Increased lymph node positivity in multifocal and multicentric breast cancer

Lymph Node Positivity: Indication for Preoperative MRI?

BACKGROUND

The purpose was to determine what factors help predict benefit from preoperative MRI.

METHODS

We conducted an IRB approved retrospective review of patients with breast cancer who underwent preoperative MRI (2018-2021). Patients were divided into a cohort of no new disease detected on MRI versus new disease detected.

RESULTS

Of 420 patients with a new diagnosis of breast cancer who underwent preoperative MRI, 17% had new multicentric, multifocal, or contralateral disease detected. There was no difference between the two cohorts for age (p = 0.23), race (p = 0.45), family history (p = 0.47), breast density (p = 0.14), or hormone status (p = 0.90). In multivariate analysis, age (p = 0.61, OR 0.99), race (p = 0.58, OR 1.26), family history (p = 0.54, OR 0.82), breast density (p = 0.83, OR 0.87), grade (p = 0.87, OR 1.09), tumor size (p = 0.37, OR 0.92), and use of neoadjuvant therapy (p = 0.41, OR 0.72) were not predictive of detection of additional new disease. Presence of positive nodes on ultrasound or mammogram was associated with new or multifocal disease on MRI (p = 0.0005, OR 3.48). Pre-MRI positive nodes increased the likelihood of detection of new disease (p = 0.0002, OR 3.04). Preoperative MRI resulted in more extensive surgery than indicated for 22.2% of the no new disease detected cohort and 6.9% of the new multicentric disease cohort (p < 0.001).

CONCLUSIONS

Patients with nodal disease detected in their evaluation are more likely to have new multifocal, multicentric, or contralateral disease detected on MRI. The use of preoperative MRI may be particularly helpful in patients with node-positive disease in identifying additional disease that would alter surgical management.

The value of total tumor diameter in unilateral multifocal papillary thyroid carcinoma: a propensity score matching analysis

Background

Tumor multifocality is frequently observed in papillary thyroid carcinoma (PTC). However, the maximum tumor diameter (MTD), currently utilized in various staging schemes, might not accurately indicate the level of aggressiveness exhibited by multifocal tumors. We aimed to investigate the relationship between total tumor diameter (TTD) and clinicopathological features of papillary thyroid carcinoma.

Methods

Retrospective data analysis was done on 1936 individuals who underwent complete thyroidectomy for PTC. Patients were classified into subgroups according to unilateral multifocality, central lymph node metastasis (CLNM) and lateral lymph node metastasis (LLNM). The relationships of clinicopathological features among these groups were analyzed.

Results

Unilateral multifocality was observed in 117 patients. The clinicopathological features of the unilateral multifocal PTC were similar to the unifocal PTC with approximate TTD. The unilateral multifocality played no independent role in CLNM and LLNM. Moreover, the efficiency of TTD in predicting CLNM and LLNM was significantly higher than that of MTD.

Conclusion

In the case of unilateral multifocal PTC, TTD is a more accurate indicator of the biological characteristics of the tumor than MTD.

Comparing the outcome between multicentric/multifocal breast cancer and unifocal breast cancer: A systematic review and meta-analysis

Objective

This systematic review and meta-analysis compares the outcome between MMBC and unifocal breast cancer (UFBC), in order to provide a theoretical basis for the design of an appropriate clinical therapeutic strategy of MMBC patients.

Methods

PubMed, Embase, The Cochrane Library, Web of science, CNKI, WanFang Data, CBM and VIP database were searched from inception to July 2021, and observational studies reporting the outcome of patients with MMBC and UFBC were included. We extracted or calculated the mortality rates of MMBC and UFBC patients; and obtained the hazard ratios; odds ratios; relative risks; and the corresponding 95% confidence intervals from the eligible studies. All the meta-analyses were conducted by using the Stata 15.0 software.

Results

31 eligible studies comprising a total of 15,703 individuals were included. The meta-analysis revealed that MMBC did not have a significant association with poor overall survival (HR=1.04, 95% CI=0.96-1.12), disease-free survival (HR= 1.07, 95% CI= 0.84-1.36), breast cancer-specific survival (HR=1.42, 95% CI= 0.89-2.27), recurrence-free survival (HR= 0.878, 95% CI= 0.652-1.182), local recurrence-free survival (HR= 0.90, 95% CI= 0.57-1.42), and contralateral breast cancer risk (RR= 0.908, 95% CI= 0.667-1.234). However, MMBC appeared to have a correlation with a slightly higher risk of death (OR=1.31, 95% CI=1.18-1.45).

Conclusion

Patients with MMBC appeared to have a higher risk of death, however, it may not be independently associated with poorer outcomes. Considering the inter-study heterogeneity and other limitations, our results need to be validated by further multicenter prospective studies with a large sample size in the future.

Total tumor diameter is a better indicator of multifocal papillary thyroid microcarcinoma: A propensity score matching analysis

BACKGROUND

Accurate evaluation of the risk of papillary thyroid microcarcinoma (PTMC) is the key to treatment. However, the maximum diameter (MD), which is currently used in various staging systems, may not truly reflect the aggressiveness of multifocal tumors.

METHODS

Clinical and pathological data for 1001 patients with papillary thyroid carcinoma who underwent surgery at the Hangzhou First People's Hospital were retrospectively analyzed. First, the relationship between total tumor diameter (TTD) and clinicopathological features in multifocal PTMC was explored. Then, patients were divided into subgroups according to the TTD. The baseline was consistent after using the propensity score matching method, and the differences between groups were compared. In addition, the effectiveness of TTD and MD in evaluating central lymph node metastasis (CLNM) was analyzed and compared.

RESULTS

TTD is associated with a range of clinicopathological features, including lymph node metastasis, extrathyroidal extension, and risk stratification. Assuming the same MD and number of foci, the invasiveness of multifocal PTMC with TTD >1 cm was significantly higher than that with TTD <1 cm, and even higher than unifocal non-PTMC. Moreover, the efficiency of TTD in predicting CLNM was also significantly higher than that of MD.

CONCLUSION

For multifocal PTMC, TTD is a more realistic indicator of tumor biological characteristics than MD. The aggressiveness of PTMC with TTD >1 cm was significantly enhanced, and surgical treatment should be actively sought in such cases.

Phase Compensation Technique for Effective Heat Focusing in Microwave Hyperthermia Systems

In this paper, effective electromagnetic (EM) focusing achieved with a phase compensation technique for microwave hyperthermia systems is proposed. To treat tumor cells positioned deep inside a human female breast, EM energy must be properly focused on the target area. A circular antenna array for microwave hyperthermia allows EM energy to concentrate on a specific target inside the breast tumor. Depending on the cancerous cell conditions in the breast, the input phases of each antenna are calculated for single and multiple tumor cell locations. In the case of multifocal breast cancer, sub-array beam focusing via the phase compensation technique is presented to enhance the ability of EM energy to concentrate on multiple targets while minimizing damage to normal cells. To demonstrate the thermal treatment effects on single and multiple tumor locations, the accumulation of the specific absorption rate (SAR) parameter and temperature changes were verified using both simulated and experimental results.

The effects of apoptosis and apelin on lymph node metastasis in invasive breast carcinomas

This study aimed to evaluate the biological and clinical significance of apelin-36 in breast cancer and to compare apelin-36 expression and apoptotic index in both breast tissue and metastatic lymph nodes in patients with invasive breast carcinoma. In this study, both tumor tissue and metastatic lymph nodes of the same patient were collected from 60 cases of invasive breast carcinoma patients (IDC, ILC) and 20 cases of normal breast tissue with no tumor from mammoplasty were used as the control group. The expression of apelin was examined with immunohistochemically, and the apoptotic index was examined with TUNEL methods. According to Kruskal-Wallis analysis, there was a significant difference between IDC and the control group when the apelin expression was compared between the breast tissues (p = 0.001). There were significant differences between the three groups when comparing relationships with apoptotic index (p < 0.001). According to the Mann-Whitney U test, both tumor size and expression of apelin in lymph nodes in ILCs were significantly higher than IDCs. (p = 0.026, p = 0.024, respectively). According to correlation analysis, there was a good correlation between the expression of apelin in breast tissue and apelin expression in lymph nodes (p = 0.000). It is also found a similar relationship in terms of the apoptotic index (p = 0.000). In addition, the negative correlation was found between apelin expression and the apoptotic index in breast tissues (p = 0.003). Based on these results, apelin-36 can be used as a marker for determining the metastasis potential in invasive breast cancer.

