Duct carcinoma in situ. Relationship of extent of noninvasive disease to the frequency of occult invasion, multicentricity, lymph node metastases, and short-term treatment failures

Evaluation of the Efficacy of Postoperative Adjuvant Therapy for HER2-Positive Ductal Carcinoma in Situ with Microinvasion

A retrospective study on 90 eligible HER2+ ductal carcinoma in situ with microinvasion (DCIS-MI) patients was performed with a median follow-up time of 57 months. The baseline was consistent between the 4-cycle and 6-cycle chemotherapy groups. There were more patients with multiple foci of micrometastasis in the target therapy group in the two groups with or without target therapy (p < 0.01). Postoperative chemotherapy with a 4-cycle regimen can achieve the expected therapeutic effect in patients with HER2+ DCIS-MI, but the role of target therapy in HER2+ DCIS-MI patients has not been confirmed.

A bicellular fluorescent ductal carcinoma in situ (DCIS)-like tumoroid to study the progression of carcinoma: practical approaches and optimization

Recently, many types of 3D culture systems have been developed to preserve the physicochemical environment and biological characteristics of the original tumors better than the conventional 2D monolayer culture system. There are various types of models belonging to this culture, such as the culture based on non-adherent and/or scaffold-free matrices to form the tumors. Agarose mold has been widely used to facilitate tissue spheroid assembly, as it is essentially non-biodegradable, bio-inert, biocompatible, low-cost, and low-attachment material that can promote cell spheroidization. As no studies have been carried out on the development of a fluorescent bicellular tumoroid mimicking ductal carcinoma in situ (DCIS) using human cell lines, our objective was to detail the practical approaches developed to generate this model, consisting of a continuous layer of myoepithelial cells (MECs) around a previously formed in situ breast tumor. The practical approaches developed to generate a bi-cellular tumoroid mimicking ductal carcinoma in situ (DCIS), consisting of a continuous layer of myoepithelial cells (MECs) around a previously formed in situ breast tumoroid. Firstly, the optimal steps and conditions of spheroids generation using a non-adherent agarose gel were described, in particular, the appropriate medium, seeding density of each cell type and incubation period. Next, a lentiviral transduction approach to achieve stable fluorescent protein expression (integrative system) was used to characterize the different cell lines and to track tumoroid generation through immunofluorescence, the organization of the two cell types was validated, specific merits and drawbacks were compared to lentiviral transduction. Two lentiviral vectors expressing either EGFP (Enhanced Green Fluorescent Protein) or m-Cherry (Red Fluorescent Protein) were used. Various rates of a multiplicity of infection (MOI) and multiple types of antibodies (anti-p63, anti-CK8, anti-Maspin, anti-Calponin) for immunofluorescence analysis were tested to determine the optimal conditions for each cell line. At MOI 40 (GFP) and MOI 5 (m-Cherry), the signals were almost homogeneously distributed in the cells which could then be used to generate the DCIS-like tumoroids. Images of the tumoroids in agarose molds were captured with a confocal microscope Micro Zeiss Cell Observer Spinning Disk or with IncuCyte® to follow the progress of the generation. Measurement of protumoral cytokines such as IL-6, IL8 and leptin confirmed their secretion in the supernatants, indicating that the properties of our cells were not altered. Finally the advantages and disadvantages of each fluorescent approach were discussed. This model could also be used for other solid malignancies to study the complex relationship between different cells such as tumor and myoepithelial cells in various microenvironments (inflammatory, adipose and tumor, obesity, etc.). Although, this new model is well established to monitor drug screening applications and perform pharmacokinetic and pharmacodynamic analyses.

Clinicopathological characteristics, treatments, and prognosis of breast ductal carcinoma in situ with microinvasion: A narrative review

Background

Ductal carcinoma in situ with microinvasion (DCIS-MI) is defined as ductal carcinoma in situ (DCIS) with a microscopic invasive focus ≤1 mm in the longest diameter. The current literature is controversial concerning the clinical prognostic features and management of DCIS-MI. This narrative review described recently reported literature regarding the characteristics, treatment, and prognosis of it.

Methods

Searching PubMed for relevant articles covering the period of 1982 to 2021 using the following terms by MeSH and free-word: breast cancer, microinvasion, DCIS, DCIS-MI, and invasive ductal carcinoma (IDC).

Results

DCIS-MI tends to express more aggressive pathological features such as necrosis, HER2+, ER- or PR-, and high nuclear grade. The overall prognosis of DCIS-MI is typically good, however, some indicators such as young age, HR-, HER2+ and multimicroinvasive lesions, were associated with worse prognoses. And there are also conflicting results on the differences between the prognoses of DCIS-MI and DCIS or T1a-IDC. Postoperative chemotherapy and anti-HER2 therapy still have uncertain benefits and are more likely to be used to treat high-risk patients who are HR- orHER2+ to improve the prognosis.

Conclusion

DCIS-MI has more aggressive pathological features, which may suggest its biological behavior is worse than that of DCIS and similar to early IDC. Although the overall prognosis of DCIS-MI is good, when making decisions about adjuvant therapy clinicians need to give priority to the hormone receptor status, HER2 expression and axillary lymph node status of patients, because these may affect the prognosis and treatment response.

Regional Lymph Node Metastasis and Axillary Surgery of Microinvasive Breast Cancer: A Population-Based Study

Microinvasive breast cancer (MBC for short) is a rare entity with the decision of axillary surgery under debate in clinical practice. We aimed to unravel the lymph node metastasis (LNM) rate, axillary surgery, and prognosis of MBC based on 11,692 patients derived from the Surveillance Epidemiology and End Results (SEER) database between 2003 and 2015. In this retrospective study, 19.5% (2276/11,692) of patients received axillary lymph node dissection (ALND), 80.5% (9416/11,692) received non-ALND. In the total cohort, 10-year breast cancer-specific survival (BCSS) was 96.3%, and the LNM rate was 6.4% (754/11,692). Multivariate analyses showed that LNM had the strongest predictive weight (N3, HR 14.200, 95% CI 7.933−25.417; N2, HR 12.945, 95% CI 7.725−21.694; N1, HR 3.05, 95% CI 2.246−4.140, all p < 0.001). Kaplan−Meier analyses showed that ALND did not confer a survival benefit on 10-year BCS in patients with N0 (94.7% vs. 97.1%, p < 0.001) and in patients with 1−2 positive nodes (92.1% vs. 89.5%, p = 0.355), respectively, when compared to non-ALND. Our study demonstrated that the vast majority of MBC have a low LNM rate and excellent prognosis; patients with LNM showed poor prognosis. Assessment of lymph node status is necessary, and non-ALND surgery is required and sufficient for MBC with 0−2 positive nodes.

