Patterns of practice of regional nodal irradiation in breast cancer: results of the European Organization for Research and Treatment of Cancer (EORTC) NOdal Radiotherapy (NORA) survey

Radiotherapy to regional nodes in early breast cancer: an individual patient data meta-analysis of 14 324 women in 16 trials

BACKGROUND

Radiotherapy has become much better targeted since the 1980s, improving both safety and efficacy. In breast cancer, radiotherapy to regional lymph nodes aims to reduce risks of recurrence and death. Its effects have been studied in randomised trials, some before the 1980s and some after. We aimed to assess the effects of regional node radiotherapy in these two eras.

METHODS

In this meta-analysis of individual patient data, we sought data from all randomised trials of regional lymph node radiotherapy versus no regional lymph node radiotherapy in women with early breast cancer (including one study that irradiated lymph nodes only if the cancer was right-sided). Trials were identified through the EBCTCG's regular systematic searches of databases including MEDLINE, Embase, the Cochrane Library, and meeting abstracts. Trials were eligible if they began before Jan 1, 2009. The only systematic difference between treatment groups was in regional node radiotherapy (to the internal mammary chain, supraclavicular fossa, or axilla, or any combinations of these). Primary outcomes were recurrence at any site, breast cancer mortality, non-breast-cancer mortality, and all-cause mortality. Data were supplied by trialists and standardised into a format suitable for analysis. A summary of the formatted data was returned to trialists for verification. Log-rank analyses yielded first-event rate ratios (RRs) and confidence intervals.

FINDINGS

We found 17 eligible trials, 16 of which had available data (for 14 324 participants), and one of which (henceforth excluded), had unavailable data (for 165 participants). In the eight newer trials (12 167 patients), which started during 1989-2008, regional node radiotherapy significantly reduced recurrence (rate ratio 0·88, 95% CI 0·81-0·95; p=0·0008). The main effect was on distant recurrence as few regional node recurrences were reported. Radiotherapy significantly reduced breast cancer mortality (RR 0·87, 95% CI 0·80-0·94; p=0·0010), with no significant effect on non-breast-cancer mortality (0·97, 0·84-1·11; p=0·63), leading to significantly reduced all-cause mortality (0·90, 0·84-0·96; p=0·0022). In an illustrative calculation, estimated absolute reductions in 15-year breast cancer mortality were 1·6% for women with no positive axillary nodes, 2·7% for those with one to three positive axillary nodes, and 4·5% for those with four or more positive axillary nodes. In the eight older trials (2157 patients), which started during 1961-78, regional node radiotherapy had little effect on breast cancer mortality (RR 1·04, 95% CI 0·91-1·20; p=0·55), but significantly increased non-breast-cancer mortality (1·42, 1·18-1·71; p=0·00023), with risk mainly after year 20, and all-cause mortality (1·17, 1·04-1·31; p=0·0067).

INTERPRETATION

Regional node radiotherapy significantly reduced breast cancer mortality and all-cause mortality in trials done after the 1980s, but not in older trials. These contrasting findings could reflect radiotherapy improvements since the 1980s.

FUNDING

Cancer Research UK, Medical Research Council.

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.

A Questionnaire Survey of Current Practice in the Management of Internal Mammary Lymph Nodes in Breast Cancer

Background Radiotherapy (RT) is an important modality in the management of breast cancers (BC). Large randomized trials have suggested that prophylactic regional nodal irradiation inclusive of internal mammary lymph nodes (IMLN) reduces BC-related mortality. However, the adoption of IMLN-RT has been variable due to relative benefits and toxicity concerns.

Methods A survey was emailed to radiation oncologists (ROs) across the country wherein they were asked about their practice regarding IMLN-RT in BC.

Results We received 128 responses, which included radiation oncologists across both private institutions (PIs) and government institutions (GIs). Fifty-six (43.8%) routinely offer prophylactic(p) IMLN-RT and an additional 15 (11.71%) suggested they would have offered it in the absence of logistic constraints. Almost all, 121 (94.5%) radiate the IMLN in case of radiologically positive lymph nodes (LNs).

