Eight-year follow up result of the OTOASOR trial: The Optimal Treatment Of the Axilla - Surgery Or Radiotherapy after positive sentinel lymph node biopsy in early-stage breast cancer: A randomized, single centre, phase III, non-inferiority trial

Postmastectomy radiotherapy in T1-2 patients with one to three positive lymph nodes - Past, present and future

PAST: The role of post-mastectomy radiotherapy (PMRT) in patients with tumor <5 cm and one to three positive lymph nodes after axillary dissection (ALND) is vigorously debated. Initial doubts over the efficacy and safety of PMRT in these patients were partially overcome by improvement in technology and systemic treatments. Several randomized controlled clinical trials confirmed benefit of PMRT in N1 patients, which were meta-analyzed by the Early Breast Cancer Trialists' Collaborative Group (EBCTCG). This meta-analysis provides the sole high-level evidence to guide clinical decision-making. PRESENT: Nevertheless, concerns have been evoked around these results, most notably concerning the patient selection bias and the era in which the patients were treated. More recent studies, albeit retrospective, are in contrast with this level I evidence, unequivocally reporting inferior recurrence rates in control arms than those of the EBCTCG meta-analysis. Taken together, these results suggest that one solution would not fit all N1 patients and that patient selection for PMRT shall be stratified upon risks factors. Most prominent of such factors identified are: patient age; number and ratio of positive lymph nodes; histological features such as lymphovascular invasion; and hormone receptor expression. FUTURE: A prospective randomized controlled trial SUPREMO will release its final results in 2023 and shed light onto the subject. Genomic tumor cell profiling will likely provide further guidelines in terms of risk stratification. SUPREMO translational sub-study will also offer material for genomic analyses. A cross-field tendency to forgo nodal dissection in favor of sentinel lymph node biopsy followed by nodal irradiation might eventually render the question of PMRT indication after ALND irrelevant.

Which target volume should be considered when irradiating the regional nodes in breast cancer? Results of a network-meta-analysis

Purpose/objective(s)

Radiation treatment to the regional nodes results in an improvement in survival in breast cancer according to a meta-analysis of randomized trials. However, different volumes were targeted in these studies: breast or chestwall only (WBI/CWI), inclusion of the medial supraclavicular region and axillary apex (MS + WBI/CWI) or additional inclusion of the internal mammary chain (IM + MS + WBI/CWI). The benefit of treating the medial supraclavicular region and axillary apex compared to tangential breast or chestwall irradiation only remains unclear.

Materials/methods

A literature search was conducted identifying trials for adjuvant radiation volumes in nodal irradiation after breast surgery and axillary treatment. Events and effect sizes were extracted from the publications for the endpoints of overall survival (OS), breast cancer-specific survival (BCSS), disease-free survival (DFS), distant metastasis-free survival (DMFS) and loco-regional control (LRC). A network meta-analysis was performed using MetaXL V5.3 with the inverse variance heterogeneity model.

Results

We found two randomized studies (n = 5836) comparing comprehensive nodal irradiation to sole breast treatment as well as one randomized (n = 1407) and one prospective cohort study (n = 3377) analysing the additional treatment of the internal mammary chain against sole local and supraclavicular and axillary apex radiation. Compared to WBI/CWI alone the treatment of IM + MS + WBI/CWI (HR = 0.88; CI:0.78-0.99; p = 0.036) results in improved OS unlike MS + WBI/CWI (HR = 0.99; CI:0.86-1.14; p = 0,89). These results are confirmed in BCSS: IM + MS + WBI/CWI (HR = 0.82; CI:0.72-0.92; p = 0.002) and MS + WBI/CWI (HR = 0.96; CI:0.79-1.18; p = 0.69). PFS is significantly improved with the treatment of MS + WBI/CWI (OR = 0.83; CI:0.71-0.97; p = 0.019). Both nodal treatment volumes improve LRC (MS + WBI/CWI OR = 0.74; CI:0.62-0.87; p = 0.004 and IM + MS + WBI/CWI OR = 0.60; CI:0.43-0.86; p < 0,001). Yet only the internal mammary nodes provide a benefit in DMFS (MS + WBI/CWI HR = 0.97; CI:0.81-1.16; p = 0.74 and IM + MS + WBI/CWI HR = 0.84; CI:0.75-0.94; p = 0.002).