Axillary staging in ductal carcinoma in situ with microinvasion: A meta-analysis

INTRODUCTION

Ductal carcinoma in situ with microinvasion (DCISM); arguably a more aggressive subtype of DCIS, currently has variable recommendations governing its staging and management in the UK. As a result, there is ongoing controversy surrounding the most appropriate management of DCISM, in particular the need of axillary staging.

METHOD

A search was conducted on the databases MEDLINE and Embase using the keywords: breast, DCISM, microinvasion, "ductal carcinoma in situ with microinvasion", sentinel lymph node biopsy, SLNB, axillary staging was performed. 23 studies were selected for analysis. Primary outcome was the positivity of metastasis of lymph node; secondary outcome looked at characteristics of DCISM that may affect node positivity.

RESULTS

A total of 2959 patients were included. Significant heterogeneity was observed amongst the studies with regards to metastases (I² = 61%; P < 0.01). Lymph node macrometastases was estimated to be 2%. Significant subgroup difference was not observed between SLNB technique and lymph node macrometastases (Q = 0.74; p = 0.69). Statistical significance was observed between the focality of the DCISM and lymph node macrometastases (Q = 8.71; p = 0.033).

CONCLUSION

Although histologically more advanced than DCIS, DCISM is not linked with higher rates of clinically significant metastasis to axillary lymph nodes. Survival rates are very similar to those seen in cases of DCIS. Current evidence suggests that axillary staging in cases of DCISM will not change their overall management, thus may only be an unnecessary and inconvenient additional intervention considering the majority of DCISM diagnoses are made from post-operative pathology samples. A multidisciplinary team approach evaluating pre-operative clinical and histological information to tailor the management specific to individual cases of DCISM would be a preferred approach than routine axillary staging.

Clinical characteristics of breast ductal carcinoma in situ with microinvasion: a narrative review

Ductal carcinoma in situ (DCIS) with microinvasion (DCIS-MI) is defined as the extension of cancer cells beyond the basement membrane into adjacent tissue with no focus larger than 1 mm or a maximum diameter of less than 1 mm for multiple invasive foci. DCIS-MI constitutes approximately 1% of all breast cancer cases and 5% to 10% of cases of DCIS. The current literature is controversial concerning the clinical prognostic features and management of DCIS-MI. This narrative review described recently reported literature regarding the characteristics, diagnosis, treatment, and prognosis of DCIS-MI.

Correlation of size and focality with prognosis in small breast carcinoma: a single institution case series

Aim of the study

The clinical behavior and prognosis of small multifocal and microinvasive breast cancers are still debated together with the best method of assessing tumor size in multiple invasive carcinomas. This study evaluates the clinico-pathological features of single and multiple breast cancers up to 0.5 cm in order to evaluate the rate of recurrences.

Materials and methods

We retrospectively analyzed 170 node-negative patients consecutively treated at European Institute of Oncology from 2001 to 2006. We divided them into Group I (pT1mi) and Group II (pT1a) furtherly divided in subgroups, according to focality and aggregate diameter. For each group we assessed tumor size, (multi)focality, extensive in situ component (EIC), histology, grade, peritumoral vascular invasion (PVI), hormonal receptor status (HR), HER-2 expression, Ki67 expression.

Results

We observed that the frequency of local recurrences and distant metastases in group I was higher among those with a single focus; whereas in group II, it was higher in multifocal carcinomas. Then, by comparing the two groups, the prognosis was better in multiple pT1mi than in similarly sized unifocal pT1a.

Conclusions

Microinvasive carcinomas are associated with a good prognosis, even if they seem to have a more aggressive intrinsic biological behavior. Multifocality seems to be correlated with a worse prognosis in case of invasive carcinomas pT1a. In case of microinvasive carcinomas, by contrast, multifocality per se does not seem to affect the recurrence rate.

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One of the prognostic features of breast cancer is the size.

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Microscopic quantification of microinvasive carcinoma, mostly in multifocal cases, is still difficult to be standardized.

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Our study compares 170 single/multiple small breast cancers, treated at single institution to evaluate recurrence rate.

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Local and distant recurrences were better in multiple pT1mi(m) carcinoma than in similarly sized, unifocal pT1a.

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In microinvasive carcinomas, multifocality per se does not affect the recurrence rate.

Is it ductal carcinoma in situ with microinvasion or "Ductogenesis"? The role of myoepithelial cell markers

Mammary myoepithelial cells have been under-recognized for many years since they were considered less important in breast cancer tumorigenesis compared to luminal epithelial cells. However, in recent years with advances in genomics, cell biology, and research in breast cancer microenvironment, more emphasis has been placed on better understanding of the role that myoepithelial cells play in breast cancer progression. As the result, it has been recognized that the presence or absence of myoepithelial cells play a critical role in the assessment of tumor invasion in diagnostic breast pathology. In addition, advances in screening mammography and breast imaging has resulted in increased detection of ductal carcinoma in situ and consequently more diagnosis of ductal carcinoma in situ with microinvasion. In the present review, we discuss the characteristics of myoepithelial cells, their genomic markers and their role in the accurate diagnosis of ductal carcinoma in situ with microinvasion. We also share our experience with reporting of various morphologic features of ductal carcinoma in situ that may mimic microinvasion and introduce the term of ductogenesis.

Duct carcinoma in situ: A personal perspective

In the recent past, DCIS was a rare diagnosis established by biopsy of palpable breast masses or nipple changes. Mammography increased the frequency of a DCIS diagnosis by 20 × resulting in a tsunami of small circa 10 mm lesions detected only by mammography. The impact of pathologic technique in examining and characterizing such lesions is reviewed, and the development of algorithms incorporating prognostic factors and histology based on serial sequential processing techniques are described and contrasted with those which relied on tissue sampling. The development of the initial clinical trails of irradiation all demonstrated the significant benefit of irradiation but none could identify subsets with a more favorable outcome. The latter was precluded by their common practice of tissue sampling: Size could not be calculated and margin width and microinvasion could not be reliable demonstrated. Multigene signature assays are increasingly being utilized, most prominently Oncotype DCIS. However, these assays must be interpreted in conjunction with the limitations set forth in the validating studies-in the case of Oncotype DCIS-the size, margin width, and grade which defined the baseline study (E5194). Tamoxifen and other anti-hormonal agents (aromatase inhibitor therapy) have been shown to have a limited impact on ipsilateral recurrence which makes their use given their morbidities problematic. Such interventions do impact the frequency of contralateral occult in situ and invasive lesions. In the one study which permitted a comparison of local recurrence in irradiated vs nonirradiated breast, there was no added benefit of Tamoxifen in irradiated breasts. Some are attempting to identify a low-risk subset of DCIS which can be treated without surgical re-excision for margins or adjuvant irradiation. These studies are in progress but surrogates identified within the Van Nuys prospective series defined by grade and inadequate margins (≤ 1 mm) would suggest a significant recurrence and progression rate. DCIS remains a work in progress both in terms of classification and treatment. However, limited our progress in these areas we have certainly advanced from the oft-proclaimed mantra: "Radiation and Tamoxifen are standard of care."

