Yao, Katharine

Importance Many patients are diagnosed with atypical lesions or lobular carcinoma in situ (LCIS); however, evidence- and consensus-based guidelines for the management of many of these lesions are limited. Observations The American Society of Breast Surgeons, in collaboration with the Society of Breast Imaging and College of American Pathology, assembled a steering group to create guidelines for the management of atypical lesions and LCIS, inclusive of flat epithelial atypia (FEA), atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), classic LCIS (C-LCIS), and the variant LCIS forms pleomorphic LCIS (P-LCIS) and florid LCIS (F-LCIS). The natural history of ADH, ALH, and C-LCIS suggests that these lesions are associated with an elevated future breast cancer risk; therefore, patients diagnosed with these lesions should be recommended to undergo comprehensive risk assessment and counseling about breast cancer risk-reducing strategies. The magnitude of future breast cancer risk associated with P-LCIS and F-LCIS remains uncertain, yet if these lesions are determined to be hormone receptor positive, risk-reducing medications should be considered. There is no evidence that FEA is associated with an elevated future breast cancer risk. A second pathology review confirmation is recommended for ADH, should be considered for FEA, and is not necessary for ALH or LCIS. Currently available evidence supports the need to diagnostically excise most ADH, P-LCIS, and F-LCIS cases identified on core biopsy, although some ADH cases fulfilling strict criteria and multidisciplinary consensus can be observed. P-LCIS and F-LCIS require a negative margin, but ADH does not. ALH and C-LCIS can be safely observed if the core biopsy diagnosis is concordant with imaging features (ie, radiographic-pathologic concordance is established). Provided radiologic-pathologic concordance is confirmed, diagnostic excision is generally not indicated after a diagnosis of FEA alone. Conclusions and Relevance These guidelines provide evidence-informed, consensus-based recommendations for the management of atypical lesions of the breast, including ADH, ALH, FEA, C-LCIS, P-LCIS, and F-LCIS. Practicing clinicians who treat patients with atypical breast lesions or LCIS should consider integrating these guidelines into clinical management.

Abstract Current genomic assays provide prognostic information and guide chemotherapy decisions in early-stage hormone receptor–positive/human epidermal growth factor receptor 2–negative (HR+/HER2−) breast cancer, but limited tissue sampling may incompletely capture tumor heterogeneity. We developed and validated an image-based artificial intelligence (AI) model integrating dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and clinicopathologic features to predict recurrence risk in early-stage HR+/HER2 − breast cancer. In this retrospective multi-institutional study, the model was trained using pre-treatment imaging and clinicopathologic data from 522 patients and independently validated in 550 additional patients treated between 2010 and 2023. By analyzing spatial tumor characteristics, the model generated individualized recurrence risk scores that outperformed clinicopathologic features alone. In the validation cohort, median age was 53 years (range, 24–90), 15.6% of patients self-identified as African American, 89.7% had clinical T1–T2 disease, and 34.4% had 1–3 positive lymph nodes. Five-year recurrence-free survival was 93.8% (95% CI, 90.0–96.2%) among patients classified as low risk compared with 82.6% (95% CI, 74.8–88.1%) among those classified as high risk, corresponding to an adjusted hazard ratio of 2.28. Prognostic performance was maintained across clinically relevant subgroups, including age and nodal status. These findings support the potential of a noninvasive image-based AI approach for real-time prognostication and treatment personalization in early-stage HR+/HER2 − breast cancer.

Importance The management of infectious and inflammatory lesions of the breast remains controversial. The expert panel focused on management recommendations for 3 of the most common infectious breast conditions, as very few evidence-based guidelines for the management of these conditions exist. Observations Clinicians should distinguish between infectious and noninfectious lactational mastitis (LM) because the former often requires interventions whereas the latter requires supportive care only. Patients with infectious LM often have thick fluid collections that are not amenable to aspiration and usually require a stab incision with drain placement (but no packing) to resolve the infection. Operative drainage is only required if the patient cannot tolerate an office procedure. If a phlegmon is present, antibiotics should be prescribed for at least 10 days. The diagnosis of granulomatous mastitis (GM) requires pathology confirmation with characteristic findings on core biopsy. Cystic neutrophilic granulomatous mastitis (CNGM) is a specific form of GM associated with a granulomatous reaction to Corynebacterium infection and should be empirically treated with doxycycline. For patients without findings characteristic of CNGM and no other associated bacterium identified, there is no role for empiric antibiotic use. Granulomatous mastitis cases often recur and can take up to 18 months to resolve. Patients who have GM cases with worsening symptoms should be treated with repeated intralesional steroid injections; surgical excision or repeated aspirations should be avoided. Cases refractory to intralesional steroid injection may require oral steroids or even advanced biologic agents such as methotrexate or azathioprine. Periductal mastitis with squamous metaplasia of lactiferous ducts (PDM-SMOLD) is a distinct entity from other periductal mastitis cases that can present with recurrent abscesses and should be treated with antibiotics and aspiration for fluid collections. Operative excision for PDM-SMOLD is required for those patients who present with a fistula or recurrent episodes typically using a radial incision to remove the diseased ducts within and below the nipple. Conclusions and Relevance Evidence-informed, consensus-, and expert opinion–based guidelines for the management of infectious and inflammatory conditions of the breast were developed. Clinicians can use these guidelines to appropriately manage these conditions for which clinical care often varied in the past.