Conclusion

Expanding the radiation field to the axillary apex and supraclavicular nodes after axillary node dissection reduced loco-regional recurrences without improvement in overall and cancer-specific survival. A prolongation in survival due to regional nodal irradiation is achieved when the internal mammary chain is included. This derives from a reduction in distant metastasis.

Evolution of the Use of Completion Axillary Lymph Node Dissection in Patients with T1/2N0M0 Breast Cancer and Tumour-Involved Sentinel Lymph Nodes Undergoing Mastectomy: A Cohort Study

BACKGROUND

In breast cancer, completion axillary lymph node dissection (cALND) was previously recommended for patients with at least one tumour-affected sentinel lymph node (SLN). Several prospective trials predominantly in patients undergoing breast-conserving surgery showed no benefit and increased arm morbidity with this procedure. We report the influence of these trials on clinical practice of patients undergoing mastectomy.

METHODS

We analysed prospectively collected data from patients with primary invasive breast cancer treated at German breast cancer units between January 2008 and December 2015. Time trends of cALND rates were analysed in patients undergoing mastectomy for T1/2N0M0 breast cancer with one or two tumour-involved SLNs. Multivariable logistic regression was used to determine factors influencing the decision not to perform cALND.

RESULTS

Among the entire study cohort of 166,074 patients treated at 179 breast cancer units, 4093 patients (2%) had T1/2N0M0 breast cancer with one or two tumour-involved SLNs and underwent mastectomy. cALND rates decreased from 89.9% in 2010 to 55.5% in 2015 (p < 0.001). Rates decreased from 82% to 8% in patients with micrometastatic SLN disease and from 93% to 63% in those with macrometastasis (p < 0.001). In multivariable analysis, factors associated with omission of cALND were treatment at a general, nonacademic hospital, pT1 status, older age, higher number of removed SLNs, fewer tumour-affected SLNs, and SLN micrometastasis (all p < 0.001).

CONCLUSIONS

Despite limited evidence from prospective trials relating to the omission of cALND specifically in patients undergoing mastectomy, our nationwide data show that use of cALND decreased in these patients in routine clinical practice.

The Evolving and Multidisciplinary Considerations in Nodal Radiation in Breast Cancer

The therapeutic management of regional lymph nodes in breast cancer has seen a remarkable change in the past 2 decades. Clinical trials have refined our knowledge regarding the biology of the disease including the prognostic significance of disease in the regional lymph nodes. The contemporary management of lymph nodes is also influenced by advances in surgical technique, radiation oncology delivery systems, and effective systemic therapy regimens. This paper describes the role of regional nodal irradiation in the context of the de-escalation of axillary surgery, improved understanding of the molecular and pathologic features, and increasing use of neoadjuvant chemotherapy.

Axillary management still needed for patients with sentinel node micrometastases

More attention has been paid to the axillary management over the past 50 years, and clinical practice has been changed as results of the random controlled trials. The American College of Surgeons Oncology Group Z0011 and International Breast Cancer Study Group (IBCSG) 23-01 trials provided high-level evidence to support the omission of axillary lymph nodes dissection (ALND) in sentinel lymph node (SLN)-positive patients receiving breast-conserving surgery (BCS) and adjuvant systemic treatment. In patients treated with BCS, whole breast irradiation (WBI) with tangential fields could lead to substantial axillary irradiation and control the residual tumor burden in axilla, whereas (intraoperative) partial breast irradiation has no therapeutic effect on these residual axillary metastases. In the observation group of the IBCSG 23-01 trial, 425 patients received BCS and 80 (18.8%) of them just underwent intra-operative radiotherapy. While the 10-year axillary recurrence rate was acceptable low (1.7%, 8/467) in the no ALND group, it was 4.5% (6/134) in patients without axillary management, which was significantly higher than that of 0.6% (2/333) in patients with axillary management (P=0.0024). Should we accept an axillary recurrence rate as high as 4.5% in patients with only SLNs micrometastases? What is the best way to control the residual tumor burden in the axilla and decrease the recurrence rate if there is no ALND? The evidence showed that both WBI after BCS (Z0011, AATRM [Agència d’Avaluació de Tecnologia i Recerca Mèdiques]) and axillary regional nodal irradiation after mastectomy/BCS OTOASOR (Optimal Treatment Of the Axilla - Surgery Or Radiotherapy), AMAROS (After Mapping of the Axilla: Radiotherapy Or Surgery) could control the regional residual tumor burden when the SLN is positive and an ALND is omitted. In the modern era, systemic therapy could further decrease the risk of local/regional recurrences. After the subanalysis of the POSNOC (POsitive Sentinel NOde: adjuvant therapy alone versus adjuvant therapy plus Clearance or axillary radiotherapy), SERC (Sentinelle Envahiet Randomisation du Curage), and Dutch BOOG (BOrstkanker Onderzoek Groep) trials, a prediction model might be established to identify those patients who could beneft from no axillary management as a guide to clinical practice. At present, axillary management should still be required for patients with SLN micrometastases.

