Mucinous carcinoma of the breast: a pathologic study of 82 cases

A novel nomogram and risk classification system for predicting lymph node metastasis of breast mucinous carcinoma: A SEER-based study

BACKGROUND

Mucinous breast cancer (MBC) is a rare disease, and patients with lymph node metastasis (LNM) have a poor prognosis. We aimed to explore the predictive factors of LNM and to construct a nomogram for predicting the risk of LNM and to identify the suitable axillary surgery for patients with diverse risks.

PATIENTS AND METHODS

Data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Chi-square and rank-sum tests were used to analyze the differences between groups. Survival analysis was performed with Kaplan-Meier curves and log-rank tests. Independent factor identification and nomogram construction were performed with logistic regression analysis. The nomogram was qualified with a discrimination and calibration plot. Propensity score matching was performed to balance the disparities between groups.

RESULTS

Patients with metastatic lymph nodes have a worse prognosis. Univariate and multivariate analyses indicated that tumor size, grade, and age were independent risk factors for LNM. The nomogram constructed with these three factors can predict the risk of LNM with high accuracy (AUC: 0.767, 95% CI: 0.697-0.838) and good calibration. Based on the nomogram, a risk classification system satisfactorily stratified the patients into 3 groups with diverse risks of LNM. In the low-risk group, there were no significant differences between sentinel lymph node biopsy and no axillary surgery. In the middle- and high-risk groups, both SLNB and axillary lymph node dissection were superior to no axillary surgery, with similar survival benefits.

CONCLUSIONS

The nomogram based on tumor size, grade, and age could conveniently and accurately predict the risk of LNM in MBC and assist clinicians in optimizing surgical strategies.

Construction of a Prognostic Nomogram Model for Patients with Mucinous Breast Cancer

Objective

The objective of the study is to develop a nomogram for estimating three- and five-year survival rates in mucinous breast cancer patients.

Methods

Between 2010 and 2016, the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) were searched as a data source for patients associated with mucinous breast cancer (MBC). A total of 3964 patients were recruited after screening. The multivariate Cox model and the univariate Kaplan-Meier (KM) approach were employed to evaluate the independent prognostic markers, followed by developing a nomogram for estimating three- and five-year survival rates in MBC patients. Consequently, the consistency index (C-index) was employed to assess the predictive accuracy of the generated nomogram.

Results

Age, race, T stage, M stage, surgery, and radiotherapy were all independent predictive biomarkers for the MBC patients (P < 0.05). The nomogram was finally developed based on the underlined factors. Furthermore, the C-index of 0.803 and reliable calibration curves were obtained in the nomogram's assessment.

Conclusions

In patients with mucinous breast cancer, the proposed nomogram provides a viable tool for accurate prognostic prediction. In clinical practice, it could serve as a personalized diagnosis tool, estimate prognosis, and help in suggesting treatment plans for patients with MBC.

Overall Survival in Patients with Mucinous Carcinoma of Breast: A Population-Based Study

Purpose

Mucinous carcinoma of the breast (MCB) is a rare malignant tumour. Therefore, it is urgent to establish a survival prediction model for MCB patients.

Methods

Clinicopathological and follow-up data of MCB patients diagnosed between 2010 and 2015 were retrieved from the Surveillance, Epidemiology, and End Result (SEER) database. The significant factors were screened out and generated Kaplan-Meier (K-M) curves for each prognostic factor. Additionally, these factors were then utilized to build a nomogram for predicting 3-, 4-, and 5-year overall survival (OS) of MCB patients. The nomogram was evaluated using calibration curves, receiver operating characteristic (ROC) curves and decision curve analysis (DCA).

Results

Moreover, a total of 4326 MCB patients were retrieved. Age, American Joint Committee on Cancer (AJCC) stage, surgery, radiotherapy and bone metastasis were identified as independently prognosis factors for OS. The corresponding areas under the ROC curves (AUCs) of the nomogram at 3, 4 and 5 years in the training and validation set were 0.770, 0.788, 0.805, 0.778, 0.797, and 0.802, respectively. The calibration curves and DCA revealed that the prediction model had an excellent performance. Finally, the risk stratification system confirmed that the powerful role of the nomogram in distinguishing results and risk stratification.

Conclusion

Briefly, the nomogram incorporating various clinicopathological indicators was established for MCB patients and may facilitate clinical decision-making.

Clinicopathological and Molecular Analysis of 45 Cases of Pure Mucinous Breast Cancer

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.

Evaluation of efficacy of chemotherapy for mucinous carcinoma: a surveillance, epidemiology, and end results cohort study

Background

In this study, we investigated the impact of chemotherapy on breast cancer-specific survival (BCSS) in patients with mucinous carcinoma using the surveillance, epidemiology, and end results (SEER) database.

Methods

A large-scale SEER-based retrospective analysis was conducted; 13,329 patients with mucinous carcinoma from 1994 to 2014 were identified. Clinicopathological characteristics were compared using the chi-square test. BCSS curves were generated using the Kaplan-Meier method. The prognostic significance of all demographic and clinicopathological characteristics and treatment patterns were calculated using univariate and multivariate regression analyses.

Results

Mucinous carcinoma was demonstrated to be less aggressive than invasive ductal carcinoma and predicted a better prognosis in the Kaplan-Meier analysis (hazard ratios = 0.336, 95% confidence interval: 0.308-0.368, p < 0.001). Univariate and multivariate analyses revealed that chemotherapy did not provide any additional benefit for patients with mucinous carcinoma. Predictors for receiving chemotherapy were younger age, estrogen receptor-negative, progesterone receptor-negative, and human epidermal growth factor receptor 2-positive status, higher grade, larger tumor size, lymph node involvement, radiation reception, and mastectomy. Further subgroup analysis verified that regardless of the hormone receptor (HR) and lymph node (LN) status, patients did not benefit from chemotherapy.

Conclusion

Our study showed that patients with HR+/LN- mucinous carcinoma did not benefit from chemotherapy and that chemotherapy could not improve the survival of all subtypes of mucinous carcinoma based on large-scale SEER data. These results support that patients with mucinous carcinoma could be exempt from chemotherapy. Additional research is needed to further evaluate the impact of adjuvant treatments, particularly in patients with favorable histology.

Special subtypes with favorable prognosis in breast cancer: A registry-based cohort study and network meta-analysis

BACKGROUND

We aimed to explore whether cribriform and adenoid cystic carcinoma had comparable prognoses to mucinous, tubular and papillary carcinoma, which were long recognized as favorable histologies by NCCN guidelines.

METHODS

A retrospective analysis based on the Surveillance, Epidemiology, and End Results Study (SEER) database (1994-2014) was conducted. The prognostic significance of all clinicopathological factors was calculated using univariate and multivariate analyses. A systematic review based on PubMed and network meta-analysis was conducted.