Fifty-six ROs (43.8%) offered prophylactic IMLN-RT in node-negative disease. Among those who did not offer IMLN-RT, most (84.72%) felt the clinical evidence was equivocal. Of the 56 who offered pIMLN-RT, 34/56 (60.71%) offered to locally advanced tumors, 20/56 (35.71%) offered to all inner and central tumors (ICQT), 29/56 (51.78%) to > 4 axillary LN-positive and 9/56 (16.07%) to any axillary LN-positive. The majority, i.e., 36/56 (64.28%) radiated upper three intercostal spaces, 9 (16.07%) radiated upper five intercostal spaces, and 6 (10.9%) decided based on tumor location, while 5 (9%) irradiated one space below the involved space.

Overall, simulation-based planning was undertaken in 99% of PIs as opposed to 89% of GIs (p = 0.03). The majority of ROs, i.e., 92 (72.4%) preferred IMRT to IMLN-RT.

In addition, the surgical approach to IMLN was practiced by surgeons at 18 (14%) centers, of which 13 (72.22%) operated the IMLN when radiologically evident. The IMLN dissection was preferentially performed for second and third intercostal spaces as suggested in 10 (55.55%) responses, while 8 (44.44%) performed thoracoscopic dissection of the IMLN chain. The distribution of prophylactic, definitive IMLN-RT, and IMLN dissection did not differ significantly between GI and PI (p = NS).

Conclusions pIMLN-RT is still not the standard protocol in most centers citing equivocal evidence in the literature. Logistics, though different in GIs and PIs, did not impact the decision of pIMLN-RT. Further efforts would be required to standardize practice in IMLN across India.

Should the management of radiation therapy for breast cancer be standardized? Results of a survey on current French practices in breast radiotherapy

Background

Breast cancer is the most frequent cancer in women in France. Its management has evolved considerably in recent years with a focus on reducing iatrogenic toxicity. The radiotherapy indications are validated in multidisciplinary consultation meetings; however, questions remain outstanding, particularly regarding hypofractionated radiotherapy, partial breast irradiation, and irradiation of the internal mammary chain and axillary lymph node area.

Materials and methods

An online survey was sent to 47 heads of radiotherapy departments in France. The survey consisted of 22 questions concerning indications for irradiation of the supraclavicular, internal mammary and axillary lymph node areas; irradiation techniques and modalities; prescribed doses; and fractionation.

Results

Twenty-four out of 47 centers responded (response rate of 51%). This survey demonstrated a wide variation in the prescribed dose regimen, monoisocentric radiotherapy, and indications of irradiation of the lymph node areas.

Conclusion

This survey provides insight into the current radiotherapy practice for breast cancer in France. It shows the need to standardize practices.

Breast clinical target volume: HU-based glandular CTVs and ESTRO CTVs in modern and historical radiotherapy treatment planning

PURPOSE

The current study aimed to compare contouring of glandular tissue only (gCTV) with the clinical target volume (CTV) as defined according to European Society for Radiotherapy and Oncology (ESTRO) guidelines (eCTV) and historically treated volumes (marked by wire and determined by palpation and anatomic landmarks) in breast cancer radiotherapy.

METHODS

A total of 56 consecutive breast cancer patients underwent treatment planning based solely on anatomic landmarks/wire markings ("wire based"). From these treatment plans, the 50% and 95% isodoses were transferred as structures and compared to the following CT-based volumes: eCTV; a Hounsfield unit (HU)-based automatic contouring of the gCTV; and standardized planning target volumes (PTVs) generated with 1‑cm safety margins (resulting in the ePTVs and gPTVs, respectively).

