Ductal Carcinoma In Situ of the Breast: The Van Nuys Experience by Treatment

Abstract: Ductal carcinoma in situ (DCIS) represents a broad biologic spectrum of disease with a wide range of treatment approaches. A lack of clear and universally accepted treatment criteria has resulted in a diverse range of confusing clinical recommendations, distressing to both patients and clinicians. Data is presented on 543 patients treated at The Breast Center in Van Nuys, California: 228 by mastectomy, 185 by excision plus radiation therapy, and 130 by excision alone. The local recurrence-free survival at 5 years was 98% for mastectomy patients, 87% for those who received excision plus radiation therapy, and 79% for those treated with excision alone. The difference between each of the recurrence-free survival curves was statistically significant. Margin width was an important predictor of which breast preservation patients were most likely to benefit from postexcisional radiation therapy. There was no benefit from the addition of radiation therapy for patients with margin widths of 10 mm in every direction. The benefit was intermediate for patients with margin widths of 1–9 mm. Patients with margin widths less than 1 mm received the most benefit from postoperative radiation therapy. Radiation therapy is not without side effects and it should not be routinely added to every breast preservation patient's therapeutic plan. Careful consideration must be given to its risks versus its potential benefits. Numerous prognostic factors, such as nuclear grade, the presence of comedo-type necrosis, tumor size, and margin width can all be used to aid in the treatment decision-making process.     

Prognostic Factors and Local Recurrence in Patients with Ductal Carcinoma In Situ of the Breast

Abstract: Local recurrence is an important event when it occurs in a patient previously treated for ductal carcinoma in situ. Therefore, the ability to predict the probability of local recurrence after breast preservation therapy would be extremely valuable in the treatment decision-making process. In an attempt to predict the likelihood of local recurrence, 30 prognostic factors were evaluated in 622 patients with ductal carcinoma in situ treated at the Van Nuys Breast Center from 1979 through June 1996. Four factors emerged as significant independent predictors of local recurrence. These included treatment, tumor size, margin width, and pathologic classification.     

Breast-Conserving Therapy for Ductal Carcinoma in Situ: The Van Nuys Experience with Excision Plus Radiation Therapy

Abstract: The incidence of ductal carcinoma in situ (DCIS) of the breast has increased significantly in the last 15 years paralleling increases in the use of screening mammography. During that time, breast-conserving therapy for DCIS has become an established treatment option for patients with DCIS. 185 patients with pure DCIS treated with excision and radiation therapy were studied. The risk of local recurrence increased as nuclear grade or the diameter of the primary tumor increased. It decreased as margin width increased. Tumors containing predominantly comedo histology had an increased local recurrence rate when compared with noncomedo lesions. There was no difference in local recurrence rates for patients treated 4 or 5 days per week. The median time to local recurrence was 53 months. At 12 years, the actuarial local recurrence rate was 24% for all patients. The breast-cancer specific mortality over the same 12 year period was 3%. The increasing incidence of DCIS necessitates that current treatment options undergo continuous re-evaluation. Although it is likely that selected subsets of low-risk patients can be adequately treated with excision and observation, it is equally likely that patients at high risk for local recurrence will require radiation therapy as part of their management if breast preservation is chosen. Our data suggests that histologic factors such as large tumor size, narrow margin width, high nuclear grade, and comedo architecture may aid in selecting which patients require the addition of radiation therapy to their treatment regimen and which patients do not if breast preservation is chosen.     

Ductal carcinoma in situ: USC/Van Nuys Prognostic Index and the impact of margin status

As our knowledge of ductal carcinoma in situ (DCIS) continues to evolve, treatment decision-making has become increasingly complex and controversial for both patients and physicians. Treatment options include mastectomy, and breast conservation with or without radiation therapy. Data produced from the randomized clinical trials for DCIS has provided the basis for important treatment recommendations, but are not without limitations. In this article, we review our prospectively collected database consisting of 1036 patients with DCIS treated at the Van Nuys Breast Center and the USC/Norris Comprehensive Cancer Center. We review the use of the USC/Van Nuys Prognostic Index, a clinical algorithm designed to assist physicians in selection of appropriate treatments, and examine the impact of margin status as a sole predictor of local recurrence.     