RESULTS

From the SEER database, the histologic subtypes of breast cancer (tubular, cribriform, adenoid cystic, mucinous, and papillary) were sorted by overall survival (OS) (94.4%, 91.6%, 90.8%, 87.6%, and 84.2%, respectively) and tubular, cribriform, mucinous, papillary, and adenoid cystic carcinoma by breast cancer-specific survival (BCSS) (99.4%, 98.4%, 97.7%, 95.2%, and 94.9%, respectively). A network meta-analysis combining 11 studies (886,649 patients) was conducted, which demonstrated consistent outcomes. SEER-based analyses revealed that, among the favorable subtypes, systemic chemotherapy did not improve OS or BCSS in hormone receptor-positive, node-negative patients, validating that these subtypes are generally associated with excellent outcomes, for which systemic chemotherapy may not be warranted.

CONCLUSIONS

Our data are consistent with guidelines suggesting that the mucinous, tubular, and papillary subtypes of breast cancer have favorable histologies. SEER data and meta-analysis supports this favorable category to include adenoid cystic and cribriform carcinoma, whose OS and BCSS outcomes are comparable to the former three. These findings add to the body of data, suggesting that patients with these histologic subtypes confer excellent prognosis, which may guide optimal therapeutic management strategies.

Mucinous versus medullary breast carcinoma: mammography, ultrasound, and MRI findings

Mucinous and medullary breast cancers (BCs) have different histological substrates that manifest as different imaging features on mammography, ultrasound, and MRI. The aim of the present review is to demonstrate the differences between these two rare BC subtypes and to describe the microscopic features, review the imaging methods for detection of both cancer subtypes, illustrate the imaging findings and present useful pearls and pitfalls. Out of a total of 30 patients with mucinous BC and nine with medullary BC, we have selected typical and also unusual imaging features that best represent these cancers. The patients underwent a mammography and breast ultrasound followed by magnetic resonance imaging. We briefly exhibit histological characteristics for a better understanding of the imaging aspects.

Comparison of the Distribution Pattern of 21-Gene Recurrence Score between Mucinous Breast Cancer and Infiltrating Ductal Carcinoma in Chinese Population: A Retrospective Single-Center Study

Purpose

This retrospective study aimed to evaluate the distribution pattern and prognostic value of 21-gene recurrence score (RS) in Chinese patients with mucinous breast cancer (MC) and compared with infiltrating ductal carcinoma (IDC).

Materials and Methods

Patients diagnosed with MC or IDC from January 2010 to January 2017 were retrospectively recruited. Reverse transcriptase–polymerase chain reaction assay of 21 genes was conducted to calculate the RS. Univariate and multivariate analyses were performed to assess the association between RS and clinicopathological factors. Survival outcomes including disease-free survival (DFS) and overall survival (OS) were estimated by Kaplan-Meier method and compared by log-rank test.

Results

The MC cohort included 128 patients and the IDC cohort included 707 patients. The proportions of patients with a low (RS < 18), intermediate (18-30), or high risk (RS > 30) were 32.0%, 48.4%, and 19.5% in MC cohort, and 26.9%, 46.8% and 26.3% in IDC cohort. The distribution of RS varied significantly according to different Ki-67 index and molecular subtype in both cohorts. Moreover, the receipt of chemotherapy was associated with RS in both cohorts. Among patients with MC, tumor stage was related to the DFS (p=0.040). No significant differences in DFS and OS were found among MC patients in different RS risk groups (OS, p=0.695; DFS, p=0.926).

Conclusion

RS was significantly related to Ki-67 index and molecular subtypes in MC patients, which is similar in IDC patients. However, RS was not able to predict DFS and OS in patients with MC.

Omission of adjuvant radiotherapy following breast-conserving surgery for elderly women with early-stage pure mucinous breast carcinoma

Background

We aimed to ascertain population-based practice patterns and survival outcomes of postoperative radiotherapy following breast conserving-surgery (BCS) in elderly women (aged ≥65 years) with early-stage pure mucinous breast carcinoma (PMBC).

Methods

Patients aged ≥65 years diagnosed with T1–2N0 and hormone receptor-positive PMBC between 1990 and 2010 were identified from the Surveillance, Epidemiology, and End Results database. Binomial logistic regression, Kaplan-Meier method, Multivariate Cox proportional hazards models, and propensity score matching (PSM) were used for statistical analysis.

Results

We enrolled 3416 patients, including 1225 (35.9%) and 2191 (64.1%) in the no-radiotherapy and radiotherapy cohorts, respectively. The percentage of patients receiving postoperative radiotherapy following BCS was significantly lower after 2004 (59.5% between 2004 and 2010), relative to that before 2004 (71.1% between 1990 and 2003; P < 0.001). Before PSM, the 10-year breast cancer-specific survival (BCSS) rates were 98.1 and 93.2% for patients with and without postoperative radiotherapy (log-rank test, P < 0.001), respectively. In the PSM cohort, receiving postoperative radiotherapy was associated with better BCSS rates, with 10-year BCSS rates of 97.6 and 94.5% in patients with and without postoperative radiotherapy, respectively (log-rank test, P = 0.001). Multivariate Cox proportional analysis indicated that receiving postoperative radiotherapy was an independent factor associated with better BCSS before (P < 0.001) and after PSM (P = 0.001), relative to those not receiving postoperative radiotherapy.

Conclusions

This study shows a decreasing utilization of postoperative radiotherapy following BCS of elderly PMBC patients over time. However, postoperative radiotherapy following BCS should be administered for elderly women with PMBC owing to independent association with better survival.

Comparison of Clinical Features and Treatment Results of Mix Mucinous Carcinomas and Other Atypical Carcinomas of the Breast

Objective

There are multiple subtypes of breast cancer with different biological and pathological features and accordingly exhibit different clinical behaviors. The aim of this study was to compare the treatment modalities, clinical features and prognostic characteristics of Mix Mucinous Carcinomas (MMBC) and other rare tumors of the breast.

Materials and Method

A total of 2152 patients who were operated on for breast cancer in our clinic between 2010-2019, with pathological diagnoses of tubular, pure mucinous, mix mucinous or papillary carcinoma were enrolled in the study. Patients were divided into two groups as mix mucinous patients (Group1) and other rare tumors (Group2). The demographic, clinical and prognostic characteristics and treatment approaches were compared between Groups, and additionally between the subtypes of Group 2.

Results

42 patients participated in our study. Group 1 consisted of 7 patients, and Group2 consisted of 35 patients. The subtypes in Group2 were papillary (n=21), pure mucinous (n=10) and tubular (n=4). Progesterone Receptor Positivity was found to be significantly higher in Group 2 patients than in Group1 patients (p=0.005, p<0.05). Multicentricity rates in the tumors of the patients in Group1 were found to be statistically significantly higher than the patients in Group 2 (p=0.024, p<0.05). In subtype analysis in Group2, there were no statistically significant differences parameters in the subgroups (p>0.05). Mean survival was 19.5+5.6 (8.5-30.5) months in Group 1 and 46.3+5.2 (36.1-56.6) months, in Group2 when evaluated separately (p:0.002).

