Trends in use and outcome of postoperative radiotherapy following mastectomy: A population-based study

Adjuvant Therapy for Elderly Breast Cancer Patients after Breast-Conserving Surgery: Outcomes in Real World Practice

We aimed to evaluate the standard of care of adjuvant radiotherapy (RT) after breast-conserving surgery (BCS) in elderly female patients (≥65 years) treated outside of clinical trials and to identify potential factors related to the omission of RT and the interaction with endocrine therapy (ET). All women treated with BCS at two major breast centers between 1998 and 2014 were evaluated. Data were provided by the Tumor Registry Munich. Survival analyses were conducted using the Kaplan-Meier method. Prognostic factors were identified using multivariate Cox regression analysis. The median follow-up was 88.4 months. Adjuvant RT was performed in 82% (2599/3171) of patients. Irradiated patients were younger (70.9 vs. 76.5 years, p < 0.001) and were more likely to receive additional chemotherapy (p < 0.001) and ET (p = 0.014). Non-irradiated patients more often had non-invasive DCIS tumors (pTis: 20.3% vs. 6.8%, p < 0.001) and did not undergo axillary surgery (no axillary surgery: 50.5% vs. 9.5%, p < 0.001). Adjuvant RT was associated with improved locoregional tumor control after BCS in invasive tumors (10-year local recurrence-free survival (LRFS): 94.0% vs. 75.1%, p < 0.001, 10-year lymph node recurrence-free survival (LNRFS): 98.1% vs. 93.1%, p < 0.001). Multivariate analysis confirmed significant benefits for local control with postoperative RT. Furthermore, RT led to increased locoregional control even in patients who received ET (10-year LRFS 94.8% with ET + RT vs. 78.1% with ET alone, p < 0.001 and 10-year LNRFS: 98.2% vs. 95.0%, p = 0.003). Similarly, RT alone had significantly better locoregional control rates compared to ET alone (10-year LRFS 92.6% with RT alone vs. 78.1% with ET alone, p < 0.001 and 10-year LNRFS: 98.0% vs. 95.0%, p = 0.014). The present work confirms the efficacy of postoperative RT for breast carcinoma in elderly patients (≥65 years) treated in a modern clinical setting outside of clinical trials, even in patients who receive ET.

Association between regional nodal irradiation and breast cancer recurrence-free interval for patients with low-risk, node-positive breast cancer

PURPOSE/OBJECTIVE(S)

Randomized clinical trials have shown that regional nodal irradiation (RNI) in patients with unselected N1 breast cancer improves breast cancer-specific survival. However, the benefit of RNI in women with biologically low risk, N1 breast cancer is uncertain. We conduct a population-based study to determine if RNI is associated with improved breast cancer recurrence-free interval (BCRFI) in this population.

MATERIALS/METHODS

Patients aged 40-79 with pT1-2pN1 (node-positive) breast cancers diagnosed from 2005 to 2014 were identified. Inclusion criteria were modeled off the TAILOR RT study, which is a randomized non-inferiority clinical trial designed to assess the value of RNI in low-risk N1 patients. Eligible patients had BCS (breast-conserving surgery) or mastectomy & axillary lymph node dissection (ALND) with 1-3 positive nodes, BCS and sentinel lymph node biopsy (SLNB) with 1-2 positive nodes, or mastectomy and SLNB with 1 positive node. Additionally, patients had Luminal A breast cancers, as approximated by: estrogen receptor positive (Allred 6-8/8), progesterone receptor positive (Allred 6-8/8), human epidermal growth factor receptor 2 (HER2)-negative, and grade 1-2 immunohistochemical testing. All patients were prescribed hormonal treatment. The primary endpoint of BCRFI, which was the time to any breast cancer recurrence or breast cancer-related death, was analyzed using multivariate competing risks analysis.

RESULTS

The cohort included 1,169 women with a median follow-up of 9.2 years. Radiation treatments were: none (151 treated with mastectomy alone), breast-only (133) and locoregional (885). Patients undergoing RNI were younger (median 58 versus 62 years), more likely to have 2-3 macroscopic lymph nodes involved and more often received chemotherapy (all p<0.05). The 10-year estimate of BCRFI was 90% without RNI versus 90% with RNI (p=0.5). On multivariable analysis, RNI was not a significant predictor of BCRFI (HR=1.0, p=0.9).

CONCLUSION

In this retrospective analysis, RNI was not associated with improved BCRFI for women with biologically low risk, N1 breast cancer. We advocate accrual to the ongoing TAILOR RT study.

Guidance and Standards for Breast Cancer Care in Europe

The increasing incidence and mortality rates of breast cancer have led to the necessity of initiating and developing clinical practice guidelines in order to optimize cancer control and provide patients with the best care. These guidelines are either national or issued by reputed relevant European societies-like European Society for Medical Oncology. Many of the recommendations are concordant in-between the guidelines. However, there are still considerable discrepancies to be noted between guidelines from different European countries, which could hinder physicians from implementing their recommendations. The present paper summarizes and compares the recommendations included in the various European guidelines.