An Overview of the History and Epidemiology of Ductal Carcinoma In Situ of the Breast

Abstract: Since the first pathologic studies of breast cancer were undertaken in the nineteenth century, an intraepithelial stage has been recognized in the transition from normal tissue to invasive cancer. In 1932 this was labeled in situ breast carcinoma, but was rarely diagnosed and considered only a clinical oddity. With the establishment of screening mammography over the past 20 years, both the ductal and lobular types of in situ breast carcinoma have been increasingly diagnosed. The lobular variant, lobular carcinoma in situ (LCIS), is now considered a marker of risk for subsequent invasive cancer, and is managed expectantly without surgical ablation. The ductal form, ductal carcinoma in situ (DCIS), is considered a true premalignant lesion, which should be treated largely in the same way as invasive breast carcinoma. An understanding of the epidemiology and biologic implications of DCIS is necessary for a rational approach to treatment.     

The Role of Radiotherapy for Patients with Ductal Carcinoma In Situ

Abstract: Some patients with ductal carcinoma in situ (those with small low-to moderate-grade tumors excised with wide margins) appear to be good candidates for treatment with surgery alone. There is no agreement on the exact features defining this subgroup, however. Radiotherapy will reduce the risk of recurrence further even in this subgroup. Other patients with uninvolved microscopic resection margins have a low risk of failure when treated with surgery and radiotherapy. Patients with involved margins may be at increased risk of recurrence even after irradiation, although data on this point are contradictory. Since salvage therapy for patients with local failure after initial breast conserving therapy is not perfect at preventing subsequent local-regional or distant recurrences, such patients might be more appropriately treated with mastectomy. The ultimate risk of dying of breast cancer is small for patients with DCIS, regardless of the initial treatment approach. Each patient's preferences must be accorded great weight in making treatment decisions. It is the duty of her physicians to inform her of the potential risks and benefits of all treatment options.     

The Diagnosis and Treatment of Ductal Carcinoma In Situ of the Breast

Abstract: Ductal carcinoma in situ of the breast is the most favorable presentation of breast cancer; therefore appropriate local treatment is imperative. Intraductal carcinoma is being diagnosed more frequently with the increasing use of screening mammography. A number of pathologic features have been identified which are useful for classification and for prognostic information. In addition, the molecular pathology and its relationship to tumor behavior and prognosis is becoming more well understood. The role of axillary dissection has been examined in a number of series and is generally agreed to be unnecessary for this presentation of breast cancer, allowing many women to avoid the sequela of axillary surgery. This review discusses the use of breast conservation treatment and the evolving indications for excision alone in the treatment of ductal carcinoma in situ. The outcomes for breast conservation therapy from both randomized trials and institutional series have confirmed excellent survival rates. Salvage therapy for local recurrence is frequently successful, resulting in nearly equivalent survivals in women undergoing breast conservation therapy compared to mastectomy. In addition, intriguing but preliminary results from both breast cancer prevention studies and trials looking at the use of tamoxifen for intraductal cancer suggest a local control benefit in women using the drug.     

Lobular Carcinoma In Situ of the Breast

LCIS was first described in 1941 as a distinct pathologic entity by Foote and Stewart who called it a "rare form of mammary carcinoma." It is thought to represent a transitional intra-epithelial, or in situ, stage in the evolution of breast cancer from hyperplastic breast epithelium. With the wide application of mammography, its detection has increased in recent years, being found in approximately 1% of all breast biopsy specimens and 5% of all breast malignancies. Its true incidence is unknown, because the absence of any clinical or radiographic manifestations makes its detection completely arbitrary and random. LCIS has distinct pathologic features characterized by proliferation of bland, homogeneous malignant cells within the terminal duct-lobular apparatus. The lobular architecture and investing basement membrane remain intact with no evidence of invasion into the surrounding stoma. It is assumed to be widely disseminated throughout all breast tissue whenever it is found, having close to 100% incidence of multicentricity and bilaterality. The cells are typically of low histologic and nuclear grade, highly estrogen receptor positive, and have tumor marker characteristics of indolent growth and good prognosis. This is very different from its noninvasive ductal counterpart, DCIS, which is typified by more aggressive cytologic and biologic characteristics. Although LCIS imparts as much as a 12-fold increased risk of subsequent invasive breast carcinoma, its natural history suggests it is more of a marker of risk rather than a true premalignant lesion. Most subsequent malignancies occur more than 15 years after diagnosis, and are ductal rather than lobular. This risk is also equally applied to both breasts, regardless of which breast contains the diagnosed focus. Subsequent invasive breast cancers are typically early with very low mortality, most likely due to the strict mammographic surveillance provided to these women. Although originally treated by mastectomy, most now manage LCIS by careful non-operative observation, in the same way that other risk factors such as family history or atypical hyperplasia are managed. In fact, it has been questioned whether there should be any real distinction between lobular hyperplasia and LCIS. There is no role for excision of biopsy sites of LCIS to obtain clear margins, nor for cytotoxic chemotherapy. However, the NSABP P-1 Prevention Trial strongly suggests that subsequent risk can be significantly reduced by tamoxifen. The only rational surgical treatment, if ablation is judged necessary, would be bilateral mastectomy, which appears far too aggressive in view of its low overall risks. Further investigation should clarify the optimal management of LCIS.     