Conclusion

The prognosis of pure mucinosis (PMBC) and other atypical cancers of the breast compared to the (MMBC) is quite good. Rare pathological types of breast cancer can have favorable outcomes when treated with necessary oncological principles.

Rare epithelial breast cancer: surgery and adjuvant therapy

Breast cancer is a heterogenous disease, exhibiting a wide range of morphological phenotypes shaping its prognosis and clinical course. However, optimal management of rarer breast cancer subtypes is often undefined and controversial in literature due to the lack of large studies and randomised trials. This review aims to discuss the treatment of 13 rare epithelial subtypes, focussing on surgery and adjuvant therapies.

Clinical Implication of HER2 Status in Hormone Receptor-Positive Mucinous Breast Cancer

PURPOSE

Mucinous carcinoma (MC) is a rare breast cancer with favorable outcome. Unlike typical breast cancer, the current guidelines do not recommend chemotherapy or anti-human epidermal growth factor receptor 2 (HER2) therapy for hormone receptor (HR)-positive MC, regardless of HER2 status. We evaluated the prognostic implication of HER2 status in HR-positive MC.

METHODS

We retrospectively reviewed the data of 471 patients with pure MC (stages I-III) who underwent curative surgery. We analyzed 5-year disease-free survival (DFS) and distant metastasis-free survival (DMFS), according to clinicopathological characteristics.

RESULTS

The median follow-up duration was 79.0 months. Overall, the 5-year DFS rate was 95.7% and the 5-year DMFS rate was 96.2%. Nodal status was the only significant factor for DFS (relative risk [RR], 3.40; 95% confidence interval [CI] 3.40-9.67, p = 0.021). Among HR-positive/node-negative patients with tumor size ≥ 3 cm, HER2-positive patients showed significantly worse DFS (RR, 8.76; 95% CI 1.45-52.76, p = 0.018) and DMFS (RR, 11.37; 95% CI 1.37-74.70, p = 0.011). This finding was consistently significant, when combining both "HR-positive/node-negative/tumor size ≥ 3 cm" and "HR-positive/node-positive" MC (n = 125) for DFS (RR, 4.30; 95% CI 1.43-12.97, p = 0.009) and DMFS (RR, 4.93; 95% CI 1.63-14.90, p = 0.005). Intriguingly, within this subgroup, among HER2-positive tumors, whereas 5-year DFS was 60.2% in patients who did not receive trastuzumab, 100% of those who received trastuzumab were disease free (p = 0.053).

CONCLUSIONS

In HR-positive, node-negative MC with tumor size ≥ 3 cm, patients with HER2-positive MC showed worse survival, suggesting a potential role of an anti-HER2 strategy in this subgroup.

Predictors for Survival and Distribution of 21-Gene Recurrence Score in Patients With Pure Mucinous Breast Cancer: A SEER Population-Based Retrospective Analysis

BACKGROUND

Pure mucinous breast cancer (PMBC) is a rare pathologic type of breast cancer, the prognostic factors of which have not been clearly defined. This study aimed to analyze the prognostic markers and distribution of 21-gene recurrence score (RS) in patients with PMBC.

PATIENTS AND METHODS

Utilizing the Surveillance, Epidemiology, and End Results (SEER) database, a retrospective analysis of PMBC cases was conducted. Multivariate analyses were used to evaluate the indicators for prognosis and the correlations between RS and traditional clinicopathologic characteristics. Disease was subdivided into 4 molecular phenotypes using estrogen receptor (ER) status and tumor grade.

RESULTS

Of the 8048 patients, most had ER-positive and node-negative tumors. Multivariate analysis revealed that molecular phenotype as well as age, race, tumor size, and lymph node status was an independent prognostic factor for patients with PMBC (P < .05). The 5-year breast cancer-specific survival of patients among different phenotypes was significantly different (97.9% for ER-positive and grade I tumor, 96.9% for ER-positive and grade II-III tumor, 96% for ER-negative and grade I tumor, 90.1% for ER-negative and grade II-III tumors, P < .001). The proportions of patients categorized into low, intermediate, and high RS risk group were 64.9%, 31.9%, and 3.2%, respectively. Grade, progesterone receptor status, and age were identified as independent variables associated with RS.

CONCLUSION

PMBC had favorable biological features and relatively good prognosis. Molecular phenotype as well as age, race, tumor size, and lymph node status were independent prognostic markers. Furthermore, age, progesterone receptor status, and grade could independently predict RS.

Prognosis of subtypes of the mucinous breast carcinoma in Chinese women: a population-based study of 32-year experience (1983-2014)

Purpose

The heterogeneous nature of the mucinous breast cancer (MBC), with its pure (PMBC) and mixed subtypes (MMBC), calls for precise prognosis assessment.

Methods

We analyzed 197 consecutive MBC patients, including 117 PMBC and 80 MMBC, who were treated from 1983 to 2014. The clinicopathological features, treatment choice, disease-free survival (DFS) and overall survival (OS) were compared among PMBC, MMBC and MMBC subgroups. Prognostic factors of PMBC and MMBC were identified.

Results

Compared to PMBC, MMBC had more lymph node metastasis (p = 0.043), Her2 positivity (p = 0.036), high Ki-67 index (defined as>20%, p = 0.026) and anti-Her2 targeted therapy (p = 0.016). The 5-year DFS of PMBC and MMBC were 90.4% and 86.2%, whereas the 5-year OS were 99.0% and 98.7%. No significant difference was found in DFS or OS among all MBC subtypes. High Ki-67 (p = 0.020) appeared as DFS factor in PMBC, while anti-Her2 targeted therapy (p = 0.047) as the DFS predictors in MMBC.

Conclusion

MMBC manifested similar 5-year survival to PMBC in Chinese woman, suggesting that intra-tumoral heterogeneity might not interfere with MBC short-term prognosis.

Clinical Nomogram for Predicting Survival Outcomes in Early Mucinous Breast Cancer

Background

The features related to the prognosis of patients with mucinous breast cancer (MBC) remain controversial. We aimed to explore the prognostic factors of MBC and develop a nomogram for predicting survival outcomes.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database was searched to identify 139611 women with resectable breast cancer from 1990 to 2007. Survival curves were generated using Kaplan-Meier methods. The 5-year and 10-year cancer-specific survival (CSS) rates were calculated using the Life-Table method. Based on Cox models, a nomogram was constructed to predict the probabilities of CSS for an individual patient. The competing risk regression model was used to analyse the specific survival of patients with MBC.

