Clinicopathological Analysis of 117 Female Patients Diagnosed with Pure Mucinous Breast Cancer

Background: Pure mucinous breast carcinoma is a relatively rare subtype of breast malignancy. This study is to investigate the clinical and pathologic features of pure mucinous breast carcinoma. Patients andMethods: A retrospective review of our database of patients who presented with breast cancer was performed. The medical records of 1,060 patients with invasive breast cancer who underwent surgery were reviewed. Results: 28 patients with pure mucinous breast cancer were identified. The mean age was 55.28 ± 15.73 years. 17 patients underwent modified radical mastectomy; 11 underwent breast-conserving therapy. The tumor size was T1 in 19 patients, T2 in 8 patients, and T3 in 1 patient. None of the patients had lymph node metastasis. There was no distant metastasis. 18 were stage I, and 10 were stage II. Estrogen receptor, progesterone receptor, HER-2, and P53 were positive in 96, 93, 0, and 28%, respectively. Median follow-up was 42 months (range 1-84 months). 1 patient had local recurrence. The overall survival rate was 100%. Conclusion: Pure mucinous breast carcinoma has a favorable prognosis. Less invasive treatment might be optional. Larger data samples with longer follow-up would be necessary to gain a better understanding of this disease.

Objective: To explore the MRI features of the pure mucinous breast carcinoma(PMBC) and the correlation with cell density and the expression of immunohistochemistry. Methods: MRI features of 35 pure mucinous carcinomas were retrospectively analyzed from January 2011 to May 2016 in Guangdong General Hospital. MR images were reviewed for shape, margin, the signal intensity, enhancement patterns of tumors and diffusion weighted imaging (DWI) features and apparent diffusion coefficient (ADC) value. All the patients were detected by immunohistochemical staining with expression of ER, PR, CerbB-2, Ki-67 and Her-2. Correlations between MRI features of PMBC and cell density and the expression of immunohistochemistry were analyzed. Results: A total of 16 oval masses(16/35, 45.7%) and 10 round masses(10/35, 28.6%)were found in 35 PMBC with clear boundary(26/35, 74.3%) and lobulated shape(31/35, 88.6%). Very high signal intensity on T(2)-weighted images was found in 33 PMBC (33/35, 94.3%) and early enhancement rate was 115%±9% for PMBC. 28 PMBC demonstrated persistent enhancing pattern on time-signal intensity curve and 7 PMBC demonstrated plateau pattern.Mean ADC value was (1.91±0.06)×10(-3)mm(2)/s for PMBC. There was significant difference with early enhancement rate and ADC value between PMBC with more or less quantities of cellular mucin (P<0.05). There was no significant difference with ER, PR, CerbB-2, Her-2 and Ki-67 expression between PMBC with more or less quantities of cellular mucin (all P>0.05). Conclusions: PMBC has distinctive MRI features. The prognosis of PMBC is better from correlation between MRI features, cell density and the expression of immunohistochemistry.

Pure mucinous breast carcinoma (PMBC) is characterized by clusters of tumor cells floating in abundant extracellular mucin and can be classified into paucicellular (Type A) and hypercellular (Type B) subtypes. However, the clinicopathological and genomic differences between these two subtypes have not been well characterized. We retrospectively investigated the clinicopathologic features of 45 cases of surgically removed PMBC (31 Type A and 14 Type B). We also performed whole-exome sequencing (WES) in eight cases of PMBC. We found that Type B PMBC occurs at an older age and shows more aggressive clinical behavior than Type A. WES analysis revealed that HYDIN was the most frequently mutated gene in both types of PMBC. Although Type B PMBC showed a tendency toward more frequent genetic alterations, there were no statistically significant differences between the two subtypes in single nucleotide variants or insertions or deletions of bases associated with moderate or high effects. Our results provide additional evidence that PMBCs are clinicopathologically and genetically heterogeneous and lack pathognomonic genetic alterations. Further, Type B PMBC is more frequently associated with lymph node metastasis than Type A.