Comparison of breast cancer patients who underwent partial mastectomy (PM) with mini latissimus dorsi flap (MLDF) and subcutaneous mastectomy with implant (M + I) regarding quality of life (QOL), cosmetic outcome and survival rates

PURPOSE

The latissimus dorsi muscle has long been used in breast cancer (BC) patients for reconstruction. This study aimed to compare early stage BC patients who had partial mastectomy (PM) with mini latissimus dorsi flap (MLDF) and subcutaneous mastectomy with implant (MI) with respect to quality of life (QoL), cosmetic outcome (CO), and survival rates.

PATIENTS AND METHODS

The data of patients who underwent PM + MLDF (Group 1) and M + I (Group 2) between January 2010 and January 2018 were evaluated. Both groups were compared in terms of demographics, clinical and pathological characteristics, surgical morbidity, survival, quality of life, and cosmetic results. The EORTC-QLQ C30 and EORTC-QLO BR23 questionnaires and the Japanese Breast Cancer Society (JBCS) Cosmetic Evaluation Scale were used to assess the quality of life and the cosmetic outcome, respectively.

RESULTS

A total of 317 patients were included in the study, 242 (76.3%) of them in group 1 and 75 (23.6%) of them in group 2. Median follow-up time was 56 (14-116) months. There were no differences identified between the groups in terms of tumor histology, hormonal receptors and HER-2 positivity, surgical morbidity, and 5-year overall and disease-free survival. Group 2 patients were significantly younger than group 1 (p = 0.003). The multifocality/multicentricity rate was higher in group 2 (p ≤ 0.001), whereas tumor size (p = 0.009), body mass index (BMI, p = 0.006), histological grade (p ≤ 0.001), lymph node positivity (p = 0.002), axillary lymph node dissection (ALND) rate (p = 0.005), and presence of lympho-vascular invasion (LVI, p = 0.013) were significantly higher in group 1. When the quality of life was assessed by using the EORTC QLQ C30 and BR23 questionnaires, it was seen that the body image perception (p < 0.001) and nausea/vomiting score (p = 0.024) were significantly better in PM + MLDF group whereas physical function score was significantly better in M + I group (p = 0.012). When both groups were examined in terms of cosmesis with JBCS Cosmetic Evaluation Scale, good cosmetic evaluation score was significantly higher in patients in MLDF group (p = 0.01).

DISCUSSION

The results of this study indicate that in comparison to M + I procedure, the PM + MLDF procedure provides significantly superior results in terms of body image and cosmetic result with similar morbidity and oncologic outcomes. In selected patients with small breasts and a high tumor/breast ratio, PM + MLDF may be an alternative to subcutaneous mastectomy and implant.

Multicentric breast cancer with heterogeneous histopathology: a multidisciplinary review

Multiple synchronous (multifocal or multicentric) ipsilateral breast cancers with heterogeneous histopathology are a rare clinical occurrence, however, their incidence is increasing due to the use of MRI for breast cancer screening and staging. Some studies have demonstrated poorer clinical outcomes for this pattern of breast cancer, but there is no evidence to guide clinical practice. In this multidisciplinary review, we reflect on pathology and molecular characteristics, imaging findings, surgical management including conservation and reconstructive options and approach to the axilla, and the role of chemotherapy and radiotherapy. Multidisciplinary discussions appear decisive in planning an appropriate surgical choice and defining the correct systemic treatment tailored to each clinical condition.

Revisiting multifocal breast cancer: a clonality study of ductal carcinoma using whole exome sequencing

Multifocal breast cancer (MFBC), ductal type, has been hypothesized to arise by one of two mechanisms: either through intramammary/intralymphatic spread from a single index tumor (MBC-1), or as multiple independent tumors with each focus carrying its corresponding ductal carcinoma in-situ (MBC-2). In order to improve our understanding of MFBC pathogenesis, we employed laser capture microdissection coupled with whole-exome sequencing to study clonal origin in MFBC. We selected three cases of MBC-1 (C1 to C3) and MBC-2 (C4 to C6) and analyzed three foci from each case. MBC-1 cases were histologically similar and showed a strong predilection for satellite foci, vascular invasion and nodal metastasis when compared to MBC-2. Our bioinformatics approach provided strong evidence for clonal relationships in MBC-1, as demonstrated by distinct clusters of genes conserved across all tumor foci. Conversely, no gene clusters were shared across all the foci in MBC-2, suggesting multiple independent tumors. These findings provide further support for the two distinct pathogenetic mechanisms in MFBC.

Determinants for non-sentinel node metastases in primary invasive breast cancer: a population-based cohort study of 602 consecutive patients with sentinel node metastases

Background

Sentinel node biopsy (SNB) is the standard procedure for axillary staging in patients with clinically lymph node negative invasive breast cancer. Completion axillary lymph node dissection (c-ALND) may not be necessary for all patients as a significant number of patients have no further metastases in non-sentinel nodes (non-SN) and c-ALND may not improve survival. The first aim of our study is to identify clinicopathological determinants associated with non-SN metastases. The second aim is to determine the impact of the number of sentinel node (SN) with macro-metastases and the type of SN metastases on metastatic involvement in non-SN.

Methods

This is a retrospective study of 602 patients with primary invasive breast cancer operated on with SNB and c-ALND in Lund and Malmö during 2008–2013. All these patients had micro- and/or macro-metastases in SNs. Information was retrieved from the national Information Network for Cancer Care (INCA). The risk of metastases to non-SNs were analyzed in relation to clinicopathological determinants such as age, screening mammography, tumour size, tumour type, histological grade, estrogen status, progesterone status, HER2 status, multifocality and lymphovascular invasion. Additionally, we compared the association between the number of the SN and the type of metastases in SN with the risk of metastases to non-SNs. Binary logistic regression was used, yielding odds ratios (OR) with 95% confidence intervals (CI).

Results

We found that 211 patients (35%) had metastases in non-SNs and 391 patients (65%) had no metastases in non-SNs. Lobular type (18%) of breast cancer (1.73; 1.0 1-2.97) and multifocal (31.3%) tumours (2.20; 1.41–3.44) had a high risk of non-SNs metastases. As compared to only micro-metastases, the presence of macro-metastases in SNs was associated with a high risk of metastases to non-SNs (4.91; 3.01–8.05). The number of SN with macro-metastases, regardless of the number of SNs removed by surgery, increases the risk of finding non-SNs with metastases. The total number of SN removed by surgery had no impact on diagnosis of metastases in non-SNs. No statistically significant associations were observed regarding other studied determinants.

Conclusion

We conclude in the present study that lobular cancer and multifocal tumours were associated with a high risk of non-SN involvement. The presence of the macro-metastases in SNs and the number of SN with macro-metastases has a positive association with presence of metastases in non-SNs. The total number of SNs removed by surgery had no impact on finding metastases in non-SNs. These factors may be valuable considering whether or not to omit c-ALND.

Local Control of Breast Conservation Therapy versus Mastectomy in Multifocal or Multicentric Breast Cancer: A Systematic Review and Meta-Analysis

Objective

Breast conservation therapy (BCT) for female patients with multifocal or multicentric (MF/MC) breast cancer remains controversial. The purpose of the present meta-analysis was to explore whether BCT was feasible for female patients with MF/MC breast cancer and to compare the results of treatment with those of female patients with unifocal breast cancer who underwent BCT and female patients with MF/MC breast cancer who underwent mastectomy.