RESULTS

The 95% isodose volume of the wire-based plan was larger than the eCTV by 352.39 ± 176.06 cm³ but smaller than the ePTV by 157.58 ± 189.32 cm³. The 95% isodose was larger than the gCTV by 921.20 ± 419.78 cm³ and larger than the gPTV by 190.91 ± 233.49 cm³. Patients with larger breasts had significantly less glandular tissue than those with small breasts. There was a trend toward a lower percentage of glandular tissue in older patients.

CONCLUSION

Historical wire and anatomic landmarks-based treatment planning sufficiently covers the glandular tissue and the theoretical gPTV generated for the glandular tissue. Modern CT-based CTV and PTV definition according to ESTRO results in a larger treated volume than the historical wire-based techniques. HU-standardized glandular tissue contouring results in a significantly smaller CTV and might be an option for reducing the treatment volume and improving reproducibility of contouring between institutions.

Tricks and tips for target volume definition and delineation in breast cancer: Lessons learned from ESTRO breast courses

Delineation of target and 'organ at risk' volumes is a critical part of modern radiation therapy planning, the next essential step after deciding the indication, patient discussion and image acquisition. Adoption of volume-based treatment planning for non-metastatic breast cancer has increased greatly along with the use of improved planning techniques, essential for modern therapy. However, identifying the volumes on a planning CT is no easy task. The current paper is written by ESTRO's breast course faculty, providing tricks and tips for target volume definition and delineation for optimal postoperative breast cancer irradiation.

Internal mammary node irradiation in node-positive breast cancer treated with mastectomy and taxane-based chemotherapy

BACKGROUND

It is important to continually reevaluate the risk/benefit calculus of internal mammary node irradiation (IMNI) in the era of modern systemic therapy. We aimed to investigate the effect of IMNI on survival in node-positive breast cancer treated with mastectomy and anthracycline plus taxane-based chemotherapy.

METHODS

We analyzed 348 patients who underwent mastectomy and anthracycline plus taxane-based chemotherapy for node-positive breast cancer between January 2006 and December 2011. All patients received postoperative radiation therapy (RT) with IMNI (n = 105, 30.2%) or without IMNI (n = 243, 69.8%). The benefit of IMNI for disease-free survival (DFS) and overall survival (OS) was evaluated using multivariate analysis and inverse probability of treatment weighting (IPTW) to adjust for unbalanced covariates between the groups.

RESULTS

After a median follow-up of 95 months, the 10-year locoregional recurrence-free survival rate, DFS, and OS in all patients were 94.8%, 77.4%, and 86.2%, respectively. The IPTW-adjusted hazard ratio (HR) for the association of IMNI (vs. no IMNI) with DFS and OS was 0.208 (95% confidence intervals (CI) 0.045-0.966) and 0.460 (95% CI, 0.220-0.962), respectively. In multivariate analysis, IMNI was a favorable factor for DFS (HR, 0.458; P = 0.021) and OS (HR 0.233, P = 0.018).

CONCLUSIONS

IMNI was associated with improved DFS and OS in node-positive patients treated with mastectomy, post-mastectomy RT, and taxane-based chemotherapy, although the rate of locoregional recurrence was low.

Hypofractionated breast irradiation: a multidisciplinary review of the Senonetwork study group

The multidisciplinary management represents a crucial part of the care for cancer patients, resulting in better clinical and process outcomes, with evidence of improved survival among different cancer primary sites, including breast. According with international recommendations established by the European Society of Breast Cancer Specialists (EUSOMA), all breast-cancer patients have to be evaluated by a multidisciplinary team including radiologist, pathologist, surgeon, medical oncologist and radiation oncologist. Thus, variations in clinical practice of each specialty should be discussed and shared with all team members to guarantee a fruitful cooperation among the involved specialists. During the last decades, radiation treatment was deeply changed by the evidence-based adoption of hypofractionated radiotherapy (HFRT) as standard of treatment in patients with early-stage breast cancer undergoing conservative surgery. Moreover, mature randomized data have showed that partial breast irradiation (PBI) is an effective and safe alternative to whole breast irradiation in selected patients with low-risk early-stage breast cancer. Based on this background, we reviewed indications and critical issues of HFRT and PBI analyzing impact of their adoption from a multidisciplinary perspective.