Exploring the efficacy of extended endocrine therapy in pure mucinous breast carcinoma

Objective To explore clinical characteristics,pathology,prognosis and proper treatment of pure mucinous breast carcinoma(PMBC).Methods Retrospective analysis Was carried out on patients with PMBC who were admitted from Jan.2004 to Dec.2010.Results PMBC patients accounted for 2.6%of all the patients with breast cancer treated at the same period.The mean age of PMBC patients was(55.28±15.73)years,ranging from 32 years to 81 years.The tumor diameter was from 1 to 10 cm and axillary lymph node involvement was 0%.Immunohistochemieal detection showed the positive rate of estrogen receptor(ER),progesterone receptor(PR),HER-2 and p53 was 96%,92%,0%and 32%respectively.All patients underwent operation and polychemotherapy(cyclophosphamide+Adriamycin,Paclitaxel+Adriamyein).12 cases received tamoxifen,13 cases received letrozole and 8 cases received postoperative irradiation.All the patients were followed up from 1 month to 6 years and the overall survival rate was 100%.Conclusions PMBC is a favorable histological type of breast carcinoma with good prognosis.Proper surgical and adjuvant therapy is important to improve survival rate and life quality.Molecular biologic parameters should be given enough consideration into prognosis evaluation. Key words: Pure mucinous breast carcinoma; Pathology; Treatment; Prognosis

Pure mucinous breast carcinoma (PMBC) is a rare pathologic finding. Few studies have addressed the biologic features of PMBC and prognostic factors among patients with this disease. We performed a study to compare PMBC and invasive ductal carcinoma (IDC) by means of a large database to reliably assess the biologic phenotype and clinical behavior of PMBC. A total of 2,511 patients who met the inclusion criteria were identified from 1999 to 2010; 2,202 patients had pure IDC and 309 had PMBC. Clinical and biologic features, overall survival, and recurrence/metastasis-free survival (RFS) were compared for both groups. PMBC had favorable characteristics including smaller size, lower rates of lymph node positivity, lower stage, higher expression of hormone receptors, and less HER2 overexpression. Patients with PMBC had better 10-year RFS (71 %) than patients with IDC (64 %). Multivariate analysis revealed that node status and tumor, node, metastasis system (TNM) stage were statistically significant prognostic factors for survival. RFS curves stratified for node status revealed a highly significant difference between node negative and node positive patients. Additionally, patients with PMBC underwent breast-conserving surgery (BCS) more frequently than patients with IDC, and the 5-year overall survival rate of the BCS group was not significantly different from the total mastectomy group. PMBC in Chinese women showed less aggressive behavior and had a better prognosis than IDC, and this favorable outcome was maintained after 10 years. Node status and TNM stage appeared to be the most significant predictors of worse prognosis. BCS should be preferred over mastectomy in the treatment of early-stage PMBC.

The Oncotype DX 21-gene test can be used to predict chemotherapy efficacy in patients with estrogen receptor (ER)-positive and HER2-negative breast cancer; however, the data on the 21-gene recurrence score (RS) for mucinous breast carcinoma (MBC) are limited. The present study aimed to evaluate the distribution pattern and clinical value of the 21-gene RS in patients with MBC. A total of 38 pure MBC (PMBC) and 11 mixed MBC (MMBC) cases were retrospectively analyzed, and a total of 29 ER-positive and HER2-negative MBCs underwent the Oncotype DX 21-gene test. There were no statistically significant differences between the PMBCs and MMBCs in age, tumor size and molecular subtype; however, patients with MMBC showed a significantly higher incidence rate of nodal metastases compared with that in patients with PMBC (72.7 vs. 16.2%, respectively). Following surgery, 87.8 and 59.2% of the enrolled patients received endocrine therapy and chemotherapy, respectively. With a median follow-up of 65.6 months, the 5-year disease-free survival and overall survival rates were 97.0 and 100.0%, respectively. The 21-gene test revealed that the proportions of patients with MBC categorized into low (RS <18), intermediate (RS ≥18-30) and high (RS ≥30) risk groups were 51.7, 44.8 and 3.5%, respectively, and there was no statistically significant difference between the PMBC and MMBC cases. Notably, among the genes in the 21-gene RS testing, the expression levels of cathepsin V, progesterone receptor (PR) and CD68 were significantly higher in the PMBC group compared with that in the MMBC group. In conclusion, the current study demonstrated that patients with MBC had a favorable prognosis, and both PMBC and MMBC cases had a low- and intermediate-risk RS, which suggests that a considerable proportion of patients may be able to avoid chemotherapy. In addition, the high expression level of PR, based on the 21-gene test in PMBCs, indicated that they may have a more favorable response to endocrine therapy than MMBCs.