Results

There were 136569 (97.82%) infiltrative ductal cancer (IDC) patients and 3042 (2.18%) MBC patients. Patients with MBC had less lymph node involvement, a higher frequency of well-differentiated lesions, and more estrogen receptor (ER)-positive tumors. Patients with MBC had significantly higher 5 and10-year CSS rates (98.23 and 96.03%, respectively) than patients with IDC (91.44 and 85.48%, respectively). Univariate and multivariate analyses showed that MBC was an independent factor for better prognosis. As for patients with MBC, the event of death caused by another disease exceeded the event of death caused by breast cancer. A competing risk regression model further showed that lymph node involvement, poorly differentiated grade and advanced T-classification were independent factors of poor prognosis in patients with MBC. The Nomogram can accurately predict CSS with a high C-index (0.816). Risk scores developed from the nomogram can more accurately predict the prognosis of patients with MBC (C-index = 0.789) than the traditional TNM system (C-index = 0.704, P< 0.001).

Conclusions

Patients with MBC have a better prognosis than patients with IDC. Nomograms could help clinicians make more informed decisions in clinical practice. The competing risk regression model, as a more rational model, is recommended for use in the survival analysis of patients with MBC in the future.

Clinicopathological Characteristics of Mucinous Breast Cancer: A Retrospective Analysis of a 10-Year Study

Background

Mucinous breast carcinoma (MC) is a special type of breast cancer that presents with a large amount of extracellular mucin. MC comprises approximately 4% of all invasive breast cancers. This type of tumor has a better prognosis and higher incidence in peri- and post-menopausal patients. Pathologically, there are two main subtypes of MC: pure and mixed. In this study, we describe 10 years of experience with MC at the Zhejiang Cancer Hospital in China, specifically, clinical data, histological findings and immunohistochemical features.

Methods

We identified MC patients who were diagnosed as operable and completed clinical treatment from January 2001 to January 2011. The clinicopathological data included the age at diagnosis, tumor size, TNM stage, presence and number of lymph node (LN) metastases, estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2) status and p53 expression. If the tumor was defined as mixed mucinous carcinoma (MMC), IHC was performed on a non-mucinous part, such as invasive ductal and lobular cancer. We evaluated the clinical characteristics of all MC patients using chi-square, one-way ANOVA and LSD tests. We also studied the correlations between all of the clinical parameters and LN metastasis in a binary logistic regression analysis. We used ten consecutive years of data that were collected at Zhejiang Cancer Hospital.

Results

We identified 48 cases of pure mucinous carcinoma (PMC) and 77 cases of MMC. The 48 PMC cases consisted of 38 PMC-A and 10 PMC-B subtypes. The MMCs were divided into two groups, those with partial mixed mucinous breast carcinoma (pMMC, 58 cases) and those with main mixed mucinous breast carcinoma (mMMC, 19 cases). pMMC was defined by tumors with less than 50% mucinous components, while mMMC was defined by tumors where the mucinous component accounted for 50% to 90% of the tumor. No significant differences in the clinicopathological characteristics were noted between the patients with PMC-A and those with PMC-B. The tumor size was larger in the mMMC than PMC cases (44.84 mm vs. 30.06 mm, p = 0.021). The number of positive LN metastases was greater in pMMC than PMC patients (p = 0.024). The clinical stages were significantly different among the three groups, with the pMMC group having more stage III-IV patients than the other two groups (p = 0.005). The incidence of LN metastasis was also higher in the pMMC cases (pMMC vs. mMMC and PMC, 50% vs. 31.58% and 18.75%, p = 0.003). The PMC patients had much lower p53 expression than the other two groups (PMC vs. pMMC and mMMC, 27.08% vs. 55.17% and 57.89%, p = 0.007). The tumor size (>30mm), p53 expression and less proportion of the mucinous component are associated with risk of LN metastasis.

Conclusion

Based on the results of this study, we conclude that the tumor size, status of LN metastasis, clinical stage, and p53 mutation rate may differ between MMC and PMC patients. The tumor size (>30mm), p53 mutation and less proportion of the mucinous component should be considered risk factors of LN metastasis in MC patients.

Nuclear staining of fgfr-2/stat-5 and runx-2 in mucinous breast cancer

Mucinous carcinoma (MBC) is a rare subtype of breast cancer characterized by the production of variable amounts of mucin, with a prognosis better than that of non-mucinous carcinomas (NMBC). The aim of this project was to evaluate the expression of STAT-5, RUNX-2, and FGFR-2 in a cohort of MBC and compare it with that of NMBC using standard immunohistochemistry. STAT-5 and RUNX-2 are two transcription factors with cytoplasmic and/or nuclear localization that have been related to FGFR-2, a tyrosine kinase growth factor receptor that can interact with STAT-5 and with PR in the nuclei of breast cancer cells. Membranous, cytoplasmic, and nuclear staining were evaluated and expressed as the percentage of stained cells (0-100%) multiplied by the staining intensity (0-3), thus obtaining an index ranging from 0 to 300. Nuclear and/or cytoplasmic immunoreactivity of the three proteins were detected in a high number of NMBC. Nuclear FGFR-2 staining correlated with nuclear STAT-5 (p<0.05) and nuclear RUNX-2 (p<0.01) in both tumor types; however MBC had a significant higher expression of nuclear FGFR-2 (p<0.01) and RUNX-2 (p<0.05) than that of NMBC, and displayed positive immunoreactivity of the 3 proteins in 70.8% of the cases. These results suggest that these proteins may have a role in the progression of the mucinous phenotype, in which nuclear STAT-5 may inhibit RUNX-2 prometastatic effect.

The significance of extracellular mucin in breast fine needle aspiration specimens

OBJECTIVE

To determine if all breast fine needle aspiration (FNA) specimens with abundant extracellular mucin require excisional biopsy.

METHODS

Fifty cases of breast FNA containing extracellular mucin, reported with a recommendation for biopsy and with histological follow-up were reviewed. Cellular features were noted, and the cases reclassified ignoring the presence of mucin and then correlated with histological outcome.

RESULTS

Subsequent histology showed benign changes in 20% (10/50), two cases (4%) of atypical ductal hyperplasia (ADH) and 76% (38/50) to be malignant lesions, including three cases of ductal carcinoma in situ (DCIS). When the FNA cases were reviewed disregarding the presence of mucin, 11 cases were reclassified as benign and one case that contained mucin-like material but no epithelial cells reviewed as non-diagnostic. All cases of invasive mixed and mucinous carcinoma (MC) would have been reported with a recommendation for histological examination. In addition, the three cases each of fibroadenoma (FA) and a benign mucocoele-like lesion (MLL) were correctly identified as benign. However, two cases each of DCIS and ADH would have been reported benign with no recommendation for further histology.

CONCLUSIONS

Breast FNA specimens with mucinous material may arise from sampling of a range of benign and malignant processes; however, a biopsy should be recommended, even in cases of low cellularity, owing to sampling problems and the frequent co-occurrence of significant lesions. FNA is highly accurate at predicting carcinoma with mucinous differentiation although it is not possible to reliably predict if the lesion represents pure MC or a mixed carcinoma.

