Chest wall recurrence in pT1-2N0-1 breast cancer patients after mastectomy without radiotherapy

De-escalated radiotherapy for HER2-overexpressing breast cancer patients with 1-3 positive lymph nodes undergoing anti-HER2 targeted therapy

Background

In the era of anti-HER2 targeted therapy, the potential clinical feasibility of considering HER2-overexpressing breast cancer cases presenting with 1-3 positive axillary lymph nodes as low-risk, and thereby contemplating postoperative radiotherapy reduction, remains an important subject for in-depth examination. The aim of this retrospective study was to evaluate the effectiveness of de-escalated radiotherapy in T1-2N1M0 HER2-overexpressing breast cancer patients receiving anti-HER2 targeted therapy. Specifically, omitting regional lymph node irradiation (RNI) after breast-conserving surgery and only performing whole-breast irradiation or omitting postmastectomy radiation therapy.

Methods

A retrospective analysis was conducted on 429 patients with stage T1-2N1M0 primary invasive HER2-overexpressing breast cancer from our center between 2004 and 2018. Patients who received anti-HER2 targeted therapy were divided into an RNI group and a no RNI group to assess the role of RNI. The prognostic role of RNI was investigated via the Kaplan-Meier method and Cox proportional hazards modeling.

Results

The median follow-up time was 46.8 months (range 7.1-225.8 months). In the anti-HER2 targeted therapy group RNI yielded no significant improvements in invasive disease-free survival (IDFS) (p = 0.940), local-regional recurrence-free survival (p = 0.380), distant metastases-free survival (p = 0.698), or overall survival (p = 0.403). Estrogen receptor (ER) status (hazard ratio [HR] 0.105, 95% confidence interval [CI] 0.023-0.749, p = 0.004) and lymph vascular invasion status (LVI) (HR 5.721, 95% CI 1.586-20.633, p = 0.008) were identified as independent prognostic factors for IDFS, and ER-positive and LVI-negative patients exhibited better prognoses.

Conclusion

Omitting RNI may be a safe option in T1-2N1 HER2-overexpressing breast cancer patients receiving standardized anti-HER2 targeted therapy; particularly in ER-positive or LVI-negative subgroups.

Preservation of the Pectoral Fascia in Mastectomy With Immediate Reconstruction: A Nationwide Survey

INTRODUCTION

Pectoral fascia (PF) removal during mastectomy still seems to be the standard procedure. However, preservation of the PF might improve postoperative and cosmetic outcomes, without compromising oncological safety. Here, we report on a national survey among Dutch plastic surgeons and oncological breast surgeons to evaluate their techniques and opinions regarding the PF.

MATERIALS AND METHODS

A survey based study was performed in the Netherlands, in which both plastic surgeons and oncological breast surgeons were included, each receiving a different version of the survey. The surveys were distributed to 460 and 150 e-mail addresses, respectively.

RESULTS

A total of 68 responses were included from more than half of all Dutch medical centers. The results of this study indicate that circa one in five plastic surgeons and breast surgeons routinely preserve the PF during mastectomies and even more surgeons preserve the PF in specific cases. The surgical techniques and opinions regarding PF preservation widely differ between surgeons.

CONCLUSIONS

Preservation of the PF does occur in a substantial part of the Dutch medical centers and techniques and opinions are contradictory. Future studies on this topic should clarify the effect of PF preservation on oncological safety, complication rates, postoperative pain, cosmetic outcomes, and patient satisfaction.

Suggestion for the omission of post-mastectomy chest wall radiation therapy in patients who underwent skin-sparing/nipple-sparing mastectomy

AIM

Both skin-sparing mastectomy (SSM) and nipple-sparing mastectomy (NSM) have been widely adopted. Although postmastectomy radiation therapy (PMRT) can improve clinical outcomes, it can worsen cosmesis following reconstruction. Therefore, identifying risk factors of ipsilateral breast tumor recurrence (IBTR) could help de-escalate PMRT after NSM/SSM in patients with pT1-2 disease.