Outcomes After Breast Conservation Treatment with Radiation in Women with Ductal Carcinoma In Situ and Prior Nonbreast Malignancy

Abstract:  Management of ductal carcinoma in situ (DCIS) of the breast is controversial, as not all patients progress to invasive carcinoma. This report analyzes the outcomes after breast conservation treatment (BCT) with radiation in patients with DCIS following prior malignancy at another anatomic site. The study cohort was comprised of 14 women with DCIS who were treated between 1978 and 2003. The median age at diagnosis of DCIS was 54 years (mean 56; range 37–78) and for the prior nonbreast malignancy was 44 years (mean 47; range 27–76). All patients underwent breast conservation surgery followed by whole breast radiation and tumor bed boost. The median and mean follow-up times after treatment of DCIS were 8.0 and 9.1 years, respectively (range 2–18). The median and mean interval period between the prior malignancy and DCIS was 6.0 and 8.2 years, respectively (range 1–30). There was one (7%) local failure, two (14%) contralateral breast cancers, and one (7%) death from breast cancer that occurred 7 years after BCT following contralateral invasive breast cancer. In this cohort of 14 patients treated for DCIS of the breast after a prior nonbreast malignancy, treatment for DCIS resulted in a high rate of local control and should be considered for curative intent.     

Molecular Distinction Between Atypical Ductal Hyperplasia and Ductal Carcinoma In Situ

Abstract: The increasing use of screening mammography has led to an increased detection of high-risk proliferative breast disease and premalignant breast lesions. This change in the pattern of disease presentation has highlighted the existing limitations in the understanding of the biology of these entities. It has also emphasized the significance of deficiencies involved in the morphologic recognition of the spectrum of changes that occur in precursor lesions. The criteria for morphologic distinction between atypical ductal hyperplasia (ADH) and low-grade ductal carcinoma in situ (DCIS) have remained controversial. There are also difficulties in subclassification of DCIS. To resolve some of these issues, attempts have been made to use new and emerging technologies to study these borderline breast lesions and to distinguish between ADH and DCIS. This article discusses the significance of the newly recognized biomarkers and emphasizes the need for further prospective studies.     

Apoptosis in Ductal Carcinoma in Situ of the Breast

Abstract: Programmed cell death (apoptosis) may play a role in tumor development and progression. The importance of apoptosis dysregulations in ductal carcinoma in situ (DCIS) and its relationships with p53 mutations and expression of bcl-2 has received little attention in the literature. In a series of 58 DCIS patients, we evaluated the number of apoptotic cells by the TUNEL technique in subgroups of DCIS and correlated it with immunohistochemical expression of hormone receptors, c- erb B-2, p53, bcl-2, and Ki-67 (MIB-1) and DNA content measured by image cytometry. High apoptotic index (greater than 3%) was related to high tumor grade, negative hormone receptors, c- erb B-2 overexpression, aneuploidy and lack of bcl-2 immunohistochemical stain. Apoptosis was not related to p53 or proliferative index. The findings are similar to those found in infiltrating breast cancer.     