Importance Many patients are diagnosed with benign breast lesions; however, evidence- and consensus-based guidelines for the management of benign breast disease (BBD) are limited. Observations The American Society of Breast Surgeons (ASBrS) and the Society of Breast Imaging (SBI) developed guidelines for the management of benign fibroepithelial lesions (FELs) using a modified Delphi consensus methodology and public comment. There was strong consensus that core biopsy–proven concordant fibroadenomas without atypia only require excision if they were symptomatic, patient preferred, attained a certain size, or demonstrated substantive growth over time on clinical examination. There was strong consensus that when removing a fibroadenoma, complete excision without transection of the mass is recommended and surgeons should consider aesthetics, sensation, and other factors when selecting incision placement. Patients with core biopsy–proven concordant fibroadenomas do not require imaging follow-up and may return to age-appropriate screening. Many benign phyllodes tumors (BPTs) present as an FEL on core biopsy, and these lesions along with any lesions with suspicion of or concern for phyllodes tumors (PTs) require surgical excisional biopsy with complete excision of the mass. Re-excision of a BPT is not required for patients with a positive margin for BPT, but a margin re-excision may be considered if the mass was transected or there is concern of residual disease after excisional biopsy. Patients with BPT who have undergone excision do not require follow-up imaging and may return to age-appropriate screening. Conclusions and Relevance Evidence-informed, consensus and expert opinion-based guidelines for the management of benign FELs of the breast were developed. These guidelines provide clarification on the controversial management of benign FELs of the breast. Any practicing clinicians who treat patients with benign FELs should integrate these guidelines into treatment of their patients.

Abstract Background Surgical planning and local-regional treatment of breast cancer relies on accurate assessment of disease extent including the primary tumor size and the presence/absence of multiple tumor foci. As a staging modality for breast cancer, MRI has shown high sensitivity for detection of additional foci of diseases within the index breast. However, the impact of preoperative breast MRI on reducing re-excision rates and improving local control is less clear. Data from the COMICE trial in the UK suggested that routine use of pre-operative breast MRI did not alter rates of re-excision; however issues have been raised about the lack of quality standards for the MR imaging that may have resulted in the negative results of this trial. Retrospective data suggest that local recurrence is not impacted by use of breast MRI. In concert with data showing no improvement in clinical outcomes of breast cancer patients, concerns have been raised that routine use of preoperative breast MRI is associated with increased rates of mastectomy and delays to surgery. Therefore, the application of MRI for preoperative surgical staging remains controversial. In order to address this ongoing controversy, a joint effort has been launched by ACOSOG and ACRIN for a prospective clinical trial focused on evaluating the impact of preoperative breast MRI on clinically relevant patient outcomes. An important part of this collaboration is implementation of standards of how MRI findings should be clinically managed and used to direct localization methods and surgical planning, thereby creating guidelines for subsequent patient intervention. Trial design/eligibility criteria: A prospective multicenter trial will include women eligible for BCT by standard criteria and randomized between current standard of care, clinical examination and mammography (+/− ultrasound) and the same plus preoperative breast MRI. The study will focus on women at the highest risk of local recurrence: ER/PR/HER-2 negative (triple negative) and HER-2 amplified breast cancers. Specific aims: To compare the rates of local recurrence following breast conserving therapy in a cohort randomized to preoperative staging with mammography or mammography plus breast MRI. Additionally, a comparison of rates of re-operation, time to local recurrence, survival outcomes, contralateral breast cancer rates, rates of multicentric disease and other secondary aims will be performed. Costs and quality of life measures will also be investigated. Statistical methods: A stratified logrank test and Cox partial likelihood score test will be used to assess whether the distribution of LR times differs with respect to diagnostic work-up approach having adjusted for tumor stage. Cox modeling with the Cox partial likelihood score test will be used to examine the strength of association between these time to event distributions and such additional potential prognostic factors as menopausal status, chemotherapy, radiation therapy, ER, PR, number of positive lymph nodes, HER-2/neu expression, Nottingham grade, and Ki-67 expression. Target Accrual: 556 patients Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT2-05-06.