Background

Although the survival benefit of dual epidermal growth factor receptor 2 (HER2) blockade with trastuzumab and pertuzumab was definitely demonstrated in HER2-amplified early breast cancer, sufficient biomarkers are urgently required to explain the heterogeneous response to dual HER-2 blockade therapy. The prognostic significance of immune infiltration in TRYPHAENA trial was investigated to tailor treatment in current analysis.

Methods

Among the 225 HER2-amplified early breast cancer patients randomly assigned to trastuzumab/pertuzumab concurrently or sequentially with standard chemotherapy as neoadjuvant therapy in TRYPHAENA trial, 162 patients with available gene expression profile and complete follow-up data were enrolled. The normalized gene expression matrix (GSE109710) based on the NanoString nCounter array was downloaded from Gene Expression Omnibus database and further used to estimate the immune infiltration score (IIS) for each patient by the Immune Cell Abundance Identifier tool. A cut-off of IIS to stratify patients was determined by the R-based survminer package. Multivariable Cox proportional event-free survival (EFS) hazard ratios were preformed.

Results

Among the 162 women included in the analysis (median [range] age, 49.0 [27-81] years), the pathologic complete response (pCR) rate was 50.0% (21/42) in patients with a high IIS (>0.628) and 66.7% (80/120) in patients with a low SII (≤0.628). At a median follow-up of 4.7 years, the multivariable-adjusted hazard ratio for EFS was 2.933 (95%CI, 1.223-7.033) for the high IIS and 0.356 (95%CI, 0.127- 0.999) in patients who achieved pCR, respectively. Table: 7P

Cox regression for EFS

Conclusions

Our analysis demonstrates an independent prognostic value of IIS in patients receiving trastuzumab/pertuzumab-based neoadjuvant chemotherapy.

Clinical trial identification

NCT00976989.

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.

Background

Mastectomy is the most common type of surgery after neoadjuvant chemotherapy (NACT). We aimed to characterize the factors associated with mastectomy even after good response to NACT.

Methods

Women treated with NACT in Stockholm between 2007-2017 (N=1463) were identified in the Swedish National Quality Register for Breast Cancer. Logistic regression analyses were used to identify factors associated with mastectomy in women with small residual tumor, defined as ypT≤20 mm in the mastectomy specimen. The ratio between tumor volume (including all foci and cancer in situ) and excised breast volume was calculated in order to describe the tumor-affected proportion on a randomly selected subset of women having a mastectomy (n=136).

Results

A total of 1041 women (71.2%) underwent mastectomy and 422 (28.8%) breast conserving surgery (BCS). In the mastectomy group, 551 (52.9%) had a residual invasive tumor extent of ≤20 mm. Factors independently associated with having a mastectomy and ypT≤20 mm after NACT were diagnosis in the earlier study periods [2007-2010 (OR 11.09, 95% CI 6.42-19.16, p<.001) and 2011-2014 (OR 2.92, 95% CI 2.10-4.07, p<.001)], younger age [age <40 (OR 2.08, 95% CI 1.39-3.13, p<.001) and age 40-49 (OR 1.61, 95% CI 1.12-2.32, p=.011)], large tumor size at diagnosis [cT3 (OR 4.25, 95% CI 2.47-7.31, p<.001) and cT4 (OR 7.42, 95% CI 2.25-24.52, p=.001)], pre-treatment biopsy being PR negative (OR 1.55, 95% CI 1.04-2.31, p=.032) or HER2 positive (OR 1.51, 95% CI 1.10-2.06, p=.011). After a median follow-up time of 3.5 years, local relapse rate was 3.3% (14/422), 3.8% (21/551) and 5.7% (28/490) in the BCS, mastectomy with ypT≤20 mm and mastectomy with ypT>20 mm groups respectively (p=.158). Only 10.3% (14/136) of women who had undergone mastectomy had >10% of breast volume consisting of tumor.

Conclusions

In this population-based study, mastectomy after NACT was commonly used even in women with good tumor response, especially in younger women and tumours with certain high-risk features. However, a strong trend of more BCS is seen in the more recent years of the study period without compromising local disease control.