Targeted Intraoperative Radiotherapy for the Management of Ductal Carcinoma In Situ of the Breast

Multiple long‐term studies have demonstrated a propensity for breast cancer recurrences to develop near the site of the original breast cancer. Recognition of this local recurrence pattern laid the foundation for the development of accelerated partial breast irradiation (APBI) approaches designed to limit the radiation treatment field to the site of the malignancy. However, there is a paucity of data regarding the efficacy of APBI in general, and intraoperative radiotherapy (IORT), in particular, for the management of ductal carcinoma in situ (DCIS). As a result, use of APBI, remains controversial. A prospective nonrandomized trial was designed to determine if patients with pure DCIS considered eligible for concurrent IORT based on preoperative mammography and contrast‐enhanced magnetic resonance imaging (CE‐MRI) could be successfully treated using IORT with minimal need for additional therapy due to inadequate surgical margins or excessive tumor size. Between November 2007 and June 2014, 35 women underwent bilateral digital mammography and bilateral breast CE‐MRI prior to selection for IORT. Patients were deemed eligible for IORT if their lesion was ≤4 cm in maximal diameter on both digital mammography and CE‐MRI, pure DCIS on minimally invasive breast biopsy or wide local excision, and considered resectable with clear surgical margins using breast‐conserving surgery (BCS). Postoperatively, the DCIS lesion size determined by imaging was compared with lesion size and surgical margin status obtained from the surgical pathology specimen. Thirty‐five patients completed IORT. Median patient age was 57 years (range 42–79 years) and median histologic lesion size was 15.6 mm (2–40 mm). No invasive cancer was identified. In more than half of the patients in our study (57.1%), MRI failed to detect a corresponding lesion. Nonetheless, 30 patients met criteria for negative margins (i.e., margins ≥2 mm) whereas five patients had positive margins (<2 mm). Two of the five patients with positive margins underwent mastectomy due to extensive imaging‐occult DCIS. Three of the five patients with positive margins underwent successful re‐excision at a subsequent operation prior to subsequent whole breast irradiation. A total of 14.3% (5/35) of patients required some form of additional therapy. At 36 months median follow‐up (range of 2–83 months, average 42 months), only two patients experienced local recurrences of cancer (DCIS only), yielding a 5.7% local recurrence rate. No deaths or distant recurrences were observed. Imaging‐occult DCIS is a challenge for IORT, as it is for all forms of breast‐conserving therapy. Nonetheless, 91.4% of patients with DCIS were successfully managed with BCS and IORT alone, with relatively few patients requiring additional therapy.     

Prognostic Significance of Oncogenic Markers in Ductal Carcinoma In Situ of the Breast: A Clinicopathologic Study

Abstract: Ductal carcinoma in situ (DCIS) is a heterogeneous malignant condition of the breast with an excellent prognosis. Until recently mastectomy was the standard treatment. As the results of the National Surgical Adjuvant Breast and Bowel Project‐17 trial and the introduction of the Van Nuys Prognostic Index (VNPI) less radical therapies are used. Objectives are to identify clinicopathologic and biologic factors that may predict outcome. Cases of DCIS diagnosed in two Belgian University Centers were included. Paraffin‐embedded material and Hematoxylin and Eosin stained slides of DCIS cases were reviewed and tumor size, margin width, nuclear grade, and comedo necrosis were assessed. Molecular markers (estrogen receptor, progesterone receptor, HER1‐4, Ki67, and c‐myc) were assayed immunohistochemically. Applied treatment strategies were correlated with the prospective use of the VNPI score. Kaplan–Meier survival plots were generated with log‐rank significance and multiple regression analysis was carried out using Cox proportional hazards regression analysis; 159 patients were included with a median age of 54 years (range 29–78); 141 had DCIS and 18 DCIS with microinvasion. The median time of follow‐up was 54 months (range 5–253). Twenty‐three patients developed a recurrence (14.5%). The median time to recurrence was 46 months (range 5–253). Before the introduction of the VNPI, 37.5% of the DCIS patients showed a recurrence while thereafter 6.7% recurred (p < 0.005). Two recurrences occurred in the VNPI group I (7.1%); seven in the VNPI group II (8.5%) (median time to recurrence 66.3 months) and 14 in the VNPI group III (28.5%) (median time to recurrence 40.2 months) (disease‐free survival [DFS]: p < 0.05). A Cox proportional hazards regression analysis indicated that tumor size, margin width, pathologic class, and age were independent predictors of recurrence, but none of the studied molecular markers showed this. Overexpression of HER4 in the presence of HER3 was found to be associated with a better DFS (p < 0.05). This study confirms the value of the VNPI score and questions the benefit of an aggressive approach in the low‐risk DCIS lesions. Independent predictors for recurrence included size, margin width, pathologic class, and age, but none of the molecular markers were part of it. Overexpression of HER4 in the presence of HER3 was associated with a better DFS.     