A Nomogram to Predict Factors Associated with Lymph Node Metastasis in Ductal Carcinoma In Situ with Microinvasion

INTRODUCTION

Ductal carcinoma in situ (DCIS) with foci of invasion measuring ≤ 1 mm (DCISM), represents < 1% of all invasive breast cancers. Sentinel lymph node biopsy (SLNB) has been a standard component of surgery for patients with invasive carcinoma or extensive DCIS. We hypothesize that selective performance of SLNB may be appropriate given the low incidence of sentinel node (SN) metastasis for DCISM. We investigated the clinicopathologic predictors for SN positivity in DCISM, to identify which patients might benefit from SLNB.

METHODS

A retrospective review of the National Cancer Database was performed for cases from 2012 to 2015. Clinical and tumor characteristics, including SN results, were evaluated, and Pearson's Chi square tests and logistic regression were performed.

RESULTS

Of 7803 patients with DCISM, 306 (4%) had at least one positive SN. Patients with positive SNs were younger, more often of Black race, had higher-grade histology and larger tumor size, and were more likely to have lymphovascular invasion (LVI; all p < 0.001). In an adjusted model, the presence of LVI was associated with the highest odds ratio (OR) for node positivity (OR 8.80, 95% confidence interval 4.56-16.96).

CONCLUSIONS

Among women with DCISM, only 4% had a positive SN. Node positivity was associated with more extensive and higher-grade DCIS, and the presence of LVI was strongly correlated with node positivity. Our data suggest that LVI is the most important factor in determining which patients with DCISM will benefit from SN biopsy.

Imaging features that distinguish pure ductal carcinoma in situ (DCIS) from DCIS with microinvasion

Patients with ductal carcinoma in situ with microinvasion (DCISM) have worse cancer-specific survival, disease-free survival and overall survival, and a higher mortality rate compared with patients with ductal carcinoma in situ (DCIS). Distinguishing DCISM from DCIS via preoperative imaging could help to predict the prognosis of patients. The present study compared the sonographic and mammographic features of patients with DCIS and DCISM. A total of 147 women (94 patients with DCIS and 53 patients with DCISM) were retrospectively included. The sonographic lesions were classified as either masses or non-mass abnormalities. The lesions observed on mammography were classified as calcifications only, mass, asymmetry or architectural distortion. Statistical comparisons were performed using the Mann-Whitney U test, χ² test, Fisher's exact test and multiple logistic regression analysis. Univariate and multivariate analyses showed that the presence of calcifications (P=0.038) and vascularity (P=0.025) on sonography were associated with DCISM. Furthermore, a lager distribution of calcifications was associated with a higher likelihood of DCISM (P=0.002). In conclusion, the presence of calcifications and vascularity on sonography or a lager distribution of calcifications on mammography may suggest DCISM.

Sentinel lymph node biopsy in microinvasive ductal carcinoma in situ

BACKGROUND

Microinvasive breast cancer is an uncommon pathological entity. Owing to the rarity of this condition, its surgical axillary management and overall prognosis remain controversial.

METHODS

A database was analysed to identify patients with microinvasive ductal carcinoma in situ (DCIS) who had surgery for invasive breast cancer at the European Institute of Oncology, Milan, between 1998 and 2010. Women who had undergone axillary staging by sentinel lymph node biopsy were included in the study.

RESULTS

Of 257 women with microinvasive breast cancer who underwent sentinel lymph node biopsy (SLNB), 226 (87·9 per cent) had negative sentinel lymph nodes (SLNs) and 31 had metastatic SLNs. Twelve patients had isolated tumour cells (ITCs), 14 had micrometastases and five had macrometastases in sentinel nodes. Axillary lymph node dissection was performed in 16 of the 31 patients with positive SLNs. After a median follow-up of 11 years, only one regional first event was observed in the 15 patients with positive SLNs who did not undergo axillary lymph node dissection. There were no regional first events in the 16 patients with positive SLNs who had axillary dissection.

CONCLUSION

Good disease-free and overall survival were found in women with positive SLNs and microinvasive DCIS. This study is in line with studies showing that SLNB in microinvasive DCIS may not be useful, and supports the evidence that less surgery can provide the same level of overall survival with better quality of life.

Microinvasive Carcinoma versus Ductal Carcinoma In Situ: A Comparison of Clinicopathological Features and Clinical Outcomes

PURPOSE

Although microinvasive carcinoma is distinct from ductal carcinoma in situ (DCIS), the clinical significance of microinvasion in DCIS remains elusive. The purpose of this study is to evaluate the clinicopathological features and clinical outcomes of microinvasive carcinoma compared with pure DCIS.

METHODS

We assessed 613 cases of DCIS and microinvasive carcinoma that were consecutively resected from 2003 to 2014 and analyzed clinicopathological variables, expression of standard biomarkers such as the estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), p53, and Ki-67, and tumor recurrence.

RESULTS

Among the 613 cases, 136 (22.2%) were classified as microinvasive carcinoma. Microinvasive carcinoma was significantly associated with DCIS with a large extent, high nuclear grade, necrosis, and comedotype architectural pattern. ER and PR expressions were dominantly observed in pure DCIS, whereas positive HER2 status, p53 overexpression, and high Ki-67 proliferation indices were more frequently observed in microinvasive carcinoma. Lymph node metastasis was found in only four cases of microinvasive carcinoma with multifocal microinvasion. In the multivariate analysis, DCIS with a large extent, comedo-type architectural pattern, and negative ER status were found to be independent predictors of microinvasion. During follow-up, 12 patients had ipsilateral breast recurrence, and no differences in recurrence rates were observed between patients with DCIS and those with microinvasive carcinoma. The triple-negative subtype was the only factor that was associated with tumor recurrence.

CONCLUSION

Microinvasive carcinomas are distinct from DCIS in terms of clinicopathological features and biomarker expressions but are similar to DCIS in terms of clinical outcomes. Our results suggest that microinvasive carcinoma can be treated and followed up as pure DCIS.

Sentinel Lymph Node Biopsy in Patients with Pure and High-Risk Ductal Carcinoma in Situ of the Breast

Aims and Background

The role of sentinel lymph node biopsy in patients initially diagnosed with ductal carcinoma in situ resides in determining the predictors of invasive disease. The aim of the present study was to examine the incidence of sentinel lymph node metastases in a selected group of patients, with characteristics of high-risk ductal carcinoma in situ, in order to determine the clinical usefulness of sentinel lymph node biopsy.

Methods

A total of 90 patients with a biopsy diagnosis of ductal carcinoma in situ were treated. Fifty-two patients with high-risk ductal carcinoma in situ had sentinel lymph node biopsy. The following characteristics of the primary tumor were considered as indicative of a risk of invasive disease: presence of palpable mass, mammographic mass, multicentric disease that required mastectomy, and histologically high nuclear grade or non-high nuclear grade with necrosis. Subdermal injections of 99mTc-labeled human albumin and subareolar injection ofblue dye were used for sentinel lymph node identification. All sentinel nodes were sectioned serially and stained with hematoxylin and eosin. Immunohistochemical analysis was performed using a cytokeratin monoclonal antibody.