Invasive micropapillary mucinous carcinoma of the breast is associated with poor prognosis

Invasive micropapillary carcinoma of breast (IMpC) is a special type of breast cancer with frequent lymph node metastasis (LNM) and poor prognosis, while pure mucinous carcinoma of breast (PMC) is generally associated with infrequent LNM and better prognosis. A similar micropapillary epithelial growth pattern has been described in PMC that was named as invasive micropapillary mucinous carcinoma (IMpMC), but its prognostic significance is as yet not known. A retrospective review of 531 cases of PMC in 43,685 cases of breast cancer diagnosed over a 10-year period was conducted to assess the frequency of IMpMC and its prognostic implications. IMpMC was identified in 134 (25.2 %) of the 531 PMC cases. Compared to conventional PMC (cPMC), IMpMC was found more frequently in younger patients and in tumors with increased frequency of LNM and lymphovascular invasion, and higher HER2 expression. In stage-matched Kaplan-Meier analysis, patients with stage II-III IMpMC suffered a decreased overall survival and recurrence-free survival (RFS) than matched cPMC patients. Multivariate analysis confirmed the presence of IMpMC morphology was an independent unfavorable predictor for LNM and RFS of PMC. However, decreased LNM, lower nuclear grade, higher expression of ER and PR, less expression of HER2, and better prognosis were identified in IMpMC when compared with IMpC (n = 281). This is the first study to show the prognostic significance of IMpMC in a large cohort. IMpMC pursues a more aggressive clinical course than cPMC and should be managed differently; therefore, recognition of IMpMC and its accurate diagnosis are clinically important.

Mucinous breast carcinoma with a lobular neoplasia component: a subset with aberrant expression of cell adhesion and polarity molecules and lack of neuroendocrine differentiation

We investigated whether some mucinous carcinomas (MUCs) are associated with lobular neoplasia (LN) components, and if so, whether this subset has any distinct biological properties. MUC specimens from 41 patients were stratified into pure and mixed types. The LN components adjacent to MUC lesions were examined histopathologically. We also tested immunohistochemically for E-cadherin, β-catenin, and the neuroendocrine markers chromogranin A and synaptophysin; and compared results between MUCs with and without LN. Of 41 patients with MUC, LN was detected in 12 patients (29%); LN alone was the noninvasive component in 8 patients (20%). Decreased E-cadherin and β-catenin expression in the MUC component was detected in 2 (17%) and 7 (58%) cases, respectively, of MUC with LN, compared with 0% (P = 0.080) and 21% (P = 0.018) in MUCs without LN. Neuroendocrine factors were frequently detected in MUCs with LN (42%) and without LN (52%), but tended to be less frequent in MUCs with only LN components (25%) than in other MUCs (55%; P = 0.133). MUCs associated with LN components appear to be a biologically characteristic subset that frequently shows decreased cell-cell adhesion, cell polarity molecules and lack of neuroendocrine differentiation.

Rare breast tumors: Review of the literature

Breast cancer tumors have different morphological phenotypes and specific histopathological types with particular prognostic and clinical characteristics. The treatment of rare malignant lesions is frequently controversial due to the absence of trials to determine the optimal managements. This review describes the spectrum of rare breast tumors indicating the clinical, epidemiological and treatment characteristics.

Clinical significance of the sub-classification of 71 cases mucinous breast carcinoma

Objective

Mucinous breast carcinoma (MBC) is classified into mixed mucinous breast carcinoma (MMBC) and pure mucinous breast carcinoma (PMBC) based on whether the tumor is with or without a component of invasive ductal carcinoma, respectively. PMBC is subtyped into hypocellular PMBC (PMBC-A) and hypercellular PMBC (PMBC-B).

Methods

Of 1,760 primary breast carcinomas, 71 were diagnosed as MBC, and were subtyped for comparison purposes.

Results

Seventy-one of all breast cancers (4.0%) were MBC, and consisted of 23 MMBC, 32 PMBC-A and 16 PMBC-B. The MBC tumors were more often hormone receptor-positive and HER2-negative than non-MBC tumors. Patients with MMBC, PMBC-B or PMBC-A, in this order, had significantly higher recurrence rates than non-MBC cases (p=0.006, log-rank).

Conclusions

In the NCCN guidelines, MBC is also regarded as “a histological type with a favorable prognosis” in a uniform manner, and “treatment for a histological type with a favorable prognosis” is recommended. However, the results of this study suggest that sub-classification-based, individualized therapeutic strategies should be considered.

MicroRNA and histopathological characterization of pure mucinous breast carcinoma

OBJECTIVE

Pure mucinous breast carcinoma (PMBC) is an uncommon histological type of breast cancer characterized by a large amount of mucin production. MicroRNA (miRNA) is a large class of small noncoding RNA of about 22 nt involved in the regulation of various biological processes. This study aims to identify the miRNA expression profile in PMBC.

METHODS

MiRNA expression profiles in 11 PMBCs were analyzed by miRNA-microarray and real-time polymerase chain reaction (PCR). Thirty-one PMBCs and 27 invasive ductal carcinoma of no special types (IDC-NSTs) were assessed by immunohistochemistry using antibodies against ER, PR-progesterone receptor, HER2, Ki-67, Bcl-2, p53, PCNA, and CK5 and 6.

RESULTS

We analyzed the miRNA expression in 11 PMBCs and corresponding normal tissues using miRNA-microarray and real-time PCR, and found that miR-143 and miR-224-5p were significantly downregulated in mucinous carcinoma tissue. Compared with IDC-NSTs, PMBC showed a significantly higher ER positive rate, lower HER-2 positive rate, and lower cell proliferation rates.

CONCLUSIONS

To our knowledge, this is the first study to demonstrate the miRNA expression profile of PMBC, and our findings may lead to further understanding of this type of breast cancer.

Uncommon Breast Malignancies: Presentation Pattern, Prognostic Issue and Treatment Outcome in an Italian Single Institution Experience

Aims and background

Often neglected by large clinical trials, patients with uncommon breast malignancies have been rarely analyzed in large series.

Patients and methods

Of 2,052 patients diagnosed with breast cancer and followed in our Institution from January 1985 to December 2009, we retrospectively collected data on those with uncommon histotypes, with the aim of investigating their presentation characteristics and treatment outcome.

Results

Rare histotypes were identified in 146 patients (7.1% of our total breast cancer population), being classified as follows: tubular carcinoma in 75 (51.4%), mucinous carcinoma in 36 (24.7%), medullary carcinoma in 25 (17.1%) and papillary carcinoma in 10 patients (6.8%). Whereas age at diagnosis was not significantly different among the diverse diagnostic groups, patients with medullary and papillary subtypes had a higher rate of lymph node involvement, similar to that of invasive ductal carcinoma. Early stage diagnosis was frequent, except for medullary carcinoma. Overall, in comparison with our invasive ductal carcinoma patients, those with rare histotypes showed a significantly lower risk of recurrence, with a hazard ratio of 0.28 (95% CI, 0.12–0.62; P = 0.002).

