Clinical characteristics and prognosis of postpartum breast cancer.

PURPOSE: Postpartum breast cancer (PPBC) is a not well-established subset of breast cancer, and only few studies address its poorer prognosis. However, previous studies show that PPBC is associated with worse outcome with higher rates of metastasis than in young women's breast cancer (YWBC). We aimed to analyze the clinical characteristics and prognosis of PPBC based on the diagnosis period of PPBC. METHODS: We retrospectively reviewed 208,780 patients with breast cancer from the Korean Breast Cancer Society registry (KBCSR) database between January 2000 and December 2014. We included premenopausal women aged 20-50 years who underwent breast cancer surgery. The patients were classified by 5-year intervals according to the diagnosis period of breast cancer, from the first birth to the breast cancer diagnosis. RESULTS: Compared with patients in the other groups, patients diagnosed within postpartum 5 years (PPBC < 5 years) group were younger, had a more advanced stage, had lower estrogen receptor (ER) and progesterone receptor (PR) expression, and had a higher human epidermal growth factor receptor 2 (HER2) positive rate. Further, PPBC < 5 years group had a worse survival rate than the nulliparous and other groups (5-year cumulative survival: PPBC < 5 years group, 89%; nulliparous group, 97.3%; 5 ≤ PPBC < 10 years group, 93%). In the multivariate analysis, the PPBC < 5 years group was associated with a worse survival rate (hazard ratio 1.55, 95% confidence interval [CI] 1.148-2.094, p 0.004) after adjustment for age at diagnosis, breast cancer stage, ER and HER2 status, Ki-67 level, and chemotherapy. CONCLUSION: Our findings indicated that patients diagnosed with breast cancer within the first 5 years after delivery had aggressive characteristics and a poor survival rate. It is important to elucidate the pathophysiology of PPBC and establish novel therapeutic strategies to improve the survival rate.

CORRIGENDUM: Correction of the first author's affiliation. Low incidence of lymph node metastasis in patients with microinvasive breast cancer: a Korean nationwide study.

[This corrects the article on p. 306 in vol. 102, PMID: 35800998.].

Low incidence of lymph node metastasis in patients with microinvasive breast cancer: a Korean nationwide study.

Purpose: Microinvasive breast cancer (MIBC) is an invasive carcinoma with a tumor dimension not exceeding 1 mm. Owing to its low incidence, the rate of axillary node metastasis and its management are not well established. The aim of this study was to assess the incidence of lymph node metastasis (LNM) and identify variables associated with LNM, as well as to evaluate the need for axillary staging in MIBC patients by analyzing nationwide data. Methods: The Korean Breast Cancer Society registry was searched to identify MIBC patients diagnosed between January 1996 and April 2020. Patients without neoadjuvant chemotherapy experiences, systemic metastasis, and missing or discordant data were eligible for the analysis. The incidence rate of LNM was determined, and variables associated with LNM were identified by multivariable regression analysis. Results: Of 2,427 MIBC patients identified, 98 (4.0%) had LNM and 12 (0.5%) had N2/3 disease. Type of breast operation (odds ratio [OR], 2.093; 95% confidence interval [CI], 1.332-3.290; P = 0.001), age (OR, 2.091; 95% CI, 1.326-3.298; P = 0.002), hormone receptor status (OR, 2.220; 95% CI, 1.372-3.594; P = 0.001), and lymphovascular invasion (OR, 11.143; 95% CI, 6.354-19.540; P < 0.001) were significantly related to LNM. Conclusion: The incidence of LNM in MIBC patients was only 4.0% in our study, suggesting that de-escalation of axillary surgical interventions could be carefully considered. The indications for axillary staging should be individualized considering tumor volume, age, hormone receptor status, and lymphovascular invasion to improve the quality of life of MIBC survivors.

The Radiological Response Rate Pattern Is Associated With Recurrence Free Survival in Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy.