Results

A positive sentinel lymph node was found in only one patient (1.9%). The patient had a double lesion, and core-needle biopsy showed an atypical ductal hyperplasia and a intermediate degree of ductal carcinoma in situ. At pathologic review of the specimen, no invasive aspect was detected.

Conclusions

The results of our study indicate that sentinel lymph node metastasis in pure ductal carcinoma in situ is extremely uncommon. We therefore suggest that sentinel lymph node biopsy might be indicated for patients with ductal carcinoma in situ detected as a palpable mass or as large extensive microcalcifications, as well as for patients who are undergoing mastectomy, especially with immediate reconstruction.

Breast Specimen Processing and Reporting With an Emphasis on Margin Evaluation: A College of American Pathologists Survey of 866 Laboratories

CONTEXT

- The College of American Pathologists (CAP) developed protocols for reporting pathologic characteristics of breast cancer specimens, including margin status. The Society of Surgical Oncology (SSO) and the American Society for Radiation Oncology (ASTRO) published treatment guidelines regarding margins in patients with invasive cancer; and SSO, ASTRO, and the American Society of Clinical Oncology (ASCO) recently published guidelines for patients with ductal carcinoma in situ.

OBJECTIVE

- To assess current practices among pathologists with regard to the processing/reporting of breast specimens, assess compliance with CAP cancer protocols, and assess alignment with SSO/ASTRO and SSO/ASTRO/ASCO guidelines.

DESIGN

- A survey concerning breast specimen processing/reporting was distributed to pathologists enrolled in the CAP Performance Improvement Program in Surgical Pathology.

RESULTS

- Ninety-four percent (716 of 764 respondents) and 91% (699 of 769 respondents) define positive margins as "tumor on ink" for invasive cancer and ductal carcinoma in situ, respectively, in compliance with CAP cancer protocols and with SSO/ASTRO and SSO/ASTRO/ASCO guidelines. Of 791 respondents who provided details regarding methods for margin evaluation, 608 (77%) exclusively examine perpendicular margins, facilitating guideline compliance. However, 183 of 791 respondents (23%) examine en face margins in at least a subset of specimens, which may preclude guideline compliance in some cases. When separate cavity (shave) margins are examined, while 517 of 586 respondents (88%) ink these specimens, 69 of 586 (12%) do not, and this may also preclude guideline compliance in some cases.

CONCLUSIONS

- A substantial proportion of survey participants report margin status for breast cancer specimens in a manner consistent with CAP cancer protocols, and in alignment with SSO/ASTRO and SSO/ASTRO/ASCO guidelines. However, there are opportunities for some laboratories to modify procedures in order to facilitate more complete adherence to guidelines.

Risk of death from breast cancer after treatment for ductal carcinoma in situ

Background

Studies to date have failed to demonstrate any survival benefit from preventing local recurrence after treatment for ductal breast carcinoma in situ (DCIS). Patient- and tumour-related risk factors for death from breast cancer in women with a primary DCIS were analysed here in a large case–control study.

Methods

A nested case–control study was conducted in a population-based cohort of women with primary DCIS between 1992 and 2012. Women who later died from breast cancer were identified. Four controls per case were selected randomly by incidence density sampling. Medical records and pathology reports were retrieved. Conditional logistic regression was used to calculate odds ratios (ORs) and 95 per cent confidence intervals for risk of death from breast cancer.

Results

From a cohort of 6964 women, 96 who died from breast cancer were identified and these were compared with a group of 318 controls. Tumour size over 25 mm or multifocal DCIS (OR 2·55, 95 per cent c.i. 1·53 to 4·25), a positive or uncertain margin status (OR 3·91, 1·59 to 9·61) and detection outside the screening programme (OR 2·12, 1·16 to 3·86) increased the risk of death from breast cancer. The risks were not affected by age or type of treatment. In the multivariable analysis, tumour size (OR 1·95, 1·06 to 3·67) and margin status (OR 2·69, 1·15 to 7·11) remained significant.

Conclusion

In the present study, large tumour size and positive or uncertain margin status were associated with a higher risk of death from breast cancer after treatment for primary DCIS. More extensive treatment was not associated with lower risk, which may be due to confounding by indication, or indicate that some DCIS has an inherent potential for metastatic spread.

Impact of Detection Method and Accompanying Ductal Carcinoma in Situ on Prognosis of T1a,bN0 Breast Cancer

Background: T1a,bN0 breast cancer is not easily detected. Before mammography became widespread, most cases were discovered only after the development of symptoms. The presence of ductal carcinoma in situ (DCIS) affects the detectability of associated invasive cancer; however, the prognostic value of concomitant DCIS is controversial. This study compared the characteristics of screening-detected and symptom-detected T1a,bN0 breast cancer, and investigated the impact of accompanying DCIS on detection and prognosis. Patients and Methods: Data were collected from a single hospital between 2000 and 2009. Of 5,690 primary breast cancers patients, 438 met the criteria for T1a,bN0M0. Logistic regression models were used to identify prognostic indicators and their association with the detection method. Survival analyses were performed to estimate distant relapse-free survival (DRFS) and breast cancer-specific survival (BCSS). Results: Tumors in 79 and 359 patients were detected by screening and development of symptoms, respectively. Symptomatic cancer patients were younger, more likely to receive a mastectomy, and had larger accompanying DCIS lesions; their 10-year DRFS rates were worse than those of patients with screening-detected tumors (91.1% vs. 100% respectively, p=0.049). Patients with large accompanying DCIS (≥2 cm) had markedly worse 10-year DRFS (77.1% vs. 97.4%, p<0.001) and BCSS (94.3% vs. 98.9%, p<0.001). Conclusion: T1a,bN0 breast cancers detected owing to symptoms are more likely to have larger accompanying DCIS. T1a,bN0 patients with large accompanying DCIS have worse DRFS and BCSS. It is important to consider associated DCIS size when evaluating prognosis in T1a,bN0 breast cancer patients.

Updates in the treatment of ductal carcinoma in situ of the breast

PURPOSE OF REVIEW

Ductal carcinoma in situ (DCIS) accounts for approximately 20% of mammographically diagnosed breast cancers. Currently, there is a trend to consider DCIS as a lesion for which treatment deescalation is advocated to avoid overtreatment, that is, radiotherapy in addition to breast-conserving surgery or even surgery at all.

