Multifocality and multicentricity in breast cancer and survival outcomes

Intertumoral heterogeneity of bifocal breast cancer: a morphological and molecular study

PURPOSE

To analyze concordance rates between individual foci of bifocal BC for histological grade, type and intrinsic subtype based on immunohistochemical (IHC) and mRNA-testing using MammaTyper.

METHODS

We evaluated histological grade and type as well as intrinsic subtype based on IHC status for estrogen and progesterone receptors, HER2 and the mitotic activity index in 158 individual foci of 79 bifocal BC. A subgroup of 31 cases additionally underwent mRNA-based subtyping using the MammaTyper (MT) test. We calculated concordance rates between individual foci, as well as Cohen's Kappa (K).

RESULTS

For 79 bifocal BC, concordance rates between individual foci for grade, histological type, and IHC-based subtype were 69.6% (K=0.53), 92.4% (K=0.81), and 74.7% (K=0.62), respectively. In the MT subgroup of 31 bifocal BC, concordance rates between individual foci for grade, histological type, IHC-based and mRNA-based intrinsic subtype were 87.1% (K=0.78), 90.3% (K=0.73), 87.1% (K=0.82), and 87.1% (K=0.7), respectively. Overall concordance between IHC- and mRNA-based subtype in the MT subgroup was 79% (K=0.7). In 6/79 cases (7.6%), testing of the smaller focus added clinically relevant information either on IHC- or mRNA-level: four cases showed high hormonal receptor expression while the expression in the larger focus was negative or low, warranting additional endocrine treatment; two cases presented with higher proliferative activity in the smaller focus, warranting additional chemotherapy.

CONCLUSION

In bifocal BC, intertumoral heterogeneity on the morphological, immunohistochemical and molecular level is common, with discordant intrinsic subtype in up to 25% between individual foci, with about 8% clinically relevant discordances.

Current understanding and distinct features of multifocal and multicentric breast cancers

BACKGROUND

Multifocal (MF) and multicentric (MC) breast cancers are referred to as synchronous, multiple ipsilateral breast cancers; however, the definitions vary among the literature, which has made understanding and analyzing these diseases challenging.

RECENT FINDINGS

The incidence ranges from 1% to 60%, with a higher prevalence in pre-menopausal women. MF and MC breast cancers, compared with unifocal breast cancers, tend to be more aggressive and are associated with lower survival rates, higher recurrence, and lymph node metastasis. Typically, patients with MF/MC breast cancers are treated with radical surgery, while breast conservation therapy may also be considered. Investigations have focused on elucidating the distinct biological features of MF/MC breast cancers, including the clonality of the cancers, the genetic alterations, and the impact of these features on disease aggressiveness and patient prognosis.

CONCLUSION

These findings will broaden the understanding of these breast cancer subtypes and aid in the development of more tailored treatment plans for patients.

Impact of multifocal or multicentric disease on local recurrence and survival in breast cancer patients with or without BRCA1/2 variants

PURPOSE

Multifocal or multicentric (MFMC) breast cancer is mainly focused on breast cancer patients with unknown BRCA status, the incidence and clinical relevance of MFMC disease in BRCA1/2 carriers is less explored to date. Our study was to investigate the incidence of MFMC disease in BRCA1/2 carriers and whether MFMC disease influences local recurrence and clinical outcomes.

METHODS

In this retrospective study, 479 breast cancer patients with BRCA1/2 variants and 1437 age-matched noncarriers were enrolled and patients received either breast-conserving therapy (BCT) or mastectomy with or without radiotherapy.

RESULTS

The rates of MFMC disease in BRCA1 and BRCA2 carriers, and noncarriers were 33.0% (61 of 185), 37.4% (110 of 294), and 31.2% (449 of 1437), respectively. MFMC disease in BRCA2 carriers was significantly higher than that in noncarriers (P = 0.039). After a median follow-up of 8.1 years, among patients treated with BCT, BRCA2 carriers with MFMC disease experienced a significantly higher rate of ipsilateral breast tumor recurrence (IBTR) than those with unifocal disease (16.7% vs 4.1%, P = 0.044). Moreover, BRCA2 carriers with MFMC disease had a significantly worse RFS (unadjusted hazard ratio [HR], 3.65 [95% CI 1.40-9.52]; P = 0.008), DRFS (unadjusted HR, 3.07 [95% CI 1.07-8.80]; P = 0.037), and OS (unadjusted HR, 4.96 [95% CI 1.18-20.02]; P = 0.029) than those with unifocal disease when treated with BCT.

CONCLUSION

MFMC breast cancer is more common in BRCA2 carriers, and BRCA2 carriers with MFMC disease treated with BCT exhibit a higher rate of IBTR and may have a poor survival.

A retrospective comparative cohort study of SEER database analysis of the prognostic value of breast-conserving surgery and mastectomy in patients with multifocal multicenter breast cancer

Background

The prognosis of multifocal multicentric breast cancer (MIBC) was related to many factors, and there are different recommendations for surgical approaches. We compare the effects of breast-conserving surgery (BCS) and mastectomy on the survival of multifocal multicenter breast cancer female patients.

Methods

A total of 38,164 female patients with pathologically confirmed multifocal multicenter invasive breast cancer from 2000 to 2018 in the Surveillance, Epidemiology, and End Results (SEER) database were extracted, and the effects of different factors on the survival of these patients were retrospectively analyzed. The patients were divided into a BCS group and a mastectomy group, and the differences of breast cancer-specific survival (BCSS) and overall survival (OS) were compared between the 2 groups.