Methods

Online databases, including PubMed and Embase, were independently searched from inception to January 2018 and reviewed by two authors. The present meta-analysis compared local relapse (LR) of BCT versus mastectomy for patients with MF/MC breast cancer and LR of patients with unifocal breast cancer versus patients with MF/MC breast cancer who underwent BCT. Ten studies comprising 19,272 patients were included.

Results

The cumulative incidence of LR was 5.6% (65/1,163) for MF/MC disease treated with BCT, 4.2% (750/17,656) for unifocal disease treated with BCT, and 2.0% (9/453) for MF/MC disease treated with mastectomy. Thus, the cumulative incidence of LR for MF/MC patients treated with BCT was significantly higher than for mastectomy (p < 0.001). However, the forest plot analysis showed no significant differences in LR between BCT and mastectomy procedures (OR = 1.22, 95% CI = 0.49-3.00, p = 0.67, I² = 0%). Compared with the unifocal group treated with BCT, BCT for MF/MC breast cancer showed a significant difference in LR (OR = 2.25, 95% CI = 1.48-3.42, p = 0.0001, I² = 0%).

Conclusion

The LR of BCT for patients with MF/MC breast cancer was higher than that of BCT for patients with unifocal breast cancer. However, no significant difference was found in the incidence of LR between the BCT group and the mastectomy group in patients with MF/MC breast cancer.

The Prognostic Impact of Synchronous Ipsilateral Multiple Breast Cancer: Survival Outcomes according to the Eighth American Joint Committee on Cancer Staging and Molecular Subtype

BACKGROUND

In the current American Joint Committee on Cancer staging system of breast cancer, only tumor size determines T-category regardless of whether the tumor is single or multiple. This study evaluated if tumor multiplicity has prognostic value and can be used to subclassify breast cancer.

METHODS

We included 5,758 patients with invasive breast cancer who underwent surgery at Samsung Medical Center, Seoul, Korea, from 1995 to 2012.

RESULTS

Patients were divided into two groups according to multiplicity (single, n = 4,744; multiple, n = 1,014). Statistically significant differences in lymph node involvement and lymphatic invasion were found between the two groups (p < .001). Patients with multiple masses tended to have luminal A molecular subtype (p < .001). On Kaplan-Meier survival analysis, patients with multiple masses had significantly poorer disease-free survival (DFS) (p = .016). The prognostic significance of multiplicity was seen in patients with anatomic staging group I and prognostic staging group IA (p = .019 and p = .032, respectively). When targeting patients with T1-2 N0 M0, hormone receptor-positive, and human epidermal growth factor receptor 2 (HER2)-negative cancer, Kaplan-Meier survival analysis also revealed significantly reduced DFS with multiple cancer (p = .031). The multivariate analysis indicated that multiplicity was independently correlated with worse DFS (hazard ratio, 1.23; 95% confidence interval, 1.03 to 1.47; p = .025). The results of this study indicate that tumor multiplicity is frequently found in luminal A subtype, is associated with frequent lymph node metastasis, and is correlated with worse DFS.

CONCLUSIONS

Tumor multiplicity has prognostic value and could be used to subclassify invasive breast cancer at early stages. Adjuvant chemotherapy would be necessary for multiple masses of T1-2 N0 M0, hormone-receptor-positive, and HER2-negative cancer.

Prognostic impact of multifocal and multicentric breast cancer versus unifocal breast cancer

PURPOSES

The clinical behavior of multifocal and multicentric breast cancers (MMBCs) is not well characterized. We conducted this study to ascertain whether patients with MMBCs have a worse prognosis than patients with unifocal breast cancers (UBC).

METHODS

The subjects of this retrospective study were 734 consecutive patients who underwent definitive surgery for invasive breast carcinoma at our hospital between January 2004 and December 2006. MMBC was defined as ≥ 2 separate invasive unilateral breast tumors and pathological T stage was redefined based on the sum of the maximum diameter of each tumor. We evaluated disease-free survival (DFS) using the Kaplan-Meier method and Cox proportional hazards models.

RESULTS

Of the 734 patients, 136 (18.5%) had MMBC. The pathological T stage of 36 of the patients with MMBC was upstaged by adopting the sum of each focus. MMBC did not have any survival impact, but MMBC upstaged by the modified pathological T stage was associated with worse DFS than non-upstaging MMBC (P = 0.004). Multivariate analysis revealed that upstaging MMBC was an independent factor for poor prognosis and worse DFS (HR 2.757, P = 0.043).

CONCLUSIONS

MMBC itself may not be predictive of a worse prognosis; however, the sum of the invasive diameters of MMBC might be an important prognostic factor. Further studies are needed to confirm the prognosis associated with MMBC, taking into consideration the biological characteristics of each invasive focus.

Systematic review of the impact of breast-conserving surgery on cancer outcomes of multiple ipsilateral breast cancers

Background

The clinical effectiveness of treating ipsilateral multifocal (MF) and multicentric (MC) breast cancers using breast‐conserving surgery (BCS) compared with the standard of mastectomy is uncertain. Inconsistencies relate to definitions, incidence, staging and intertumoral heterogeneity. The primary aim of this systematic review was to compare clinical outcomes after BCS versus mastectomy for MF and MC cancers, collectively defined as multiple ipsilateral breast cancers (MIBC).

Methods

Comprehensive electronic searches were undertaken to identify complete papers published in English between May 1988 and July 2015, primarily comparing clinical outcomes of BCS and mastectomy for MIBC. All study designs were included, and studies were appraised critically using the Newcastle–Ottawa Scale. The characteristics and results of identified studies were summarized.

Results

Twenty‐four retrospective studies were included in the review: 17 comparative studies and seven case series. They included 3537 women with MIBC undergoing BCS; breast cancers were defined as MF in 2677 women, MC in 292, and reported as MIBC in 568. Six studies evaluated MIBC treated by BCS or mastectomy, with locoregional recurrence (LRR) rates of 2–23 per cent after BCS at median follow‐up of 59·5 (i.q.r. 56–81) months. BCS and mastectomy showed apparently equivalent rates of LRR (risk ratio 0·94, 95 per cent c.i. 0·65 to 1·36). Thirteen studies compared BCS in women with MIBC versus those with unifocal cancers, reporting LRR rates of 2–40 per cent after BCS at a median follow‐up of 64 (i.q.r. 57–73) months. One high‐quality study reported 10‐year actuarial LRR rates of 5·5 per cent for BCS in 300 women versus 6·5 per cent for mastectomy among 887 women.

Conclusion

The available studies were mainly of moderate quality, historical and underpowered, with limited follow‐up and biased case selection favouring BCS rather than mastectomy for low‐risk patients. The evidence was inconclusive, weakening support for the St Gallen consensus and supporting a future randomized trial.

The Effect of Total Size of Lesions in Multifocal/Multicentric Breast Cancer on Survival

BACKGROUND

In this study, we aimed to assess the prognostic performance of determining the T stage according to the total size of lesions compared with the size of the largest lesion in the breast in patients with multifocal/multicentric (MF/MC) breast cancer.

PATIENTS AND METHODS

The charts of the patients with MF/MC breast cancer who were diagnosed between 2003 and 2014 were reviewed. The T stage of MF/MC tumors was determined according to the largest lesion size (T_max) as well as the sum of the longest diameters of the lesions (T_sum) in the breast.

RESULTS

Multifocal/multicentric tumors were identified in 323 of 3890 patients (8.3%) with breast cancer. Ten-year rates of overall survival (OS; 75% and 74%; P = .965) and disease-free survival (DFS; 66% and 61%; P = .817) were similar in patients with unifocal and MF/MC tumors, respectively. When the T stage was determined by summing the sizes of the lesions, the T stage of 67 (20.7%) and 63 (19.5%) patients advanced from T1 to T2 and from T2 to T3, respectively. Thus, the T stage increased in 130 patients (40.2%) according to American Joint Committee on Cancer. Discriminatory ability of T_sum was better than T_max in terms of OS and DFS, as shown with higher Royston D and Harrel C statistics and Schemper V values.

CONCLUSION

The new T classification proposed in this report stands out as a better predictive classification particularly in patients with low disease burden.

