Outcomes of Margin Reexcision after Oncoplastic Breast Reduction.

Tissue rearrangement after an oncoplastic breast reduction may complicate identification of margins during reexcision. Little is known about outcomes of reoperation in this setting. Methods: This is a single-institution, retrospective analysis of outcomes of margin reexcisions after lumpectomy with concurrent oncoplastic Wise-pattern reduction from 2015 to 2020. Outcomes assessed were the rate of successful breast conservation, in-breast recurrence, wound issues or complications, effect on cosmesis, and delay to onset of adjuvant therapy. Results: From 2015 to 2020, 649 patients underwent lumpectomy with oncoplastic Wise-pattern reduction. Forty-seven patients (7.2%) had greater than or equal to one positive margin(s); of these, 28 went directly to mastectomy, and 19 underwent margin reexcision. Residual disease was found in seven of 19 patients (37%) at reexcision. The rate of successful breast-conserving therapy was 95% with a mean follow-up of 31 months. There was one (5%) in-breast recurrence (invasive ductal carcinoma [IDC] occurring 30 months after the original operation); this patient had a mastectomy for treatment of her recurrence. The overall complication rate was 37%. Radiation was administered to 18 patients (95%), and two patients (11%) had delay of radiation past 6 weeks due to wound complications. Of the 14 patients with photographs available, 12 of 14 patients (86%) were blindly assessed to have equivalent or better cosmesis after margin reexcision (versus initial lumpectomy). Conclusion: Margin reexcision after oncoplastic breast reduction with Wise-pattern is feasible and effective, and can be done without compromising the initial cosmetic results.

A Validated Model for Identifying Patients Unlikely to Benefit From the 21-Gene Recurrence Score Assay.

BACKGROUND: Predicting recurrence risk and chemotherapy benefit in early-stage breast cancer can be challenging, and Oncotype DX (ODX) is often used to gain insight. However, it is still unclear whether ODX can benefit in all cases. To clarify ODX's usefulness we sought to develop a model using readily available pathologic markers to help clinicians make that determination. PATIENTS AND METHODS: Clinical pathologic data from 221 hormone receptor-positive, HER2-negative invasive breast cancer patients was used to create a model. The model was then validated on a second institution's set of 319 patients. RESULTS: The model has 2 simple rules: low grade and positive progesterone receptor tumors (LG+PR) are low risk, and high grade or low estrogen receptor (ER) (ER < 20%) tumors (HG/LER) are high risk. The TAILORx (Trial Assigning Individualized Options for Treatment (Rx)) trial thresholds of Recurrence Score (RS) ≤ 10, when chemotherapy is of little benefit, and RS ≥ 26 when chemotherapy might be beneficial were used to judge model performance. Impressively, the misclassifications of an HG/LER patient who has an RS ≤ 10 were 0% and 2%, and for LG+PR patients who had an RS ≥ 26 were 0% and 2.6%. In the validation set, 28% (66 of 232) of the indeterminate group (neither in the HG/LER nor the LG+PR groups) had an RS ≤ 10 or an RS ≥ 26; this group might clinically benefit from ODX. CONCLUSION: A simple 2-rule model based on readily available pathologic data was developed and validated, which categorized patients into high and low risk for recurrence. Identification of patients who are unlikely to benefit from ODX testing could result in significant cost avoidance.

Does breast tumor heterogeneity necessitate further immunohistochemical staining on surgical specimens?

BACKGROUND: Prognostic and predictive tumor markers in breast cancer are most commonly performed on core needle biopsies (CNB) of the primary tumor. Because treatment recommendations are influenced by these markers, it is imperative to verify strong concordance between tumor markers on CNB specimens and the corresponding surgical specimens (SS). STUDY DESIGN: A prospective study was performed on 165 women (205 samples) with breast cancer diagnosed from January 2009 to July 2011. Tumor type, grade, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor 2 (HER2), and Ki67 expression by immunohistochemical (IHC) testing were retrospectively analyzed in the CNB and SS. Contingency tables and agreement modeling were performed. RESULTS: There was substantial agreement between the CNB and SS for PR% and HER2; moderate agreement for tumor type, grade, and ER%; and fair agreement for Ki67%. In 8% of patients (n = 13), tumor heterogeneity was seen. In heterogeneous tumors the overall concordance between the CNB and SS was worse, especially for HER2. Six of these patients had areas of tumor that were positive for HER2, which were not detected in their CNBs. Nine patients had multiple distinct molecular subtypes within their tumor(s). CONCLUSIONS: The heterogeneous distribution of antigens in breast cancer tumors raises concern that the CNB may not adequately represent the true biologic profile in all patients. There is strong concordance for tumor type, ER, and PR between CNB and SS (although a quantitative decline was noted from CNB to SS); however, HER2 activity does not appear to be adequately detected on CNB in patients with heterogeneous tumors. These data suggest that IHC testing on the CNB alone may not be adequate to tailor targeted therapy in all patients.