Explore the vast range of titles available.

BackgroundInvasive lobular carcinoma (ILC) of the breast is known for high risk of late recurrence, yet some patients still recur within 5 years of diagnosis. Determining factors associated with early/late recurrence could help tailor treatment and surveillance strategies.MethodsUsing an institutional database, we evaluated patients with ILC and ≥ 5 years of follow-up or recurrence within 5 years. We used multivariate logistic regression and the Kaplan-Meier method to evaluate which clinicopathologic features and treatment strategies were associated with recurrence < 5 years since diagnosis versus recurrence ≥ 5 years since diagnosis. Additionally, we explored the association between Clinical Treatment Score 5 (CTS5) with early versus late recurrence.ResultsAmong 513 cases of stage I–III ILC, there were 75 early and 54 late recurrences during a median follow-up period of 9.4 years. Early recurrence was associated with larger tumors (mean 4.2 cm vs. 2.9 cm, p < 0.0001), higher incidence of > 3 positive nodes (32.4% vs. 9.11%, p > 0.0001), and more aggressive tumor biology (low/negative progesterone receptor expression, higher grade, and higher Ki67). Late recurrence was associated with younger age (mean 55.6 vs. 59.2 years, p = 0.037) and elevated body mass index (BMI > 25 kg/m2 in 60.1.0% vs. 45.4%, p = 0.021). Omission of adjuvant endocrine therapy or radiotherapy after lumpectomy conferred increased risk of early rather than late recurrence.ConclusionFactors related to tumor aggressiveness and treatment were associated with early recurrence, whereas patient related factors were related to late recurrence. These data may help guide treatment strategies and surveillance approaches for patients with ILC.

Background Invasive lobular carcinoma (ILC) is the second most common subtype of breast cancer. Although mammography is known to have low sensitivity for ILC, there are no data to guide the optimal surveillance after treatment. We explored surveillance strategies after breast-conserving surgery (BCS) for ILC and determined the proportion of imaging-detected recurrences versus interval cancers. Methods From an institutional database of 813 women, we retrospectively identified patients who underwent BCS for stage I–III ILC and subsequently had a recurrence. We categorized patients by surveillance strategy and determined the modality of recurrence detection. Interval cancer rates for local recurrences were compared across surveillance strategies using the Chi-square test. We evaluated overall survival with the log-rank test and a Cox proportional hazards model. Results We included 58 patients with ILC who had a recurrence after BCS. Of these, 22 (37.9%) had local recurrence, 27 (46.6%) had distant recurrence, and 9 (15.5%) had both local and distant recurrence. Most patients underwent routine mammographic surveillance (65.2%), with 19.6% having supplemental breast magnetic resonance imaging (MRI) and 15.2% having no surveillance. The interval cancer rate was significantly higher in the mammographic surveillance group compared with the MRI surveillance group (61.9% vs. 16.7%; p  < 0.001). Conclusion In this study of patients with recurrence after BCS for primary treatment of stage I–III ILC, we found that most local recurrences were not detected by surveillance mammography. These data support further investigation of supplemental imaging beyond mammography specifically for patients with ILC who undergo BCS.

Purpose Patients with invasive lobular carcinoma (ILC) face high rates of positive margins and completion mastectomy, which can be improved with the use of specific techniques, such as oncoplastic surgery. However, prior studies have shown that type of breast cancer surgery performed is also associated with patient factors such as elevated body mass index (BMI). Thus, this study investigates whether BMI impacts the type of surgical interventions in patients with ILC. Methods A retrospective analysis of 705 patients with stage I–III ILC from an institutional database was conducted. Patients were stratified by BMI (underweight, normal weight, overweight, obese). Pearson’s Chi-square, ANOVA, and multivariable logistic regression were used to evaluate the relationship between BMI and surgical procedures. Results Breast-conserving surgery (BCS) was the initial operation in 60% of patients, with no significant difference by BMI. Among those undergoing BCS, patients with obese BMI were significantly more likely to undergo oncoplastic surgery (46.9% vs. 7.7%, 37.3%, and 33.6% for underweight, normal, and overweight, respectively, p  = 0.032). Obese BMI patients undergoing mastectomy were less likely to have reconstruction compared to those with underweight, normal weight, and overweight BMI (44.2% vs. 50%, 71.1%, and 64.1%, p  = 0.002). Conclusion Overweight/obese BMI patients with ILC underwent different surgical interventions compared to those with lower BMI. While initial BCS rates were similar, overweight/obese patients had higher oncoplastic surgery rates in BCS and lower reconstruction rates in mastectomy. Further research is needed to understand BMI’s impact on surgical decisions and outcomes in ILC.

Purpose Primary site surgery for metastatic breast cancer improves local control but does not impact overall survival. Whether histologic subtype influences patient selection for surgery is unknown. Given differences in surgical management between early-stage lobular versus ductal disease, we evaluated the impact of histology on primary site surgery in patients with metastatic breast cancer. Methods The National Cancer Database (NCDB, 2010–2016) was queried for patients with stage IV HR-positive, HER2-negative invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC). We compared clinicopathologic features, primary site surgery rates, and outcomes by histologic subtype. Multivariable Cox proportional hazard models with and without propensity score matching were used for overall survival (OS) analyses. Results In 25,294 patients, primary site surgery was slightly but significantly less common in the 6,123 patients with ILC compared to the 19,171 patients with IDC (26.9% versus 28.8%, p  = 0.004). Those with ILC were less likely to receive chemotherapy (41.3% versus 47.4%, p  < 0.0001) or radiotherapy (29.1% versus 37.9%, p <  0.0001), and had shorter OS. While mastectomy rates were similar, those with ILC who underwent lumpectomy had significantly higher positive margin rates (ILC 15.7% versus IDC 11.2%, p =  0.025). In both groups, the odds of undergoing surgery decreased over time, and were higher in younger patients with T2/T3 tumors and higher nodal burden. Conclusion Lobular histology is associated with less primary site surgery, higher positive margin rates, less radiotherapy and chemotherapy, and shorter OS compared to those with HR-positive HER2-negative IDC. These findings support the need for ILC-specific data and treatment approaches in the setting of metastatic disease.