RECENT FINDINGS

The long-term follow-up updates of the four first-generation randomized trials comparing lumpectomy with and without radiation therapy have confirmed that radiation halves the local failure rates. However, radiotherapy is not associated with a survival benefit just as affirmed by the recently published evaluation of the Surveillance, Epidemiology, and End Results registries database, including 108,196 women with DCIS. Nevertheless, the risk of dying of breast cancer increases about factor 18 after experience of an invasive local recurrence. That means at least some DCIS have the potential to progress to a life threatening disease. At the same time, none of the recently updated prospective trials that tested the outcome after excision alone in low-risk DCIS achieved a 10-year local failure rate below 10%.

SUMMARY

DCIS is not a uniform disease. Its clinical behaviour is heterogeneous, but up to date no citeria are available that allow a precise identification of patients with low or very low progression risk who do not need irradiation. Therefore, excision followed by radiotherapy is still the standard of care in patients undergoing breast conservation. Promising new approaches for risk estimation have to be validated prospectively before their use in daily practice can be recommended.

Is adjuvant chemotherapy necessary for patients with microinvasive breast cancer after surgery?

Objective: Survival and treatment of patients with microinvasive breast cancer (MIBC) remain controversial. In this paper, we evaluated whether adjuvant chemotherapy is necessary for patients with MIBC to identify risk factors influencing its prognosis and decide the indication for adjuvant chemotherapy. Methods: In this retrospective study, 108 patients with MIBC were recruited according to seventh edition of the staging manual of the American Joint Committee on Cancer (AJCC). The subjects were divided into chemotherapy and non-chemotherapy groups. We compared the 5-year disease-free survival (DFS) and overall survival (OS) rates between groups. Furthermore, we analyzed the factors related to prognosis for patients with MIBC using univariate and multivariate analyses. We also evaluated the impact of adjuvant chemotherapy on the prognostic factors by subgroup analysis after median follow-up time of 33 months (13-104 months). Results: The 5-year DFS and OS rates for the chemotherapy group were 93.7% and 97.5%, whereas those for the non-chemotherapy group were 89.7% and 100%. Results indicate that 5-year DFS was superior, but OS was inferior, in the former group compared with the latter group. However, no statistical significance was observed in the 5-year DFS (P=0.223) or OS (P=0.530) rate of the two groups. Most relevant poor-prognostic factors were Ki-67 overexpression and negative hormonal receptors. Cumulative survival was 98.2% vs. 86.5% between low Ki-67 (≤20%) and high Ki-67 (>20%). The hazard ratio of patients with high Ki-67 was 16.585 [95% confidence interval (CI), 1.969-139.724; P=0.010]. Meanwhile, ER(-)/PR(-) patients with MIBC had cumulative survival of 79.3% compared with 97.5% for ER(+) or PR(+) patients with MIBC. The hazard ratio for ER(-)/PR(-) patients with MIBC was 19.149 (95% CI, 3.702-99.057; P<0.001). Subgroup analysis showed that chemotherapy could improve the outcomes of ER(-)/PR(-) patients (P=0.014), but not those who overexpress Ki-67 (P=0.105). Conclusions: Patients with MIBC who overexpress Ki-67 and with negative hormonal receptors have relatively substantial risk of relapse within the first five years after surgery. However, adjuvant chemotherapy can only improve the outcomes of ER(-)/PR(-) patients, but not those who overexpress Ki-67. Further studies with prolonged follow-up of large cohorts are recommended to assess the prognostic significance and treatment of this lesion.

Unresected Breast Cancer: Evolution of Imaging Findings Following Cryoablation

Cryoablation has been used to treat both benign and malignant breast tumors. In all but one published case, cryoablation in breast cancer has been followed by post-procedural tumor resection. We present a case of an 85-year-old woman with two nonpalpable breast cancers treated with cryoablation with 18 months of mammographic, ultrasound and histologic follow-up.

A note from history: Landmarks in history of cancer, part 7

In the 2 and half decades reviewed (1970-1995), research established that chromosomal translocation, deletion, and DNA amplification are prerequisites to cancerogenesis and that oncogenes, tumor-suppressor genes, growth factors, and cytokines play crucial roles in the pathomechanism of cancer. Human papillomavirus, human immunodeficiency virus, herpes virus, and hepatitis B virus were identified as cancer-causing viruses. Several laboratory tests were developed for the detection of primary and recurrent cancers, and cancer prevention by screening methods was popularized. Sonography, computerized tomography, magnetic resonance imaging, positron emission tomography, excision of sentinel lymph nodes, and immunohistochemical techniques became routine procedures. Clinicopathologic staging and classification of tumors were standardized. Limited surgery, adjuvant and neoadjuvant chemoradiation, and the therapeutic use of monoclonal antibodies, tumor vaccines, and targeted chemotherapy became routine practice. The decline in cancer incidence and mortality demonstrated that cancer prevention and advancement in oncology are pivotal to success in the crusade against cancer. Above all, it was clearly established that the care of patients with cancer can be accomplished best in a multidisciplinary setting involving surgical oncologists, radiologists, radiation therapists, medical oncologists, surgical pathologists, and laboratory scientists. In conclusion, the 25 years from 1970 and 1995 are the high-water mark in clinical oncology, and this is the period when oncology turned from art to science.

Clinicopathologic characteristics and molecular subtypes of microinvasive carcinoma of the breast

Patients with microinvasive carcinoma often have favorable prognosis, but it remains unclear whether this special type of breast cancer represents a distinct morphological entity with its own biological features and clinical behavior distinct from those of ductal carcinoma in situ (DCIS). The study is a retrospective analysis of a large patient cohort from a single institution. One hundred and thirty one microinvasive carcinoma and 451 DCIS cases were collected. ER, PR, HER2, and Ki67 were examined by immunohistochemistry in pathological sections. We assessed the clinicopathologic characteristics, molecular features, and survival status of microinvasive carcinoma and compared to those of DCIS. Microinvasive carcinoma differed from DCIS with respect to tumor size, lymph node status, and initial presentation (P < 0.05). There was a significant difference in nuclear grade among microinvasive carcinoma of different molecular subtype (P < 0.05). The clinicalpathologic features and outcomes of patients with microinvasive carcinoma were similar to those with DCIS. The 5-year OS rate for microinvasive carcinoma and DCIS patients was 99.0 and 99.2%, respectively. A combination of pathologic, clinical, and molecular factors may ultimately reveal more powerful and robust measures for disease classification than any one modality alone. Microinvasive carcinoma does not significantly predict for worse DFS or OS in comparison with patients with DCIS.

