Quality assessment of neoadjuvant therapy use in breast conservation: barriers to implementation

Characterizing Response to Neoadjuvant Chemotherapy in Invasive Lobular Breast Carcinoma

BACKGROUND

Pathological complete response (pCR) after neoadjuvant chemotherapy (NCT) for breast cancer is associated with improved survival and facilitates conservative surgical strategies. Invasive lobular carcinoma (ILC) has been observed to have decreased response to NCT compared with invasive ductal carcinoma (IDC). This study seeks to evaluate national trends in the use of NCT for ILC compared with IDC, and determine if there is a subset of ILC patients who demonstrate favorable response rates.

METHODS

This is a study using the National Cancer Database. The cohort consisted of patients with stage 1-3 ILC treated between 2010 and 2014, and a reference cohort of patient with IDC. For patients receiving NCT, pCR was assessed and clinically relevant variables were used in multivariable logistic regression models for each histologic subtype, modeling for pCR achievement. Survival analysis was performed for each histologic group to evaluate potential survival benefits of achieving pCR.

RESULTS

Our study cohort consisted of 384,887 women, of which 9.7% had ILC. A significantly lower rate of pCR after NCT was found in the cases of ILC compared with those of IDC (8.7% versus 23.2%). Increased response was seen in ILC patients with HER2-positive and TNBC subtypes. A survival benefit was demonstrated in patients with ILC who achieved pCR.

CONCLUSIONS

While response to NCT in patients with ILC is uncommon, our findings demonstrate a selective benefit for patients with HER2-positive tumors and TNBC. In addition, pCR is correlated with a clear survival advantage in ILC.

Breast-conserving surgery in locally advanced breast cancer submitted to neoadjuvant chemotherapy. Safety and effectiveness based on ipsilateral breast tumor recurrence and long-term follow-up

OBJECTIVE:

To evaluate ipsilateral breast tumor recurrence after breast-conserving surgery for locally advanced breast cancer.

METHODS:

A retrospective observational cohort study was performed in patients with locally advanced breast cancer submitted to breast-conserving surgery after neoadjuvant chemotherapy based on an adriamycin-cyclophosphamide-paclitaxel regimen. We evaluated the clinical, pathologic, immunohistochemistry, and surgical factors that contribute to ipsilateral breast tumor recurrence and locoregional recurrence. A Kaplan-Meier analysis and Cox model were used to evaluate the main factors related to disease-free survival.

RESULTS:

Of the 449 patients who received neoadjuvant chemotherapy, 98 underwent breast-conserving surgery. The average diameter of the tumors was 5.3 cm, and 87.2% reached a size of up to 3 cm. Moreover, 86.7% were classified as clinical stage III, 74.5% had T3-T4 tumors, 80.5% had N1-N2 axilla, and 89.8% had invasive ductal carcinoma. A pathologic complete response was observed in 27.6% of the tumors, and 100.0% of samples had free margins. The 5-year actuarial overall survival rate was 81.2%, and the mean follow-up was 72.8 months. The rates of ipsilateral breast tumor recurrence and locoregional recurrence were 11.2% and 15.3%, respectively. Multifocal morphology response was the only factor related to ipsilateral breast tumor recurrence disease-free survival (p=0.04). A multivariate analysis showed that the pathologic response evaluation criteria in solid tumors (RECIST)-breast cutoff was the only factor related to locoregional recurrence disease-free survival (p=0.01).

CONCLUSIONS:

Breast-conserving surgery is a safe and effective therapy for selected locally advanced breast tumors.

Utilization of neoadjuvant chemotherapy varies in the treatment of women with invasive breast cancer

BACKGROUND

Treatment with neoadjuvant chemotherapy (NAC) has made it possible for some women to be successfully treated with breast conservation therapy (BCT ) who were initially considered ineligible. Factors related to current practice patterns of NAC use are important to understand particularly as the surgical treatment of invasive breast cancer has changed. The goal of this study was to determine variations in neoadjuvant chemotherapy use in a large multi-center national database of patients with breast cancer.

METHODS

We evaluated NAC use in patients with initially operable invasive breast cancer and potential impact on breast conservation rates. Records of 2871 women ages 18-years and older diagnosed with 2907 invasive breast cancers from January 2003 to December 2008 at four institutions across the United States were examined using the Breast Cancer Surgical Outcomes (BRCASO) database. Main outcome measures included NAC use and association with pre-operatively identified clinical factors, surgical approach (partial mastectomy [PM] or total mastectomy [TM]), and BCT failure (initial PM followed by subsequent TM).

RESULTS

Overall, NAC utilization was 3.8%l. Factors associated with NAC use included younger age, pre-operatively known positive nodal status, and increasing clinical tumor size. NAC use and BCT failure rates increased with clinical tumor size, and there was significant variation in NAC use across institutions. Initial TM frequency approached initial PM frequency for tumors >30-40 mm; BCT failure rate was 22.7% for tumors >40 mm. Only 2.7% of patients undergoing initial PM and 7.2% undergoing initial TM received NAC.

CONCLUSIONS

NAC use in this study was infrequent and varied among institutions. Infrequent NAC use in patients suggests that NAC may be underutilized in eligible patients desiring breast conservation.