Determining the indications for post mastectomy radiotherapy: moving from 20th century clinical staging to 21st century biological criteria

The trade-off of post-mastectomy radiotherapy usage for the breast cancer patients aged 70 years or older: a study based on SEER database

BACKGROUND

This study aimed to investigate the role of post-mastectomy radiotherapy (PMRT) in the female aged 70 years or older diagnosed with breast cancer, which is still controversial.

METHODS

This retrospective study enrolled female breast cancer women aged 70 + years following mastectomy from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) was performed to reduce covariable imbalance. A nomogram was created to predict the 1,3,5-years overall survival (OS) and divide patients into three risk groups.

RESULTS

After matching, PMRT were associated with significant improvement in breast cancer-specific survival (BCSS) and OS (p < 0.001). By contrast, the BCSS and OS benefit from PMRT were not significant in patients with T1N1 tumor (BCSS: HR = 0.716, p = 0.249;OS:HR = 0.908, p = 0.572), and T2N1 tumor (BCSS:HR = 0.866, p = 0.289;OS:HR = 0.879, p = 0.166). Stratified by subtype, the HR+/HER-2- subtype and the HR-/HER-2- subtype (all p < 0.001) have a significant prolonged survival, yet not significant BCSS difference are shown in the HER-2 + tumor. In the low-risk group as determined by the nomogram, the use of PMRT did not significantly improve OS (p = 0.203).

CONCLUSIONS

This study demonstrated that PMRT improves the survival of females with elderly breast cancer, while for T1-2N1 breast cancer patients, the omission of PMRT could be considered. Furthermore, the nomogram we constructed could be used as a decision tool for the omission of PMRT in low-risk elderly patients.

Trends and variation in treatment of early breast cancer in European certified breast centres: an EUSOMA-based analysis

BACKGROUND

Practice indicators (PI) measure provided care making use of real-world data. This study describes trends and variations in adjuvant treatment of early breast cancer (EBC) using the European Society of Breast Cancer Specialists (EUSOMA) database.

METHODS

The analysis was conducted on anonymous cumulative data registered by 56 certified breast centres, which all entered at least 500 new diagnoses in the database in the 10-year period 2010-2019. Practice trends of radiotherapy, endocrine treatment, chemotherapy, and anti-HER2 therapy were evaluated. The association with age group (<50, 50-69, ≥70) and geographical area of the centre (Northern, Central, Southern Europe; NE, CE, SE) was assessed with the Pearson Chi2 test for independence in contingency tables.

RESULTS

In total, 150,150 patients with EBC were selected. Overall, radiotherapy was administered more frequently in NE centres, and conversely, endocrine, chemo-, and anti-HER2 therapy were used more frequently in SE centres (p<0.001). 46.9% of the pN1 patients received postmastectomy radiotherapy, with significant differences by age and geographical region (p < 0.001). Adjuvant endocrine treatment for endocrine-sensitive carcinoma in situ was administered in 46.1%, with a decreasing trend during the study period (58.5-34.5%; p < 0.001). Anti-HER2 therapy was delivered in 75.6% of all patients with HER2BC T1a/bN0, patients older than 70 received anti-HER2 in 67.6% in SE compared to 31.3% in NE centres.

CONCLUSION

Important variations in EBC management between European certified breast centres have been demonstrated. PI using real-world data can help to monitor, evaluate, and eventually guide and align good clinical practice in the management of breast cancer.

The Association Between Survival and Receipt of Post-mastectomy Radiotherapy According to Age at Diagnosis Among Women With Early Invasive Breast Cancer: A Population-Based Cohort Study

AIMS

Clinical trials of post-mastectomy radiotherapy (PMRT) for early invasive breast cancer (EIBC) have included few older women. This study examined whether the association between overall survival or breast cancer-specific survival (BCSS) and receipt of PMRT for EIBC altered with age.