The clinical features and prognosis of mucinous breast carcinoma (MBC) are unclear because of its rarity. The aim was to describe the clinicopathological features and prognosis of patients with MBC in comparison with nonmucinous breast carcinoma (NMBC). Furthermore, we described the biological behavior of pure mucinous breast carcinoma (PMBC) by comparing clinicopathological features and prognosis with mixed mucinous breast carcinoma (MMBC). We reviewed the records of 5,872 consecutive patients diagnosed with breast carcinoma who were resected surgically from March 2003 to October 2010. Among them, 117 patients with MBC were compared to 5,575 patients with NMBC. Furthermore, 88 patients with PMBC were compared to 29 patients with MMBC. There were statistical differences in age, pN stage, ER level, and PR level between the patients with MBC and NMBC. There were statistical differences in pT stage and pN stage between the patients with PMBC and MMBC. The overall five-year survival of patients with MBC was 88.1 % as compared with 81.9 % for patients with NMBC. The overall five-year survival of patients with PMBC was 91.3 % as compared with 80.4 % for patients with MMBC. The overall five-year survival of patients with PMBC was 91.3 % as compared with 81.9 % for patients with NMBC. PMBC tended to have a better prognosis in comparison with other types of breast carcinoma.

Pure mucinous breast carcinoma with micropapillary pattern (MUMPC) was proposed as a new histopathological variant of pure mucinous carcinoma (PMC) with tumor cells forming a micropapillary architecture. The Classification of Tumours of the Breast by the World Health Organization, however, does not differentiate MUMPC as a distinct subtype. There is currently no consensus whether tumors that exhibit these features are classified as PMC or invasive micropapillary carcinoma (IMPC) with associated mucin production. A 45-year-old woman was examined for a tumor in her left breast. Upon physical examination, an elastic hard mass of around 5 cm along with accompanying skin flare and ulceration was palpated in the upper outer quadrant of the left breast. Mammary ultrasonography revealed a clearly marginated hypoechoic tumor of 55.0 × 46.9 × 37.0 mm in size in the upper outer quadrant of the left breast. A vacuum-assisted biopsy (VAB) was performed in the same site and histopathological diagnosis of PMC was made. Contrast-enhanced magnetic resonance imaging (MRI) showed a T1W1 low-intensity signal and a T2W1 high-intensity signal at the primary focus, ring enhancement of the tumor margin, and stranding enhancement inside the tumor. A preoperative diagnosis of left breast cancer (PMC), cT4bN1M0, stage IIIB, luminal B-like was made. We performed a simple mastectomy with axillary lymph node dissection. A 55.0 × 48.1 × 37.1 mm tumor with the gelatinous cut surface was excised. Histopathological examination of the excised specimen revealed mucin lake formation in the tumor containing clusters of atypical cells. The atypical cells showed swollen, irregular nuclei and a papillary growth pattern that lead to the diagnosis of MUMPC.

To study the clinicopathologic features of pure mucinous carcinomas of the breast with diffuse micropapillary pattern. Twenty-six cases of micropapillary variant of pure mucinous carcinoma of the breast were retrospectively reviewed by light microscopy, immunohistochemistry and clinical data analyses. The age of 26 female patients ranged from 30 to 77 years old, of which 12 cases with clinical details available were mean 54 years old. The tumor diameter ranged from 0.8 to 9.0 cm (mean 3.2 cm). Ipsilateral axillary nodal metastases were identified in 3 cases. Cutaneous involvement was also found in 2 cases. The tumor cells showed the similar architectural arrangement as in invasive micropapillary carcinoma, with peripheral borders of the cell clusters highlighted by epithelial membrane antigen. Various amount of mucin occupied the retraction spaces around the tumor cells. Compared with conventional pure mucinous carcinoma of the breast, mucinous carcinomas with micropapillary pattern showed different nuclear grades (19 cases of grade I, 2 cases of grade II, 5 cases of grade III). The micropapillary cell clusters varied in size (22 cases of big micropapillary and 4 cases of small). Intraductal carcinoma was observed in 12 cases. Calcification and psammoma bodies were observed in 8 cases. Immunophenotyping, the tumor cells were with higher expression of hormone receptors, but HER2 were negative. Ki-67 positive index was 1% ∼ 70%. Neuroendocrine differentiation was observed in 6 cases. The micropapillary variant of pure mucinous carcinoma of the breast, which mainly occurs in younger women, may carry the similar propensity for angioinvasion and nodal metastasis as infiltrating micropapillary carcinoma at least in cases with high nuclear grade. This morphologic subtype needs to be distinguished from conventional pure mucinous carcinoma of the breast and treated properly.