Low Risk of Development of a Regional Recurrence After an Unsuccessful Repeat Sentinel Lymph Node Biopsy in Patients with Ipsilateral Breast Tumor Recurrence

BACKGROUND

Unlike sentinel lymph node biopsy (SLNB) in the primary setting, the repeat SLNB (rSLNB) in patients with ipsilateral breast tumor recurrence (IBTR) is challenging, because it is difficult to visualize and/or harvest a sentinel lymph node in every patient. Regional treatments options and safety in terms of regional disease control after such an unsuccessful rSLNB remain unclear. This study assesses factors associated with the performance of axillary lymph node dissection (ALND) after unsuccessful rSLNB and evaluates the occurrence of regional recurrences.

METHODS

Data were obtained from the Sentinel Node and Recurrent Breast Cancer (SNARB) study. In 239 patients, the rSLNB was unsuccessful, of whom 60 patients underwent ipsilateral ALND.

RESULTS

A shorter time interval between primary treatment and IBTR, and a primary negative SLNB were significantly associated with a higher probability to be treated with ALND after unsuccessful rSLNB (P < 0.001). The 5-year regional-recurrence rate was 0.0% in the ALND group compared with 3.7% in the group treated without ALND (P = 0.113). Of the 179 patients treated without ALND, after a median follow-up of 5.1 years (range 0.3-13.2), 7 (3.9%) developed a regional recurrence as first event after unsuccessful rSLNB. None of the seven recurrences occurred in the ipsilateral axilla. Univariable analysis showed no factors associated with regional recurrence as first event after unsuccessful rSLNB (P > 0.05).

CONCLUSIONS

The present study demonstrates that the risk of regional recurrence in patients with an IBTR and an unsuccessful rSLNB is negligible, irrespective of the use of ALND. This suggests that there is no need for additional treatment of the axilla after an unsuccessful rSLNB.

Retrospectively validating the results of the ACOSOG Z0011 trial in a large Asian Z0011-eligible cohort

PURPOSE

The Z0011 trial demonstrated that axillary dissection (ALND) could be omitted during breast-conserving therapy for cT1-2N0 breast cancers with 1-2 metastatic SLNs. However, that result has not been validated in a larger cohort and the significance of the small number of SLNs remains unclear. This study aimed to validate the Z0011 results within an Asian Z0011-eligible cohort and determine whether the number of sentinel lymph nodes (SLNs) influenced the Z0011-based outcomes.

METHODS

Data from Asian patients who fulfilled the Z0011 criteria were collected from five hospitals. Disease recurrence (DR) was compared between patients who underwent ALND or SLN dissection (SLND) alone. Propensity-score matching was performed to reduce the effects of potential selection biases.

RESULTS

During 2010-2016, 1750 Asian patients had 1-2 SLN metastases and fulfilled the Z0011 criteria. These patients included 707 cases treated using SLND alone (40%) and 967 patients with ≤ 2 SLNs (55%). Ninety-five patients (5.4%) experienced DR at a median interval of 50 months, although the rates of DR were similar in the ALND and SLND groups. The adjusted hazard ratios for DR after ALND omission were 0.95 (95% CI 0.55-1.64) among the entire cohort and 0.83 (95% CI 0.34-2.03) among patients with ≤ 2 SLNs.