Internal mammary and medial supraclavicular lymph node chain irradiation in stage I-III breast cancer (EORTC 22922/10925): 15-year results of a randomised, phase 3 trial

BACKGROUND

10-year results from several studies showed improved disease-free survival and distant metastasis-free survival, reduced breast cancer-related mortality, and variable effects on overall survival with the addition of partial or comprehensive regional lymph node irradiation after surgery in patients with breast cancer. We present the scheduled 15-year analysis of the European Organisation for Research and Treatment of Cancer (EORTC) 22922/10925 trial, which aims to investigate the impact on overall survival of elective internal mammary and medial supraclavicular (IM-MS) irradiation.

METHODS

EORTC 22922/10925, a randomised, phase 3 trial done across 46 radiation oncology departments from 13 countries, included women up to 75 years of age with unilateral, histologically confirmed, stage I-III breast adenocarcinoma with involved axillary nodes or a central or medially located primary tumour. Surgery consisted of mastectomy or breast-conserving surgery and axillary staging. Patients were randomly assigned (1:1) centrally using minimisation to receive IM-MS irradiation at 50 Gy in 25 fractions (IM-MS irradiation group) or no IM-MS irradiation (control group). Stratification was done for institution, menopausal status, site of the primary tumour within the breast, type of breast and axillary surgery, and pathological T and N stage. Patients and investigators were not masked to treatment allocation. The primary endpoint was overall survival analysed according to the intention-to-treat principle. Secondary endpoints were disease-free survival, distant metastasis-free survival, breast cancer mortality, any breast cancer recurrence, and cause of death. Follow-up is ongoing for 20 years after randomisation. This study is registered with ClinicalTrials.gov, NCT00002851.

FINDINGS

Between Aug 5, 1996, and Jan 13, 2004, we enrolled 4004 patients, of whom 2002 were randomly assigned to the IM-MS irradiation group and 2002 to the no IM-MS irradiation group. At a median follow-up of 15·7 years (IQR 14·0-17·6), 554 (27·7%) patients in the IM-MS irradiation group and 569 (28·4%) patients in the control group had died. Overall survival was 73·1% (95% CI 71·0-75·2) in the IM-MS irradiation group and 70·9% (68·6-72·9) in the control group (HR 0·95 [95% CI 0·84-1·06], p=0·36). Any breast cancer recurrence (24·5% [95% CI 22·5-26·6] vs 27·1% [25·1-29·2]; HR 0·87 [95% CI 0·77-0·98], p=0·024) and breast cancer mortality (16·0% [14·3-17·7] vs 19·8% [18·0-21·7]; 0·81 [0·70-0·94], p=0·0055) were lower in the IM-MS irradiation group than in the control group. No significant differences in the IM-MS irradiation group versus the control group were seen for disease-free survival (60·8% [95% CI 58·4-63·2] vs 59·9% [57·5-62·2]; HR 0·93 [95% CI 0·84-1·03], p=0·18), or distant metastasis-free survival (70·0% [67·7-72·2] vs 68·2% [65·9-70·3]; 0·93 [0·83-1·04], p=0·18). Causes of death between groups were similar.

INTERPRETATION

The 15-year results show a significant reduction of breast cancer mortality and any breast cancer recurrence by IM-MS irradiation in stage I-III breast cancer. However, this is not converted to improved overall survival.

FUNDING

US National Cancer Institute, Ligue Nationale contre le Cancer, and KWF Kankerbestrijding.

Development and external validation of a nomogram to predict four or more positive nodes in breast cancer patients with one to three positive sentinel lymph nodes

Objective

To develop a nomogram for predicting the possibility of four or more positive nodes in breast cancer patients with 1–3 positive sentinel lymph nodes (SLN).