PurposeThe aim of this study was to explore the clinical and pathological characteristics of pure mucinous breast carcinoma (PMBC) according to internal echogenicity on ultrasonography (US). MethodsThirty-three patients with PMBC diagnosed at surgery were included in this study. Cases of PMBC were classified according to internal echogenicity on US. The imaging features on magnetic resonance (MR) imaging and clinicohistopathological characteristics were compared between the hypoechogenic and the isoechogenic to hyperechogenic groups. ResultsEleven cases of PMBC (33.3%) exhibited hypoechogenicity on US, while 22 cases (66.7%) exhibited isoechogenicity or hyperechogenicity. Of the isoechogenic to hyperechogenic PMBCs, 95.5% showed a high signal on T2-weighted images, which was a significantly greater percentage than was observed for the hypoechogenic group (54.5%) (P=0.010). Of the hypoechogenic PMBCs, 63.6% showed a washout pattern in the delayed phase, which was substantially more than the result of 23.8% observed for the isoechogenic to hyperechogenic PMBCs (P=0.053). ConclusionPMBCs with isoechogenicity or hyperechogenicity were more likely to show a high signal intensity on T2-weighted images than hypoechogenic PMBCs. However, other MR imaging and clinicohistopathological characteristics were not significantly different between the two groups.

Pure mucinous breast carcinoma (PMBC) is even rarer and accounts for about 2% of all primary breast carcinoma. It is composed entirely of tumour cells with abundant extracellular mucin and without admixing of infiltrating ductal carcinoma. We studied a total of ten cases of Pure Mucinous Breast Carcinoma. Here we describes each case of demographic features and histopathological features of PMBC. The results of immunohistochemistry of Estrogen receptor (ER), Progesterone receptor (PR), Human epidermal growth factor receptor 2(HER-2neu) were also noted in this case series. All the cases were female and above 50 years of age. Out of 10 cases, 6 cases have the tumour’s location on the left side of the breast and 4 cases have the tumour’s location on the right side of the breast. All the cases belong to the lower grading and staging of the tumour. Only one case had positive lymph node status.Hormone receptor status of all the cases has ER &amp; PR positive expression, HER-2neu negative expression and low Ki 67 labelling index. To conclude, PMBC was associated with lower-grade tumours, lower-stage, infrequent lymph node metastasis and luminal type A hormonal receptor status. These favourable findings suggest that PMBC has a better prognosis and may give a better response to hormonal therapy.

Background: Mucinous carcinoma is the third most common histological subtype of breast cancer after ductal and lobular carcinomas, accounting for approximately 3% of invasive breast cancers. Although considered a favourable subtype with de-escalation of treatment recommended in the National Comprehensive Cancer Network guidelines, recurrence can occur and supporting data is limited. We thus examined prognostic factors of pure mucinous breast cancer (PMBC) in an international multicentre cohort study. Methods: Patients diagnosed between January 2000 to December 2015 with hormone receptor-positive HER2-negative stage I to III PMBC, invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) at 6 centers in Singapore, Taiwan, Korea and Japan were evaluated. Cox proportional hazards regression analyses were used to compare relapse-free survival (RFS), distant relapse-free survival (DRFS) and overall survival (OS) by histological subtypes, and to identify prognostic factors for PMBC. Results: Of 23,105 women eligible for analysis, 20,684 had IDC, 1,475 had ILC and 946 had PMBC. The median follow-up was 6.6 years; 5-year RFS, DRFS and OS for PMBC were 94.6%, 96.5% and 98.1% respectively. On multivariable cox regression analyses, PMBC demonstrated superior RFS (hazard ratio [HR] = 0.70, 95% CI: 0.56 - 0.88), DRFS (HR = 0.69, 95% CI: 0.53 - 0.89) and OS (HR = 0.70, 95% CI: 0.52 - 0.93) compared to IDC, while ILC had comparable survival outcomes as IDC. When restricted to only PMBC, significant independent prognostic factors for RFS included ethnicity (vs Chinese, “Others” [non-Chinese/Japanese/Korean, mainly Malay and Indian]: HR = 2.62, 95% CI 1.23 – 5.57), older age (vs &amp;lt; 40 years, &amp;gt;70 years: HR = 3.53, 95% CI 1.67 – 7.46), tumor size (vs T1, T3-4: HR = 2.79, 95% CI 1.45 – 5.37), positive lymph nodes (HR = 2.04, 95% CI: 1.10 – 3.77), use of radiotherapy (HR = 0.54, 95% CI 0.33 – 0.91) and endocrine therapy (HR = 0.31, 95% CI 0.12 – 0.77). On further analysis, the inferior RFS, DRFS and OS in older patients (&amp;gt;70 years) were driven largely by non-breast cancer deaths rather than relapses. Use of endocrine therapy was also associated with superior DRFS (HR = 0.26, 95% CI 0.09 – 0.73) but not OS. In a subgroup analysis, use of chemotherapy was associated with improved DRFS (HR = 0.25, 95% CI 0.08 – 0.82) and OS (HR = 0.07, 95% CI 0.01 – 0.37) with a trend in RFS (HR = 0.41, 95% CI 0.14 – 1.24) for lymph node-positive PMBC; no differences in outcomes were observed for the lymph node-negative subgroup. Conclusions: Larger tumor size, lymph node positivity and ethnicity were significant factors for RFS in PMBC. Use of endocrine therapy was associated with superior RFS and DRFS, while chemotherapy was associated with better DRFS and OS for lymph-node positive PMBC. Citation Format: Ryan Tan, Whee Sze Ong, Kyung-Hun Lee, Seri Park, Jabed Iqbal, Yeon Hee Park, Jeong-Eon Lee, Jong Han Yu, Ching-Hung Lin, Yen-Shen Lu, Makiko Ono, Takayuki Ueno, Yoichi Naito, Tatsuya Onishi, Geok hoon Lim, Su-Ming Tan, Han-Byoel Lee, Jiwon Koh, Han Suk Ryu, Wonshik Han, Veronique Kiak Mien Tan, Fuh-Yong Wong, Seock-Ah Im, Puay Hoon Tan, Yoon-Sim Yap. Prognostic factors in non-metastatic hormone receptor-positive HER2-negative mucinous breast cancer: an international multicentre cohort study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-05-36.