PURPOSE: The aim of this study was to evaluate the radiological response rate patterns during neoadjuvant chemotherapy (NAC) in patients with breast cancer. METHODS: Patients who underwent NAC with two specific chemotherapy regimens (doxorubicin with cyclophosphamide or doxorubicin with docetaxel) and who underwent a response evaluation every two cycles were included in the study. The initial response ratio was defined as the ratio of the largest tumor diameter at diagnosis to that after two cycles of NAC. The latter response ratio was defined as the ratio between the tumor size after two cycles and that after four cycles of NAC. The radiological response rate pattern was divided into three groups: the fast-to-slow response group (F-S group, initial response ratio > latter response ratio + 20%), slow-to-fast response group (S-F group, latter response ratio > initial response ratio + 20%), and constant response group (less than 20% difference between the initial and latter response ratios). RESULTS: In total, 177 patients were included in the analysis. Forty-two (23.9%) patients were categorized into the F-S group, 26 (14.8%) into the S-F group, and 108 (61.2%) into the constant group. Clinicopathologic factors did not differ according to radiologic response rate patterns. The median follow-up period was 50 months (range, 3-112) months. In the univariate analysis, the F-S group had a significantly worse recurrence-free survival than the S-F and constant groups (hazard ratio [HR], 3.63; 95% confidence interval [CI], 1.05-12.46; p = 0.041). The F-S group also presented with significantly worse survival than the S-F group in the multivariate analysis (HR, 3.45; 95% CI, 1.00-11.89; p = 0.049). CONCLUSION: The F-S group had a poorer survival rate than the S-F group. Radiological response rate patterns may be useful for accurate prognostic assessments, especially when considering post-neoadjuvant therapy.

Analysis of risk factors associated with survival in human epidermal growth factor receptor 2-positive ductal carcinoma in situ using Korean Breast Cancer Society Database.

PURPOSE: This study was performed to identify the risk of mortality in patients diagnosed with human epidermal growth factor receptor 2 (HER2)-positive ductal carcinoma in situ (DCIS). METHODS: We selected 2,592 patients with HER2-positive DCIS from Korean Breast Cancer Society (KBCS) database between January 1997 and December 2019. Patients who received neoadjuvant chemotherapy were excluded. Logistic regression analysis was used to determine the association between clinical factors and overall death after adjusting for tumor and clinical characteristics. Mortality data were modified using the Statistics Korea data. RESULTS: Thirty deaths (1.2%) were identified out of 2,592 patients in the KBCS database. In the univariate logistic regression analysis, older age, higher body mass index (BMI), type of breast surgery (mastectomy), estrogen receptor-negative, progesterone receptor-negative, and exposure to endocrine therapy were significant clinical factors associated with death. In the multivariate analysis, age (hazard ratio [HR], 1.062; 95% confidence interval [CI], 1.015-1.111; P = 0.006), BMI (HR, 1.179; 95% CI, 1.032-1.347, P = 0.016), breast surgery type (mastectomy vs. lumpectomy; HR, 0.285; 95% CI, 0.096-0.844; P = 0.024), and endocrine therapy (HR, 0.314; 95% CI, 0.099-0.995; P = 0.049) were significant risk factors for mortality. CONCLUSION: Advanced age, higher BMI, mastectomy, and the absence of endocrine therapy were factors associated with poor survival of patients with HER2-positive DCIS. This finding requires further validation combined with additional analysis of large databases.

The association between the expression of nuclear Yes-associated protein 1 (YAP1) and p53 protein expression profile in breast cancer patients.