Intratumoral heterogeneity and subclonal diversification of early breast cancer

Heterogeneity has long been recognized as a feature of some primary breast cancers manifesting as mixed histopathological subtypes or variable expression of the therapeutic targets ER, PgR and HER2. The recent emergence of next generation sequencing (NGS) technologies has revolutionized our understanding of the extent and nature of subclonal diversification. Careful examination of primary breast cancers often reveals multiple genomically distinct subclones that may contain driver alterations that follow spatial patterns of segregation. Subclonality is of clinical relevance as it forms the substrate of selection and can give rise to aggressive clinical features such as invasiveness, metastasis and treatment resistance. However, spatial and temporal intra-tumoral heterogeneity pose fundamental challenges to representative sampling and consequently the feasibility of a personalized medicine approach. Fundamental clinical and biological questions are starting to be addressed by applying NGS to the study of intra-tumoral heterogeneity and the insights that it provides should be used to better inform the prospective design of clinico-genomics trials.

Multifocal Invasive Ductal Cancer: Distinguishing Independent Tumor Foci From Multiple Satellites

Patients with multifocal breast cancers (MBCs) have a poorer prognosis than patients with unifocal breast cancers. Studies have attributed this to tumor size underestimation in MBC. An alternative hypothesis is that some MBCs behave in a fashion analogous to the "satellite" and "in-transit metastasis" observed in melanoma and, thereby, are more clinically aggressive. We identified 79 cases of MBC, which we classified into 2 groups: study cases defined as ≥2 morphologically similar tumor foci with ≥1 focus without in situ carcinoma (n = 21); and a control group defined as ≥2 morphologically similar or dissimilar foci with associated in situ carcinoma in all foci (n = 58). The odds of being a study case is 1.86 (95% confidence interval [CI] 1.26-2.74) times greater per unit increase in number of tumor foci (median of 4 tumor foci; P = .002). Study cases were 73.33 (95% CI = 8.91-603.16) times more likely to have lymphovascular invasion (LVI) and 14.72 (95% CI = 4.37-49.61) times more likely to have nodal metastases. Grade I/II tumors were 0.20 (95% CI = 0.07-0.59) times less likely to be study cases. There was a significant positive interaction ( P < 0.001) indicated by the relationship of LVI status and nodal status with the study case and control group. We conclude that there is a subset of MBC that presents with more numerous tumor foci and a higher rate of nodal metastasis. The aggressive behavior of these cases may be attributed to their proclivity for LVI.

Is Pre-Operative Axillary Staging with Ultrasound and Ultrasound-Guided Fine-Needle Aspiration Reliable in Invasive Lobular Carcinoma of the Breast?

Axillary ultrasound (US) with US-guided fine-needle aspiration (US-FNA) for suspicious lymph nodes is important for pre-operative staging and planning of surgical management. Invasive lobular carcinoma (ILC) metastases were previously thought to be difficult to detect, but with a limited amount of evidence. This study investigated the ability of US and US-FNA to detect ILC metastases by assessing 142 patients with ILC. The sensitivity of US in detection of metastasis was 52.3%, and US was able to exclude 96% of N2 and N3 axillary metastases. The false-negative rate of US-FNA in detection of metastasis for suspicious lymph nodes on US was 34.8%, and lymph nodes with longer maximal dimensions were associated with false-negative US-FNA results. Multiplicity of breast lesions and maximal cortical thickness ≥3.1 mm of lymph nodes were independently associated with metastasis. Although pre-operative US in ILC can reliably exclude advanced axillary nodal disease, US-FNA results should be carefully interpreted.

Assessment of Tumor Heterogeneity, as Evidenced by Gene Expression Profiles, Pathway Activation, and Gene Copy Number, in Patients with Multifocal Invasive Lobular Breast Tumors

BACKGROUND

Invasive lobular carcinoma (ILC) comprises approximately ~10-20% of breast cancers. In general, multifocal/multicentric (MF/MC) breast cancer has been associated with an increased rate of regional lymph node metastases. Tumor heterogeneity between foci represents a largely unstudied source of genomic variation in those rare patients with MF/MC ILC.

METHODS

We characterized gene expression and copy number in 2 or more foci from 11 patients with MF/MC ILC (all ER+, HER2-) and adjacent normal tissue. RNA and DNA were extracted from 3x1.5 mm cores from all foci. Gene expression (730 genes) and copy number (80 genes) were measured using Nanostring PanCancer and Cancer CNV panels. Linear mixed models were employed to compare expression in tumor versus normal samples from the same patient, and to assess heterogeneity (variability) in expression among multiple ILC within an individual.

RESULTS

35 and 34 genes were upregulated (FC>2) and down-regulated (FC<0.5) respectively in ILC tumor relative to adjacent normal tissue, q<0.05. 9/34 down-regulated genes (FIGF, RELN, PROM1, SFRP1, MMP7, NTRK2, LAMB3, SPRY2, KIT) had changes larger than CDH1, a hallmark of ILC. Copy number changes in these patients were relatively few but consistent across foci within each patient. Amplification of three genes (CCND1, FADD, ORAOV1) at 11q13.3 was present in 2/11 patients in both foci. We observed significant evidence of within-patient between-foci variability (heterogeneity) in gene expression for 466 genes (p<0.05 with FDR 8%), including CDH1, FIGF, RELN, SFRP1, MMP7, NTRK2, LAMB3, SPRY2 and KIT.

CONCLUSIONS

There was substantial variation in gene expression between ILC foci within patients, including known markers of ILC, suggesting an additional level of complexity that should be addressed.

Is breast conservative surgery a reasonable option in multifocal or multicentric tumors?

The incidence of multifocal (MF) and multicentric (MC) carcinomas varies widely among clinical studies, depending on definitions and methods for pathological sampling. Magnetic resonance imaging is increasingly used because it can help identify additional and conventionally occult tumors with high sensitivity. However, false positive lesions might incorrectly influence treatment decisions. Therefore, preoperative biopsies must be performed to avoid unnecessary surgery. Most studies have shown higher lymph node involvement rates in MF/MC tumors than in unifocal tumors. However, the rate of local recurrences is usually low after breast conservative treatment (BCT) of MC/MF tumors. It has been suggested that BCT is a reasonable option for MC/MF tumors in women aged 50-69 years, with small tumors and absence of extensive ductal carcinoma in situ. A meta-analysis showed an apparent decreased overall survival in MC/MF tumors but data are controversial. Surgery should achieve both acceptable cosmetic results and negative margins, which requires thorough preoperative radiological workup and localization of lesions. Boost radiotherapy techniques must be evaluated since double boosts might result in increased toxicity, namely fibrosis. In conclusion, BCT is feasible in selected patients with MC/MF but the choice of surgery must be discussed in a multidisciplinary team comprising at least radiologists, surgeons and radiotherapists.

Utility of estrogen receptor, progesterone receptor, and HER-2/neu analysis of multiple foci in multifocal ipsilateral invasive breast carcinoma

OBJECTIVES

To determine the frequency of estrogen receptor (ER), progesterone receptor (PR), and HER-2/neu (HER2) testing multiple foci of ipsilateral invasive breast carcinoma at our institution and to evaluate resulting change in treatment recommendation.

METHODS

We identified 165 consecutive cases of multifocal invasive breast cancer over a 10-year period (2005-2014). Clinicopathologic features and treatment recommendation were assessed by slide and chart review.

RESULTS

Seventy (42.4%) of 165 patients had two or more foci tested. In the first 6 years (2005-2010), frequency of testing two or more foci was 31.6% and increased to 70.6% in 2014. Seven (10%) of 70 had a clinically significant difference in ER/PR and/or HER2 status, five (7.1%) with a difference in HER2, one (1.4%) in ER/PR, and one (1.4%) in both ER/PR and HER2. All cases with difference in status had different histology and/or the largest focus was the most positive one.

CONCLUSIONS

Our findings support current recommendations to evaluate additional smaller tumor foci in multifocal invasive breast cancer if the focus is of different grade or histology. Additional features, including specific histology, grade, and ER, PR, and HER2 status of the largest focus, should also be considered when selecting cases for which testing of additional foci may be of benefit.