Background: Mucinous breast carcinoma (MBC) is a subtype of breast cancer categorized by the presence of extracellular mucin and has more favorable prognosis than invasive carcinoma of no special type of breast cancer. The present study incorporates 27 years of practical experience from a breast disease research center-based series of cases regarding MBC and invasive ductal carcinoma (IDC).Method: In this retrospective study, we studied the medical documents of 7,739 patients in the Breast Disease Research Center, Shiraz University of Medical Sciences, from December 1993 to January 2019. TNM data, demographic status, pathologic stage, histological grade, hormonal receptor data, recurrence, overall survival (OS), and disease-free survival (DFS) were reviewed. We also statistically evaluated the clinical and histopathological differences of pure, mixed MBC, and IDC using SPSS, version 21.0 (IBM, USA). P<0.05 was considered as statistically significant.Results: A total of 78 and 31 patients were observed to have pure and mixed MBC, respectively, and 5,774 breast cancer patients had IDC. The pure MBC group showed a lower histological grade and pathologic stage and a larger tumor size compared with mixed MBC (P<0.001). The pure MBC patients had significantly less perinural and lymphovascular invasion and had less HER-2 positive status in comparison with IDC patients (P=0.023). The DFS and OS did not differ the between groups.Conclusion: MBC is a rare diagnosis with a favorable prognosis due to low lymph node metastases.

e13598 Background: The present study was conducted to investigate the influence of marital status on survival of pure mucinous breast carcinoma(PMBC) based on surveillance, epidemiology, and end results (SEER) databases. Methods: Data were extracted from the SEER database on eligible patients diagnosed with pure mucinous breast carcinoma between 1998 and 2015. Patients were divided into married groups (including common law) and not married groups (including single[never married]/unmarried or domestic Partner、Divorced、Separated、Widowed). Survival curves were generated using the kaplan-meier method, and survival differences were estimated using the log-rank test. Multivariate Cox proportional risk models were used to assess independent risk factors for survival. Results: A total of 14972 eligible pure mucinous breast carcinoma patients were enrolled from the SEER database, including 7462(49.84%) married and 7510(50.16%) not married patients. The OS and CSS were significantly greater in married patients than not married patients (79.27 vs 62.49% for OS and 96.07 vs 93.34% for CSS, both P =0.000). Married patients were more likely to be more younger (aged≥75) (21.5% vs. 44.1%), cancer stage were even lower(stage I)(69.6% vs. 62.6%), (stage II)(28.6% vs. 33.9%), (stage III)(0.6% vs. 0.9%), (stage IV)(1.3% vs. 2.5%), more patients received breast conserving surgery(67.4% vs. 62.9%), chemotherapy(15.3% vs. 11.0%) and radiation therapy(54.3% vs. 43.1%), also no recurrent lymph node metastasis was observed(82.8% vs. 74.6%) compared to unmarried group(All P =0.000). The multivariate Cox proportional hazards model showed that marriage is an independent protective factor for OS (HR = 1.356, 95% CI: 1.271-1.446, P =0.000) and CSS (HR = 1.942, 95% CI: 1.681–2.644, P =0.000). Conclusions: Marital status was an independent prognostic indicator in PMBC patients. Research data showed that married pure mucinous breast carcinoma patients can obtain better OS and CSS than unmarried patients.