METHODS

We retrospectively reviewed patients treated with SSM (N = 400) and NSM (N = 156) in patients with pT1-2N0-1 disease between 2009 and 2016. Seventy-four patients received PMRT with 50-50.4 Gy in 25-28 fractions. The Cox proportional hazards model was used to analyze the prognostic factors of IBTR.

RESULTS

With a median follow-up of 66.2 months, 17 IBTR events were observed, with 5-year IBTR-free rate of 97.2%. Although only one IBTR was observed after PMRT, there was no statistical difference in the 5-year IBTR-free rate (PMRT vs. no PMRT, 98.6% vs. 97.0%, p = 0.360). Multivariable analyses demonstrated that age ≤45 years and lymphovascular invasion (LVI) were adverse features of IBTR. The low-risk group (0 risk factor) showed a better 5-year IBTR-free rate than the high-risk group (≥1 risk factor) (100.0% vs. 95.8%, p = 0.003). In the high-risk group, PMRT slightly improved 5-year IBTR-free rate compared with no PMRT (98.6% vs. 95.2%, p = 0.166). In addition, PMRT increased 5-year cumulative incidence of reconstruction failure (10.0% vs. 2.8%, p = 0.001).

CONCLUSION

We identified risk factors (age and LVI) related to IBTR following upfront SSM/NSM with pT1-2 disease. As a hypothesis-generating study, de-escalation of PMRT by omitting chest wall irradiation in selective patients could improve reconstruction-related complications without compromising oncologic outcomes.

Biomimetic multifunctional nanozymes enhanced radiosensitization for breast cancer via an X-ray triggered cascade reaction

Radiotherapy has been widely applied for breast cancer treatment in the clinic, while improving the radiation sensitivity of tumors and protecting normal tissues from radiation damage has drawn considerable attention. In this study, we reported a biomimetic multifunctional nanozyme (BSA@CeO/Fe²⁺), which can be used as a radiosensitizer for breast cancer treatment. It was demonstrated that BSA@CeO/Fe²⁺ presented a pH dependent multiple enzyme like activity that enhances the hydroxyl radical level by cascade catalytic reactions in a tumor microenvironment to obtain a desirable tumor-suppression rate (83.07%). Moreover, BSA@CeO/Fe²⁺ was also proved to reduce reactive oxygen species levels in normal cells. Additionally, BSA@CeO/Fe²⁺ nanozymes showed no obvious toxicity by routine blood examination and blood biochemistry assays. Therefore, this work provided a promising strategy for nanocatalytic tumor therapy by rationally designing biomimetic nanozymes with multienzymatic activities for achieving high radiotherapy efficacy and excellent biosafety simultaneously.

Postmastectomy Radiation Therapy in Patients With Minimally Involved Lymph Nodes: A Review of the Current Data and Future Directions

Radiation therapy for patients with pN1mi or pN1 disease breast cancer undergoing mastectomy has been debated for a long time. Even in low metastatic burden in sentinel node biopsy, occult non-sentinel axillary nodal involvement can exist. Radiotherapy can sterilize axillary metastatic burden and seems to contribute a very low local recurrence rate in mastectomy patients with minimally involved lymph nodes. However, it should be considered that systemic therapy is evolving and the local recurrence difference between radiotherapy and no radiotherapy is relatively small. Regarding postmastectomy radiotherapy in patients pN1mi or pN1 cancer, published prospective clinical trial results should be considered; however, there are no such relevant results of clinical trials yet. Consideration of postmastectomy radiation therapy in pN1mi or pN1 patients should be based on identifying the high-risk group in terms of recurrence, stage, or tumor biology. When radiotherapy is determined, radiation oncologists should attempt individualized treatment approaches, such as irradiation field, and consider specific settings, such as neoadjuvant therapy. In this review, the role of radiotherapy in mastectomy patients with minimally involved lymph nodes and the relevant considerations are discussed.