Identifying factors impacting the efficacy of postmastectomy radiotherapy in patients with early-stage breast cancer and one to two positive lymph nodes

INTRODUCTION

In women with T1-2 breast cancer and one to two positive axillary lymph nodes (LN) at low risk for recurrence, postmastectomy radiation therapy (PMRT) may provide insufficient benefit to justify its toxicity. This study evaluated the interaction of factors associated with overall survival (OS) after PMRT in these patients.

METHODS

The National Cancer Database was queried for women with T1-2 breast cancer undergoing mastectomy with one to two positive LN identified on lymphadenectomy. Patients were grouped according to number of positive LN and then stratified by PMRT use. Differences in OS were evaluated.

RESULTS

Multivariable modeling demonstrated an interaction effect of age on the efficacy of PMRT. In patients more than or equal to 60 years old, PMRT was associated with improved survival when adjusting for age and tumor grade in patients with 1 to 2 positive LN (risk ratio = 0.62, 95% confidence interval = 0.40-0.93, P = .018). In patients less than 60 years old, tumor size and grade, but not PMRT, were associated with improved OS.

CONCLUSION

For women with T1-2 breast cancer and one to two positive LN, PMRT's association with OS is influenced by age, tumor grade, and number of positive LN. PMRT appears to be associated with improvements in OS in older patients, but not younger patients, regardless of tumor size or nodal status.

Impact of surface-guided positioning on the use of portal imaging and initial set-up duration in breast cancer patients

OBJECTIVE

The impact of optical surface guidance on the use of portal imaging and the initial set-up duration in patients receiving postoperative radiotherapy of the breast or chest wall was investigated.

MATERIAL AND METHODS

A retrospective analysis was performed including breast cancer patients who received postoperative radiotherapy between January 2016 and December 2016. One group of patients received treatment before the optical surface scanner was installed (no-OSS) and the other group was positioned using the additional information derived by the optical surface scanner (OSS). The duration of the initial set-up was recorded for each patient and a comparison of both groups was performed. Accordingly, the differences between planned and actually acquired portal images during the course of radiotherapy were compared between both groups.

RESULTS

A total of 180 breast cancer patients were included (90 no-OSS, 90 OSS) in this analysis. Of these, 30 patients with left-sided breast cancer received radiotherapy in deep inspiration breath hold (DIBH). The mean set-up time was 10 min and 18 s and no significant difference between the two groups of patients was found (p = 0.931). The mean set-up time in patients treated without DIBH was 9 min and 45 s compared to 13 min with DIBH (p < 0.001), as portal imaging was performed in DIBH. No significant difference was found in the number of acquired to the planned number of portal images during the entire radiotherapy treatment for both groups (p = 0.287).

CONCLUSION

Optical surface imaging is a valuable addition for primary patient set-up. The findings confirm that the addition of surface-based imaging did not prolong the clinical workflow and had no significant impact on the number of portal verification images carried out during the course of radiotherapy.

Risk of loco-regional recurrence and distant metastases of patients with invasive breast cancer up to ten years after diagnosis - results from a registry-based study from Germany

BACKGROUND

Population-based estimates of the long-term risk of loco-regional recurrence and distant metastases of breast cancer (BRC) patients are scant, as most published studies used hospital-based cohorts or participants of clinical trials. This work aims to extend available knowledge by providing population-based long-term estimates of the cumulative risk of BRC recurrence up to 10 years after diagnosis.

METHODS

Data from the population-based Saarland Cancer Registry were used and included 9359 female patients with primary invasive BRC diagnosed between 1999 and 2009. Estimates of the cumulative incidence (CI) of BRC recurrence were derived for patients who had received local surgery with free resection margins by type of recurrence and stratified by age, tumor characteristics and major treatment options, taking into account mortality from any cause as a competing risk.

RESULTS

The 10-year CI of BRC recurrence was 16%. For loco-regional recurrence and distant metastases alone it was 8 and 11%, respectively. The estimates showed substantial variation and were particularly increased if tumors were advanced (T1/2N+ 23%, T3/4N0 24%, T3/4N+ 34%), of high grade (23%), or of 'HER2/neu positive' (28%) or 'triple negative' subtype (23%), respectively.

CONCLUSIONS

The derived estimates reflect the risk of 'real world' patients and may therefore extend available knowledge. These data are thus of great relevance for clinicians, their patients and researchers. The study likewise demonstrated the usefulness of cancer registries for a population-based monitoring of the effectiveness of cancer care in terms of disease recurrence as a major treatment related outcome measure.

Post-mastectomy radiation in node-positive breast cancer in Ontario

More recent guidelines are more supportive for post-mastectomy radiation in all node-positive breast cancer patients. We examined the rate and predictors of post-mastectomy radiation receipt in Ontario Canada from 2010 to 2014. Of 6535 node-positive post-mastectomy patients, 73.9% received radiation. The rate was 68.7% (2903/4227) among women with 1-3 positive nodes. Radiation was less likely to be administered to women who were older, had high levels of comorbidity, or presented with early stages of breast cancer. Regional practice variation was reassuringly modest.