Re-evaluating the role of sentinel lymph node biopsy in microinvasive breast carcinoma

The role of sentinel lymph node biopsy in microinvasive breast carcinoma is unclear. We examined the incidence of lymph node metastasis in patients with microinvasive carcinoma who underwent surgery at our institution. Retrospective review of our pathology database was performed (1994-2012). Of 7000 patients surgically treated for invasive breast carcinoma, 99 (1%) were classified as microinvasive carcinoma. Axillary staging was performed in 81 patients (64, sentinel lymph node biopsy; 17, axillary lymph node excision). Seven cases (9%) showed isolated tumor/epithelial cells in sentinel nodes. Three of these seven cases showed reactive changes in lymph nodes, papillary lesions in the breast with or without displaced epithelial cells within biopsy site tract, or immunohistochemical (estrogen receptor, progesterone receptor, and HER2) discordance between the primary tumor in the breast and epithelial cells in the lymph node, consistent with iatrogenically transported epithelial cells rather than true metastasis. The remaining four cases included two cases, each with a single cytokeratin-positive cell in the subcapsular sinus detected by immunohistochemistry only, and two cases with isolated tumor cells singly and in small clusters (<20 cells per cross-section) by hematoxylin and eosin and immunohistochemistry. The exact nature of cytokeratin-positive cells in the former two cases could not be determined and might still have represented iatrogenically displaced cells. In the final analysis, only two cases (3%) had isolated tumor cells. Three of these four cases had additional axillary lymph nodes excised, which were all negative for tumor cells. At a median follow-up of 37 months (range 6-199 months), none of these patients had axillary recurrences. Our results show very low incidence of sentinel lymph node involvement (3%), only as isolated tumor cells, in microinvasive carcinoma patients. None of our cases showed micrometastases or macrometastasis. We recommend reassessment of the routine practice of sentinel lymph node biopsy in patients with microinvasive carcinoma.

Incidence of and risk factors for sentinel lymph node metastasis in patients with a postoperative diagnosis of ductal carcinoma in situ

Background

Positive sentinel lymph nodes (SLNs) are found in up to 13 per cent of women with a preoperative diagnosis of ductal carcinoma in situ (DCIS) of the breast and in up to 4 per cent of those with a postoperative diagnosis. This retrospective national register study investigated the incidence of positive SLNs in women with a postoperative diagnosis of DCIS, and the value of additional tumour sectioning to identify occult tumour invasion.

Methods

All surgical patients with a final histopathological diagnosis of pure DCIS registered in the Swedish national breast cancer register in 2008 and 2009 were eligible. Additional sectioning was performed on archived primary tumour tissue from women with SLN metastasis (including cases of isolated tumour cells) and matched SLN-negative control patients with the aim of detecting occult invasion.

Results

SLN tumour deposits were reported in 11 of 753 women who had SLN biopsy (macrometastases, 2; micrometastases, 3; isolated tumour cells, 6), resulting in a SLN positivity rate of 0·7 per cent (5 of 753). Occult invasion was found in one (9 per cent) of these 11 patients and in two (10 per cent) of 21 control patients. No risk factors for SLN metastasis were identified.

Conclusion

SLN positivity is rare in women with a histopathological diagnosis of pure DCIS. Additional primary tumour assessment may reveal occult invasion in both SLN metastasis-positive and -negative patients. The value of performing SLN biopsy in the setting of a preoperative diagnosis of DCIS was limited, and current Swedish practice should therefore be questioned.

Impact of full-field digital mammography on pre-operative diagnosis and surgical treatment of mammographic microcalcification

Accurate pre-operative diagnosis of impalpable breast lesions correlates closely with the number of surgical procedures required for treatment. Correct diagnosis of mammographic microcalcification (MM) as ductal carcinoma in situ (DCIS) or invasive breast cancer is important because lesions upgraded to malignant diagnosis at surgery require repeat surgical procedures in 44 % of cases. Despite correct pre-operative diagnosis of MM, 26 % require second therapeutic operations to achieve surgical clearance. Theoretically, improved conspicuity of malignant MM using digital mammography could improve diagnostic work-up and improve surgical outcomes for MM. To determine the impact of full-field digital mammography (FFDM) on the diagnostic accuracy and positive predictive value (PPV) of biopsy of MM and surgical management of MM, screening and symptomatic cases with MM (n = 1,479) were reviewed for women imaged between August 2007 and March 2010 using screen-film mammography (SFM) (n = 711), and using FFDM, imaged between April 2010 to March 2012 (n = 768). Demographic information including pre and postoperative diagnosis, and number and types of surgical procedures were recorded. Overall, 302 (128 invasive) and 251 (110 invasive) malignant lesions were diagnosed using SFM and FFDM, respectively. Reduction in PPV of biopsy was observed (SFM 42.5 %; FFDM 32.7 %, p < 0.001). Correct pre-operative diagnosis was achieved at first attempt more often with FFDM (SFM 80.6 %; FFDM 89.5 %, p < 0.001). For lesions with pre-operative diagnosis, B5 more cases achieved surgical clearance with a single therapeutic operation with FFDM (SFM 66.3 %; FFDM 76.7 %, p = 0.017), and more lesions over 2 cm underwent mastectomy as the initial surgical procedure (SFM 47.0 %; FFDM 62.9 %, p = 0.005). Correct pre-operative diagnosis of MM using digital mammography reduced second therapeutic operations but increased mastectomy rate in larger cancers over two centimetres. This will increase concerns about treatment of lesions detected in the screening programme with widespread use of digital mammography.

Ductal carcinoma in situ of the breast: current concepts and future directions

CONTEXT

In situ carcinomas of the breast constitute 15% to 30% of all newly diagnosed breast cancer cases; 80% of these in situ lesions belong to the ductal carcinoma in situ (DCIS) category. Similar to invasive breast carcinomas, DCIS is not a single disease but rather many distinct diseases with different histopathologic and molecular characteristics, a propensity to progress to invasive disease, and differential response to treatment.

OBJECTIVE

To review the classic pathologic parameters of clinical significance and the differential diagnosis of the DCIS lesions, present our new understanding of the importance of biomarkers, and discuss innovative approaches for targeted therapy in DCIS.

DATA SOURCES

Extensive review of the relevant peer-reviewed literature.

CONCLUSIONS

In DCIS, improved understanding of the underlying biologic pathways of tumor progression is expected to lead to more accurate classification and innovative targeted treatment approaches for the management of these lesions.

Biology, treatment, and outcome in very young and older women with DCIS

BACKGROUND

This study examines a modern cohort of women with ductal carcinoma-in-situ (DCIS) in order to identify potential differences in clinical presentation, treatments, and outcome based on age.

METHODS

From 1996 to 2009, a total of 2037 patients with pure DCIS were treated. Clinical presentation, pathologic factors, type of surgery and adjuvant therapy, and local recurrence rates among age groups were compared and analyzed. Median follow-up was 5.2 years.