Is it beneficial for patients with pT1-2N1M0 breast cancer to receive postmastectomy radiotherapy? An analysis based on RecurIndex assay

The benefit of postmastectomy radiotherapy (PMRT) for pT1-2N1M0 breast cancer patients currently remains controversial. This study was conducted to investigate whether pT1-2N1M0 breast cancer patients could benefit from PMRT based on RecurIndex assay. The clinical data of 213 pT1-2N1M0 breast cancer patients were retrospectively analyzed. Through RecurIndex assay, 81 cases were assessed as the low risk, and 132 as the high risk. Compared to low-risk patients, high-risk patients especially those not receiving PMRT had a significantly increased risk of recurrence and metastasis, and worse 7-year local-regional recurrence-free interval (LRFI), distance recurrence-free interval (DRFI) and recurrence-free survival (RFS) rates. PMRT-based subgroup analysis indicated no significant differences between the low-risk patients with and without PMRT in 7-year LRFI, DRFI, RFS and overall survival (OS) rates, but apparent differences were all shown between the high-risk patients with and without PMRT in 7-year LRFI, DRFI, RFS and OS rates. Overall, for pT1-2N1M0 breast cancer patients at low risk of recurrence and metastasis stratified by RecurIndex assay, there may be a phenomenon of no PMRT benefits, while for those at high risk, use of PMRT may produce survival benefits.

Prognostic factors for breast cancer patients with T1-2 tumors and 1-3 positive lymph nodes and the role of postmastectomy radiotherapy in these patients

PURPOSE

The purpose of this study was to identify independent prognostic factors for breast cancer patients with T1-2 tumors and 1-3 positive lymph nodes, and discuss the role of postmastectomy radiotherapy(PMRT) in these patients.

METHODS

Between January 2005 and December 2015, the data on 840 eligible patients with breast cancer were retrospectively reviewed. Of these patients, 368 women received PMRT and 472 did not. The endpoints were locoregional recurrence (LRR) and distant metastasis (DM).

RESULTS

With a median follow-up of 62.0 months, multivariate analysis identified the following independent risk factors for increased LRR: tumor size ≥ 4 cm (HR: 2.994, 95% CI: 1.190-7.535, P = 0.020), ER- and PR-negative tumor (HR: 2.540, 95% CI: 1.165-5.537, P = 0.019), preoperative high neutrophil-to-lymphocyte ratio (NLR) (HR: 4.716, 95% CI: 1.776-12.528, P = 0.002)and low neutrophil-to-monocyte ratio (NMR) (HR: 0.231, 95% CI: 0.084-0.633, P = 0.004). And independent risk factors for increased DM: ER- and PR-negative tumor (HR: 2.540, 95% CI: 1.880-5.625, P = 0.000), high NLR (HR: 2.693, 95% CI: 1.426-5.084, P = 0.002) and low NMR (HR: 0.460, 95% CI: 0.257-0.824, P = 0.009). The high-risk patients (≥ 2 risk factors) had worse LRRFS and DFS than low-risk patients (0-1 risk factor) (all, P < 0.05). In the subgroup analysis, both low- and high-risk patients received PMRT had better LRRFS and DFS than those who without PMRT (all, P < 0.05), and the high-risk patients received PMRT had similar 5-year rates of LRRFS and DFS than low-risk patients who without PMRT (94.5 vs. 94.3%, P = 0.402; 83.4 vs.87.4%, P = 0.877, respectively).

CONCLUSIONS

Tumor size, ER/PR status, preoperative NLR and NMR were independent predictors of risk of recurrence. PMRT could improve locoregional control even in low-risk subgroup of breast cancer patients with T1-2 tumors and 1-3 positive lymph nodes significantly.

Real-world impact of postmastectomy radiotherapy in T1-2 breast cancer with one to three positive lymph nodes

Background

The utility of postmastectomy radiotherapy (PMRT) in breast cancer patients with T1-2 (tumor size ≤5 cm) and N1 (one to three lymph nodes involved) disease remains controversial. The aim of this population-based study was to investigate the effectiveness of PMRT in this patient subset in the current clinical practice.

Methods

We included T1-2N1 breast cancer patients treated with mastectomy from 2004 to 2012 using the data form the Surveillance, Epidemiology, and End Results program. The association of PMRT administration with breast cancer-specific survival was determined using multivariable Cox analysis.