Conclusions

According to our analysis, patients with uncommon breast malignancies are often diagnosed at an early stage, resulting in a good prognosis with standard treatment.

Estrogen switches pure mucinous breast cancer to invasive lobular carcinoma with mucinous features

Mucinous breast cancer (MBC) is mainly a disease of postmenopausal women. Pure MBC is rare and augurs a good prognosis. In contrast, MBC mixed with other histological subtypes of invasive disease loses the more favorable prognosis. Because of the relative rarity of pure MBC, little is known about its cell and tumor biology and relationship to invasive disease of other subtypes. We have now developed a human breast cancer cell line called BCK4, in which we can control the behavior of MBC. BCK4 cells were derived from a patient whose poorly differentiated primary tumor was treated with chemotherapy, radiation and tamoxifen. Malignant cells from a recurrent pleural effusion were xenografted in mammary glands of a nude mouse. Cells from the solid tumor xenograft were propagated in culture to generate the BCK4 cell line. Multiple marker and chromosome analyses demonstrate that BCK4 cells are human, near diploid and luminal, expressing functional estrogen, androgen, and progesterone receptors. When xenografted back into immunocompromised cycling mice, BCK4 cells grow into small pure MBC. However, if mice are supplemented with continuous estradiol, tumors switch to invasive lobular carcinoma (ILC) with mucinous features (mixed MBC), and growth is markedly accelerated. Tamoxifen prevents the expansion of this more invasive component. The unexpected ability of estrogens to convert pure MBC into mixed MBC with ILC may explain the rarity of the pure disease in premenopausal women. These studies show that MBC can be derived from lobular precursors and that BCK4 cells are new, unique models to study the phenotypic plasticity, hormonal regulation, optimal therapeutic interventions, and metastatic patterns of MBC.

Outcome of pure mucinous breast carcinoma compared to infiltrating ductal carcinoma: a population-based study from China

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Mucinous carcinoma of the breast in comparison with invasive ductal carcinoma: clinicopathologic characteristics and prognosis

Purpose

Mucinous carcinoma (MC) of the breast is a rare histologic type of mammary neoplasm. The objective of this study was to evaluate the long-term disease-free survival (DFS) and overall survival (OS) of MC.

Methods

We conducted a retrospective analysis of all MC cases reported to a database between 1994 and 2010. Clinicopathological characteristics and survival of 268 MC cases were reviewed and compared with 2,455 invasive ductal carcinoma-not otherwise specified (IDC-NOS) cases.

Results

The MC cases were of a younger age, involved less lymph nodes, lower stage, more expression of hormonal receptors, and less HER2 overexpression compared to the IDC-NOS cases. The 5-year DFS rate for MC was 95.2% compared to 92.0% for IDC-NOS. The 5-year OS rate for MC was 98.9% compared to 94.9% for IDC-NOS. Multivariate analysis using Cox regression revealed that the mucinous type was a significant prognostic factor for DFS with lower nodal status (N stage) and hormonal therapy. For OS, only N stage was the most significant prognostic factor followed by adjuvant chemotherapy and adjuvant hormonal therapy.

Conclusion

MC was shown to be associated with a better DFS than IDC-NOS, but it had a similar OS. Nodal status and adjuvant therapy appear to be more significant predictors of prognosis than histologic subtype.

A cytomorphological study of secretions in breast cancer

Background:

Secretions are seen in a range of breast cancer that includes invasive ductal carcinoma, mucinous carcinoma and secretory carcinoma. Evaluation of the quantity and location of secretions and the contours of the cell clusters complement cell morphology could improve diagnostic cytopathological criteria.

Aim:

To identify the range of breast carcinomas with secretions on fine-needle aspiration.

Materials and Methods:

A retrospective study of 160 patients with breast carcinoma was carried out. The tumors were typed by evaluating the quantity and location of secretions, cellularity and nuclear grade.

Results:

Secretions were seen in 16 of 160 breast carcinomas. Eleven were invasive ductal carcinoma (IDC), three were mucinous and two were secretory carcinomas. In IDC, minimal intracytoplasmic secretions were seen in 10, nuclear grades of 2 and 3 in 9, cell clusters with irregular margins in 6, and necrosis in 4. All mucinous and secretory carcinomas were nuclear grade 1. Extensive extracellular secretions and cell clusters with rounded contours were seen in mucinous carcinomas. In secretory carcinomas, the secretions were predominantly intracellular; stringy vasculature was a unique feature.

Conclusion:

Secretions in breast cancer are seen in a range of lesions that include IDC, mucinous, and secretory carcinomas. The quantity and location of secretions in breast cancer offer clues to differentiating these.

Imaging findings in mucinous breast carcinoma and correlating factors

OBJECTIVE

To investigate the factors influencing mammographic and sonographic features of mucinous breast carcinoma.

MATERIALS AND METHODS

Forty-six patients diagnosed as mucinous breast carcinoma between March 2005 and April 2009 were studied. Mammographies of all patients and sonographies of 41 patients were analyzed retrospectively. Microscopic slides were re-evaluated by a pathologist in order to estimate the volume of extracellular mucus which was classified as: (+), less than 50% of mucus; (++), 50-80% of mucus; and (+++), more than 80% of mucus.

RESULTS

Thirty-one (61.3%) cases of pure mucinous type and 2 (33.3%) of mixed mucinous carcinoma presented as masses had well-defined margins on mammography. No correlation was found between margin characteristics and histological type as well as extracellular mucus rates. Denser breasts and young age group had significantly higher ratios of tumors presented with ill-defined masses than its counterpart. Sonographically, 100% lesions showed a hypoechoic lesion, 76.5% lesions in pure type and 71.4% lesions in mixed type showed a heterogeneous internal echo. No correlation was found between sonographic findings and histological type as well as extracellular mucus rates. Lesions with >40 positivity PCNA had higher ratio presented as ill-defined margins than those of ≤40% positivity PCNA.

CONCLUSIONS

The most common appearance of mucinous breast carcinoma is a mass on mammography and a hypoechoic lesion with heterogeneous internal echo on sonography. Mammographic margins and sonographic findings have no relation with histological type and extracellular mucus rate. Mammographic margin features are correlated with breast density and age and PCNA.

