Society registry database. Multiple variables were analyzed in the records of patients who underwent breast reconstruction from January 2005 to March 2017 at a single institution.ResultsAt Seoul National University Hospital, the total number of reconstruction cases increased 13-fold from 2005 to 2016. The proportion of immediate breast reconstruction (IBR) cases out of all cases of total mastectomy increased from 4% in 2005 to 52.0% in 2016. The proportion of delayed breast reconstruction (DBR) cases out of all cases of breast reconstruction and the overall number of DBR cases increased from 8.8% (20 cases) in 2012 to 18.3% (76 cases) in 2016. After NHIS coverage was initiated, the proportions of IBR and DBR showed statistically significant increases (P<0.05). Among the IBR cases, the percentage of prosthesis-based reconstructions increased significantly (P<0.05), but this trend was not found with DBR. Total mastectomy became significantly more common after the expansion of NHIS coverage (P<0.05).ConclusionsOver the last decade, there has been an increase in mastectomy and breast reconstruction, and the pace of increase accelerated after the expansion of NHIS coverage. It is expected that breast reconstruction will be a routine option for patients with breast cancer under the NHIS.

Neoadjuvant Chemotherapy and Prognosis of Pregnancy-Associated Breast Cancer: A Time-Trends Study of the Korean Breast Cancer Registry Database.

PurposePregnancy-associated breast cancer (PABC) is rare, and its cause and prognosis are not well known. Additionally, treatment is limited with respect to the risk to the fetus. The purpose of this study was to investigate the characteristics and treatment trends of PABC and the survival rate according to the treatment.MethodsIn the Korean Breast Cancer Society Registry database, women younger than 50 years and who were diagnosed with breast cancer from 1996 to 2015 were included. PABC was defined as breast cancer diagnosed during pregnancy or within 1 year after delivery.ResultsWe examined 411 patients with PABC and 83,381 patients with non-PABC. Over time, the proportions of patients undergoing breast-conserving surgery and sentinel lymph node biopsy increased, and neoadjuvant chemotherapy and radiation therapy administration rates also increased. In the past, the overall survival of patients with PABC was poorer than that of patients with non-PABC, but there was no difference in overall survival rates in more recent years. There was no difference in overall survival rates between patients who received neoadjuvant chemotherapy (hazard ratio [HR], 1.28; 95% confidence interval [CI], 0.66–2.49; p=0.459), but PABC conferred poorer prognosis than non-PABC in patients receiving adjuvant chemotherapy (HR, 1.63; 95% CI, 1.27–2.08; p<0.001).ConclusionThere was no difference in the prognosis between patients with PABC and those with non-PABC receiving neoadjuvant chemotherapy. The increase in neoadjuvant chemotherapy according to current treatment guidelines is expected to improve the survival rate of patients with PABC.

Comparative Study between Sentinel Lymph Node Biopsy and Axillary Dissection in Patients with One or Two Lymph Node Metastases.

PurposeSentinel lymph node biopsy (SLNB) is a standard axillary surgery in early breast cancer. If the SLNB result is positive, subsequent axillary lymph node dissection (ALND) is a routine procedure. In 2011, the American College of Surgeons Oncology Group Z0011 trial revealed that ALND may not be necessary in early breast cancer with one or two positive sentinel lymph nodes. The purpose of this study was to compare outcomes among Korean patients with one or two positive axillary lymph nodes in the final pathology who did and did not undergo ALND.MethodsA total of 131,717 patients from the Korea Breast Cancer Society registry database received breast cancer surgery from January 1995 to December 2014. Inclusion criteria were T stage 1 or 2, one or two positive lymph nodes, and having received breast-conserving surgery (BCS), whole breast radiation therapy, and no neoadjuvant therapy. We analyzed the differences in disease-specific survival (DSS) and overall survival (OS) between patients who received SLNB only and those who underwent SLNB+ALND.ResultsA total 4,442 patients met the inclusion criteria, with 1,268 (28.6%) in the SLNB group and 3,174 (71.4%) in the SLNB+ALND group. There were no differences in DSS and OS between the two groups (p=0.378 and p=0.925, respectively). The number of patients who underwent SLNB alone for one or two positive lymph nodes increased continuously from 2004 to 2014.ConclusionKorean patients with early breast cancer and 1 or 2 positive axillary lymph nodes who received BCS plus SLNB showed no significant difference in DSS and OS regardless of whether they received ALND. The findings of this retrospective study demonstrate that omitting ALND can be considered when treating selected patients with early breast cancer who have one or two positive lymph nodes.

Clinicopathologic Characteristics of Pregnancy-Associated Breast Cancer: Results of Analysis of a Nationwide Breast Cancer Registry Database

PurposeThis study aimed to evaluate the clinicopathological characteristics of pregnancy-associated breast cancer (PABC) in comparison with non-pregnancy associated breast cancer (non-PABC).MethodsA total of 344 eligible patients with PABC were identified in the Korean Breast Cancer Society Registry database. PABC was defined as ductal carcinoma in situ, invasive ductal carcinoma, or invasive lobular carcinoma diagnosed during pregnancy or within 1 year after the birth of a child. Patients with non-PABC were selected from the same database using a 1:2 matching method. The matching variables were operation, age, and initial stage.ResultsPatients with PABC had significantly lower survival rates than patient with non-PABC (10-year survival rate: PABC, 76.4%; non-PABC, 85.1%; p=0.011). PABC patients had higher histologic grade and were more frequently hormone receptor negative than non-PABC patients. Being overweight (body mass index [BMI], ≥23 kg/m2), early menarche (≤13 years), late age at first childbirth (≥30 years), and a family history of breast cancer were more common in the PABC group than in the non-PABC group. Multivariate analysis showed the following factors to be significantly associated with PABC (vs. non-PABC): early menarche (odds ratio [OR], 2.165; 95% confidence interval [CI], 1.566–2.994; p<0.001), late age at first childbirth (OR, 2.446; 95% CI, 1.722–3.473; p<0.001), and being overweight (OR, 1.389; 95% CI, 1.007–1.917; p=0.045).ConclusionEarly menarche, late age at first childbirth, and BMI ≥23 kg/m2 were more associated with PABC than non-PABC.