Results

Of the 38,164 patients included in the analysis, 14,533 (38.08%) underwent BCS and 23,631 (61.92%) underwent mastectomy. Multivariate analysis showed that age, grading, staging, number of lesions, radiotherapy, and BCS would affect the independent factors of BCSS and OS in patients. The median follow-up time was 108 months [interquartile range (IQR): 64-162 months). Multifactorial Cox proportional model analysis of prognostic risk showed that BCS reduced BCSS in patients older than 70 years [hazard ratio (HR): 1.35; 95% confidence interval (CI): 1.2-1.53; P<0.001], stage I and II, positive hormone receptor (HR), all 2-3 lesions, no radiotherapy (HR: 1.46; 95% CI: 1.33-1.6; P<0.001) and no chemotherapy (HR: 1.42; 95% CI: 1.28-1.57; P<0.001); BCS also reduced OS in patients over 40 years of age, stages I, II, and IIIC, all molecular subtypes, all HR-positive or negative, 2-3 lesions, and no radiotherapy (HR: 1.38; 95% CI: 1.31-1.46; P<0.001) and no chemotherapy (HR: 1.36; 95% CI: 1.29-1.44; P<0.001) patients. Multivariate Cox regression showed that BCS is an adverse factor for BCSS [adjusted HR 1.2 (1.11-1.3), P<0.001] and OS [adjusted HR 1.24 (1.19-1.3), P<0.001].

Conclusions

In early, good prognosis, treatment-sensitive patients, there is no survival advantage for BCS and more BCSS and OS benefit for mastectomy patients.

Axillary Staging Is Not Justified in Postmenopausal Clinically Node-Negative Women Based on Nodal Disease Burden

BACKGROUND

RxPONDER showed no benefit of adjuvant chemotherapy in postmenopausal women with estrogen receptor (ER) positive/human epidermal growth factor receptor 2 (HER2) negative breast cancer and limited nodal burden (pN1) with a recurrence score ≤ 25, suggesting that axillary staging could be omitted in cN0 patients if significant numbers of such women do not have pN2-3 disease. Here we evaluate the pN2-3 disease rate in a large cohort of postmenopausal women presenting with cN0 breast cancer.

PATIENTS AND METHODS

Consecutive postmenopausal patients presenting with T1-2N0 breast cancer who underwent axillary surgery from February 2006 to December 2011 were identified. Clinicopathologic characteristics associated with pN2-3 disease were examined using chi-square or Fisher's exact tests.

RESULTS

Of 3363 postmenopausal women with cT1-2N0 breast cancer (median age 58 years, IQR 48-67 years), median tumor size was 1.3 cm (IQR 0.90-1.90cm). Post-axillary staging, 2600 (77.3%) were pN0, 643 (19.1%) were pN1, and 120 (3.6%) were pN2-3. The pN2-3 disease rate did not differ across subtypes (4.4% HER2+, 3.5% HR-/HER2-, 3.5% HR+/HER2-, p = 0.70). In the subset with HR+/HER2- tumors, on multivariable analysis, age < 65 years (odds ratio [OR] 2.38, 95% confidence interval [CI] 1.32-4.49), lymphovascular invasion (OR 5.29, 95% CI 2.72-11.2), multifocal/centric tumors (OR 3.08, 95% CI 1.79-5.32), and tumor size > 2 cm (OR 5.51, 95% CI 3.05-10.4) were significantly associated with pN2-3 nodal burden. Of 506 patients with tumors > 2 cm, 49 (9.7%) had pN2-3 disease; in the subset of 90 patients age < 65 years who had multifocal/centric tumors > 2 cm, 23 (25.6%) had pN2-3 disease.

CONCLUSIONS

In postmenopausal women with cN0 disease, pN2-3 nodal burden is uncommon; omitting axillary staging would not miss a significant number of patients who might benefit from adjuvant chemotherapy. Information available preoperatively indicating a higher risk of nodal disease such as younger age and large, multifocal tumors should be considered in the multidisciplinary management of the axilla.

The epidemiological and clinicopathological characteristics of multifocal/multicentric breast cancer in the Egyptian Delta and its impact on management strategies

BACKGROUND

Multifocal (MFBC)/multicentric (MCBC) breast cancer is being more recognized due to the improved imaging modalities and the greater orientation with this form of breast cancer, however, optimal surgical treatment, still poses a challenge. The standard surgical treatment is mastectomy, however, breast-conserving surgeries (BCS) may be appropriate in certain situations.

METHODS

A total of 464 cases of MF/MCBC out of 4798 cases of breast cancer were retrospectively analyzed from the database of the Oncology Center, Mansoura University (OCMU), between January 2008 and December 2019.

RESULTS

Radiologic involvement of multiple quadrants was reported in 27.9% by ultrasonography, 19% by mammography, and 59.1% by magnetic resonance imaging. BCS was performed in 32 cases (6.9%) while 432 cases underwent a mastectomy. Postoperative pathology revealed infiltration of other quadrants grossly in 23.5%, and under the microscope in 63.6% of the examined cases. Mean disease-free and overall survival were 95.5 and 164.6 months, respectively. When compared with MFBC, MCBC showed higher pathologic tumor size (p < 0.001), higher stages (p < 0.001), higher recurrence rates (p = 0.006), and lower DFS (P = 0.009) but with similar OS (P = 0.8).

CONCLUSION

Mastectomy is still the primary treatment option for MCBC with higher recurrence rates compared with MFBC. However, BCS for properly selected MFBC is considered oncologically safe, following the same rules of breast conservation for unifocal disease.