Disease recurrence and survival in patients with multifocal breast cancer: a follow-up study with 7-year results

BACKGROUND

Few studies have shown that multifocal breast cancer (MBC) has poorer outcomes compared with unifocal breast cancer (UBC). Currently, there is no long-term data on disease recurrence and survival in patients with MBC. The aim of this study is to evaluate whether patients with MBC have worse outcomes compared with UBC in respect to disease recurrence and survival.

METHODS

This is a retrospective study of patients diagnosed with stage I-III MBC from 2000 to 2007 in comparison with UBC with a median follow-up of 7 years. Prognostic factors were prospectively collected from the breast cancer unit database. Univariate and multivariable analyses for disease recurrence and survival were performed as well as Kaplan-Meier curves.

RESULTS

A total of 152 patients were included; 75 with MBC, 77 with UBC. The multifocal group was treated more aggressively with mastectomy (73% versus 25%, P < 0.0001) and chemotherapy (53% versus 42%). Breast cancer recurred in nine (11.7%) patients in the UBC group and nine (12%) patients in the MBC group respectively (hazard ratio (HR): 1.13, 95% confidence interval (CI): 0.45-2.86, P = 0.794). There were 10 (13%) mortalities in the unifocal group as compared with 11 (14.7%) in the multifocal group (HR: 1.02, 95% CI: 0.42-2.48, P = 0.969). There were no statistically significant differences in the all-cause mortality and disease recurrence rates between both groups.

DISCUSSION

There were no statistically significant differences in disease recurrence or mortality rates between MBC and UBC at a median follow-up of 7 years. However, patients in the MBC group received more aggressive treatment than the unifocal group.

[Sentinel lymph node-multicentric and multifocal tumors: a valid technique?]

Sentinel node biopsy without complementary axillary lymph node dissection was validated for T1-2 N0 unifocal breast cancer without previous treatment since several years. In the situation of multifocal multicentric breast tumors, this procedure was considered as a contraindication. The aim of this work was to analyse literature results to determine if sentinel lymph node biopsy can be considered as a valid option without complementary axillary lymph node dissection for negative sentinel lymph node.

Uncovering the genomic heterogeneity of multifocal breast cancer

Multifocal breast cancer (MFBC), defined as multiple synchronous unilateral lesions of invasive breast cancer, is relatively frequent and has been associated with more aggressive features than unifocal cancer. Here, we aimed to investigate the genomic heterogeneity between MFBC lesions sharing similar histopathological parameters. Characterization of different lesions from 36 patients with ductal MFBC involved the identification of non‐silent coding mutations in 360 protein‐coding genes (171 tumour and 36 matched normal samples). We selected only patients with lesions presenting the same grade, ER, and HER2 status. Mutations were classified as ‘oncogenic’ in the case of recurrent substitutions reported in COSMIC or truncating mutations affecting tumour suppressor genes. All mutations identified in a given patient were further interrogated in all samples from that patient through deep resequencing using an orthogonal platform. Whole‐genome rearrangement screen was further conducted in 8/36 patients. Twenty‐four patients (67%) had substitutions/indels shared by all their lesions, of which 11 carried the same mutations in all lesions, and 13 had lesions with both common and private mutations. Three‐quarters of those 24 patients shared oncogenic variants. The remaining 12 patients (33%) did not share any substitution/indels, with inter‐lesion heterogeneity observed for oncogenic mutation(s) in genes such as PIK3CA, TP53, GATA3, and PTEN. Genomically heterogeneous lesions tended to be further apart in the mammary gland than homogeneous lesions. Genome‐wide analyses of a limited number of patients identified a common somatic background in all studied MFBCs, including those with no mutation in common between the lesions. To conclude, as the number of molecular targeted therapies increases and trials driven by genomic screening are ongoing, our findings highlight the presence of genomic inter‐lesion heterogeneity in one‐third, despite similar pathological features. This implies that deeper molecular characterization of all MFBC lesions is warranted for the adequate management of those cancers. © 2015 The Authors. Pathological Society of Great Britain and Ireland.

Characteristics of Multifocal and Multicentric Breast Cancers

BACKGROUND

Multifocality and multicentricity are increasingly recognized in breast cancer. However, little is known about the characteristics and biology of these cancers and the clinical implications are controversial.

METHODS

A retrospective, institutional database was used to compare characteristics of multifocal (MF) and multicentric (MC) breast cancers with unifocal (UF) cancers to study concordance of histology and receptor status among primary and secondary foci and to evaluate predictors of lymph node positivity using multivariate logistic regression.

RESULTS

Of 1495 invasive cancers, 1231 (82.3 %) were UF, 169 (11.3 %) were MF, and 95 (6.4 %) were MC cancers. When MF and MC cancers were compared with UF cancers, MC but not MF cancers were associated with young age at diagnosis, larger tumor size, lymphovascular invasion, and node positivity. MF but not MC tumors were more likely to be ER/PR+Her2+ tumors and less likely to be triple-negative cancers compared with UF tumors. MF tumors were more likely to be infiltrating ductal carcinomas with an extensive intraductal component, and MC tumors were more likely to be infiltrating lobular carcinomas. Concordance of histology and receptor status between primary and secondary foci was high and was similar for both MF and MC cancers. Multicentricity remained an independent predictor of lymph node positivity on multivariate analysis.

CONCLUSION

MF and MC tumors seem to be biologically different diseases. MC is clinicopathologically more aggressive than MF disease and is more frequently associated with younger age and larger tumor size and also is an independent predictor of node positivity.

Multifocal and multicentric breast cancer is associated with increased local recurrence regardless of surgery type

Multifocal and multicentric breast cancers have been correlated with poor prognostic factors and worse outcomes versus unifocal disease. We evaluated the impact of multifocal and multicentric disease versus case controls with unifocal disease, matching for age, grade, T-, and N-stage. A total of 110 patients with multifocal (n = 93) or multicentric (n = 17) disease and 263 matched case controls were identified with a median follow-up of 53 months and 64 months, respectively. The actuarial local control rates for the multifocal/multicentric and unifocal group were 88% and 97%, respectively at both 5 and 10 years (p < 0.001). On multivariate analysis, multifocal/multicentric disease remained associated with higher local recurrence after controlling for other covariates including surgery type. The disease-free survival rates in the multifocal/multicentric group at 5 and 10 years were 75% and 71%, respectively, versus 87% and 78% at 10 years (p = 0.01). On multivariate analysis, multifocal/multicentric disease was no longer associated with worse disease-free survival. There was no difference in the cohorts in terms of regional control, overall survival, or cancer specific survival. Our findings suggest that multifocal/multicentric disease may be associated with worse outcomes versus unifocal disease regardless of type of surgery. This suggests a more biologically aggressive cancer and may be an important consideration when managing these patients. Further studies are needed to better understand the impact of multifocal/multicentric breast cancers on outcomes.

Comparison of the histopathology and prognosis of bilateral versus unilateral multifocal multicentric breast cancers

Background

Multiple breast cancers may present with different clinical and biological characteristics. The data indicate that multifocal (MF), multicentric (MC), and bilateral synchronous (BS) breast cancers (BC) are more aggressive and have an equivalent or moderately poorer survival rate compared with unilateral cases. However, a comparison of these multiple breast cancers has not been covered in the literature. The aim of this study was to describe the histopathological characteristics of patients suffering from MF, MC, and BS breast carcinoma and to compare their prognoses.

Methods

Retrospective data for MF, MC, and BS breast carcinoma patients treated in five different breast cancer units in Turkey between 2003 and 2012 were collected. MF and MC cancers were defined as more than one lesion in the same quadrant or in separate quadrants, respectively.