Materials and methods

Retrospective analysis of data of patients from two institutions was conducted. The inclusion criteria were: invasive breast cancer; clinically node negative; received lumpectomy or mastectomy plus SLN biopsy followed by axillary lymph node dissection (ALND); and pathologically confirmed T1-2 tumor, with 1–3 positive SLNs. Patients from one institution formed the training group and patients from the other the validation group. Univariate and multivariate analyses were performed to identify the predictors of four or more positive nodes. These predictors were used to build the nomogram. The area under the receiver operating characteristic curve (AUC) was calculated to assess the accuracy of the model.

Results

Of the 1480 patients (966 patients in the training group, 514 in the validation group), 306 (20.7%) had four or more positive nodes. Multivariate stepwise logistic regression showed number of positive (p < .001) and negative SLN (p < .001), extracapsular extension (p < .001), pT stage (p = .016), and tumor location in outer upper quadrant (p = .031) to be independent predictors of four or more positive nodes. The nomogram was built using these five factors. The AUC was 0.845 in the training group and 0.804 in the validation group.

Conclusion

The proposed nomogram appears to accurately estimate the likelihood of four or more positive nodes and could help radiation oncologists to decide on use of regional nodal irradiation (RNI) for breast cancer patients with 1–3 positive nodes but no ALND.

•

Five predictors of four or more positive nodes in breast cancer patients were identified.

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A nomogram was built using these five factors.

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The nomogram was validated on an external cohort.

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The proposed nomogram predicts four or more positive nodes with high accuracy.

•

The nomogram can help in decision making on use of regional nodal irradiation.

Patient-reported acute fatigue in elderly breast cancer patients treated with and without regional nodal radiation

PURPOSE

Although regional nodal irradiation (RNI) improves outcomes in breast cancer (BC) patients, it is associated with increased toxicity. Therefore, controversy still exists surrounding its indications. The purpose of this study was to evaluate and compare patient-reported acute fatigue in elderly BC patients with and without regional nodal radiation (RNI).

METHODS

Elderly breast cancer patients (≥ 65 years) treated with adjuvant radiotherapy (RT) between 2012 and 2017 were identified from a prospective database. The validated Edmonton Symptom Assessment System-revised (ESAS-r) questionnaire, which assesses fatigue, was completed prior to (baseline), during, at end of RT and first follow-up (3-6 months). Symptoms were rated on a 10-point Likert scale, with higher scores indicating higher fatigue. Patient's treatment characteristics were also recorded prospectively. This was a retrospective study which identified elderly breast cancer patients who had received adjuvant radiation, completed ESAS-r prospectively and provided research consent for using ESAS-r. Patients were divided into two cohorts: those who received RNI (cohort 1) and those who did not (cohort 2). A minimal clinically important difference (MID) was defined using an anchor of ≥ 1-point compared to baseline. The proportion of patients reporting a change in fatigue at the end of RT was evaluated. To test the robustness of the results, dynamic changes of fatigue scores over time were further compared between the cohorts using a general linear mixed model (GLMM) after assuming individual patient with random effect. Univariate and multivariable logistic regression were conducted to assess the association between RNI and MID after adjusting for potential confounders. In addition to longitudinal analysis, a multivariable mixed effect model was developed to determine the association of RNI with fatigue after adjusting for potential confounders. A two-tailed p value ≤ 0.05 was considered statistically significant.