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.

Association of Molecular Biomarker Heterogeneity With Treatment Pattern and Disease Outcomes in Multifocal or Multicentric Breast Cancer

Purpose

This study aimed to evaluate the rates of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki67 heterogeneity in multifocal or multicentric breast cancer (MMBC) and its association with treatment pattern and disease outcomes.

Methods

MMBC patients with ER, PR, HER2, and Ki67 results for each tumor focus were retrospectively analyzed using Kappa test and categorized into the homogeneous group (Homo group) and the heterogeneous group (Hetero group). Chi-square tests were performed to compare the clinical features and treatment options between the groups. Disease-free survival (DFS) and overall survival (OS) rates were estimated from Kaplan–Meier curves and compared between two groups.

Results

A total of 387 patients were included, and 93 (24.0%) were classified into the Hetero group. Adjuvant endocrine therapy was more frequently assigned for patients in the Hetero group than in the Homo group (84.9% vs. 71.7%, p = 0.046). There was no difference in terms of adjuvant anti-HER2 therapy (28.3% vs. 19.6%, p = 0.196) and chemotherapy (69.9% vs. 69.8%, p = 0.987) usage between the two groups. At a median follow-up of 36 months, DFS rates were 81.2% for the Hetero group and 96.5% for the Homo group (p = 0.041; adjusted HR, 2.95; 95% CI, 1.04–8.37). The estimated 3-year OS rates for the groups were 95.8% and 99.5%, respectively (p = 0.059; adjusted HR, 5.36; 95% CI, 0.97–29.69).

Conclusion

Heterogeneity of ER, PR, HER2, or Ki67 was present in 24.0% patients with MMBC. Biomarkers heterogeneity influenced adjuvant endocrine therapy usage and was associated with worse disease outcomes, indicating further clinical evaluation.

Recurrent breast cancer diagnosis delayed by COVID-19 pandemic

We describe the case of a 65-year-old female with a history of left-sided ductal carcinoma in situ in 2008. Mammography in January 2020 demonstrated calcifications in the previously affected breast. Subsequent stereotactic biopsy results were benign. In the months that followed, the patient experienced breast changes but avoided returning to the facility as the COVID-19 pandemic worsened. In August of 2020, the patient returned for a repeat mammogram, which indicated 2 suspicious masses in the left breast. Further analysis through ultrasound-guided core biopsy ultimately led to a left mastectomy and lymph node biopsy, which were performed in September 2020. Pathology results revealed multifocal invasive ductal carcinoma stage IIB.

Performance of dedicated breast positron emission tomography in the detection of small and low-grade breast cancer

PURPOSE

This study compares the sensitivity of dedicated breast positron emission tomography (DbPET) and whole body positron emission tomography (WBPET) in detecting invasive breast cancer based on tumor size and biology. Further, we explored the relationship between maximum standardized uptake value (SUVmax) of DbPET and biological features of the tumor.

METHODS

A total of 639 invasive breast cancer lesions subjected to both DbPET and WBPET before surgery, between January 2016 and May 2019, were included in the study. The sensitivity of DbPET and WBPET in detection and the biology of the tumor according to the clinicopathological features were retrospectively evaluated.

RESULTS

The overall sensitivity of DbPET was higher than that of WBPET (91.4% vs. 80.3%, p < 0.001). Subcentimetric tumors were significant (80.9% vs. 54.3%, p < 0.001). Regardless of the nuclear grade, DbPET could detect more lesions than WBPET. The SUVmax was positively correlated with tumor size (R = 0.395, p < 0.001) and the nuclear grade (p < 0.001). Luminal A-like breast cancer had significantly lower SUVmax values than the other subtypes (p < 0.001).

CONCLUSIONS

DbPET is superior to WBPET in the detection of subcentimetric, low-grade breast cancers. Further, by using SUVmax, DbPET can distinguish luminal A-like breast cancer from the other subtypes.

Concordance Between 21-Gene Recurrence Scores in Multifocal or Multicentric Breast Carcinomas Differs by Age and Histologic Subtype

BACKGROUND

Among patients with multifocal or multicentric (MF/MC) breast cancer (BC) of similar morphology, concordance in Oncotype DX recurrence scores (RS) between tumors has been reported to be 87%. The effect of age and variation in histologic subtypes on RS concordance according to TAILORx criteria is unknown.

METHODS

We identified patients with MF/MC, estrogen receptor-positive, HER2-negative, node-negative BC with two or more RS results treated at our institution from 2009 to 2018. Patients were analyzed by age group (≤ 50 and > 50 years). Low- and high-risk cut-offs were RS ≤ 25 and > 25 for age > 50 years, and RS ≤ 20 and > 20 for age ≤ 50 years. RS concordance was defined as no change in management based on RS variation between lesions.

RESULTS

Overall, 120 patients with MF/MC BC were identified-82 (68.3%) aged > 50 years and 38 (31.7%) aged ≤ 50 years. Patients aged ≤ 50 years had higher mean RS for both multifocal (20 vs. 14; p = 0.006) and multicentric (17 vs. 13; p = 0.003) tumors and more frequently had high-risk tumors (p < 0.0001). Among patients aged > 50 years, 95.1% had RS concordance between tumors (same subtype, 98.2%; variable subtype, 88.9%; p = 0.1). Among patients aged ≤ 50 years, RS concordance was 81.6%.

CONCLUSIONS

Among patients with MF/MC BC, RS concordance was high, particularly in those aged > 50 years with tumors of the same histologic subtype. RS testing of one focus may be sufficiently prognostic and predictive in patients aged > 50 years, regardless of subtype concordance. Testing of individual foci should be considered in patients aged ≤ 50 years due to a higher likelihood of RS discordance.

