Locoregional recurrence-associated factors and risk-adapted postmastectomy radiotherapy for breast cancer staged in cT1-2N0-1 after neoadjuvant chemotherapy

The prognostic differences and the effect of postmastectomy radiotherapy between post-chemotherapy ypT1-2ypN1 and de novo pT1-2N1 breast cancer

BACKGROUND

The prognosis and the value of postmastectomy radiotherapy (PMRT) between post-chemotherapy ypT1-2ypN1 and de novo pT1-2N1 breast cancer (BC) remain controversial. We aimed to evaluate the prognostic differences and the effect of PMRT between the two patient subsets.

METHODS

Patients diagnosed with pT1-2N1M0 BC were identified between 2010 and 2018. The study endpoints were overall survival (OS), breast cancer-specific survival (BCSS), locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS) and disease-free survival (DFS). The chi-square test, Kaplan-Meier method and Cox regression analysis were used for data analysis.

RESULTS

Total number of 2103 pT1-2N1M0 BC patients were included in the study, including 270 post-chemotherapy (97 without PMRT, 173 with PMRT) and 1833 de novo cases (993 without PMRT, 840 with PMRT). No significant differences were found between post-chemotherapy ypT1-2ypN1 and de novo pT1-2N1 BC patients in 5-year OS (p = 0.068), BCSS (p = 0.054), LRFS (p = 0.241), DMFS (p = 0.104) or DFS (p = 0.08). PMRT did not improve any survival outcome in patients receiving neoadjuvant chemotherapy; however, the PMRT group had a better 5-year BCSS (97.0% vs. 95.8%, p = 0.033) in de novo pT1-2N1 BC. Cox multivariate analysis demonstrated that PMRT was a significant independent predictor of BCSS (HR 0.628; 95% CI, 0.403-0.978; p = 0.04) in de novo pT1-2N1 patients.

CONCLUSIONS

There seemed no survival difference in post-chemotherapy ypT1-2ypN1 and de novo pT1-2N1 BC patients with contemporary systemic therapy. In addition, PMRT might be exempted in patients with post-chemotherapy ypT1-2ypN1 BC, while not in patients with de novo pT1-2N1 BC.

Postmastectomy Radiotherapy After Neoadjuvant Chemotherapy in cT1-2N+ Breast Cancer Patients: A Single Center Experience and Review of Current Literature

Purpose

Postmastectomy radiotherapy (PMRT) after neoadjuvant chemotherapy (NAC) in breast cancer patients with initial clinical stage cT1-2N+, especially for those who achieved ypT1-2N0, is still controversial. This study was to evaluate the survival prognosis of cT1-2N+ patients after NAC with or without PMRT, and to discuss the selection of patients who may omit PMRT.

Patients and Methods

From January 2005 to December 2017, 3055 female breast cancer patients underwent mastectomy in our medical center, among whom 215 patients of cT1-2N+ stage, receiving NAC with or without PMRT were finally analyzed. The median follow-up duration was 72.6 months. The primary endpoint was disease-free survival (DFS), and secondary endpoint was overall survival (OS). Comparison was conducted between PMRT and non-PMRT subgroups.

Results

Of the 215 eligible patients, 35.8% (77/215) cT1-2N+ patients achieved ypT0-2N0 after NAC while 64.2% (138/215) of the patients remained nodal positive (ypT0-2N+). The 5-year DFS of ypT0-2N0 non-PMRT was 79.5% (95% confidence interval [CI] 63.4-95.6%). No statistically significant difference was observed between the ypT0-2N0 PMRT and non-PMRT subgroups for the 5-year DFS (78.5% vs 79.5%, p = 0.673) and OS (88.8% vs 90.8%, p = 0.721). The 5-years DFS didn't obviously differ between the ypT0-2N0 non-PMRT subgroup and cT1-2N0 subgroup (79.5% vs 93.3%, p = 0.070). By using Cox regression model in multivariate analyses of prognosis in ypT0-2N+ PMRT subgroup, HER2 overexpression and triple-negative breast cancer were significantly poor predictors of DFS and OS, while ypN stage was significant independent predictors of OS.

Conclusion

An effective response to NAC (ypT0-2N0) indicates a sufficiently favorable prognosis, and PMRT might be omitted for cT1-2N+ breast cancer patients with ypT0-2N0 after NAC.