MATERIALS AND METHODS

The study used patient-level linked cancer registration, routine hospital and radiotherapy data for England and Wales. It included 31 243 women aged ≥50 years diagnosed between 2014 and 2018 with low- (T1-2N0), intermediate- (T3N0/T1-2N1) or high-risk (T1-2N2/T3N1-2) EIBC who received a mastectomy within 12 months from diagnosis. Patterns of survival were analysed using a landmark approach. Associations between overall survival/BCSS and PMRT in each risk group were analysed with flexible parametric survival models, which included patient and tumour factors; whether the association between PMRT and overall survival/BCSS varied by age was assessed using interaction terms.

RESULTS

Among 4711 women with high-risk EIBC, 86% had PMRT. Five-year overall survival was 70.5% and BCSS was 79.3%. Receipt of PMRT was associated with improved overall survival [adjusted hazard ratio (aHR) 0.75, 95% confidence interval 0.64-0.87] and BCSS (aHR 0.78, 95% confidence interval 0.65-0.95) compared with women who did not have PMRT; associations did not vary by age (overall survival, P-value for interaction term = 0.141; BCSS, P = 0.077). Among 10 814 women with intermediate-risk EIBC, 59% had PMRT; 5-year overall survival was 78.4% and BCSS was 88.0%. No association was found between overall survival (aHR 1.01, 95% confidence interval 0.92-1.11) or BCSS (aHR 1.16, 95% confidence interval 1.01-1.32) and PMRT. There was statistical evidence of a small change in the association with age for overall survival (P = 0.007), although differences in relative survival were minimal, but not for BCSS (P = 0.362).

CONCLUSIONS

The association between PMRT and overall survival/BCSS does not appear to be modified by age among women with high- or intermediate-risk EIBC and, thus, treatment recommendations should not be modified on the basis of age alone.

Validation of a prognostic scoring system for postmastectomy locoregional recurrence in breast cancer

Background

To date, it remains unclear which patients with breast cancer (BC) benefit from post-mastectomy radiotherapy (PMRT). Cheng et al. developed and validated a scoring system based on 4 prognostic factors for locoregional recurrence (LRR) to identify patients in need for PMRT. These factors include age, estrogen receptor status, lymphovascular status and number of affected axillary lymph nodes.

Purpose

To validate the scoring system for LRR in BC developed by Cheng et al. by using an independent BC database.

Methods and materials

We retrospectively identified 1989 BC cases, treated with mastectomy (ME) with or without PMRT at the University Hospitals Leuven between 2000 and 2007. The primary endpoint was 5-year locoregional control rate with and without PMRT, according to the LRR score.

Results

Median follow-up time was 11.4 years. After excluding patients with missing variables 1103 patients were classified using the LRR scoring system: 688 (62.38%) patients were at low risk of recurrence (LRR score 0–1), 335 (30.37%) patients were at intermediate risk of recurrence (LRR score 2–3) and 80 (7.25%) patients were at high risk of recurrence (LRR score ≥4). 5-year locoregional control rates with and without PMRT were 99.20% versus 99.21% (p = 0.43) in the low-risk group; 98.24% versus 85.74% (p < 0.0001) in the intermediate-risk group and 96.87% versus 85.71% (p = 0.10) in the high-risk group respectively.

Conclusion

Our validation of the LRR scoring system suggests it can be used to point out patients that would benefit from PMRT. We recommend further validation of this scoring system by other independent institutions before application in clinical practice.

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Post-mastectomy radiotherapy.

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Scoring system by Cheng et al.

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Based on 4 factors.

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Age, estrogen receptor, lymphovascular status, affected axillary lymph nodes.

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Intermediate and high-risk patients could benefit from post-mastectomy radiotherapy.