Sentinel Node Biopsy in Ductal Carcinoma In Situ Patients

Background: Sentinel lymph node (SLN) mapping is an effective and accurate method of evaluating the regional lymph nodes in breast cancer patients. The SLN is the first node that receives lymphatic drainage from the primary tumor. Patients with micrometastatic disease, previously undetected by routine hematoxylin and eosin (H&E) stains, are now being detected with the new technology of SLN biopsy, followed by a more detailed examination of the SLN that includes serial sectioning and cytokeratin immunohistochemical (CK IHC) staining of the nodes.Methods: At Moffitt Cancer Center, 87 patients with newly diagnosed pure ductal carcinoma in situ (DCIS) lesions were evaluated by using CK IHC staining of the SLN. Patients with any focus of microinvasive disease, detected on diagnostic breast biopsy by routine H&E, were excluded from this study. DCIS patients, with biopsy-proven in situ tumor by routine H&E stains, underwent intraoperative lymphatic mapping, using a combination of vital blue dye and technetium-labeled sulfur colloid. The excised SLNs were examined grossly, by imprint cytology, by standard H&E histology, and by IHC stains for CK. All SLNs that had only CK-positive cells were subsequently confirmed malignant by a more detailed histological examination of the nodes.Results: CK IHC staining was performed on 177 SLNs in 87 DCIS breast cancer patients. Five of the 87 DCIS patients (6%) had positive SLNs. Three of these patients were only CK positive and two were both H&E and CK positive. Therefore, routine H&E staining missed microinvasive disease in three of five DCIS patients with positive SLNs. In addition, DCIS patients with occult micrometastatic disease to the SLN underwent a complete axillary lymph node dissection, and the SLNs were the only nodes found to have metastatic disease. Of interest, four of the five nodepositive patients had comedo carcinoma associated with the DCIS lesion, and one patient had a large 9.5-cm low grade cribriform and micropapillary type of DCIS.Conclusions: This study confirms that lymphatic mapping in breast cancer patients with DCIS lesions is a technically feasible and a highly accurate method of staging patients with undetected micrometastatic disease to the regional lymphatic basin. This procedure can be performed with minimal morbidity, because only one or two SLNs, which are at highest risk for containing metastatic disease, are removed. This allows the pathologist to examine the one or two lymph nodes with greater detail by using serial sectioning and CK IHC staining of the SLNs. Because most patients with DCIS lesions detected by routine H&E stains do not have regional lymph node metastases, these patients can safely avoid the complications associated with a complete axillary lymph node dissection and systemic chemotherapy. However, DCIS patients with occult micrometastases of the regional lymphatic basin can be staged with higher accuracy and treated in a more selective fashion.Presented at the 52nd Annual Meeting of Society of Surgical Oncology, Orlando, Florida, March 4–7, 1999.     

Ductal Carcinoma In Situ: The Impact of Screening on Clinical Presentation and Pathologic Features

Abstract: It has been suggested that mammographic screening may produce an overdiagnosis bias leading to unnecessary treatment for inconsequential ductal-carcinomain-situ lesions. To assess the malignant potential of ductal carcinoma in situ, we compared pathologic features and presentation of ductal carcinoma in situ in patients treated before (1969–1985) and after (1986–1990) the intensified use of screening at our institution. We reviewed 204 cases of ductal carcinoma in situ in patients treated between 1969 and 1990. Histologic slides were available for 145 patients. Pathologic features evaluated included histologic subtype and nuclear grade. When the prescreening era was compared with the postscreening era, the incidence of palpable mass decreased from 54% to 12%, ductal discharge decreased from 14% to 3%, Paget's disease decreased from 10% to 3%, and mammographically detected lesions increased from 19% to 80%. The incidence of comedo subtype increased from 14% to 36% (p = 0.0195). Seven percent of palpable masses and 38% of mammographically detected ductal-carcinoma-in-situ lesions were of the comedo subtype, which presented almost exclusively as a mammographic abnormality (p < 0.0015). Grade 1 lesions decreased from 38% to 28%, and grade 3 lesions increased from 24% to 33%. Palpable masses tended to be lower grades and mammographically detected lesions tended to be higher grades. The malignant potential of mammographically detected lesions as determined by grade and histologic subtype is greater than that of symptomatic ductal carcinoma in situ. Mode of presentation does not appear to be a useful prognostic factor. Mammographically detected ductal carcinoma in situ is not an inconsequential finding and should not be treated as such.     