RESULTS

There were 132 patients (6.5 %) aged <40, 1,690 (83 %) aged 40-70, and 215 (10.5 %) aged >70. Younger patients (<40) were significantly more likely to have a family history of breast cancer, present with clinical symptoms, undergo mastectomy with immediate reconstruction, and have a contralateral prophylactic mastectomy (P < 0.05). Older patients (>70) were significantly less likely to use adjuvant radiotherapy and tamoxifen (P < 0.05). No significant differences were found in DCIS size, estrogen receptor status, necrosis, or contralateral breast cancer based on age. Among women <40, 29.3 % had evidence of multicentric disease versus 17.7 and 13.3 % in the women aged 40-70 and those >70, respectively (P = 0.004). On multivariate analysis, younger age (<40), larger-size DCIS (≥1.5 cm), and no use of radiotherapy were significant independent predictors of locoregional recurrence. The 5 year rates of local recurrence were 10.1 % in women <40 compared with 3.2 % in older women (P = 0.005).

CONCLUSIONS

Younger patients with DCIS more often have multicentric disease, present with clinical findings, and opt for or require mastectomy with immediate reconstruction. Conservative surgery is only appropriate for younger patients if adjuvant radiotherapy is delivered.

The role of breast MR imaging in pre-operative determination of invasive disease for ductal carcinoma in situ diagnosed by needle biopsy

OBJECTIVES

To evaluate whether magnetic resonance (MR) imaging features can predict the presence of occult invasion in cases of biopsy-proven pure ductal carcinoma in situ (DCIS).

METHODS

We retrospectively reviewed 92 biopsy-proven pure DCIS in 92 women who underwent MR imaging. The following MR imaging findings were compared between confirmed DCIS and invasive breast cancer (IBC): lesion size, type, morphological and kinetic assessments by ACR BI-RADS MRI, and findings of fat-suppressed T2-weighted (FS-T2W) imaging.

RESULTS

Sixty-eight of 92 (74%) were non-mass-like enhancements (NMLE) and 24 were mass lesions on MR imaging. Twenty-one of 68 (31%) NMLE and 13 of 24 (54%) mass lesions were confirmed as IBC. In NMLE lesions, large lesions (P = 0.007) and higher signal intensities (SI) on FS-T2W images (P = 0.032) were significantly associated with IBC. Lesion size remained a significant independent predictor of invasion in multivariate analysis (P = 0.032), and combined with FS-T2W SIs showed slightly higher observer performances (area under the curve, AUC, 0.71) than lesion size alone (AUC 0.68). There were no useful findings that enabled the differentiation of mass-type lesions.

CONCLUSIONS

Breast MR imaging is potentially useful to predict the presence of occult invasion in biopsy-proven DCIS with NMLE.

KEY POINTS

MR mammography permits more precise lesion assessment including ductal carcinoma in situ A correct diagnosis of occult invasion before treatment is important for clinicians This study showed the potential of MR mammography to diagnose occult invasion Treatment and/or aggressive biopsy can be given with greater confidence MR mammography can lead to more appropriate management of patients.

Bilateral DCIS following gynecomastia surgery. Role of nipple sparing mastectomy. A case report and review of literature

Bilateral ductal carcinoma in situ of breast is a very rare disease in men. Ductal carcinoma in situ (DCIS) is an abnormal proliferation that involves the ductal epithelium and it has the potential of evolving into an invasive tumour. Gynaecomastia (female like breast in men) is a benign condition though it is associated with a reported 3% incidence of unilateral invasive breast cancer.(2) Synchronous bilateral breast cancer in association with gynaecomastia is exceptionally rare. The recommended treatment for DCIS in male is mastectomy. So far only 2 cases of bilateral DCIS in male patients has been reported in the literature treated with skin and nipple sparing mastectomies. We report another case of synchronous bilateral DCIS in a male treated with skin and nipple sparing mastectomies. A 44 year-old man with history of long-standing gynecomastia. He had no identifiable risk factor for the development of cancer. His pre operative assessment of breast including mammograms was normal. He underwent bilateral subcutaneous mastectomies, with subsequent incidental diagnosis of synchronous bilateral ductal carcinoma in situ. The case was discussed in multidisciplinary team meeting and the need for further surgery was felt including excision of nipple areola complex. However considering patient wishes, cosmetic outcome and recent literature it was decided to preserve nipple areola complex (NAC) with regular follow up evaluation. Our patient at completion of 18 months of treatment is doing well with no signs of local recurrence.

Heterogeneity of focal breast lesions and surrounding tissue assessed by mammographic texture analysis: preliminary evidence of an association with tumor invasion and estrogen receptor status

AIM

This pilot study investigates whether heterogeneity in focal breast lesions and surrounding tissue assessed on mammography is potentially related to cancer invasion and hormone receptor status.

MATERIALS AND METHODS

Texture analysis (TA) assessed the heterogeneity of focal lesions and their surrounding tissues in digitized mammograms from 11 patients randomly selected from an imaging archive [ductal carcinoma in situ (DCIS) only, n = 4; invasive carcinoma (IC) with DCIS, n = 3; IC only, n = 4]. TA utilized band-pass image filtration to highlight image features at different spatial frequencies (filter values: 1.0-2.5) from fine to coarse texture. The distribution of features in the derived images was quantified using uniformity.

RESULTS

Significant differences in uniformity were observed between patient groups for all filter values. With medium scale filtration (filter value = 1.5) pure DCIS was more uniform (median = 0.281) than either DCIS with IC (median = 0.246, p = 0.0102) or IC (median = 0.249, p = 0.0021). Lesions with high levels of estrogen receptor expression were more uniform, most notably with coarse filtration (filter values 2.0 and 2.5, r(s) = 0.812, p = 0.002). Comparison of uniformity values in focal lesions and surrounding tissue showed significant differences between DCIS with or without IC versus IC (p = 0.0009).

CONCLUSION

This pilot study shows the potential for computer-based assessments of heterogeneity within focal mammographic lesions and surrounding tissue to identify adverse pathological features in mammographic lesions. The technique warrants further investigation as a possible adjunct to existing computer aided diagnosis systems.

The influence of clinicopathological features on the predictive accuracy of conventional breast imaging in determining the extent of screen-detected high-grade pure ductal carcinoma in situ

INTRODUCTION

The extent of calcified ductal carcinoma in situ (DCIS) detected by screening mammography is a determinant for treatment with breast conserving surgery (BCS). However, DCIS may be uncalcified and almost a quarter of patients with DCIS treated initially by BCS either require a second operation or are found to have unexpected invasive disease following surgery. Identification of these cases might guide selective implementation of additional diagnostic procedures.

METHODS

A retrospective review of patients with a preoperative diagnosis of pure high-grade DCIS at the Southampton and Salisbury Breast Screening Unit over a ten-year period was carried out. Mammograms were reviewed independently by a consultant radiologist and additional factors including the Breast Imaging Reporting and Data System (BI-RADS(®)) breast density score, DCIS extent and disease location within the breast recorded.

RESULTS

Unexpected invasive disease was found in 35 of 144 patients (24%). Within our unit the re-excision rate for all screen-detected DCIS is currently 23% but for patients included in this study with high-grade DCIS the re-excision rate was 39% (34/87). The extent of DCIS (p=0.008) and lack of expression of the oestrogen receptor (ER) predicted the requirement for re-excision in both univariate (p=0.004) and multivariate analysis (p=0.005).