Legal entity responsible for the study

Karolinska Institutet.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.

Background

Non-mass enhancing breast lesions pose a diagnostic dilemma and a clinical challenge that are encountered commonly in clinical practice. Suspicion of breast cancer makes it an important entity for a radiologist and medical oncologist.

Methods

All patients with clinical suspicion of Breast disease were included in the study. MRI reveals MR-BIRADS 4 and 5 non mass enhancing lesions and further underwent biopsy/post MRM/BCS/lumpectomy in our hospital. After inclusion/exclusion criteria clinically meaningful 128 non-mass lesions were assessed further for distribution pattern, internal enhancement pattern and kinetics.

Results

128 non-mass lesions were analyzed in n= 127 patients. 83 lesions were malignant and MR-BIRADS 5 category dominated (66/128, 51.5 %). Most common pattern of distribution/internal enhancement/curve type were segmental (47, 36.72%), clumped (64, 50%) and washout curve type (99, 77.34%) respectively. Regarding association with malignancy, odds ratio of lesions with segmental/regional/multiple regional distribution pattern was 13.5 (95% CI= 5.6-32.5), clumped/clustered ring internal enhancement pattern was 43.07 (95% CI= 14.3-129.6) and washout curve type was 17.8 (95% CI= 6.0-52.3). The sensitivity of the washout curve type for diagnosis of malignancy was 93.9%. The specificity of clumped/clustered ring internal enhancement pattern was 88.9%.

Conclusions

Segmental/regional/multiple regional distribution patterns, clumped/clustered ring internal enhancement pattern and washout curve type was the most powerful indicator for malignant pathology in non-mass enhancing lesions. The study envisaged the unmet need for consensus on the characterization of non-mass enhancing lesions in most of the previously done studies.

Legal entity responsible for the study

Rajiv Gandhi Cancer Institute and Research Center.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.

Background

Some breast cancer patients can achieve pathologic complete response (pCR) for breast and/or axillary lymph node after neoadjuvant systemic therapy (NST). If the breast achieved pCR confirmed by extensive biopsy, the necessity of breast surgery has been questioned. Whereas, the appropriate management of the axilla in breast pCR patients is rarely studied. This cohort study was designed to retrospectively evaluate the status of axillary lymph nodes in relation to breast pCR and identify patients who may be eligible for omission of axillary surgery.

Methods

This study in a single institution concluded operable breast patients who received NST followed by standard breast and nodal surgery from 2015 to 2019. The rates of axillary pCR (ypN0) were compared between patients who did or did not achieve breast pCR (ypT0/is).

Results

Among 258 patients, 70 (27.1%) patients achieved ypT0/is, and there was no statistical difference according to patients’ age, menopausal status, clinical tumor size and lymph node status when compared with non-ypT0/is patients. Patients with HER2-positive and triple-negative (TN) subtypes have a higher incidence of ypT0/is than patients with luminal subtype (P<0.001). Overall, the rate of ypN0 in ypT0/is group was higher than in non-ypT0/is group (87.1% vs 34.6%, P<0.0001). For cN0 (clinically assessed negative lymph node before NST) patients, although there was no difference of ypN0 rates between ypT0/is group and non-ypT0/is group (100% vs. 85.7%, P=0.1534), the high value of ypN0 rate in ypT0/is group (100%) provided evidence of axillary surgery omission. In addition, for cN+ (clinically assessed positive lymph node before NST) patients, the ypT0/is group population was more likely to achieve ypN0 than non-ypT0/is population (82.7% vs 22.9%, P<0.0001). Moreover, more cN+ patients achieved ypN0 in ypT0 group than in ypTis group (94.3% vs 58.8%, P= 0.0034), and the high rate number (94.3%) also indicated possibility of axillary surgery omission.

Conclusions

Evidence supported that, for cN0 patients who achieved ypT0/is, and cN+ patients who achieved ypT0, axillary surgery may be omitted.

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.