RESULTS

Of the 1198 patients, 859 had provided research consent and completed the ESAS-r at baseline and any other time-point and were included in the longitudinal analysis (cohort 1 = 159, cohort 2 = 700), while 637 (cohort 1 = 135, cohort 2 = 502) patients completed the ESAS-r at baseline and end of radiotherapy and were included in the anchor-based analysis. Mean age at diagnosis was similar between the groups: cohort 1; 71.5 ± 5.7 vs. cohort; 2 72 ± 5.4 years (total 71.8 ± 5.5). Overall, cohort 1 had higher stage (Stage 3: 32.7% vs 3.6%, p < 0.001) and reception of chemotherapy (68.6% vs. 16.1%, p < 0.001). Mean baseline fatigue was higher for cohort 1 vs. 2 (2.7 ± 2.5 vs. 2.1 ± 2.3, p = 0.006). On univariate and multivariable analyses, RNI was not associated with an increased odd of MID for fatigue at the end of RT (44% vs. 47%; OR 0.89, 95% CI 0.61-1.30, p = 0.56). After adjusting for confounders (age, duration of RT, endocrine therapy), treatment with RNI was not associated with increased odds of worse fatigue at the end of RT (OR 1.33, 95% CI 0.85-2.10, p = 0.22). Higher baseline fatigue (OR 0.86, 95% CI 0.79-0.92, p < 0.001) and receipt of chemotherapy had decreased odds (OR 0.50, 95% CI 0.32-0.86, p = 0.001) and were the only factors associated with decreased odds of MID. Dynamic changes showed a significant worsening of fatigue scores over time (p < 0.001) towards the end of RT and recovery at first follow-up (p < 0.001) with no difference between the cohorts (p = 0.38); both experienced parallel worsening of fatigue levels over time (cohort*time p = 0.71 and cohort*time²p = 0.78). On multivariable analysis earlier stage, the absence of chemotherapy and higher baseline depression were independent predictors of worse fatigue scores over time (p = 0.01, p = 0.003, and p = 0.02, respectively).

CONCLUSION

The addition of RNI in elderly BC patients is not associated with a significant worsening of patient-reported fatigue. Predictors of acute fatigue will enable shared decision making between patients and clinicians.

Utilization patterns and temporal trends of internal mammary nodal irradiation at a tertiary cancer center

PURPOSE

The role and uptake of internal mammary nodal irradiation (IMNI) is variable. This study was designed to quantify the rates and determinants of IMNI at a tertiary cancer center.

METHODS

Consecutively treated breast cancer patients receiving adjuvant locoregional radiation therapy (RT) from January 1, 2012 to December 31, 2017 were sorted by IMNI receipt, disease risk and time period of RT delivery (2012-2015 vs 2016-2017). Differences between risk categories and groups were evaluated using χ²/Fisher's and Mann-Whitney test for categorical and continuous variables, respectively. Univariable and multivariable logistic regression analysis was done to determine factors associated with IMNI receipt.

RESULTS

A total of 1566 patients were eligible, with 376 in Group 1 (IMNI), and 1190 in Group 2 (no IMNI). The proportion of patients receiving IMNI increased significantly each year (p < 0.0001), and 83% of patients receiving IMNI had pT1-2/pN1 disease. On univariable analysis, younger age, lymphovascular invasion, medial/central quadrant, higher stage, PR negative, mastectomy, axillary dissection, receipt of chemotherapy and nodal positivity had higher odds of IMNI. On multivariable analysis, younger age (p =  < 0.001), medial/central quadrant (p = 0.0026), PR negative (p = 0.0011), mastectomy (p = 0.0055), increasing nodal positivity (p < 0.0001) and late cohort (p = 0.001) had increased likelihood of IMNI. The use of deep-inspiration breath hold was significantly higher in those receiving IMNI (45% vs 26%, p < 0.0001), and permitted achievement of acceptable mean heart and lung doses.

CONCLUSIONS

There was a significant increase in IMNI utilization after 2015. Younger age, medial/central quadrant, PR-negative and node-positive disease predicted for receipt of IMNI. Modern RT techniques permit the safe delivery of IMNI.

Impact of Regional Nodal Irradiation on the Outcomes of N1 Breast Cancer Patients Referred for Adjuvant Treatment: A Patient-Level Pooled Analysis of 2 Clinical Trials

PURPOSE

To evaluate the impact of regional nodal irradiation (RNI) among N1 operable breast cancer patients who underwent adequate axillary dissection and received adjuvant chemotherapy.