Results

There were 507 patients (271 MF, 147 MC, and 89 BS) treated in this time period. BS breast carcinoma patients were younger than the other groups (44.83 ± 9.6, 47.27 ± 11.6, and 51.11 ± 11.8 years for BS, MF, and MC breast carcinoma patients, respectively). MFBC and MCBC patients in this study were younger than the ages reported in Western literature, but this result was similar to the ages reported in Eastern literature. The five-year survival rates and recurrence rates were not statistically different among groups (P = 0.996 and P = 0.263, respectively). According to univariate analyses, tumor size, histological grade, and lymph node status were statistically significant factors that affected survival. However, only lymph node involvement was significant for survival according to multivariate analyses.

Conclusions

The clinical significance of MF, MC, and BS breast cancers is still unclear and their influence on prognosis is controversial. Disease-free and overall survival rates of BS breast cancers might be similar to MF and MC breast cancers.

Evolving paradigms in multifocal breast cancer

The 7th edition of the TNM defines multifocal breast cancer as multiple simultaneous ipsilateral and synchronous breast cancer lesions, provided they are macroscopically distinct and measurable using current traditional pathological and clinical tools. According to the College of American Pathologists (CAP), the characterization of only the largest lesion is considered sufficient, unless the grade and/or histology are different between the lesions. Here, we review three potentially clinically relevant aspects of multifocal breast cancers: first, the importance of a different intrinsic breast cancer subtype of the various lesions; second, the emerging awareness of inter-lesion heterogeneity; and last but not least, the potential introduction of bias in clinical trials due to the unrecognized biological diversity of these cancers. Although the current strategy to assess the lesion with the largest diameter has clearly its advantages in terms of costs and feasibility, this recommendation may not be sustainable in time and might need to be adapted to be compliant with new evolving paradigms in breast cancer.

Effect of multifocality and multicentricity on outcome in early stage breast cancer: a systematic review and meta-analysis

Women with multifocal or multicentric breast tumors (multifocality henceforth) have been reported to have greater probability of nodal metastasis and relapse and worse survival than women with unifocal tumors. However, these associations have been inconsistent and multifocality is not taken into account by staging guidelines and prognostic models. A systematic review of electronic databases identified publications exploring the association between multifocality and overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), and loco-regional relapse (LRR). The hazard ratios (HRs) for OS and DFS for multifocal compared to unifocal tumors were extracted from multivariable analyses and included in a meta-analysis. For studies not reporting multivariable analyses, odds ratios (OR) were estimated from Kaplan-Meier curves for all endpoints at 5 and 10 years. Twenty-two studies comprising 67,557 women were included. Multifocality was reported in 9.5 % of patients. Classical prognostic factors were well balanced between unifocal and multifocal populations. In multivariable analyses, multifocality was associated with significantly worse OS (HR 1.65; P = 0.02), and a non-significant association with worse DFS (HR 1.96; P = 0.07). In univariable analyses, multifocality was associated with worse OS, DFS, DSS, and LRR at 5 years (OR 1.39, P = 0.02; OR 1.52, P = 0.02; OR 1.56, P = 0.03; and OR 3.23, P = 0.02, respectively). Similar estimates were observed at 10 years, but statistical significance was only reached for DSS and LRR. Mutifocality appears to be associated with a worse prognosis, however, substantial inter-study heterogeneity limits the precise determination of increased risk. Further validation of the independent prognostic impact of multifocality is warranted.

The classification of invasive carcinoma of the breast

The classification of invasive breast carcinoma assists diagnosis, allows for comparison of different patient groups in clinical trials and facilitates epidemiological analysis. For the individual patient, accurate tumor classification informs clinical decision-making with emphasis on assessment of prognosis and treatment formulation. Tumor grade is an independent prognostic indicator and is calculated by assessing specific tumor characteristics microscopically. The Tumor Node Metastasis staging system, produced by the American Joint Committee on Cancer Union for International Cancer Control, combines information about the primary tumor size, the status of the regional lymph nodes and the presence or absence of distant metastases at diagnosis to classify disease. In recent years, the use of gene expression profiling technology has led to the development of the molecular classification of breast cancer and has highlighted the importance of hormone receptor and HER2 oncogenic pathways, with particular reference to targeted chemotherapy. Tumor typing involves the identification of 'no special type' carcinoma with variable clinical, histological and molecular characteristics and 'special type' carcinomas that are usually associated with a particular set of prognostic and predictive indices. Some special type carcinomas have unique biological features that influence diagnostic investigation and clinical management.

Comparing the outcome between multicentric and multifocal breast cancer: what is the impact on survival, and is there a role for guideline-adherent adjuvant therapy? A retrospective multicenter cohort study of 8,935 patients

Multifocal (MF) and multicentric (MC) breast cancers have been comprehensively studied, and their outcomes have been compared with unifocal (UF) tumors. We attempted to answer the following questions: (1) Does MF/MC presentation influence the outcome concerning BC mortality?, (2) Is there an impact of guideline-adherent adjuvant treatment in these BC subtypes?, and (3)What is the influence of guideline violations concerning surgery (breast-conserving surgery versus mastectomy) on the survival of MF/MC BC patients? Between 1992 and 2008, we retrospectively analyzed 8,935 breast cancer patients from 17 participating breast cancer centers within the BRENDA study group. Of 8,935 breast cancer patients, 7,073 (79.2 %) had UF tumors, 1,398 (15.6 %) had MF tumors, and 464 (5.2 %) had MC tumors. RFS was significantly worse for MF/MC BC patients compared to patients with UF tumors (MF p = 0.007; MC p = 0.019). OAS was significantly worse for MC patients but not for MF patients compared to patients with UF tumors (MF p = 0.321; MC p = 0.001). Guideline adherence was significantly lower in patients with MF (n = 580; 41.5 %) and MC (n = 204; 44.0 %) compared to patients with UF (n = 3,871; 54.7 %) (p < 0.001) tumors. Guideline violations were associated with a highly significant deterioration in survival throughout all subgroups except for MC, with respect to RFS and OAS. For 100 %-guideline-adherent patients, we could not find any significant differences in RFS and OAS after adjusting by nodal status, grade, and tumor size. Furthermore, we could not find any significant differences in RFS and OAS in patients with MF or MC stratified by breast-conserving therapy (BCT lumpectomy and radiation therapy) and mastectomy. There is a strong association between improved RFS and OAS in patients with MF/MZ BC. There are no significant differences in RFS and OAS for patients with breast-conserving therapy or mastectomy.

Breast cancer multifocality and multicentricity and locoregional recurrence

The impact of multifocal (MF) or multicentric (MC) breast cancer on locoregional (LR) control rates is unknown. Methods. MF was defined as two or more separate invasive tumors in the same quadrant of the breast. MC was defined as two or more separate invasive tumors occupying more than one quadrant of the same breast. Patients were categorized by LR treatment: breast conservation therapy (BCT; n = 256), mastectomy (n = 466), or mastectomy plus postmastectomy radiation therapy (PMRT; n = 184). All patients with MC disease had mastectomy (10 patients treated with BCT for MC disease were excluded). The Kaplan-Meier product limit method was used to calculate 5-year LR control rate. Cox proportional hazards models were used to determine independent associations of multifocality or multicentricity with LR control. Results. A total of 906 patients had either MF disease (n = 673) or MC disease (n = 233). With median follow-up of 52 months, the 5-year LR control rate was 99% for MF, 96% for MC, and 98% for unifocal tumors (p = .44). Subset analysis revealed no difference in LR control regardless of the LR treatment (p = .67 for BCT, p = .37 for mastectomy, p = .29 for mastectomy plus PMRT). There were five in-breast recurrences after BCT in the MF group. MF and MC did not have an independent impact on LR control rate on multivariate analysis. Conclusion. MF and MC disease are not independent risk factors for LR recurrence. Patients with MF and MC breast cancer had rates of LR control similar to those of their unifocal counterparts. These data suggest that BCT is a safe option for patients with MF tumors and that MF or MC disease alone is not an indication for PMRT.

Effect of multiple invasive foci on breast cancer outcomes according to the molecular subtypes: a report from the Korean Breast Cancer Society

BACKGROUND

In this study, the prognostic impact of the presence of the multifocal or multicentric tumor (MMT) and its association with molecular subtypes were investigated.