Association of 21-gene recurrence score and locoregional recurrence in early breast cancer patients

BACKGROUND: The 21-gene recurrence score (RS) assay has been validated to predict the risk of disease-free survival in estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative early breast cancer patients. However, its relation with locoregional recurrence (LRR) risk is unclear. OBJECTIVE: This study aimed to explore the ability of RS to predict LRR risk. METHODS: Consecutive ER-positive, HER2-negative, pT1, pN0-1, and M0 early breast cancer patients were analyzed retrospectively. According to RS, patients were divided into low- (RS < 18), intermediate- (RS 18–30), and high-risk (RS ⩾ 31) groups. The primary endpoint was LRR. Subgroup analysis was conducted according to different nodal statuses and surgery types. RESULTS: A total of 1558 patients were enrolled: 354 (22.7%), 788 (50.6%), and 416 (26.7%) patients in the low-, intermediate-, and high-risk groups, respectively. The median follow-up time was 53 months, and 2, 8, and 14 LRR events were observed in the low-, intermediate-, and high-risk groups, respectively (P= 0.004). Both univariate (P= 0.009) and multivariate (P= 0.010) analyses demonstrated that 21-gene RS was correlated with LRR. Compared to low-risk patients, high-risk patients were at greater risk of LRR (HR 5.75, 95% CI 1.30–25.31, P= 0.021). Among pN0 (P= 0.033), pN1 (P= 0.049) and postmastectomy patients (P= 0.012), 21-gene RS remained predictive of the risk of LRR. CONCLUSION: The 21-gene RS assay was significantly associated with the risk of LRR in ER-positive, HER2-negative early breast cancer patients. Among patients with different nodal statuses and patients receiving mastectomy, RS remained predictive of the risk of LRR.

Postmastectomy radiotherapy for all node positive patients: The case against

Postmastectomy radiotherapy (PMRT) is accepted as the standard of care for women with early breast cancer with 4 or more involved axillary nodes. However the role of PMRT in women with 1-3 involved nodes remains controversial and guidelines vary. We present the arguments against advocating postmastectomy radiotherapy for all women with node positive breast cancer.

Immediate and delayed autologous abdominal microvascular flap breast reconstruction in patients receiving adjuvant, neoadjuvant or no radiotherapy: a meta-analysis of clinical and quality-of-life outcomes

BACKGROUND

Effects of postmastectomy radiotherapy (PMRT) on autologous breast reconstruction (BRR) are controversial regarding surgical complications, cosmetic appearance and quality of life (QOL). This systematic review evaluated these outcomes after abdominal free flap reconstruction in patients undergoing postoperative adjuvant radiotherapy (PMRT), preoperative radiotherapy (neoadjuvant radiotherapy) and no radiotherapy, aiming to establish evidence-based optimal timings for radiotherapy and BRR to guide contemporary management.

METHODS

The study was registered on PROSPERO (CRD42017077945). Embase, MEDLINE, Google Scholar, CENTRAL, Science Citation Index and ClinicalTrials.gov were searched (January 2000 to August 2018). Study quality and risk of bias were assessed using GRADE and Cochrane's ROBINS-I respectively.

RESULTS

Some 12 studies were identified, involving 1756 patients (350 PMRT, 683 no radiotherapy and 723 neoadjuvant radiotherapy), with a mean follow-up of 27·1 (range 12·0-54·0) months for those having PMRT, 16·8 (1·0-50·3) months for neoadjuvant radiotherapy, and 18·3 (1·0-48·7) months for no radiotherapy. Three prospective and nine retrospective cohorts were included. There were no randomized studies. Five comparative radiotherapy studies evaluated PMRT and four assessed neoadjuvant radiotherapy. Studies were of low quality, with moderate to serious risk of bias. Severe complications were similar between the groups: PMRT versus no radiotherapy (92 versus 141 patients respectively; odds ratio (OR) 2·35, 95 per cent c.i. 0·63 to 8·81, P = 0·200); neoadjuvant radiotherapy versus no radiotherapy (180 versus 392 patients; OR 1·24, 0·76 to 2·04, P = 0·390); and combined PMRT plus neoadjuvant radiotherapy versus no radiotherapy (272 versus 453 patients; OR 1·38, 0·83 to 2·32, P = 0·220). QOL and cosmetic studies used inconsistent methodologies.