BACKGROUND: Yes-associated protein 1 (YAP1) is a key effector molecule regulated by the Hippo pathway and described as a poor prognostic factor in breast cancer. Tumor protein 53 (TP53) mutation is well known as a biomarker related to poor survival outcomes. So far clinical characteristics and survival outcome according to YAP1 and TP53 mutation have been poorly identified in breast cancer. PATIENTS AND METHODS: Retrospectively, 533 breast tumor tissues were collected at the Seoul St Mary's hospital and Gangnam Severance Hospital from 1992 to 2017. Immunohistochemistry with YAP1 and p53 specific antibodies were performed, and the clinical data were analyzed. RESULTS: Mutant p53 pattern was associated with aggressive tumor features and advanced anatomical stage. Inferior overall survival (OS) and recurrence free survival (RFS) were related with mutant p53 pattern cases with low nuclear YAP1 expression (P = 0.0009 and P = 0.0011, respectively). Multivariate analysis showed that mutant p53 pattern was an independent prognostic marker for OS [hazard ratios (HR): 2.938, 95% confidence intervals (CIs): 1.028-8.395, P = 0.044] and RFS (HR: 1.842, 95% CIs: 1.026-3.304). However, in cases with high nuclear YAP1 expression, there were no significantly difference in OS and RFS according to p53 staining pattern. CONCLUSION: We found that mutant p53 pattern is a poor prognostic biomarker in breast tumor with low nuclear YAP1 expression. Our findings suggest that interaction between nuclear YAP1 and p53 expression pattern impact survival outcomes.

Clinical Features of Breast Cancer in South Korean Patients with Germline TP53 Gene Mutations.

PURPOSE: Li-Fraumeni syndrome (LFS) is a rare autosomal cancer syndrome caused by a germline mutation in the TP53 gene. Breast cancer in LFS patients is of various subtypes; however, limited data are available on the clinicopathological features of these subtypes and their appropriate treatments. This study aimed to review the clinical features and treatments for breast cancer in South Korean patients with germline TP53 mutations. METHODS: Data on the clinicopathological features and treatment of all breast cancer patients with LFS were collected retrospectively from the available database of 4 tertiary hospitals in the Republic of Korea. RESULTS: Twenty-one breast cancer cases in 12 unrelated women with confirmed germline TP53 mutations were included in the study. The median age at diagnosis was 33.5 years. The histopathological diagnosis included invasive ductal carcinoma (n = 16), ductal carcinoma in situ (n = 3), and malignant phyllodes tumor (n = 2). While 42% and 31% of the cases were positive for estrogen and progesterone receptors, respectively, 52.6% were human epidermal growth factor receptor 2 (HER2) positive, and 21% were triple-negative. The treatments included mastectomy (52%) and breast-conserving surgery (38%). Five patients underwent radiotherapy (RT). The median follow-up period was 87.5 (8-222) months. There were 3 ipsilateral and 4 contralateral breast recurrences during the follow-up, and 8 patients developed new primary cancers. In the post-RT subgroup, there were 2 ipsilateral and 2 contralateral breast recurrences in 1 patient, and 4 patients had a new primary cancer. CONCLUSION: As reported in other countries, breast cancer in LFS patients in South Korea had an early onset and were predominantly but not exclusively positive for HER2. A multidisciplinary approach with adherence to the treatment guidelines, considering mastectomy, and avoiding RT is encouraged to prevent RT-associated sequelae in LFS patients.

Clinical Features and Factors Associated With Surgical Treatment in Patients With Complicated Colonic Diverticulitis.

PURPOSE: Colonic diverticulitis is uncommon in Korea, but the incidence is rapidly increasing nowadays. The clinical features and the factors associated with complications of diverticulitis are important for properly treating the disease. METHODS: A retrospective review of the medical records of 225 patients that were prospectively collected between October 2007 and September 2016 was conducted. RESULTS: Diverticulitis was detected mainly in men and women aged 30 to 50 years. Diverticulitis more frequently affected the right colon (n = 194, 86.2%), but age was higher in case of left colonic involvement (42 years vs. 57 years, P < 0.001). Percentages of comorbidities (65.6% vs. 23.8%, P < 0.001), complications (65.6% vs. 6.2%, P < 0.001), and surgical treatment (50.0% vs. 4.1%, P < 0.001) were significantly higher in patients with left colonic diverticulitis. In the multivariate analysis, a risk factor for complicated diverticulitis was left colonic involvement (P < 0.001; relative risk [RR], 47.108; 95% confidence interval [CI], 12.651-175.413). In complicated diverticulitis, age over 50 was the only significant risk factor for surgical treatment (P = 0.024; RR, 19.350; 95% CI, 1.474-254.023). CONCLUSION: In patients over 50 years of age with left colonic diverticulitis, a preventive colectomy should be reconsidered as one of the options for treatment.