Clinicopathological characteristics of mucinous carcinoma of the breast in Korea: comparison with invasive ductal carcinoma-not otherwise specified

Clinicopathological characteristics and prognostic factors of mucinous carcinoma (MC) were compared with invasive ductal carcinoma-not otherwise specified (IDC-NOS). Clinicopathological characteristics and survivals of 104 MC patients were retrospectively reviewed and compared with those of 3,936 IDC-NOS. The median age at diagnosis was 45 yr in MC and 47 yr in IDC-NOS, respectively. The sensitivity of mammography and sonography for pure MC were 76.5% and 94.7%, respectively. MC showed favorable characteristics including less involvement of lymph node, lower stage, more expression of estrogen receptors, less HER-2 overexpression and differentiated grade, and better 10-yr disease-free survival (DFS) and overall survival (OS) (86.1% and 86.3%, respectively) than IDC-NOS (74.7% and 74.9%, respectively). Ten-year DFS of pure and mixed type was 90.2% and 68.8%, respectively. Nodal status and stage were statistically significant factors for survival. MC in Koreans showed similar features to Western populations except for a younger age of onset than in IDC-NOS. Since only pure MC showed better prognosis than IDC-NOS, it is important to differentiate mixed MC from pure MC. Middle-aged Korean women presenting breast symptoms should be examined carefully and evaluated with an appropriate diagnostic work-up because some patients present radiologically benign-like lesions.

Mucinous Lesions of the Breast

Breast lesions associated with extracellular mucin production are uncommon and constitute a wide spectrum of lesions ranging from benign cyst to mucinous carcinoma. Intracytoplasmic mucin can be seen rarely in benign metaplasias but is a common finding in invasive and in situ carcinomas. In this article, we discuss the differential diagnosis of breast lesions associated with mucin production and other entities that show histologic changes that mimic mucin production.

Immunohistochemical expression of GCIP in breast carcinoma: relationship with tumour grade, disease-free survival, mucinous differentiation and response to chemotherapy

AIMS

Grap2 and cyclin-D interacting protein (GCIP) is a putative tumour suppressor in human cancer. The aim was to investigate its prognostic significance in human breast carcinoma.

METHODS AND RESULTS

Immunohistochemical analysis of breast carcinoma specimens from 107 female patients was performed. Decreased cytoplasmic expression of GCIP was detected in breast carcinomas compared with normal ductal epithelium (P < 0.001). Higher GCIP scores were observed in patients with lower histological grade, mucinous carcinomas and better clinical outcome (P < 0.05). Disease-free survival was significantly longer in patients with high GCIP scores than in those with low GCIP scores (P = 0.010). However, GCIP expression was independent of the status of oestrogen receptor, progesterone receptor, Her-2/neu and cancer stage. Moreover, in patients receiving neoadjuvant chemotherapy, those with higher GCIP scores showed potentially more reduction of tumour size compared with those with lower GCIP scores (borderline significance, P = 0.053).

CONCLUSIONS

The current data provide evidence that decreased expression of GCIP in vivo is present in human breast carcinoma and indicate that GCIP is a potential indicator of good prognosis. In patients receiving neoadjuvant chemotherapy, it may also have predictive value for the chemotherapeutic response.

A retrospective review with long term follow up of 11,400 cases of pure mucinous breast carcinoma

BACKGROUND

Pure mucinous breast carcinoma (PMBC) is a rare histologic type of mammary neoplasm. It has been associated with a better short-term prognosis than infiltrating ductal carcinoma (IDC) but identical long-term survival curves have been reported. The value of tumor size for TNM staging has been challenged because of the mucin content of the lesions. This study presents a large PMBC series with 20 years follow up as compared to IDC. The relative significance of a variety of common prognostic factors is calculated for this uncommon histology.

MATERIALS AND METHODS

A retrospective analysis of all PMBC cases reported in the SEER database between 1973 and 2002 was conducted. Overall survival (OS) and disease specific survival (DSS) were calculated at 5, 10, 15 and 20 years of follow up. Those curves were compared with all the IDC cases reported into the database during the same period. The prognostic significance of gender, race, laterality, age at diagnosis, T and N status, estrogen and progesterone receptors and administration of radiation therapy was calculated by univariate and multivariate analysis.

RESULTS

There were 11,422 PMBC patients reported. The median age at diagnosis was 71 years (Range 25-85). Fifty three percent of the tumors were well differentiated, 38% were moderately differentiated and the remaining 9% were poorly differentiated or anaplastic. The majority of the tumors were located in the upper outer quadrant (44%) the other 56% were roughly evenly divided between the upper inner, lower inner, lower outer and central quadrants. Eighty six percent of the patients had only localized disease at the time of surgery without nodal or distant disease while 12% had regional nodal involvement and 2% had distant metastases. The PMBC cases showed a better differentiation with lesions of lesser grade and more frequent ER/PR expression, smaller size and lesser nodal involvement when compared to the IDC cases of the same period. Kaplan Meier survival curves revealed a 5 years. breast cancer specific survival rate of 94%. Although slowly decreasing with time, 10, 15 and 20 years survival were 89%, 85% and 81% respectively compared to 82% (5 year), 72% (10 year), 66% (15 year) and 62% (20 year) for IDC. There were no significant differences in overall survival. Multivariate analysis by Cox regression revealed the nodal status (N) to be the most significant prognostic factor followed by age, tumor size (T), progesterone receptors and nuclear grade. Disease specific survival curves stratified for nodal status revealed a highly significant difference between node negative and node positive patients. The addition of radiation therapy after surgery did not significantly improve overall survival.

CONCLUSIONS

This large retrospective comparative analysis confirms the less aggressive behavior of PMBC compared to IDC. This favorable outcome is maintained after 20 years. This tumor presents typically in older patients and is rarely associated with nodal disease. Positive nodal status appears to be the most significant predictor of worse prognosis.

Management of Rare Histological Types of Breast Tumours

Breast tumours exhibit a wide range of morphological phenotypes, and specific histopathological types have particular prognostic and clinical characteristics. The management of uncommon premalignant and malignant lesions is often controversial due to the lack of large single-institution studies or randomised trials to define optimal treatments. In the era of frequent use of treatment guidelines, only a low level of evidence exists for the management of rare histological types of breast tumours. This review is divided into two parts: Firstly, the favourable histological subtypes like tubular, mucinous, medullary breast cancers, and phyllodes tumour (benign, borderline, and malignant) are discussed. The prognosis of these selected lesions is believed to be better than for invasive ductal carcinoma so that in some cases even less aggressive treatment should be considered. Patients with these specific histological types should be informed of this relatively favourable prognosis. Secondly, management recommendations for special situations like Paget's disease (tumour of the nipple) and inflammatory breast carcinoma are presented.

Prognostic Significance of Micropapillary Pattern in Pure Mucinous Carcinoma of the Breast

Breast carcinoma with micropapillary architecture is associated with aggressive behavior. Similar micropapillary pattern in pure mucinous carcinoma has been noticed and has been shown to convey poor prognosis. In this study 17 cases of pure mucinous carcinoma of the breast seen during a 10-year period have been reviewed, with special reference to micropapillary pattern. Diffuse micropapillary pattern was seen in 6 of 17 cases of mucinous carcinoma of the breast and demonstrated reverse polarity immunostaining pattern with “Epithelial Membrane Antigen.” In all cases, the tumor cells showed grade I morphology, and no lymph node metastases were noticed. All the tumors except 1 expressed strong estrogen and progesterone receptor expression, however, all the cases were negative for Her-2/neu expression. In this present study, mucinous carcinomas with micropapillary pattern showed a low nuclear grade, higher incidence of hormone receptor positivity, and lower incidence of Her-2/neu similar to mucinous carcinomas without micropapillary pattern, thus explaining their indolent behavior.