Triple-negative breast cancer: current treatment strategies and factors of negative prognosis

Breast cancer is the most common cancer in women and the most common cause of death in working-age women. According to the results of immunohistochemical studies, 10-20% of cases revealed a triple-negative type of breast cancer. This subtype is characterized by significant proliferative activity and growth rate, aggressive clinical course, and early metastasis. This leads to a suspicious prognosis and, accordingly, encourages an increase of surgical treatment radicalism and aggressive systemic treatment. This review briefly analyzes existing treatment strategies for triple-negative breast cancer with a focus on surgical treatment. Surgical treatment is an integral part of complex therapy. Currently, the attention of researchers is focused not only on the radicalism of the operation, ensuring long-term survival, but also on achieving a good cosmetic result that determines the quality of life of patients. In this aspect, organ-preserving and prosthetic methods of operations are promising, the feasibility and effectiveness of which are being discussed. The relevance of choosing the optimal method of operation is evidenced by the lack of generally accepted approaches based on informative markers for the prognosis of the course of the disease. Therefore, the choice of the optimal method of surgical treatment taking into account the individual characteristics of the patient and the tumor, indications for chemotherapy, and radiation therapy remains an unresolved issue and requires further research.

Factors Predicting Locoregional Recurrence After Neoadjuvant Chemotherapy and Nipple-Sparing/Skin-Sparing Mastectomy With Immediate Breast Reconstruction

Background

Few data are available on the risk factors of locoregional recurrence (LRR) after neoadjuvant chemotherapy (NACT) and immediate breast reconstruction (IBR) in breast cancer. Herein, we evaluated the factors predicting LRR in a large series of patients who underwent either nipple- (NSM) or skin-sparing mastectomy (SSM) with IBR after NACT.

Methods

We retrospectively analyzed 609 breast cancer patients who underwent NACT and NSM/SSM with IBR between February 2010 and June 2017. Factors associated with an increased risk of LRR were analyzed by univariate (chi-square or Fisher's exact test) and multivariate (Cox proportional hazard regression model) analyses.

Results

During a median follow-up of 63 months, LRR as the first event occurred in 73 patients, and the 5-year cumulative LRR rate was 10.8%. Multivariate analysis revealed post-NACT Ki67 ≥ 10% [hazard ratio (HR), 2.208; 95% confidence interval (CI), 1.295-3.765; P = 0.004], high tumor grade (HR, 1.738; 95% CI, 1.038-2.908; P = 0.035), and presence of lymphovascular invasion (LVI) (HR, 1.725; 95% CI, 1.039-2.864; P = 0.035) as independently associated with increased LRR risk. The 10-year LRR rate was 8.5% for patients with none of the three associated risk factors, 11.6% with one factor, 25.1% with two factors, and 33.7% with all three factors (P < 0.001).

Conclusions

Post-NACT Ki67 ≥ 10%, high tumor grade, and presence of LVI are independently associated with an increased risk of developing LRR after NACT and NSM/SSM with IBR. Future prospective trials are warranted to decrease the risk of LRR in patients with associated risk factors.

Locoregional therapy in breast cancer patients treated with neoadjuvant chemotherapy

Introduction: Neoadjuvant chemotherapy (NAC) is increasingly used preoperatively in breast cancer patients to achieve disease downstaging, reduce distant dissemination, and assess chemosensitivity. While NAC indications are expanding, knowledge of its impact on subsequent locoregional treatment with surgery and radiation therapy (RT) decisions is evolving. Radiation oncologists are often called upon to estimate locoregional recurrence (LRR) risks and provide recommendations for adjuvant RT to the breast/chest wall and regional lymph nodes postoperatively. In the non-NAC setting, adjuvant RT decisions are guided by the pathology findings after definitive surgery. In the NAC setting, decisions for or against adjuvant RT are complex, particularly in patients who achieve complete pathologic response (pCR).Areas covered: This review will examine contemporary data on NAC in patients with breast cancer and discuss its impact on surgical and RT decisions. We will also evaluate controversies in the role of LRRT for these patients, focussing on prognostic factors that include biological subtypes and pCR after NAC.Expert opinion: Advances in personalized medicine and diagnostic techniques have shifted paradigms and increased complexities in locoregional treatment decisions, particularly in the setting of NAC. Despite the challenges, our goals while we await prospective data remain focused on improving survival, minimizing toxicity, and optimizing function and cosmesis.