Missed Breast Cancer: Effects of Subconscious Bias and Lesion Characteristics

Medical errors are a substantial cause of morbidity and mortality and the third leading cause of death in the United States. Errors resulting in missed breast cancer are the most common reason for medical malpractice lawsuits against all physicians. Missed breast cancers are breast malignancies that are detectable at retrospective review of a previously obtained mammogram that was prospectively reported as showing negative, benign, or probably benign findings. Investigators in prior studies have found that up to 35% of both interval cancers and screen-detected cancers could be classified as missed. As such, in conjunction with having awareness of the most common misleading appearances of breast cancer, it is important to understand the cognitive processes and unconscious biases that can impact image interpretation, thereby helping to decrease the number of missed breast cancers. The various cognitive processes that lead to unconscious bias in breast imaging, such as satisfaction of search, inattention blindness, hindsight, anchoring, premature closing, and satisfaction of reporting, are outlined in this pictorial review of missed breast cancers. In addition, strategies for reducing the rates of these missed cancers are highlighted. The most commonly missed and misinterpreted lesions, including stable lesions, benign-appearing masses, one-view findings, developing asymmetries, subtle calcifications, and architectural distortion, also are reviewed. This information will help illustrate why and how breast cancers are missed and aid in the development of appropriate minimization strategies in breast imaging. ^©RSNA, 2020.

Synchronous Multiple Breast Cancers-Do We Need to Reshape Staging?

Background and Objectives: Current recommendations and treatment regimens in breast cancer are a reflection of its heterogeneity on multiple levels including histological subtypes, grading, molecular profiling, and numerous prognostic indices. Although based on extensive research, current guidelines are not explicit in the case of surgical specimens showing various degrees of mismatch between different parts of the same tumor and even more so between multicentric lesions. Synchronous breast cancer is the ideal prototype for studying inter- and intra-tumoral heterogeneity, therefore we envisaged that a study on patients with multicentric and multifocal lesions could contribute to the reshaping of the staging, prognosis, and treatment of breast malignancies. Material and Methods: A prospective observational study was conducted between January 2013 and May 2017 on 235 patients diagnosed with breast cancer (BC) and surgically treated at Emergency University Hospital, Bucharest. Thirty-seven patients had multiple breast tumors and were eligible for assessment of the heterogeneity of their lesions. Results: 6 were multicentric and 31 multifocal. The number of foci varied from 2 to 11. We encountered numerous mismatches between the index and the secondary tumors, as follows: 3 cases (8.1%) with histopathological mismatch, 13 (35.1%) with different grades of differentiation, 11 (29.8%) with ER (Estrogen Receptors) status mismatch, 12 (32.4%) with PR (Progesterone Receptors) status mismatch, 8 (21.6%) with molecular phenotype mismatch, and 17 (45.9%) cases with variable Ki-67. After careful analysis of index and secondary tumors, apart from the mismatches reported above, we discovered that the secondary tumors were actually dominant in 5 cases (13.5%), and therefore at least those cases had to be reclassified/restaged, as the supplementary data commanded changes in the therapeutic decision. Conclusions: For synchronous breast tumors, the current Tumor-Node-Metastasis (TNM) staging system ignores not only the histopathological and immunohistochemical characteristics of the secondary foci, but also their size. When secondary lesions are more aggressive or their cumulative mass is significantly bigger than that of the index tumor, the treatment plan should be adapted accordingly. We believe that information obtained from examining secondary foci in synchronous breast cancer and assessment of the cumulative tumoral mass should be reflected in the final staging and definitive treatment. The clinical benefit of staging the patients based on the most aggressive tumor and the cumulative tumoral burden rather than according to the biggest single tumor, will avoid under-treatment in cases with multifocal/multicentric BC displaying intertumoral mismatch.

Genomic profiling of multiple breast cancer reveals inter-lesional heterogeneity

Background

Multiplicity in breast cancer is common. Studies on multiple breast cancers have revealed high concordance in biomarker status among individual lesions. However, genomic differences among multiple lesions are not well-established. We aimed to investigate the potential genomic heterogeneity of multiple breast cancer.

Methods

Twenty-one patients with radiologically and histologically evident multiple breast cancer with similar histology were included. Two lesions from each of the 21 patients were selected, and biomarker status was evaluated for each lesion. Capture-based targeted next-generation sequencing was performed using a cancer gene panel consisting of 170 genes.

Results

We identified discordance in intrinsic subtype in 2 (10%) of the 21 patients. Pathogenic mutations were detected in 13 of the 21 patients, of whom 11 shared oncogenic variants in the two lesions. The remaining two patients yielded different mutation results for TP53, ATM, and PIK3CA. Difference in copy number alteration was observed in 7 (33%) of the 21 patients including ERBB2 (n = 2), FGFR1 (n = 2), and FGFR2 (n = 1) genes.

Conclusion

Despite similar histologic features of the individual lesions, inter-lesional genomic difference was identified in more than one-third of the patients. Inter-lesional genomic heterogeneity needs to be considered when performing a genomic test in multiple breast cancers.

Multifocal and multicentric breast cancer, is it time to think again?

Multifocal multicentric breast cancer has traditionally been considered a contraindication to breast conserving surgery because of concerns regarding locoregional control and risk of disease recurrence. However, the evidence supporting this practice is limited. Increasingly, many breast surgeons are advocating breast conservation in selected cases. This short narrative review summarises current evidence on the role of surgery in multifocal multicentric breast cancer and shows that when technically feasible the option of breast conservation is oncologically safe.