CONCLUSIONS

In this Asian Z0011-eligible cohort, ALND omission did not increase risk of DR, even among patients with ≤ 2 SLNs. Therefore, the Z0011 strategy might be safely applied in Asia, and a small number of SLNs did not significantly influence this strategy.

Does the number of removed axillary lymphnodes in high risk breast cancer patients influence the survival?

Background

The decision making process for axillary dissection has changed in recent years for patients with early breast cancer and positive sentinel lymph nodes (LN). The question now arises, what is the optimal surgical treatment for patients with positive axillary LN (pN+). This article tries to answer the following questions:

Is there a survival benefit for breast cancer patients with 3 or more positive LN (pN3+) and with more than 10 removed LN?

Is there a survival benefit for high risk breast cancer patients (triple negative or Her2 + breast cancer) and with 3 or more positive LN (pN3+) with more than 10 removed LN?

In pN + patients is the prognostic value of the lymph node ratio (LNR) of pN+/pN removed impaired if 10 or less LN are removed?

Methods

A retrospective database analysis of the multi center cohort database BRENDA (breast cancer under evidence based guidelines) with data from 9625 patients from 17 breast centers was carried out. Guideline adherence was defined by the 2008 German National consensus guidelines.

Results

2992 out of 9625 patients had histological confirmed positive lymph nodes. The most important factors for survival were intrinsic sub types, tumor size and guideline adherent chemo- and hormonal treatment (and age at diagnosis for overall survival (OAS)). Uni-and multivariable analyses for recurrence free survival (RFS) and OAS showed no significant survival benefit when removing more than 10 lymph nodes even for high-risk patients. The mean and median of LNR were significantly higher in the pN+ patients with ≤10 excised LN compared to patients with > 10 excised LN. LNR was in both, uni-and multivariable, analysis a highly significant prognostic factor for RFS and OAS in both subgroups of pN + patients with less respective more than 10 excised LN. Multivariable COX regression analysis was adjusted by age, tumor size, intrinsic sub types and guideline adherent adjuvant systemic therapy.

Conclusion

The removal of more than 10 LN did not result in a significant survival benefit even in high risk pN + breast cancer patients.

Tailored axillary surgery with or without axillary lymph node dissection followed by radiotherapy in patients with clinically node-positive breast cancer (TAXIS): study protocol for a multicenter, randomized phase-III trial

Background

Complete lymph node removal through conventional axillary dissection (ALND) has been standard treatment for breast cancer patients for almost a century. In the 1990s, however, and in parallel with the advent of the sentinel lymph node (SLN) procedure, ALND came under increasing scrutiny due to its association with significant patient morbidity. Several studies have since provided evidence to suggest omission of ALND, often in favor of axillary radiation, in selected clinically node-negative, SLN-positive patients, thus supporting the current trend in clinical practice. Clinically node-positive patients, by contrast, continue to undergo ALND in many cases, if only for the lack of studies re-assessing the indication for ALND in these patients. Hence, there is a need for a clinical trial to evaluate the optimal treatment for clinically node-positive breast cancer patients in terms of surgery and radiotherapy. The TAXIS trial is designed to fill this gap by examining in particular the value of tailored axillary surgery (TAS), a new technique for selectively removing positive lymph nodes.

Methods

In this international, multicenter, phase-III, non-inferiority, randomized controlled trial (RCT), including 34 study sites from four different countries, we plan to randomize 1500 patients to either receive TAS followed by ALND and regional nodal irradiation excluding the dissected axilla, or receive TAS followed by regional nodal irradiation including the full axilla. All patients undergo adjuvant whole-breast irradiation after breast-conserving surgery and chest-wall irradiation after mastectomy. The main objective of the trial is to test the hypothesis that treatment with TAS and axillary radiotherapy is non-inferior to ALND in terms of disease-free survival of clinically node-positive breast cancer patients in the era of effective systemic therapy and extended regional nodal irradiation. The trial was activated on 31 July 2018 and the first patient was randomized on 7 August 2018.