PATIENTS AND METHODS

We investigated the breast cancer metastasis and survival in patients with multifocal or multicentric invasive foci in the same breast. The study population includes 2882 patients in the Seoul National University Hospital Breast Care Center (SNUHBCC) dataset and 41 179 patients in Korean Breast Cancer Registry (KBCR) dataset.

RESULTS

From SNUHBCC dataset, we observed a significant role of MMT in developing distant metastasis and death when the tumors were triple-negative subtype. This subtype-specific prognostic importance of MMT in overall survival was also seen in KBCR dataset (HR, 1.32; 95% CI, 1.02-1.69). In tumors <2 cm, the hazard ratios (HRs) for node metastasis and death were similar along the tumor size change in triple-negative subtype, while other subtypes showed a stepwise increment, suggesting the biologic importance of small invasive foci in this subtype.

CONCLUSIONS

Our results demonstrate the prognostic importance of MMT in patients with triple-negative breast cancers. Small additional invasive foci in triple-negative breast cancer patients should be considered as clinically relevant tumor deposits.

The importance of multifocal/multicentric tumor on the disease-free survival of breast cancer patients: single center experience

OBJECTIVES

Multifocal/multicentric breast cancers have been comprehensively studied and their outcomes have been compared with unifocal tumors. We evaluated the impact of multifocality and multicentricity on the disease-free survival (DFS) and overall survival of breast cancer patients and tried to analyze the correlation between multifocality/multicentricity (M/M) and other prognostic factors.

MATERIAL AND METHODS

Between 1994 and 2009, we analyzed retrospectively 697 breast cancer patients. Multicentric and multifocal breast cancer were defined as the presence of 2 or more invasive tumor foci within the different quadrants of the same breast or within a same quadrant of the breast, respectively. M/M and other prognostic factors were evaluated using univariate and multivariate analyses.

RESULTS

Multifocal/multicentric tumors were seen in 107 (15.4%) of the 697 breast cancer patients. pT and pN stage were related with the presence of multifocal/multicentric tumors. As tumor size increased and the number of axillary lymph nodes metastasis increased, the incidence of M/M increased significantly (P=0.003 vs. P=0.02, respectively). Overall, the median DFS time of patients with multifocal/multicentric tumors was significantly worse than that of the unifocal tumors (55 vs. 137 mo, P<0.001). Multivariate analysis showed that the presence of M/M was the most important prognostic factor for DFS (P=0.001, hazard ratio (HR): 0.33; 95% confidence interval (CI), 0.18-0.58), as were pN stage and extracapsular extension of the tumor (P=0.01, HR: 1.74; 95% CI, 1.13-2.69) (P=0.03, HR: 1.9; 95% CI, 1.04-3.47, respectively). M/M were not also statistically significant prognostic factors in breast cancer for overall survival (P=0.06).

CONCLUSIONS

M/M imparts an unfavorable prognosis on the DFS of breast cancer patients in comparison to unifocal tumors and the presence of multifocal/multicentric tumors were associated with advanced pT and pN stages.

Multifocal breast cancer documented in large-format histology sections: long-term follow-up results by molecular phenotypes

BACKGROUND

The prognostic significance of molecular phenotype in breast cancer is well established in the literature. Recent studies have demonstrated that subgross lesion distribution (unifocal, multifocal, and diffuse) and disease extent also carry prognostic significance in this disease. However, the correlation of molecular phenotypes with subgross parameters has not yet been investigated in detail.

METHODS

In total, 444 consecutive invasive breast cancers that were documented in large-format histology slides and worked up with detailed radiologic-pathologic correlation were sampled into tissue microarray blocks and stained immunohistochemically to delineate the molecular subtypes.

RESULTS

Diffuse or multifocal distribution of the invasive component of breast carcinomas in this series was associated with a 4.14-fold respectively 2.75-fold risk of cancer-related death compared with unifocal tumors irrespective of molecular phenotype. Patients who had human epidermal growth factor receptor 2 (HER2)-positive cancers; estrogen receptor-negative, progesterone receptor-negative, and HER2-negative (triple-negative) cancers; or basal-like cancers had a 2.18-fold, 2.33-fold, and 4.07-fold risk of dying of disease, respectively, compared with patients who had luminal A carcinomas. Unifocal luminal A, HER2-positive, and basal-like cancers were associated with significantly better long-term survival outcomes than their multifocal or diffuse counterparts; luminal B and triple-negative tumors also had the same tendency. In multivariate analysis, patient age, tumor size category, lymph node status, lesion distribution, and molecular phenotypes remained significant.

CONCLUSIONS

Multifocality and diffuse distribution of the invasive component were associated with significantly poorer survival in women with breast carcinomas compared with unifocal disease in patients with luminal A, HER2 type, and basal-like cancers. Molecular classification of breast cancer is a powerful tool but gains in power when combined with conventional and subgross morphologic parameters.

Multifocality and multicentricity in breast cancer and survival outcomes

BACKGROUND

The clinicopathological characteristics and the prognostic significance of multifocal (MF) and multicentric (MC) breast cancers are not well established.

PATIENTS AND METHODS

MF and MC were defined as more than one lesion in the same quadrant or in separate quadrants, respectively. The Kaplan-Meier product limit was used to calculate recurrence-free survival (RFS), breast cancer-specific survival (BCSS), and overall survival (OS). Cox proportional hazards models were fit to determine independent associations of MF/MC disease with survival outcomes.

RESULTS

Of 3924 patients, 942 (24%) had MF (n = 695) or MC (n = 247) disease. MF/MC disease was associated with higher T stages (T2: 26% versus 21.6%; T3: 7.4% versus 2.3%, P < 0.001), grade 3 disease (44% versus 38.2%, P < 0.001), lymphovascular invasion (26.2% versus 19.3%, P < 0.001), and lymph node metastases (43.1% versus 27.3%, P < 0.001). MC, but not MF, breast cancers were associated with a worse 5-year RFS (90% versus 95%, P = 0.02) and BCSS (95% versus 97%, P = 0.01). Multivariate analysis shows that MF or MC did not have an independent impact on RFS, BCSS, or OS.

CONCLUSIONS

MF/MC breast cancers were associated with poor prognostic factors, but were not independent predictors of worse survival outcomes. Our findings support the current TNM staging system of using the diameter of the largest lesion to assign T stage.

Comparison of the subgross distribution of the lesions in invasive ductal and lobular carcinomas of the breast: a large-format histology study

To compare the lesion distribution and the extent of the disease in ductal and lobular carcinomas of the breast, we studied 586 ductal and 133 lobular consecutive cancers. All cases were documented on large-format histology slides. The invasive component of ductal carcinomas was unifocal in 63.3% (371/586), multifocal in 35.5% (208/586), and diffuse in 1.2% (7/586) of the cases. The corresponding figures in the lobular group were 27.8% (37/133), 45.9% (61/586), and 26.3% (35/133), respectively. When the distribution of the in situ and invasive component in the same tumors was combined to give an aggregate pattern, the ductal carcinomas were unifocal in 41.6% (244/586), multifocal in 31.6% (185/586), and diffuse in 26.8% (157/586) of the cases. The corresponding figures in the lobular category were 15.0% (20/133), 54.2% (72/133), and 30.8% (41/133), respectively. Ductal cancers were extensive in 45.7% (268/586), lobular in 65.4% (87/133) of the cases. All these differences were statistically highly significant (P < 0.0001). While the histological tumor type itself (ductal versus lobular) did not influence the lymph node status, multifocal and diffuse distribution of the lesions were associated with significantly increased risk of lymph node metastases in both ductal and lobular cancers.