Results

We identified 10,248 patients of this study, including 3,725 (36.3%) received PMRT and 6,523 (63.7%) patients did not receive PMRT. Use of PMRT showed increase from 2008 onward; the percentage of patients receiving PMRT was 30.6% in 2004 and was 47.1% in 2012 (P<0.001). Patients diagnosis after 2008, aged <50 years, high tumor grade, T2 stage, and ≥2 positive lymph nodes were independently related to PMRT receipt. Multivariate analysis indicated that PMRT was not related to better breast cancer-specific survival compared to those without PMRT both before (P=0.186) and after propensity score matching (P=0.137).

Conclusions

In breast cancer with T1-2N1 disease, PMRT does not appear to improve survival in the era of modern systemic therapy.

Partial chest wall radiation therapy for positive or close surgical margins after modified radical mastectomy for breast cancer without lymph node metastasis

Aim

Whole‐breast radiation therapy after breast‐conserving surgery can control local recurrence with a long‐term survival rate equivalent to that of radical mastectomy for patients with early breast cancer. However, the significance of radiation therapy for patients with positive/close margins after mastectomy remains controversial. Following radical mastectomy, no residual breast parenchyma remains, and thus radiation therapy of the entire chest wall may represent overtreatment in the patients, especially those without lymph node metastasis (N0). We therefore implemented partial chest wall radiation therapy for patients with N0 breast cancer and positive and/or close margins after mastectomy.

Methods

A total of 22 patients with N0 status but positive/close margins underwent partial chest wall radiation therapy to irradiate the predetermined clinical target volume, which had margins of at least 2 cm medial, lateral, superior, and inferior to the primary tumor bed. With reference to chest wall thickness, 4‐10‐MV photons or 5‐8‐MeV electrons with/without a bolus were delivered. The total dose was 50‐66 Gy. We compared the results with those from 18 nonradiation therapy patients using Pearson's χ² test.

Results

All patients in the partial chest wall radiation therapy group achieved good local control despite having a significantly higher proportion of positive margins (77.3%) compared with the nonradiation therapy group (27.8%) (P = 0.002). Both groups showed 100% recurrence‐ and disease‐free survival.

Conclusion

Partial chest wall radiation therapy may offer recurrence‐ and disease‐free survival without local recurrence in N0 mastectomy patients with positive/close surgical margins.

Local and regional recurrence following mastectomy in breast cancer patients with 1-3 positive nodes: implications for postmastectomy radiotherapy volume

PURPOSE

To determine the necessity of postmastectomy radiotherapy (PMRT) and which regions would be at risk for recurrence, we evaluated local and regional recurrence in breast cancer patients with 1-3 positive nodes and a tumor size of <5 cm.

MATERIALS AND METHODS

We retrospectively analyzed data of 133 female breast cancer patients with 1-3 positive nodes, and a tumor size of <5 cm who were treated with mastectomy followed by adjuvant systemic therapy between 2007 and 2016. The median follow-up period was 57 months (range, 12 to 115 months). Most patients (82.7%) were treated with axillary lymph node dissection. Adjuvant chemotherapy, endocrine therapy, and trastuzumab therapy were administered to 124 patients (93.2%), 112 (84.2%), and 33 (24.8%), respectively. The most common chemotherapy regimen was anthracycline and cyclophosphamide followed by taxane (71.4%).

RESULTS

Three patients (2.3%), 8 (6.0%), and 12 (9.0%) experienced local, regional, and distant failures, respectively. The 5-year cumulative risk of local recurrence, regional recurrence, distant metastasis, and disease-free survival was 3.1%, 8.0%, 11.7%, and 83.4%, respectively. There were no statistically significant clinicopathologic factors associated with local recurrence. Lymphovascular invasion (univariate p = 0.015 and multivariate p = 0.054) was associated with an increased risk of regional recurrence.

CONCLUSION

Our study showed a very low local recurrence in patients with 1-3 positive nodes and tumor size of <5 cm who were treated with mastectomy and modern adjuvant systemic treatment. The PMRT volume need to be tailored for each patient's given risk for local and regional recurrence, and possible radiation-related toxicities.