Discussion

Designed to test the hypothesis that TAS is non-inferior to ALND in terms of curing patients and preventing recurrences, yet is significantly superior in reducing patient morbidity, this trial may establish a new worldwide treatment standard in breast cancer surgery. If found to be non-inferior to standard treatment, TAS may significantly contribute to reduce morbidity in breast cancer patients by avoiding surgical overtreatment.

Trial registration

ClinicalTrials.gov, ID: NCT03513614. Registered on 1 May 2018.

www.kofam.ch, ID: NCT03513614. Registered on 17 June 2018.

EudraCT No.: 2018–000372-14.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3021-9) contains supplementary material, which is available to authorized users.

What Is the Best Management of cN0pN1(sn) Breast Cancer Patients?

Although the majority of breast cancer patients are clinically node-negative (cN0) at diagnosis, 15-20% will have a metastatic sentinel lymph node (SLN, pN1(sn)). While a less radical approach regarding axillary surgery in cN0 patients with a positive SLN biopsy is advocated, the limitations of 5 published trials on axillary management in pN1(sn) are discussed intensely in the literature and support the performance of ongoing validation and extension trials, especially considering the lack of data in the setting of mastectomy. As locoregional radiotherapy has a significant effect on both recurrence and survival, a standardization of locoregional radiotherapy in the situation of SLN biopsy alone in pN1(sn) patients has to be defined in the future, and de-escalation trials should embrace a truly multidisciplinary approach. This is also of utmost importance considering the fact that high-volume nodal disease requires an intensified adjuvant chemotherapy strategy to which patients omitting axillary dissection cannot be stratified. Finally, there is mounting evidence that the therapeutic role of extensive axillary surgery in low-volume nodal disease is negligible, and multidisciplinary and translational efforts must be undertaken to individualize treatment in order to gain a reasonable balance between necessary staging information and unnecessary treatment-related morbidity.

The sentinel lymph node of breast cancer and the radiation oncologist

If the indications of sentinel lymph node biopsy and axillary lymph node dissection have been the subject of many trials, the indications of radiotherapy, in the absence of axillary lymph node dissection are a matter of debate. We reviewed the available literature on this topic and tried to draw some practical applications. In case of negative result of a sentinel lymph node biopsy, patients could be viewed as having pN0 disease and indications of adjuvant radiotherapy based on this paradigm. However, when the result of a sentinel lymph node biopsy was positive and no axillary lymph node dissection performed, indications of adjuvant radiotherapy are not so clear. For example, micrometastases could indicate a nodal irradiation as in the AMAROS trial, or not as in the IBCSG trial. Indications of postmastectomy radiotherapy are also not clearly defined in this setting. In the end, a clinical proposal was designed, emphasizing the unanswered questions.

The rationale for and long-term outcome of incomplete axillary staging in elderly women with primary breast cancer

BACKGROUND

The proportion of elderly women diagnosed with breast cancer is rising. Standard treatment, including axillary staging, is often not given to these patients. This study aimed to investigate reasons to omit any surgical axillary staging or to refrain from completion axillary lymph node dissection (cALND) after positive-sentinel lymph node biopsy (SLNB); so-called "incomplete staging". Furthermore, the impact of incomplete staging on regional control and survival in patients aged 75 or older was evaluated.

METHODS

A retrospective cohort study was conducted including all primary breast cancer patients aged 75 or older, diagnosed between 2001 and 2008, and documented by the Netherlands Cancer Registry (NCR). Patients with incomplete staging were compared to patients with complete axillary staging. Survival analyses were used to determine the risk of local, regional and distant recurrence and overall survival.

RESULTS

In total, 1467 of 2116 (69%) patients were considered eligible, of whom 258 (17.2%) had incomplete axillary staging. For 93 patients, diagnosed in 6 of the 10 hospitals in the NCR-area, examination of clinical records revealed that age, comorbidities and patient preferences were the main reason for omitting complete axillary staging. The 10-year axillary recurrence rate in these 93 patients was 5.2% (95% CI, 0.03-10.1). Of the 77 patients who had died, 64 (83%) died of non-breast-cancer-related causes. No significant difference in overall survival was observed between patients with or without complete axillary staging.