Hormone Receptor Expression in Multicentric/Multifocal versus Unifocal Breast Cancer: Especially the VDR Determines the Outcome Related to Focality

The aim of this study was to evaluate the prognostic impact that hormone receptor (HR) expressions have on the two different breast cancer (BC) entities—multifocal versus unifocal BC. As the prognosis determining aspects, we investigated the overall survival (OS) and disease-free survival (DFS) by univariate and multivariate analysis. To underline the study’s conclusions, we additionally considered the histopathological grading and the tumor node metastasis (TNM) staging. A retrospective analysis was performed on survival-related events in a series of 320 breast cancer patients treated at the Department of Gynecology and Obstetrics at the Ludwig Maximillian University in Munich between 2000 and 2002. All three steroid receptors analyzed by immunohistochemistry, namely, the estrogen receptor (ER), the progesterone receptor (PR), and the vitamin D receptor (VDR), showed a significantly positive influence on the course of the disease, but only for the unifocal breast tumor patients. The prognosis of patients with multifocal breast cancer was either not affected by estrogen and/or progesterone receptor expression or even involved a worse etiopathology for the vitamin D receptor-positive patients. The estrogen receptor in unifocal breast cancer and the vitamin D receptor in multifocal breast cancer were especially identified as an independent prognostic marker for overall survival, when adjusted for age, grading, and staging. Altogether, our results strengthen the need to further investigate the behavior of the hormone receptors in breast cancer and understand why they have different effects on each focality type. Moreover, the studies for an adopted vitamin D supplementation due to breast cancer focality type must be enlarged to fully comprehend the remarkable and interesting role played by the vitamin D receptor.

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.

New and important changes in breast cancer TNM: incorporation of biologic factors into staging

INTRODUCTION

Cancer staging has historically been based solely on the anatomic extent of the tumor (T), spread to lymph nodes (N), and the presence of distant metastases (M). More recently biologic factors have been added to modify TNM stage groups to provide more accurate prognosis for patients. Areas covered: The American Joint Committee on Cancer (AJCC) updated breast cancer staging in 2016 to include T, N, M, tumor grade and expression of estrogen and progesterone receptors and HER2. Addition of these factors changed the stage group for a large fraction of cases compared to prior TNM stage groupings. This updated 'prognostic stage' provides more robust and precise prognosis information. Expert opinion: Inclusion of biological information in staging changes the meaning and the use of stage in clinical practice. This paper reviews the evidence supporting these changes, limitations affecting staging, and discusses the implications for clinical practice and the future of breast cancer staging.

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.

Breast Cancer Tissue Markers, Genomic Profiling, and Other Prognostic Factors: A Primer for Radiologists

An understanding of prognostic factors in breast cancer is imperative for guiding patient care. Increased tumor size and more advanced nodal status are established independent prognostic factors of poor outcomes and are incorporated into the American Joint Committee on Cancer (AJCC) TNM (primary tumor, regional lymph node, distant metastasis) staging system. However, other factors including imaging findings, histologic evaluation results, and molecular findings can have a direct effect on a patient's prognosis, including risk of recurrence and relative survival. Several microarray panels for gene profiling of tumors are approved by the U.S. Food and Drug Administration and endorsed by the American Society of Clinical Oncology. This article highlights prognostic factors currently in use for individualizing and guiding breast cancer therapy and is divided into four sections. The first section addresses patient considerations, in which modifiable and nonmodifiable prognostic factors including age, race and ethnicity, and lifestyle factors are discussed. The second part is focused on imaging considerations such as multicentric and/or multifocal disease, an extensive intraductal component, and skin or chest wall involvement and their effect on treatment and prognosis. The third section is about histopathologic findings such as the grade and presence of lymphovascular invasion. Last, tumor biomarkers and tumor biology are discussed, namely hormone receptors, proliferative markers, and categorization of tumors into four recognized molecular subtypes including luminal A, luminal B, human epidermal growth factor receptor 2-enriched, and triple-negative tumors. By understanding the clinical effect of these prognostic factors, radiologists, along with a multidisciplinary team, can use these tools to achieve individualized patient care and to improve patient outcomes. ^©RSNA, 2018.

Clonality analysis of multifocal ipsilateral breast carcinomas using X-chromosome inactivation patterns

The definition of multifocal breast cancer is ambiguous, and its incidence varies depending on the definition and detection methods. Multifocal breast cancers either have the same clonal origin or arise from completely distinct progenitor cells. The current American Joint Committee on Cancer Staging system and College of American Pathologists breast tumor guidelines state that only the largest tumor needs to be staged and studied immunohistochemically, on the assumption that they are of the same origin. However, some multifocal tumors have been proved to have arisen from different clones. In the present study, 71 cases of surgically resected multifocal breast cancers were selected. To detect and characterize the tumors of each clonal origin, a human androgen receptor gene (HUMARA) assay to compare the X-chromosome inactivation patterns of multiple tumors was conducted. Twenty-nine of 71 (40.8%) patients were revealed to be heterozygous for HUMARA. Sixty-four (90.1%) patients had the same X chromosome inactivated in different tumors. Seven (9.9%) cases had different inactivated X chromosomes between multifocal tumors, indicating that those tumors were from separate progenitor cells. Five (7.0%) cases showed identical histologic features but had different inactivated HUMARA alleles. According to these results, 2 separate tumors might be synchronous primary tumors, although their histopathologic characteristics are similar. Furthermore, multifocal tumors can be of different origins despite being closely located to each other. These findings suggest that separate grouping of multiple breast tumors based on their clonal origin is needed for future studies.