CONCLUSIONS

High-grade DCIS may be focally uncalcified, leading to underestimation of disease extent, which might be related to ER status. Invasive foci associated with high-grade DCIS are often mammographically occult. Exploration of additional biomarkers and targeted use of further diagnostic techniques may improve the preoperative staging of DCIS.

Long-term outcomes of invasive ipsilateral breast tumor recurrences after lumpectomy in NSABP B-17 and B-24 randomized clinical trials for DCIS

BACKGROUND

Ipsilateral breast tumor recurrence (IBTR) is the most common failure event after lumpectomy for ductal carcinoma in situ (DCIS). We evaluated invasive IBTR (I-IBTR) and its influence on survival among participants in two National Surgical Adjuvant Breast and Bowel Project (NSABP) randomized trials for DCIS.

METHODS

In the NSABP B-17 trial (accrual period: October 1, 1985, to December 31, 1990), patients with localized DCIS were randomly assigned to the lumpectomy only (LO, n = 403) group or to the lumpectomy followed by radiotherapy (LRT, n = 410) group. In the NSABP B-24 double-blinded, placebo-controlled trial (accrual period: May 9, 1991, to April 13, 1994), all accrued patients were randomly assigned to LRT+ placebo, (n=900) or LRT + tamoxifen (LRT + TAM, n = 899). Endpoints included I-IBTR, DCIS-IBTR, contralateral breast cancers (CBC), overall and breast cancer-specific survival, and survival after I-IBTR. Median follow-up was 207 months for the B-17 trial (N = 813 patients) and 163 months for the B-24 trial (N = 1799 patients).

RESULTS

Of 490 IBTR events, 263 (53.7%) were invasive. Radiation reduced I-IBTR by 52% in the LRT group compared with LO (B-17, hazard ratio [HR] of risk of I-IBTR = 0.48, 95% confidence interval [CI] = 0.33 to 0.69, P < .001). LRT + TAM reduced I-IBTR by 32% compared with LRT + placebo (B-24, HR of risk of I-IBTR = 0.68, 95% CI = 0.49 to 0.95, P = .025). The 15-year cumulative incidence of I-IBTR was 19.4% for LO, 8.9% for LRT (B-17), 10.0% for LRT + placebo (B-24), and 8.5% for LRT + TAM. The 15-year cumulative incidence of all contralateral breast cancers was 10.3% for LO, 10.2% for LRT (B-17), 10.8% for LRT + placebo (B-24), and 7.3% for LRT + TAM. I-IBTR was associated with increased mortality risk (HR of death = 1.75, 95% CI = 1.45 to 2.96, P < .001), whereas recurrence of DCIS was not. Twenty-two of 39 deaths after I-IBTR were attributed to breast cancer. Among all patients (with or without I-IBTR), the 15-year cumulative incidence of breast cancer death was 3.1% for LO, 4.7% for LRT (B-17), 2.7% for LRT + placebo (B-24), and 2.3% for LRT + TAM.

CONCLUSIONS

Although I-IBTR increased the risk for breast cancer-related death, radiation therapy and tamoxifen reduced I-IBTR, and long-term prognosis remained excellent after breast-conserving surgery for DCIS.

Molecular diversity in ductal carcinoma in situ (DCIS) and early invasive breast cancer

Ductal carcinoma in situ (DCIS) is a non-invasive form of breast cancer where cells restricted to the ducts exhibit an atypical phenotype. Some DCIS lesions are believed to rapidly transit to invasive ductal carcinomas (IDCs), while others remain unchanged. Existing classification systems for DCIS fail to identify those lesions that transit to IDC. We studied gene expression patterns of 31 pure DCIS, 36 pure invasive cancers and 42 cases of mixed diagnosis (invasive cancer with an in situ component) using Agilent Whole Human Genome Oligo Microarrays 44k. Six normal breast tissue samples were also included as controls. qRT-PCR was used for validation. All DCIS and invasive samples could be classified into the "intrinsic" molecular subtypes defined for invasive breast cancer. Hierarchical clustering establishes that samples group by intrinsic subtype, and not by diagnosis. We observed heterogeneity in the transcriptomes among DCIS of high histological grade and identified a distinct subgroup containing seven of the 31 DCIS samples with gene expression characteristics more similar to advanced tumours. A set of genes independent of grade, ER-status and HER2-status was identified by logistic regression that univariately classified a sample as belonging to this distinct DCIS subgroup. qRT-PCR of single markers clearly separated this DCIS subgroup from the other DCIS, and contains samples from several histopathological and intrinsic molecular subtypes. The genes that differentiate between these two types of DCIS suggest several processes related to the re-organisation of the microenvironment. This raises interesting possibilities for identification of DCIS lesions both with and without invasive characteristics, which potentially could be used in clinical assessment of a woman's risk of progression, and lead to improved management that would avoid the current over- and under-treatment of patients.

Is radiation indicated in patients with ductal carcinoma in situ and close or positive mastectomy margins?

PURPOSE

Resection margin status is one of the most significant factors for local recurrence in patients with ductal carcinoma in situ (DCIS) treated with breast-conserving surgery with or without radiation. However, its impact on chest wall recurrence in patients treated with mastectomy is unknown. The purpose of this study was to determine chest wall recurrence rates in women with DCIS and close (<5 mm) or positive mastectomy margins in order to evaluate the potential role of radiation therapy.

METHODS AND MATERIALS

Between 1985 and 2005, 193 women underwent mastectomy for DCIS. Fifty-five patients had a close final margin, and 4 patients had a positive final margin. Axillary surgery was performed in 17 patients. Median follow-up was 8 years. Formal pathology review was conducted to measure and verify margin status. Nuclear grade, architectural pattern, and presence or absence of necrosis was recorded.

RESULTS

Median pathologic size of the DCIS in the mastectomy specimen was 4.5 cm. Twenty-two patients had DCIS of >5 cm or diffuse disease. Median width of the close final margin was 2 mm. Nineteen patients had margins of <1 mm. One of these 59 patients experienced a chest wall recurrence with regional adenopathy, followed by distant metastases 2 years following skin-sparing mastectomy. The DCIS was high-grade, 4 cm, with a 5-mm deep margin. A second patient developed an invasive cancer in the chest wall 20 years after her mastectomy for DCIS. This cancer was considered a new primary site arising in residual breast tissue.

CONCLUSIONS

The risk of chest wall recurrence in this series of patients is 1.7% for all patients and 3.3% for high-grade DCIS. One out of 20 (5%) patients undergoing skin sparing or total skin-sparing mastectomy experienced a chest wall recurrence. This risk of a chest wall recurrence appears sufficiently low not to warrant a recommendation for postmastectomy radiation therapy for patients with margins of <5 mm. There were too few patients with positive margins to draw any firm conclusions.