Morphological heterogeneity of the simultaneous ipsilateral invasive tumor foci in breast carcinoma: a retrospective study of 418 cases of carcinomas

The aim of this paper was to assess whether the morphological appearance (i.e. histological tumor type and histological grade) of simultaneous invasive breast carcinoma foci is heterogeneous, since it is known that adjuvant therapy is established according to these parameters. Patients with simultaneous breast tumors in which only the features of the largest neoplastic focus are reported could thus be undertreated. A retrospective study of 418 cases of breast carcinomas was conducted over a 3-year period. The histological tumor types and histological grades of multifocal/multicentric carcinomas in each tumor focus were compared, and mismatches among foci were recorded. Ninety-one of the 418 cases reviewed had multiple carcinomas (21.77%). A comparison between multiple synchronous tumor foci revealed that their histological type was different in 12.08% of the cases. Mismatches among foci were also observed in 9.89% of the cases when evaluating the histological grade, and 5 out of 9 additional tumor foci with a different grade from the largest (index) tumor (55.55%) displayed a higher grade compared to the index tumor. Since the histological tumor type and histological grade of the individual foci may vary considerably within the same tumor and the additional foci may be of higher grade than the index tumor, we believe that reporting morphologic parameters with more unfavorable characteristics in addition to the parameters of the index tumor is imperative.

Multicentric/multifocal breast cancer with a single histotype: is the biological characterization of all individual foci justified?

BACKGROUND

Invasive multiple breast cancers with a single histological feature (MBCSH) are routinely assessed for biological parameters to indicate adjuvant treatments only in the largest invasive carcinomas. However, the heterogeneity of individual foci in multiple carcinomas has not been widely studied. We analyzed whether such biological features are differently expressed in different MBCSH foci.

PATIENT AND METHODS

One hundred and thirteen invasive MBCSH were tested over a 5-year period. The expression of estrogen (ER) and progesterone (PgR) receptors, Ki-67 proliferative index, expression of HER2 and tumor grading were prospectively determined in each tumor focus, and mismatches among foci were recorded.

RESULTS

Mismatches in ER status were present in 5 (4.4%) cases and PgR in 18 (15.9%) cases. Mismatches in tumor grading were present in 21 cases (18.6%), proliferative index (Ki-67) in 17 (15%) cases and HER2 status in 11 (9.7%) cases.

CONCLUSIONS

In our experience, invasive MBCSH showed heterogeneity among foci. In our clinical practice, such assessment led to 14 (12.4%) patients receiving different adjuvant treatments compared with what would have been indicated if we had only taken into account the biologic status of the primary tumor.

The gain of function of p53 cancer mutant in promoting mammary tumorigenesis

Tumor suppressor p53 is critical for suppressing all types of human cancers, including breast cancer. The p53 gene is somatically mutated in over half of all human cancers. The majority of the p53 mutations are missense mutations, leading to the expression of the full-length p53 mutants. Several hotspot mutations, including R175H, are frequently detected in human breast cancer. P53 cancer mutants not only lose tumor suppression activity but, more problematically, also gain new oncogenic activities. Despite correlation of the expression of p53 cancer mutants and the poor prognosis of human breast cancer patients, the roles of p53 cancer mutants in promoting breast cancer remain unclear. We used the humanized p53 cancer mutant knock-in (R175H) mice and mouse mammary tumor virus (MMTV)-Wnt-1 transgenic (mWnt-1) mice to specifically address the gain of function of R175H in promoting breast cancer. Although both R175H/R175HmWnt-1(R175HmWnt-1) and p53(-/-)mWnt-1 mice died from mammary tumor at the same kinetics, which was much earlier than mWnt-1 mice, most of the R175HmWnt-1 mice developed multiple mammary tumors per mouse, whereas p53(-/-)mWnt-1 and mWnt-1 mice mostly developed one tumor per mouse. The multiple mammary tumors arose in the same R175HmWnt-1 mouse exhibited different histological characters. Moreover, R175H gain-of-function mutant expands the mammary epithelial stem cells (MESCs) that give rise to the mammary tumors. As ATM suppresses the expansion of MESCs, the inactivation of ATM by R175H in mammary epithelial cells (MECs) could contribute to the expansion of MESCs in R175HmWnt-1 mice. These findings provide the basis for R175H to promote the initiation of breast cancer by expanding MESCs.

Comparison of outcomes of breast conserving therapy in multifocal and unifocal invasive breast cancer

BACKGROUND

There is controversy about whether breast conserving therapy (BCT) should be contraindicated in multifocal (MF) breast cancer. Few studies have reported on the oncologic safety of BCT in MF breast cancer.

STUDY DESIGN

We reviewed a prospective database of 1,169 women with invasive breast cancer who were treated with segmentectomy and whole breast irradiation from 1991 through 2009 and followed at our institution. Multifocal breast cancer was defined as 2 or more distinct tumors excised with a single incision or segmentectomy. We compared 2 groups, MF and unifocal breast cancer patients, with respect to demographics, tumor characteristics, adjuvant systemic therapy, local recurrence (LR), disease-free survival (DFS), and overall survival (OS).

RESULTS

One hundred sixty-four patients with MF and 999 with unifocal invasive breast cancer were treated with BCT. Median follow-up was 112 months. Compared with the unifocal group, patients in the MF group had higher 10-year LR (0.6% vs 6.1%, p < 0.001) and lower 10-year DFS (97.7% vs 89.3%, p < 0.001) and OS (98.4% vs 85.8%, p < 0.001). On multivariable analysis, multifocality was independently significantly associated with local recurrence-free survival (LRFS), DFS, and OS.

CONCLUSIONS

Our data suggest that BCT in MF breast cancer is oncologically safe but may result in a slightly inferior outcome compared with BCT in unifocal breast cancer.

Axillary lymph node status in unifocal, multifocal, and diffuse breast carcinomas: differences are related to macrometastatic disease

BACKGROUND

Multifocality in breast carcinoma is associated with an increased propensity to metastasis. However, it is not clear whether this propensity manifests in the form of macrometastases or as presumably less-significant low-volume metastatic disease.

METHODS

A total of 948 cases of invasive breast carcinoma documented in large-format histology sections and assessed with detailed radiologic-pathologic correlation were categorized as unifocal, multifocal, or diffuse on the basis of the subgross distribution of the invasive component. Rates of macrometastases (>2 mm), micrometastases (0.2-2 mm), and isolated tumor cells (<0.2 mm) in these categories were compared. The influence of tumor size and histology grade on lymph node positivity rates was also tested.

RESULTS

Macrometastases were present in 20.4% (112 of 550) of unifocal, 48.3% (172 of 356) of multifocal, and 61.9% (26 of 42) of diffuse cases (P < 0.0001). Among the macrometastatic cases, more than three nodes were involved in 18.9% (21 of 112) of unifocal, 35.5% (61 of 172) of multifocal, and 50.0% (13 of 26) of diffuse cases. The rates of micrometastases (5.1, 5.1, and 2.4% unifocal, multifocal, and diffuse, respectively) and isolated tumor cells (4.5, 3.7, and 2.4% unifocal, multifocal, and diffuse, respectively) were low and similar in all examined categories. The relative risk (RR) of having macrometastatic disease was approximately doubled (RR 2.3726, P < 0.0001) in multifocal and tripled (RR 3.0562, P < 0.0001) in diffuse compared to unifocal cases. The findings were similar for all size categories, tumor grade categories, and sentinel lymph nodes, as well as all examined lymph nodes.

CONCLUSIONS

The significantly increased lymph node positivity rates in multifocal and diffuse invasive breast carcinomas results from large-volume macrometastatic disease.

True local recurrences do not metastasize

Generally, the limits of local tumor control are in part connected with the term "field cancerization" and are known from oral, lung, prostate, or mammary cancer. With the example of breast cancer (BC), the problem of ipsilateral breast tumor recurrences (IBTR) after breast-conserving surgery will be reviewed. Three types of local recurrences are distinguished: true recurrences, new primaries, or residual tumors. Good data for BC allow the description of the time-dependent risk of these three types, relative to the diagnosis of the primary tumor, because the time of initiation and the growth duration of the IBTR can be estimated. Two hypotheses explain the data: first, local recurrences may be initiated years before the diagnosis of a primary tumor (PT) and can then appear as multifocal PT at diagnosis, and second, true local recurrences probably do not metastasize. The generalizability of these hypotheses for other tumors will be discussed.