Superparamagnetic iron oxide (SPIO) for axillary mapping in patients with ductal carcinoma in situ undergoing mastectomy: single-institution experience.

PURPOSE: Unnecessary axillary surgery can potentially be avoided in patients with DCIS undergoing mastectomy. Current guidelines recommend upfront sentinel lymph node biopsy during the index operation due to the potential of upstaging to invasive cancer. This study reviews a single institution's experience with de-escalating axillary surgery using superparamagnetic iron oxide dye for axillary mapping in patients undergoing mastectomy for DCIS. METHODS: This is a retrospective single-institution cross-sectional study. All medical records of patients who underwent mastectomy for a diagnosis of DCIS from August 2021 to January 2023 were reviewed and patients who had SPIO injected at the time of the index mastectomy were included in the study. Descriptive statistics of demographics, clinical information, pathology results, and interval sentinel lymph node biopsy were performed. RESULTS: A total of 41 participants underwent 45 mastectomies for DCIS. The median age of the participants was 58 years (IQR = 17; range 25 to 76 years), and the majority of participants were female (97.8%). The most common indication for mastectomy was diffuse extent of disease (31.7%). On final pathology, 75.6% (34/45) of mastectomy specimens had DCIS without any type of invasion and 15.6% (7/45) had invasive cancer. Of the 7 cases with upgrade to invasive disease, 2 (28.6%) of them underwent interval sentinel lymph node biopsy. All sentinel lymph nodes biopsied were negative for cancer. CONCLUSION: The use of superparamagnetic iron oxide dye can prevent unnecessary axillary surgery in patients with DCIS undergoing mastectomy.

Changes in Surgical Management of the Axilla Over 11 Years - Report on More Than 1500 Breast Cancer Patients Treated with Neoadjuvant Chemotherapy on the Prospective I-SPY2 Trial.

BACKGROUND: Axillary surgery after neoadjuvant chemotherapy (NAC) is becoming less extensive. We evaluated the evolution of axillary surgery after NAC on the multi-institutional I-SPY2 prospective trial. METHODS: We examined annual rates of sentinel lymph node (SLN) surgery with resection of clipped node, if present), axillary lymph node dissection (ALND), and SLN and ALND in patients enrolled in I-SPY2 from January 1, 2011 to December 31, 2021 by clinical N status at diagnosis and pathologic N status at surgery. Cochran-Armitage trend tests were calculated to evaluate patterns over time. RESULTS: Of 1578 patients, 973 patients (61.7%) had SLN-only, 136 (8.6%) had SLN and ALND, and 469 (29.7%) had ALND-only. In the cN0 group, ALND-only decreased from 20% in 2011 to 6.25% in 2021 (p = 0.0078) and SLN-only increased from 70.0% to 87.5% (p = 0.0020). This was even more striking in patients with clinically node-positive (cN+) disease at diagnosis, where ALND-only decreased from 70.7% to 29.4% (p < 0.0001) and SLN-only significantly increased from 14.6% to 56.5% (p < 0.0001). This change was significant across subtypes (HR-/HER2-, HR+/HER2-, and HER2+). Among pathologically node-positive (pN+) patients after NAC (n = 525) ALND-only decreased from 69.0% to 39.2% (p < 0.0001) and SLN-only increased from 6.9% to 39.2% (p < 0.0001). CONCLUSIONS: Use of ALND after NAC has significantly decreased over the past decade. This is most pronounced in cN+ disease at diagnosis with an increase in the use of SLN surgery after NAC. Additionally, in pN+ disease after NAC, there has been a decrease in use of completion ALND, a practice pattern change that precedes results from clinical trials.

Positive margins after mastectomy in patients with invasive lobular carcinoma of the breast: Incidence and management strategies.

BACKGROUND: Surgical treatment of invasive lobular carcinoma (ILC) is challenging due to its diffuse growth pattern, and the positive margin rate after mastectomy is poorly described. METHODS: We retrospectively determined the positive margin rate in those with stage I-III ILC undergoing mastectomy. We evaluated the relationship between management strategy and recurrence free survival (RFS). RESULTS: In 357 patients, the positive margin rate was 10.6% overall and 18.7% in those with T3 tumors. Having a positive margin was associated with significantly shorter RFS on multivariate analysis (p = 0.01). Undergoing additional local treatment (radiation or re-excision) for a positive margin was significantly associated with improved RFS (p = 0.004). Older women with positive margins were significantly less likely to undergo additional local therapy. CONCLUSIONS: Even mastectomy fails to clear margins in a high proportion of patients with large ILC tumors, a finding which may warrant testing neoadjuvant strategies even prior to planned mastectomy.