Correlation between numeric gadolinium-enhanced dynamic MRI ratios and prognostic factors and histologic type of breast carcinoma

OBJECTIVE

The purpose of this study was to assess the usefulness of numeric ratios from dynamic contrast-enhanced MRI in predicting histologic type of breast carcinoma and three histologic prognostic factors for invasive ductal carcinoma.

MATERIALS AND METHODS

A total of 104 patients with breast carcinoma were included in the study. Dynamic contrast-enhanced MR images were obtained every 30 seconds during the first 4.5 minutes after administration of contrast material, and peripheral contrast enhancement ratio and central contrast enhancement ratio were calculated in the early phase (1 minute after contract injection) and in the delayed phase (4 minutes after injection). Four contrast enhancement ratios were used for quantitative analysis of the following numeric ratios: early peripheral/early central, delayed peripheral/delayed central, delayed peripheral/early peripheral, and delayed central/early central. The four ratios were compared with histologic type. For invasive ductal carcinoma, the ratios were then compared with modified Scarff-Bloom-Richardson histologic grade, microvessel density, and fibrotic focus.

RESULTS

Mucinous carcinoma had significantly higher mean early peripheral/early central and delayed central/early central ratios than other types of tumors (p< 0.0001). For invasive ductal carcinoma, the mean early peripheral/early central ratio was significantly lower for modified Scarff-Bloom-Richardson grade 1 tumors than for grades 2 and 3 tumors (p < 0.0001). Early peripheral/early central ratio had a significant correlation with the ratio of peripheral to central mean microvessel density (p < 0.0001). There was also a significant difference in early peripheral/early central ratio (p < 0.0001) between tumors with a fibrotic focus and those without a fibrotic focus.

CONCLUSION

Numeric ratios obtained on gadolinium-enhanced dynamic MRI of the breast may be useful in predicting histologic type of breast carcinoma and three histologic prognostic factors for invasive ductal carcinoma: modified Scarff-Bloom-Richardson grade, microvessel density, and fibrotic focus.

A case of mucinous carcinoma of the breast that demonstrated a good pathological response to neoadjuvant chemotherapy despite a poor clinical response

A 30-year-old woman presented with a right breast tumor. Mucinous carcinoma was diagnosed by core needle biopsy (T2: 5 cm N1 M0). Despite receiving a neoadjuvant anthracycline and taxane regimen, the patient demonstrated no clinical response (NC). Based on the patient's strong preference, we performed breast-conserving surgery. On histological examination, we observed widespread mucus and a few viable malignant cells, a Grade 2 therapeutic response. Neither optimal management procedures nor guidelines for chemotherapy for primary mucinous carcinoma of the breast have been established. It is a reasonable assumption, however, that discordance between the clinical response and therapeutic response to neoadjuvant chemotherapy may occur in cases of mucinous carcinoma.

A case of non-metastatic giant mucinous carcinoma of the breast

A surgically resected case of giant mucinous carcinoma of the breast that had remained untreated for 2 years is reported. A 64-year-old postmenopausal woman presented with a large right breast mass (17.4 x 16.5 x 14.5 cm). Although she had noticed a mass in the right breast 2 years previously, she had not sought treatment. Mucinous carcinoma was diagnosed by core needle biopsy and she underwent right modified radical mastectomy with a free skin graft. There were no lymph node metastases or distant metastases. Fourteen months postoperatively, she remains well without evidence of tumor recurrence. Although several reports have suggested that pure mucinous carcinoma of the breast has a favorable prognosis, we need to follow this case until the clinical behavior and the outcome become clear.

Pure mucinous carcinoma of the breast

BACKGROUND

The lack of a standard definition of "pure" mucinous carcinoma of the breast has made it difficult to compare data from different studies. This study used the most stringent criteria to define parameters for truly pure lesions.

METHODS

Sixty-five patients were identified. The database was used to evaluate patients' demographics, tumor characteristics, and outcomes. Survival curves and predictors of survival were analyzed.

RESULTS

The mean age of presentation was 67 years. The majority (96%) of patients presented with early-stage disease. The 5- and 10-year overall survival rates were 93.6% and 72.8%, respectively. The number of involved axillary lymph nodes was the only significant predictor of death (P = 0.02).

CONCLUSIONS

Pure mucinous carcinoma of the breast has a favorable prognosis. Tumor size does not appear to impact survival, perhaps because the volume of mucin overestimates tumor burden. The number of involved axillary lymph nodes was the only significant predictor of death from disease.

Fine-needle aspiration cytology findings of an uncommon micropapillary variant of pure mucinous carcinoma of the breast: review of patients over an 8-year period

BACKGROUND

Previous attempts at subclassifying pure mucinous carcinomas of the breast based on architectural patterns and other associated features are on record. A distinctive micropapillary variant with most tumor cells arranged in micropapillae/pseudoacini has not been described previously.

METHODS

The author reviewed the histologic slides from all 556 patients who underwent wide excision/mastectomy for mammary ductal carcinoma, either in situ or invasive, at Pamela Youde Nethersole Eastern Hospital, Hong Kong, during an 8-year period from early 1994 to the end of 2001. Five patients with pure mucinous carcinoma with diffuse micropapillary architecture were noted. The cytologic features (if available) were correlated with clinical, radiologic, and pathologic findings.

RESULTS

Among the five patients with pure mammary mucinous carcinoma (micropapillary variant), three patients underwent preoperative fine-needle aspiration biopsies and had specimens available for review. The direct smears and cytospin preparations were of moderate cellularity and showed cohesive clusters and micropapillae of mildly pleomorphic tumor cells among a mucoid background. True tumor papillae with fibrovascular cores were not present. Nuclear hobnailing was observed commonly, and occasional psammoma bodies were found. There were also scanty isolated tumor cells scattered around. The pseudoacinar pattern was appreciated more readily in the cell block sections. Histologic examination of the surgical specimens showed features of pure mucinous carcinoma with diffuse micropapillary architecture. The micropapillary arrangement was confirmed further by the demonstration of a reverse polarity immunostaining pattern for epithelial membrane antigen and the identification of microvilli rimming the periphery of tumor cell clusters under the electron microscope. Peritumoral lymphovascular permeation and ipsilateral axillary lymph node metastasis was found in one of the patients.

CONCLUSIONS

The micropapillary variant of mammary mucinous carcinoma demonstrates characteristic cytologic and histologic features that warrant special attention. It may represent the mucinous counterpart of invasive micropapillary carcinoma. Further analysis of a larger series of patients, however, will be required to delineate its prognostic significance, especially its propensity for lymph node metastasis.