Mastectomy or Breast-Conserving Therapy for Early Breast Cancer in Real-Life Clinical Practice: Outcome Comparison of 7565 Cases

Although the organ preservation strategy by breast-conserving surgery (BCS) followed by radiation therapy (BCT) has revolutionized the treatment approach of early stage breast cancer (BC), the choice between treatment options in this setting can still vary according to patient preferences. The aim of the present study was to compare the oncological outcome of mastectomy versus breast-conserving therapy in patients treated in a modern clinical setting outside of clinical trials. 7565 women diagnosed with early invasive BC (pT1/2pN0/1) between 1998 and 2014 were included in this study (median follow-up: 95.2 months). In order to reduce selection bias and confounding, a subgroup analysis of a matched 1:1 case-control cohort consisting of 1802 patients was performed (median follow-up 109.4 months). After adjusting for age, tumor characteristics and therapies, multivariable analysis for local recurrence-free survival identified BCT as an independent predictor for improved local control (hazard ratio [HR]:1.517; 95%confidence interval:1.092–2.108, p = 0.013) as compared to mastectomy alone in the matched cohort. Ten-year cumulative incidence (CI) of lymph node recurrences was 2.0% following BCT, compared to 5.8% in patients receiving mastectomy (p < 0.001). Similarly, 10-year distant-metastasis-free survival (89.4% vs. 85.5%, p = 0.013) was impaired in patients undergoing mastectomy alone. This translated into improved survival in patients treated with BCT (10-year overall survival (OS) estimates 85.3% vs. 79.3%, p < 0.001), which was also significant on multivariable analysis (p = 0.011). In conclusion, the present study showed that patients treated with BCS followed by radiotherapy had an improved outcome compared to radical mastectomy alone. Specifically, local control, distant control, and overall survival were significantly better using the conservative approach. Thus, as a result of the present study, physicians should encourage patients to receive BCS with radiotherapy rather than mastectomy, whenever it is medically feasible and appropriate.

Recent Developments in Radiation Oncology: An Overview of Individualised Treatment Strategies in Breast Cancer

Radiation therapy (RT) for breast cancer has dramatically changed over the past years, leading to individualized risk-adapted treatment strategies. Historically, the choice of RT regimen was limited to conventional fractionation protocols using standard tangential fields. Nowadays, technological and technical improvements in modern RT have added a variety of other RT modalities, different fractionation schedules, and individualised treatment volumes to the portfolio of breast RT. This review aims to give a short overview on the main topics which have recently found their way into clinical practice: hypofractionated treatment protocols, accelerated partial breast irradiation (APBI) for low-risk patients, deep inspiration breath hold (DIBH) for maximal heart protection, extent of regional nodal irradiation for high-risk patients, and the implementation of new radiation techniques such as intensity modulated RT (IMRT) and volumetric modulated RT (VMAT).

Role of postoperative radiotherapy in reducing ipsilateral recurrence in DCIS: an observational study of 1048 cases

Background

The objective of the present study was to evaluate the effectiveness of postoperative radiotherapy after breast conserving surgery (BCS) in DCIS in a large patient population treated in clinical practice.

Methods

Data were provided by the population-based Munich Cancer Registry. Between 1998 and 2014, 1048 female patients with diagnosis of DCIS and treated at two Breast Care Centres were included in this observational study. The effectiveness of postoperative radiotherapy and variables predicting the use of radiotherapy were retrospectively analysed.

Results

After adjusting for age, tumour characteristics and therapies, Cox regression analysis for local recurrence-free survival identified RT as an independent predictor for improved local control (HR: 0.579; 95%CI: 0.384–0.872, p = 0.008). Ten-year cumulative incidence of in-breast recurrences was 20.0% following BCS, compared to 13.6% in patients receiving postoperative radiotherapy (p = 0.012). As an estimate for disease-specific survival, 10-year relative survival was 105.4% for patients receiving postoperative radiotherapy and 101.6% without radiotherapy. On multivariate analysis, postoperative radiotherapy was not associated with improved overall survival (HR 0.526; 95%CI: 0.263–1.052, p = 0.069). Over time, a significant increase of RT was registered: while 1998 only 42.9% of patients received postoperative radiotherapy, the proportion rose to 91.2% in 2014. Women aged < 50 years (OR: 2.559, 95%CI: 1.416–4.625, p < 0.001) or with negative hormone receptor status (OR: 2.625, 95%CI: 1.458–4.728, p = 0.001) or receiving endocrine therapy (OR: 1.762, 95%CI: 1.060–2.927, p = 0.029) were more likely to receive postoperative radiotherapy after BCS.

Conclusions

In conclusion, this study provides insights regarding the adoption and treatment pattern of postoperative RT following BCS for DCIS in a large cohort reflecting “real-life” clinical practice in this setting. Postoperative RT was found to be associated with a reduced risk of ipsilateral recurrence and no survival benefit compared to observation alone.