CONCLUSION

Evidence is conflicting and study quality was poor, limiting recommendations for the timing of autologous BRR and radiotherapy. The impact of PMRT and neoadjuvant radiotherapy appeared to be similar.

Effects of Postoperative Radiotherapy in Early Breast Cancer Patients Older than 75 Years: A Propensity-Matched Analysis

Background: Currently, there is still some controversy regarding whether early breast cancer patients with a tumor size of ≤5 cm and 1-3 positive lymph nodes should undergo postoperative radiotherapy (PRT). Materials and Methods: We obtained data from the Surveillance, Epidemiology, and End Results (SEER) 18 database. Then, we conducted propensity score matching (PSM), according to the radiotherapy record. The Kaplan-Meier and Cox regression analysis were conducted to explore prognostic factors in breast cancer. Results: A total of 6,777 patients aged 75+ years old were eligible and 2,361 patients were included after PSM. We found PRT could improve patient overall survival (OS) (P = 0.01, hazard ratio [HR] = 0.88, 95% confidence interval [CI], 0.80-0.97). Subgroup analysis revealed PRT could improve OS in patients with hormone receptor positive (HR+) (P = 0.001, HR = 0.84, 95% CI, 0.76 - 0.94) or white patients (P =0.004, HR = 0.86, 95% CI, 0.77 - 0.95). Conclusions: PRT may benefit for elderly women with early breast cancer, especially in HR+ patients or white patients. These findings may inform future optimized options whether elderly female patients with early breast cancer should undergo postoperative radiotherapy.

The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: the iBRA-2 study

Background

Immediate breast reconstruction (IBR) is routinely offered to improve quality-of-life for women requiring mastectomy, but there are concerns that more complex surgery may delay adjuvant oncological treatments and compromise long-term outcomes. High-quality evidence is lacking. The iBRA-2 study aimed to investigate the impact of IBR on time to adjuvant therapy.

Methods

Consecutive women undergoing mastectomy ± IBR for breast cancer July–December, 2016 were included. Patient demographics, operative, oncological and complication data were collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR were compared and risk factors associated with delays explored.

Results

A total of 2540 patients were recruited from 76 centres; 1008 (39.7%) underwent IBR (implant-only [n = 675, 26.6%]; pedicled flaps [n = 105,4.1%] and free-flaps [n = 228, 8.9%]). Complications requiring re-admission or re-operation were significantly more common in patients undergoing IBR than those receiving mastectomy. Adjuvant chemotherapy or radiotherapy was required by 1235 (48.6%) patients. No clinically significant differences were seen in time to adjuvant therapy between patient groups but major complications irrespective of surgery received were significantly associated with treatment delays.

Conclusions

IBR does not result in clinically significant delays to adjuvant therapy, but post-operative complications are associated with treatment delays. Strategies to minimise complications, including careful patient selection, are required to improve outcomes for patients.

Postmastectomy radiation therapy for breast cancer patients with one to three positive lymph nodes: a propensity score matching analysis

AIM

Conducting postmastectomy radiation therapy (PMRT) for breast cancer patients with one to three positive lymph nodes is still controversial.

METHODS

Propensity score matching analysis was applied to balance the clinical baseline characteristics of patients. Cox proportional hazard analysis was used to analyze the survival prognosis factors and perform subgroup analysis.

RESULTS

There was no statistical difference in overall survival and cancer-specific survival rates (all, p > 0.05) between the PMRT and non-PMRT groups. However, for subgroup patients with tumor size ≥5 cm and the number of positive lymph nodes = 3, PMRT showed a significant survival benefit.

CONCLUSION

PMRT can improve overall survival and cancer-specific survival only in breast cancer patients whose tumor size is larger than 5 cm and with three positive lymph nodes.