Evaluation of sentinel lymph node biopsy prior to axillary lymph node dissection: the role of isolated tumor cells/micrometastases and multifocality/multicentricity-a retrospective study of 1214 breast cancer patients

PURPOSE

Sentinel lymph node biopsy (SLNB) alone has thus become an accepted surgical approach for patients with limited axillary metastatic disease. We investigated to what extent isolated tumor cells (ITC) or micrometastasis in SLNBs is associated with proven tumor cells or metastasis in non-sentinel lymph nodes. Furthermore, we investigated the feasibility of SLNB in multifocal and multicentric tumors as both entities have been considered a contraindication for this technique.

METHODS

1214 women suffering from T1 and T2 invasive breast cancer, with clinically and sonographically insuspect axillary status and undergoing primary breast cancer surgery including SLNB and axillary staging in case of SLN (sentinel lymph node) metastases, were recruited into this multicentered study.

RESULTS

ITC and micrometastases were found in 2.01 and 21.4% of patients with SLN metastases (n = 299). Among patients with sentinel micrometastases, 4.7% showed further axillary micrometastases, while only two patients (3.1%) had two axillary macrometastases. Multifocal and multicentric tumors were diagnosed in 9.3 and 2.6% of our patients who at least had one SLN resected, respectively. Detection rates of SLNs did not differ between the cohorts suffering from unicentric and multifocal or multicentric disease. Moreover, the portion of tumor-free SLNs, the number of SLNs with metastasis as well as the mean number of resected SLNs did not differ.

CONCLUSIONS

No patient with sentinel node micrometastases showed more than two axillary macrometastases. Multifocal and multicentric disease is no contraindication for SLNB.

Utility of Additional Tissue Sections in Surgical Pathology

Background. To avoid diagnostic errors such as missed diagnosis and errors in staging tumors due to inadequate tissue sampling, pathologists submit additional sections (AS). Objective. This study assessed frequency, diagnostic yield, distribution, and cost of AS. Method. Among 1542 AS cases, we calculated mean AS per case; fraction of AS that altered diagnosis or stage; AS variation by tissue, malignant versus benign lesions, presence or absence of neoadjuvant therapy, mass, margin, lymph nodes, or other source, resident versus pathologist assistant (PA) dissector; and AS cost per case. Results. Overall 9.2 ± 8.8 AS were collected per case. In only 3.8% (58/1542) of cases AS altered diagnosis or stage. Urinary bladder cases provoked the most AS: 19.5 ± 15.1 per case. Significantly more AS came from malignant versus benign lesions (10.8 ± 9.7 vs 7.6 ± 7.5, P = <.0001) and from specimens treated with neoadjuvant therapy versus malignant lesions not so treated (12.3 ± 9.4 vs 10.3 ± 9.8, P = .02). Lymph nodes were sampled more heavily compared with mass, margin, and other sites combined (11.8 ± 11.4 vs 8.9 ± 8.4, P = .003), but in 78.4% (1209/1542) of cases, AS were from mass. Of diagnosis or stage altering AS cases, two thirds (38/58) were from masses, one fifth (11/58) from lymph nodes, a 10th (6/58) from margins, and a 20th (3/58) from other specimen sites. Resident versus pathologist assistant dissection caused no significant AS difference. AS contributed 40% cost per case. Conclusions. AS per case ranged widely; their diagnostic yield was low; they were highest in urinary bladder specimens, in malignant and particularly neoadjuvant-treated lesions. Although lymph nodes were most heavily sampled, most AS were from masses. Resident dissection did not increase AS and cost of AS was high.

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.

Characterisation of multifocal breast cancer using the 70-gene signature in clinical low-risk patients enrolled in the EORTC 10041/BIG 03-04 MINDACT trial

BACKGROUND

In multifocal breast cancer, guidelines recommend basing adjuvant systemic treatment decisions on characteristics of the largest lesion, disregarding multifocality as an independent prognosticator. We assessed the association between multifocal disease and both the 70-gene signature (70-GS), and distant metastasis-free survival (DMFS) in clinical low-risk breast cancer patients enrolled in the European Organisation for Research and Treatment of Cancer 10041/BIG 03-04 Microarray In Node-negative and 1 to 3 positive lymph node Disease may Avoid ChemoTherapy (MINDACT) trial.

PATIENTS AND METHODS

The analysed population consisted of enrolled patients in the MINDACT trial with clinical low-risk disease, defined by a modified Adjuvant! Online cut-off for the 10-year risk of recurrent disease or death. Eligibility criteria of MINDACT dictate that patients with multifocal disease could be included if the different lesions had similar pathological characteristics. The presence of multifocal disease was deducted from the case report form (CRF)-question for sum of diameter for all invasive tumour foci. Clinicopathological characteristics and gene expression of patients with unifocal and multifocal (largest lesion) disease were compared. Subsequently, the association between multifocal disease and the 70-GS was evaluated as well as the association between multifocality and 5-year DMFS.

RESULTS

The study included 3090 clinical low-risk patients with unifocal and 238 patients with multifocal disease. Apart from a higher prevalence of lobular tumours (21.8% versus 10.8%, by local pathology), we did not observe differences in baseline characteristics between multifocal and unifocal tumours. Patients with multifocal tumours were more likely to be at high genomic risk as compared to patients with unifocal tumours (22.7% versus 17.3%, odds ratio [OR] 1.45, 95% confidence interval [CI] 1.02-2.07, P = 0.038). We did not find a significant association between tumour focality and DMFS (97.1% for unifocal versus 96.9% for multifocal, hazard ratio [HR] = 1.55, 95% CI 0.68-3.46, P = 0.172), nor a signal for a potential interaction between the prognostic effect of the 70-GS and focality of the tumour regarding DMFS.