Oncological Outcomes of Total Skin-Sparing Mastectomy for Invasive Lobular Carcinoma of the Breast: A 20-Year Institutional Experience.

BACKGROUND: Although rates of total skin-sparing (nipple-sparing) mastectomies are increasing, the oncologic safety of this procedure has not been evaluated in invasive lobular carcinoma (ILC). ILC is the second most common type of breast cancer, and its diffuse growth pattern and high positive margin rates potentially increase the risk of poor outcomes from less extensive surgical resection. METHODS: We compared time to local recurrence and positive margin rates in a cohort of 300 patients with ILC undergoing either total skin-sparing mastectomy (TSSM), skin-sparing mastectomy, or simple mastectomy between the years 2000-2020. Data were obtained from a prospectively maintained institutional database and were analyzed by using univariate statistics, the log-rank test, and multivariate Cox proportional hazards models. RESULTS: Of 300 cases, mastectomy type was TSSM in 119 (39.7%), skin-sparing mastectomy in 52 (17.3%), and simple mastectomy in 129 (43%). The rate of TSSM increased significantly with time (p < 0.001) and was associated with younger age at diagnosis (p = 0.0007). There was no difference in time to local recurrence on univariate and multivariate analysis, nor difference in positive margin rates by mastectomy type. Factors significantly associated with shorter local recurrence-free survival were higher tumor stage and tumor grade. CONCLUSIONS: TSSM can be safely offered to patients with ILC, despite the diffuse growth pattern seen in this tumor type.

The Evolution of Our Understanding of the Biology of Cancer Is the Key to Avoiding Overdiagnosis and Overtreatment.

There has been a tremendous evolution in our thinking about cancer since the 1880s. Breast cancer is a particularly good example to evaluate the progress that has been made and the new challenges that have arisen due to screening that inadvertently identifies indolent lesions. The degree to which overdiagnosis is a problem depends on the reservoir of indolent disease, the disease heterogeneity, and the fraction of the tumors that have aggressive biology. Cancers span the spectrum of biological behavior, and population-wide screening increases the detection of tumors that may not cause harm within the patient's lifetime or may never metastasize or result in death. Our approach to early detection will be vastly improved if we understand, address, and adjust to tumor heterogeneity. In this article, we use breast cancer as a case study to demonstrate how the approach to biological characterization, diagnostics, and therapeutics can inform our approach to screening, early detection, and prevention. Overdiagnosis can be mitigated by developing diagnostics to identify indolent disease, incorporating biology and risk assessment in screening strategies, changing the pathology rules for tumor classification, and refining the way we classify precancerous lesions. The more the patterns of cancers can be seen across other cancers, the more it is clear that our approach should transcend organ of origin. This will be particularly helpful in advancing the field by changing both our terminology for what is cancer and also by helping us to learn how best to mitigate the risk of the most aggressive cancers.See all articles in this CEBP Focus section, "NCI Early Detection Research Network: Making Cancer Detection Possible."

Should we operate for an intra-abdominal emergency in the setting of disseminated cancer?

BACKGROUND: Patients with advanced cancer and an abdominal surgical emergency pose a dilemma, because rescue surgery may be futile. This study defines morbidity and mortality rates and identifies preoperative risk factors that may predict outcome. METHODS: The National Surgical Quality Improvement Program database was queried for patients with disseminated cancer undergoing emergent abdominal surgery (2005-2012). Preoperative variables were used for prediction models for 30-day major morbidity and mortality. A tree model and logistic regression were used to find factors associated with outcomes. A training dataset was analyzed and then model performance was evaluated on a validation dataset. RESULTS: Study patients had an overall 30-day major morbidity and mortality rate of 48.8% and 26%, respectively. The classification tree model for prediction for a morbidity involved the following variables: sepsis, albumin, functional status, and transfusion (misclassification rate, 36%). The tree model for mortality showed that an American Society of Anesthesiologists (ASA) score of 4 or 5 with a dependent functional status to be predictive of mortality (misclassification rate, 24%). There was agreement between models for predictive variables. CONCLUSION: The decision to operate for an abdominal emergency in the setting of disseminated cancer is difficult. Our study confirms the high risk for morbidity and mortality in this population. Preoperative factors including sepsis, increased ASA class, low serum albumin level, and patient functional dependence all predict poor outcomes.