CONCLUSION

This study demonstrates that the omission of complete axillary staging is common in selected elderly breast cancer patients with ≥2 comorbidities, with no apparent impact on regional control and 10-year overall survival.

Lymph Node Radiotherapy Instead of Extended Axillary Surgery - the New Standard?

Breast cancer treatment has undergone major changes in the last 20 years. Specifically, the role of axillary lymph node dissection has changed from radical axillary dissection with excision of a high number of lymph nodes to sentinel lymph node biopsy (SLNB). This paradigm shift is associated with a controversial debate regarding the significance of axillary staging, the need for surgery, and the role of radiotherapy. Looking ahead, lymph node staging and axillary treatment might shift from SLNB and/or axillary dissection to ultrasound-guided needle biopsy and irradiation of regional lymph nodes in order to reduce treatment-related sequelae in early-stage breast cancer.

Multidisciplinary Management of the Axilla in Patients with cT1-T2 N0 Breast Cancer Undergoing Primary Mastectomy: Results from a Prospective Single-Institution Series

BACKGROUND

The after mapping of the axilla: radiotherapy or surgery (AMAROS) trial concluded that for patients with cT1-2 N0 breast cancer and one or two positive sentinel lymph nodes (SLNs), axillary radiotherapy (AxRT) provides equivalent locoregional control and a lower incidence of lymphedema compared with axillary lymph node dissection (ALND). The study prospectively assessed how often ALND could be replaced by AxRT in a consecutive cohort of patients undergoing mastectomy for cT1-2 N0 breast cancer.

METHODS

In November 2015, our multidisciplinary group agreed to omit routine intraoperative SLN evaluation for cT1-2 N0 patients undergoing upfront mastectomy and potentially eligible for postmastectomy radiation therapy (PMRT), including those 60 years of age or younger and those older than 60 years with high-risk features. Patients with one or two positive SLNs on final pathology were reviewed to determine whether PMRT including the full axilla was an appropriate alternative to ALND.

RESULTS

From November 2015 to December 2016, 154 patients met the study criteria, and 114 (74%) formed the final study cohort. Intraoperative SLN evaluation was omitted for 76 patients (67%). Of these patients, 20 (26%) had one or two positive SLNs, and 14 of these patients received PMRT + AxRT as an alternative to ALND. Three patients returned for ALND, and three patients were observed. On univariate analysis, tumor size, LVI, number of positive lymph nodes, and receipt of chemotherapy were associated with receipt of PMRT.

CONCLUSIONS

For the majority of patients with one or two positive SLNs, ALND was avoided in favor of PMRT + AxRT. With appropriate multidisciplinary strategies, intraoperative evaluation of the SLN and immediate ALND can be avoided for patients meeting the AMAROS criteria and eligible for PMRT.

A new model to predict risk of nonsentinel lymph node status in Chinese sentinel lymph node-positive patients after neoadjuvant chemotherapy

There is no previous predictive model to assess risk of nonsentinel lymph node metastases (NSLN) in sentinel lymph node (SLN)-positive breast cancer patients after neoadjuvant chemotherapy (NAT). Our goal was to develop a new predictive model for SLN-positive patients after NAT, and validate this new model. A series of 513 patients with metastases in SLN who received NAT were used to evaluate factors affecting NSLN status. Logistic regression analysis was performed to develop a predictive model, which was validated by a subsequent prospective 138 patients. There were 115 (22.4%) patients with metastases in NSLN followed by axillary lymph node dissection (ALND). Multivariate analysis indicated that tumor (T) stage, number of positive SLN,micrometastases, extracapsular extension (ECE), and clinical response of primary tumor after NAT were significant independent predictors for the NSLN metastases. Area under the curve (AUC) of the model was 0.795 (95% CI, 0.734-0.861). When applied to the prospective series, the model accurately predicted the risk of NSLN disease, AUC was 0.772 (95% CI, 0.653-0.845). We present a new predictive model to assess the risk of NSLN status in Chinese SLN-positive breast cancer patients after NAT. The predictive model performed well in prospective validation but needs to be further studied in external center patients before application to clinical use.