CONCLUSION

In the group of clinical low-risk MINDACT patients, multifocal tumours were more likely to have a high-risk 70-GS profile compared to unifocal tumours. We did not observe a significant interaction between multifocality and the 70-GS with respect to survival without distant metastasis in these patients.

Sentinel Lymph Node Frozen-Section Utilization Declines After Publication of American College of Surgeons Oncology Group Z0011 Trial Results With No Change in Subsequent Surgery for Axillary Lymph Node Dissection

OBJECTIVES

To evaluate use of sentinel lymph node (SLN) frozen section (FS) before and after publication of the Z0011 trial.

METHODS

We identified 116 pre-Z0011 and 134 post-Z0011 patients from 18 months before and after Z0011-initiated changes. Clinicopathologic features were assessed by chart review.

RESULTS

Post-Z0011 SLN FS use markedly declined when performed with breast-conserving therapy (BCT) (P < .0001), with SLN FS in 53 (73.6%) of 72 and 19 (25.0%) of 76 in pre- and post-Z0011 groups, respectively. There was post-Z0011 decline in axillary lymph node dissection (ALND) (P = .014) but no difference in later procedures for ALND. SLN positivity was associated with larger (≥1.6 cm) tumor size (P = .002). Nodal upstage was more frequent with invasive lobular (3/32; 9.4%) vs other invasive (2/188; 1.1%) subtypes.

CONCLUSIONS

Our findings support reduced need for SLN FS for BCT patients post-Z0011. However, those with specific clinicopathologic features may derive greater benefit from SLN FS.

Breast conservation versus mastectomy for patients with T3 primary tumors (>5 cm): A review of 5685 medicare patients

BACKGROUND

Although breast conservation therapy (BCT) is standard for breast cancer treatment, patients with tumors measuring >5 cm have been excluded from clinical trials. Nevertheless, only a few small retrospective series to date have compared BCT with mastectomy for tumors measuring >5 cm. The current study was performed to determine whether survival is equivalent for BCT versus mastectomy using a large national data set.

METHODS

Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked cases were identified for patients aged ≥ 66 years undergoing breast conservation for invasive, noninflammatory, nonmetastatic breast cancer between 1992 and 2009. Propensity score-based adjustment was used to account for demographics and tumor and treatment factors.

RESULTS

A total of 5685 patients with tumors measuring >5.0 cm underwent breast surgery, with 15.6% receiving BCT. Mean ages of the patients and tumor sizes were similar. Predictors of BCT included neoadjuvant chemotherapy and postoperative radiotherapy use, higher income, breast cancer as a first malignancy, and a higher Charlson Comorbidity Index. Predictors of mastectomy included younger age, nonductal histology, higher grade, numbers of lymph nodes examined and found to be positive, American Joint Committee on Cancer stage III disease, postoperative chemotherapy use, and residential region of the country. Adjusted overall and breast cancer-specific survival were not different between patients treated with BCT and mastectomy (hazard ratio, 0.934; 95% confidence interval, 0.791-1.103 [P = .419] for overall survival; and subdistribution hazard ratio, 1.042; 95% confidence interval, 0.793-1.369 [P = .769] for breast cancer-specific survival), with each improving over time. The median follow-up was 7.0 years.

CONCLUSIONS

For Medicare patients with tumors measuring >5 cm, survival is similar between those treated with BCT and mastectomy as for patients with smaller primary tumors. Despite exclusion from randomized trials, BCT may remain an option for patients with larger tumors when deemed clinically and cosmetically amenable to surgical resection.

Prognostic Factors for Local, Loco-regional and Systemic Recurrence in Early-stage Breast Cancer

Aim: The risk of recurrence in breast cancer depends on factors such as treatment but also on the intrinsic subtype. We analyzed the risk factors for local, loco-regional and systemic recurrence, evaluated the differences and analyzed the risk of recurrence for different molecular subtypes. Material and Methods: A total of 3054 breast cancer patients who underwent surgery followed by adjuvant treatment at HSK hospital or Essen Mitte Hospital between 1998 and 2011 were analyzed. Based on immunohistochemical parameters, cancers were divided into the following subgroups: luminal A, luminal B (HER2-), luminal B (HER2+), HER2+ and TNBC (triple negative breast cancer). Results: 67 % of tumors were classified as luminal A, 13 % as luminal B (HER2-), 6 % as luminal B (HER2+), 3 % as HER2+ and 11 % as TNBC. After a median follow-up time of 6.6 years there were 100 local (3.3 %), 32 loco-regional (1 %) and 248 distant recurrences (8 %). Five-year recurrence-free survival for the overall patient collective was 92 %. On multivariate analysis, positive nodal status, TNBC subtype and absence of radiation therapy were found to be independent risk factors for all forms of recurrence. Age < 50 years, tumor size, luminal B (HER2-) subtype and breast-conserving therapy were additional risk factors for local recurrence. Compared to the luminal A subtype, the risk of systemic recurrence was higher for all other subtypes; additional risk factors for systemic recurrence were lymphatic invasion, absence of systemic therapy and mastectomy. Conclusion: Overall, the risk of local and loco-regional recurrence was low. In addition to nodal status, subgroup classification was found to be an important factor affecting the risk of recurrence.