PurposeRecent guidelines defined a new reporting category of ER-low-positive breast cancer based on immunohistochemistry (IHC). While low positivity of either hormone receptor is uncommon in invasive lobular carcinoma (ILC), we sought to investigate whether relatively low hormone receptor positivity was associated with tumor characteristics and patient outcomes in a single institutional cohort.MethodsWe searched an institutional database for cases of stage I-III ILC with available IHC reports. Based on prior published categories in ILC, ER was classified as low, medium, or high as defined by ER staining of 10–69%, 70–89%, and ≥ 90% respectively. PR low and high tumors were defined by < 20%, or ≥ 20% staining respectively. We used chi-squared tests, t-tests, and Cox proportional hazards models to evaluate associations between ER/PR categories and tumor characteristics or disease-free survival (DFS).ResultsThe cohort consisted of 707 ILC cases, with 11% of cases categorized as ER low, 15.1% as medium, and 73.8% as high. The majority (67.6%) were PR high. Patients with ER low/medium expression were significantly younger, and more likely to also have PR low and/or HER2 positive tumors compared to those that were ER high. In a Cox proportional hazards model adjusting for age, stage, grade, pleomorphic histology, and treatment, ER category was not prognostic for DFS, but PR negative and PR low status each had significantly worse DFS compared to PR high status (HR 3.5, 95% CI 1.8–6.7, p < 0.001; and HR 2.0, 95% CI 1.1–3.5, p = 0.015, respectively).ConclusionThese findings highlight the relevance of quantifying ER and PR within ILC.

While adjuvant treatment with the selective-estrogen receptor modulator (SERM) tamoxifen has been the standard of care for pre-menopausal patients with hormone receptor (HR) positive breast cancer, recent trials showed a benefit of aromatase inhibitors (AI) and ovarian function suppression (OFS) for some patients. The approach to endocrine therapy has not been well studied in pre-menopausal patients with invasive lobular carcinoma (ILC). We identified 202 pre-menopausal patients with HR positive stage I-III ILC in an institutional database. We investigated factors associated with endocrine therapy type and determined changes in systemic therapy from 1990–2021. We evaluated associations between endocrine therapy type and disease-free survival (DFS) with a multivariate Cox proportional hazards model. Of 202 patients, most (69.3%) were prescribed a SERM (99.3% tamoxifen). Those who received an AI had significantly higher stage disease. Over time, use of OFS and AI increased significantly in stage II or III cases (from 0% in 1990 to 56% after 2015 for stage II; from 0% to 80% after 2015 for stage III). Concurrently, adjuvant chemotherapy use significantly decreased in stage II cases (from 67% to 19%). In an exploratory multivariable model, longer duration of AI compared to tamoxifen was associated with significantly improved DFS (HR 0.31; 95% CI 0.11–0.86; p = 0.025). While most pre-menopausal patients received adjuvant tamoxifen, the use of OFS and AIs increased significantly over time. The association between AI use and improved DFS may be consistent with prior randomized trials and warrants further investigation into predictive factors to guide treatment selection.

OBJECTIVES/GOALS: Obesity is associated with increased incidence of breast cancer (BC), yet is not included in many lifetime-risk calculators. Obesity may impact breast cancer screening sensitivity. Retrospective studies show that bariatric surgery is associated with a lower risk of BC, but the effects of surgical weight loss on breast tissue are poorly understood. METHODS/STUDY POPULATION: We proposed a mixed-methods before and after study design to investigate the effects of surgical weight loss on breast tissue via pre- and post-weight loss breast tissue biopsies and imaging. In addition, we aimed to better understand barriers to BC screening for patients with obesity by conducting qualitative interviews. With institutional review board approval, we have begun recruiting 14 cisgender women who plan to undergo Roux-en-Y gastric bypass or sleeve gastrectomy. Participants must be at least 40 years old, with no prior history of breast biopsies or breast cancer and will undergo comprehensive breast cancer screening including mammography with quantitative density assessment, breast MRI, as well as breast core biopsies. RESULTS/ANTICIPATED RESULTS: We hypothesize that obesity and its associated metabolic changes lead to altered breast stroma, including increased inflammation, and tissue stiffness, with subsequent risk of carcinogenesis. If true, we expect to find obese women will have measurably increased inflammatory markers in their breast tissue, which are reduced after bariatric surgery. We expect that change in mammographic density may correlate with fibroglandular volume change on MRI; there are little data on change in background parenchymal enhancement in the setting of obesity and weight change and quantifying this will provide preliminary data for future work. Last, we expect that undergoing BC screening will be easier for patients after weight loss due to constraints of imaging equipment and potential bias in the screening process. DISCUSSION/SIGNIFICANCE: Screening for BC is paramount to improving outcomes yet people with obesity are screened less with worse outcomes. Studying the effects of weight loss on the breast may improve interpretation of breast imaging in the setting of obesity and identify markers of risk. Understanding barriers to screening may help us develop strategies to improve screening.