Ductal Carcinoma In Situ of the Breast

Ductal carcinoma in situ (DCIS) of the breast is a potentially invasive neoplasm. Risk factors include high estrogen states such as use of oral contraceptive (OC) pills, nulliparity, advanced age at first birth, and also family history and genetic mutations. The incidence of this usually clinically silent condition has risen in the past few decades due to widespread screening and diagnostic mammography, with final diagnosis confirmed by biopsy. At present, treatment options include total or simple mastectomy or lumpectomy with radiation. Adjuvant therapy includes antiestrogens like tamoxifen and human epidermal growth factor receptor 2 (HER2) suppression therapy. With the latest advances in chemotherapy and better understanding on the pathogenesis of the lesion, it is anticipated that more effective modalities of treatment may soon be available.     

The University of Southern California/Van Nuys prognostic index for ductal carcinoma in situ of the breast

BACKGROUND: The original Van Nuys prognostic index (VNPI) was introduced in 1996 as an aid to the complex treatment decision-making process for patients with ductal carcinoma in situ (DCIS) of the breast. This update adds patient age to the previous predictors of local recurrence in breast preservation patients. METHODS: A prospective database consisting of 706 conservatively patients with DCIS was examined using multivariate analysis. Four independent predictors of local recurrence (tumor size, margin width, pathologic classification, and age) were used to derive a new formula for the University of Southern California (USC)/VNPI. RESULTS: In all, 706 patients with pure DCIS were treated with breast preservation. There was no statistical difference in the 12-year local recurrence-free survival in patients with USC/VNPI scores of 4, 5, or 6, regardless of whether or not radiation therapy was used (P = not significant). Patients with USC/VNPI scores of 7, 8, or 9 received a statistically significant average 12% to 15% local recurrence-free survival benefit when treated with radiation therapy (P = 0.03). Patients with scores of 10, 11, or 12, although showing the greatest absolute benefit from radiation therapy, experienced local recurrence rates of almost 50% at 5 years. CONCLUSIONS: Ductal carcinoma in situ patients with USC/VNPI scores of 4, 5 or 6 can be considered for treatment with excision only. Patients with intermediate scores (7, 8, or 9) should be considered for treatment with radiation therapy or be reexcised if margin width is less than 10 mm and cosmetically feasible. Patients with USC/VNPI scores of 10, 11, or 12 exhibit extremely high local recurrence rates, regardless of irradiation, and should be considered for mastectomy, generally with immediate reconstruction or reexcision if technically possible.     

Squamous Cell Carcinoma In Situ of the Breast: Report of a Case

We present the case of a 73‐year‐old woman with pure squamous cell carcinoma in situ of the left breast. This non‐invasive malignancy exhibited pure squamous type of architectural and cytologic features without any evidence of glandular differentiation either in the initial needle core biopsy or in the subsequently performed excisional biopsy and simple mastectomy. The tumor spanned 1.6 cm, involved numerous ducts and terminal ducts and extended into lobules, and was characterized by keratinizing squamous cells with intermediate‐grade nuclei. Intercellular bridges extended between the malignant squamous cells. Keratinous debris with “pearl” formation was evident in most involved glands. No invasive carcinoma was identified. There was no evidence of metastatic disease in the ipsilateral sentinel lymph nodes. Thus far, only three cases of squamous cell carcinoma in situ of the breast have been reported in one series—none of which showed any evidence of recurrent or metastatic disease at last follow‐up. In our case, treated exclusively by surgery, there was no evidence of disease 11 years after diagnosis.     

Role of Preoperative Breast MRI in Ductal Carcinoma In Situ for Prediction of the Presence and Assessment of the Extent of Occult Invasive Component

Ductal carcinoma in situ (DCIS) is a common neoplasm that may be associated with focal invasive breast cancer lesions. The aim of our study was to evaluate the role of preoperative magnetic resonance imaging (MRI) in determining occult invasive presence and disease extent in patients with preoperative diagnosis of pure DCIS. We analyzed 125 patients with postoperative pure DCIS (n = 91) and DCIS plus invasive component (n = 34). Diagnostic mammography (MRX) showed a size underestimation rate of 30.4% while MRI showed an overestimation rate of 28.6%. Comparing the mean absolute error between preoperative MRI and MRX evaluations and final disease extent, MRI showed an improved accuracy of 51.2%. In our analysis preoperative breast MRI showed a better accuracy in predicting postoperative pathologic extent of disease, adding strength to the growing evidences that preoperative MRI can lead to a more appropriate management of DCIS patients.