Clinical implications of multifocality as a prognostic factor in breast carcinoma - a multivariate analysis study comprising 460 cases

BACKGROUND

Multifocality is not listed among prognostic factors in international breast cancer guidelines. This study aims to analyze survival in multiple breast carcinomas (MFMC cc) compared to unifocal ones (UF cc), in order to assess the prognostic impact of multifocality.

METHODS

The study included 460 breast carcinomas (2002-2006) with a median follow-up time of 104 months (74-134 months). We assessed mortality rates, overall survival at 5 years and 10 years in general, overall survival at 5 and 10 years in MFMC cc compared to UF cc, as well as median survival and survival rate according to age, T status and axillary lymph node status in MFMC cc compared to UF cc. We carried out a multivariate analysis in order to identify independent predictor factors for survival.

RESULTS

69/460 (15%) of cases were MFMC cc. Mortality rates were 56.5% in MFMC cc versus 45.1% (UF cc) (P = 0.08). 5-year overall survival was 55.9% in MFMC cc vs. 64.7% UF cc, and the 10-year overall survival was 34.9% MFMC cc vs. 52.7% UF cc (P = 0.27). Median survival in MFMC cc was 78 months (6.5 years), whereas in UF cc it was 126 months (10.5 years). However, in the multivariate analysis, survival was independently influenced only by tumor size and the presence of axillary lymph node metastases (P < 0.0001).

CONCLUSION

Breast cancer multifocality is associated with higher general mortality rates, lower 5 and 10-year overall survival, yields a lower median survival, but it does not constitute an independent prognostic factor in multivariate analysis.

[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.

Radiologist's role in breast cancer staging: providing key information for clinicians

Breast cancer is the second leading cause of cancer death in women, exceeded only by lung cancer, and the 5-year survival rate is largely dependent on disease stage. The American Joint Committee on Cancer (AJCC) staging system for breast cancer (7th edition) provides a tumor-node-metastasis (TNM) classification scheme for breast cancer that is important for determining prognosis and treatment. Ascertaining the correct stage of breast cancer can be challenging, and the importance of the radiologist's role has increased over the years. The radiologist should understand how breast cancer stage is assigned and should be familiar with the AJCC's TNM classification scheme. The authors review the AJCC's TNM staging system for breast cancer with emphasis on clinical and preoperative staging, the different imaging modalities used in staging, and the key information that should be conveyed to clinicians. Radiologic information that may alter stage, prognosis, or treatment includes tumor size; number of tumor lesions; total span of disease; regional nodal status (axillary levels I-III, internal mammary, supraclavicular); locoregional invasion (involvement of the pectoralis muscle, skin, nipple, or chest wall); and distant metastases to bone, lung, brain, and liver, among other anatomic structures.

Impact of multifocal or multicentric disease on surgery and locoregional, distant and overall survival of 6,134 breast cancer patients treated with neoadjuvant chemotherapy

BACKGROUND

The impact of tumor focality on type of surgery, local recurrence rate, and survival after neoadjuvant chemotherapy (NACT) for breast cancer is not fully understood. This study aimed to compare local recurrence-free survival (LRFS), disease-free survival (DFS), and overall survival (OS) according to focality stratified by type of surgery and pathologic complete response (pCR), with a focus on breast conservation.

METHODS

Participants (n = 6,134) in the GeparTrio, GeparQuattro, and GeparQuinto trials with operable or locally advanced tumors receiving NACT were classified as having unifocal (1 lesion), multifocal (≥ 2 lesions in 1 quadrant), or multicentric (≥ 1 lesion in ≥ 2 quadrants) disease. The study investigated LRFS, DFS, and OS according to focality stratified by type of surgery and pathologic complete response.

RESULTS

The patients were classified as having unifocal (n = 4,733, 77.1 %), multifocal (n = 820, 13.4 %), or multicentric (n = 581, 9.5 %) tumors. The respective pCR rates were 19.4, 16.5, and 14.4 %. Breast conservation was performed for 71.6, 58.5, and 30 % of these patients, respectively (P < 0.001). The LRFS rate was 92.9 % for the unifocal, 95.1 % for the multifocal, and 90.4 % for the multicentric tumors (P = 0.002). The patients with multicentric tumors but not the patients with multifocal tumors had worse DFS (P < 0.001) and OS (P = 0.009) than the patients with unifocal tumors. However, LRFS, DFS, and OS were not inferior for the patients with multicentric or multifocal tumors if pCR was achieved or breast conservation was performed after NACT.

CONCLUSION

Breast conservation is feasible for clinically multifocal or multicentric breast cancer patients who undergo NACT without worsening LRFS if tumor-free margins can be attained or if patients achieve a pCR.

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.

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.

HER2 testing of multifocal invasive breast carcinoma: how many blocks are enough?

OBJECTIVES

To determine the diagnostic yield of testing multiple blocks for HER2 in cases of multifocal breast carcinoma.

METHODS

We identified 246 consecutive cases of multifocal invasive breast carcinoma in which HER2 was tested on more than 1 tumor focus. We performed an audit of all cases with respect to tumor size, grade, and histologic type.

RESULTS

HER2 status was concordant between multiple foci in 230 (93.5%) of 246 cases, with the largest focus having the most positive HER2 result in 242 (98.4%) of 246 cases. We did not find a single case in which a smaller focus demonstrated a more positive HER2 status unless this focus was either higher grade or different histologically.

CONCLUSIONS

Our findings support the evaluation of HER2 on the largest focus, with additional testing on smaller foci having a different histologic type or higher grade.