Omission of Breast Surgery in Exceptional Responders

Residual microcalcifications after neoadjuvant systemic therapy for early breast cancer: Implications for surgical planning and long-term outcomes

Residual microcalcifications on mammograms after neoadjuvant chemotherapy (NACT) pose a challenge in surgical decision-making. This single-centre retrospective review of all patients who had NACT for breast cancer over five years, evaluated the relationship between pathological complete response and residual microcalcifications, controlling for tumour size, nodal stage, grade, and receptor status, as well as the impact of residual microcalcifications on recurrence and survival. There was no significant association between pathological complete response (pCR) and residual microcalcifications (p = 0.763). We computed hazard ratios (HR) for Time to recurrence (TTR) and overall survival (OS) which were both not significant, with HR = 2.599, [0.290, 23.264], p = 0.393 and HR = 1.362 [0.123, 15.062], p = 0.801 respectively. The predictive and prognostic significance of residual microcalcifications remains to be proven. The surgical excision of these lesions should be considered based on individual patient risk.

Prediction model for individualized precision surgery in breast cancer patients with complete response on MRI and residual calcifications on mammography after neoadjuvant chemotherapy

BACKGROUND

Identifying whether there is residual carcinoma in remaining suspicious calcifications after neoadjuvant chemotherapy (NAC) in breast cancer patients can provide crucial information for surgeons in determining the most appropriate surgical approach. Therefore, we investigated factors predicting calcifications without residual carcinoma (ypCalc_0) or with residual carcinoma (ypCalc_ca) and aimed to develop a prediction model for patients exhibiting residual suspicious calcifications on mammography but complete response on MRI after NAC.

METHODS

This retrospective study included breast cancer patients undergoing NAC, showing residual suspicious mammographic calcifications but complete response on MRI between January 2019 and December 2020 (development set) and between January 2021 and December 2022 (validation set). Multivariable logistic regression analysis identified significant factors associated with ypCalc_0. The prediction model, developed using a decision tree and factors from logistic regression analysis, was validated in the validation set.

RESULTS

The development set included 134 women (mean age, 50.6 years; 91 with ypCalc_0 and 43 with ypCalc_ca) and validation set included 146 women (mean age, 51.0 years; 108 with ypCalc_0 and 38 with ypCalc_ca). Molecular subtype (P = .0002) and high Ki-67 (P = .02) emerged as significant independent factors associated with ypCalc_0 in the development set. The prediction model, incorporating hormone receptor (HR)-/human epidermal growth factor receptor 2 (HER2)+ with high Ki-67 as ypCalc_0 predictors, and HR+/HER2- cancers or HR+/HER2+ or triple-negative (TN) cancers with low Ki-67, as ypCalc_ca predictors, achieved an area under receiver operating characteristic curve of 0.844 (95% CI 0.774-0.914) in the validation set.

CONCLUSION

Minimized surgery may be considered for managing residual calcifications in HR-/HER2+ with high Ki-67 cancers, while complete excision is recommended for HR+/HER2- breast cancers or for HR+/HER2+or TN breast cancers with low Ki-67.

Omission of breast surgery in selected breast cancer patients with excellent response to neoadjuvant systemic therapy

Modern neoadjuvant systemic therapy (NST) can result in high pathologic complete response rates (pCR) in triple negative (TN) and human epidermal growth factor receptor 2 positive (HER2+) breast cancer. The role of surgery is, therefore, being reconsidered in this rapidly evolving field. This report presents oncological outcomes of seven patients with TN or HER2+ breast cancer, with exceptional response to NST, and a post-NST image-guided vacuum assisted biopsy showing no residual disease (ypT0), who opted not to have breast surgery. The median age was 49 (IQR 36-61) years and the median tumour size at diagnosis was 50 (IQR 16-65) mm. All patients received breast radiotherapy and continued adjuvant systemic therapies as appropriate. At a median follow-up of 67 (IQR 61-77) months, all patients were alive and free of disease. This small case series supports the need for further research in 'exceptional responders' to provide safe, individualized patient-centred care.