The Effect of Postmastectomy Radiotherapy on Breast Cancer Patients After Neoadjuvant Chemotherapy by Molecular Subtype

BACKGROUND

The effect of postmastectomy radiotherapy (PMRT) on patient outcomes after neoadjuvant chemotherapy (NAC) remains controversial. We aimed to establish a model to identify the subsets benefiting from PMRT and to examine the effect of PMRT according to molecular subtype.

PATIENTS AND METHODS

We retrospectively analyzed 1118 cT1-4cN0-3M0 breast cancer patients treated with NAC and mastectomy. A nomogram predicting locoregional recurrence (LRR) was established based on 418 unirradiated patients, and X-tile analysis was performed to divide the patients into two risk groups. The effect of PMRT on LRR, distant recurrence (DR), and breast cancer mortality (BCM) was estimated for patients with different molecular subtypes in two risk groups.

RESULTS

A nomogram predicting LRR was developed using six factors: histologic classification, lymphovascular invasion, ypT stage, ypN stage, estrogen receptor status, and Ki-67 expression. Our study found that PMRT correlated with lower 5-year LRR, DR, and BCM rates for the high-risk group; however, no significant improvement in these endpoints was observed in the low-risk group. Among patients with high risk, subgroup analysis showed that LRR control was improved after PMRT for the human epidermal growth factor receptor 2 (HER2)-negative/hormone receptor (HR)-positive (HER2-/HR+), HER2-positive (HER2+)/HR+, and HER2-/HR-negative (HR-) subtypes, with hazard ratios of 0.113 (95% confidence [CI] 0.034-0.379; p < 0.001), 0.159 (95% CI 0.038-0.671; p = 0.017), and 0.243 (95% CI 0.088-0.676; p = 0.007), respectively, but not for the HER2+/HR- subtype (p = 0.468).

CONCLUSIONS

We built a nomogram showing favorable risk quantification and patient stratification. Patients in the high-risk group benefited from PMRT, but patients in the low-risk group did not. PMRT may show different benefits for each molecular subtype.

Oncologic Outcomes of Nipple-sparing Mastectomy and Immediate Reconstruction After Neoadjuvant Chemotherapy for Breast Cancer

OBJECTIVES

To evaluate the oncologic outcomes and risk factors for locoregional recurrence (LRR) and nipple-areola complex recurrence (NR) in a large series of breast cancer patients who underwent nipple-sparing mastectomy (NSM) and immediate reconstruction after neoadjuvant chemotherapy (NACT).

SUMMARY OF BACKGROUND DATA

The use of NSM and immediate reconstruction in breast cancer patients receiving NACT is increasing. However, the oncologic safety of this approach is unclear.

PATIENTS AND METHODS

A total of 310 breast cancer patients (319 breasts) who underwent NACT and NSM between February 2010 and November 2016 were retrospectively analyzed. Clinical and pathologic factors associated with increased risks of LRR and NR were analyzed using univariate (Chi-square or Fisher exact test) and multivariate (Cox proportional hazard regression model) analyses.

RESULTS

During a mean follow-up of 63 ± 22 months, 38 cases had LRR as the first event, including 6 cases of NR as the first event. The 5-year cumulative LRR and NR rates were 11.0% and 1.9%, respectively. In univariate analysis, clinical T stage, pathologic nodal status, histologic grade, lymphovascular invasion, and post-NACT Ki67 status were associated with increased LRR risk, and post-NACT Ki67 status was the only significant risk factor for NR. In multivariate analysis, post-NACT Ki67 ≥10% (hazard ratio, 4.245; 95% confidence interval, 1.865-9.663; P = 0.001) was an independent risk factor for LRR.

CONCLUSIONS

NSM and immediate reconstruction seem to be oncologically safe with acceptable LRR and NR rates for appropriately selected breast cancer patients treated with NACT. Post-NACT Ki67 ≥10% was associated with increased risk of LRR or NR, and therefore, necessitates cautious follow-up.