PATIENTS AND METHODS

This is a pooled analysis of 812 breast cancer patients referred for adjuvant systemic therapy in 2 prospective randomized studies: NCT00174655 (BIG 02/98) and NCT00312208 (BCIRG005). Overall survival was assessed according to whether patients received supraclavicular and/or internal mammary radiotherapy through Kaplan-Meier estimates. Univariate and multivariate analyses of variables affecting overall and relapse-free survival were performed through Cox regression analysis. Additionally, recurrence rates were analyzed according to regional irradiation patterns.

RESULTS

Regional relapse rates (after a median follow-up of 76 months) were 1.5% in both groups of patients who received or did not receive supraclavicular radiotherapy. The risk of regional recurrence was 0.7% in patients who received internal mammary node radiotherapy versus 1.6% in patients who did not receive internal mammary node radiotherapy. The following factors were associated with worse overall survival in multivariate Cox regression analysis: age < 40 years (P < .0001), > T1 stage (P = .003), and negative hormone receptor status (P = .002). Neither supraclavicular nor internal mammary radiotherapy was associated with improvement in overall or relapse-free survival in Cox regression analysis.

CONCLUSION

The current analysis does not endorse the routine use of supraclavicular or internal mammary radiotherapy among N1 operable breast cancer patients who have undergone adequate dissection of axillary lymph nodes and who have received standard adjuvant systemic therapy. Given the limited power and potential selection bias of the current analysis, further prospective studies are needed to tackle this research question.

Compared with intensity-modulated radiotherapy, image-guided radiotherapy reduces severity of acute radiation-induced skin toxicity during radiotherapy in patients with breast cancer

Radiotherapy (RT) is an effective treatment for breast cancer. The side effects of breast irradiation, including skin toxicity in the irradiation field, cause considerable discomfort. This study compared the severity of skin toxicity caused by image-guided RT (IGRT) and intensity-modulated RT (IMRT) combined with an electronic portal imaging device (EPID) in breast cancer. This study retrospectively analyzed 458 patients with breast cancer who had received RT. The patients were divided into two groups: 302 and 156 patients in the IMRT and IGRT groups. In the IGRT group, 8 and 148 patients had received helical tomotherapy irradiation and IMRT with cone-beam computed tomography. Simple and multiple logistic regression analyses were used to estimate the relationship between RT technique and the severity of radiation skin toxicity. In our study, 284, 97, and 6 patients exhibited grades I, II, and III radiation dermatitis (RD). Moreover, 75 patients in the IMRT group (24.80%) and 22 patients in the IGRT group (14.10%) exhibited grade II RD. All patients with grade III RD were in the IMRT group (2.00%). No patient exhibited grade IV RD. The patients in the IGRT group exhibited less severity of RD than in the IMRT group. The severity of acute RD due to IGRT is significantly lower than that due to IMRT with EPID.

Prognostic Impact of Extracapsular Lymph Node Invasion on Survival in Non-small-Cell Lung Cancer: A Systematic Review and Meta-analysis

The extracapsular tumor extension (ECE) of nodal metastasis is an important prognostic factor in different types of malignancies. However, there is a lack of recent data in patients with non-small-cell lung cancer (NSCLC). In addition, the TNM staging system does not include ECE status as a prognostic factor. This systematic review and meta-analysis has been conducted to summarize and pool existing data to determine the prognostic role of ECE in patients with lymph node-positive NSCLC. Two authors performed an independent search in PubMed using a predefined keyword list, without language restrictions with publication date since 1990. Prospective or retrospective studies reporting data on prognostic parameters in subjects with NSCLC with positive ECE or with only intracapsular lymph node metastasis were retrieved. Data were summarized using risk ratios (RR) for the survival with 95% confidence intervals (CI). The data was analyzed using Mix 2 (ref: Bax L: MIX 2.0 - Professional software for meta-analysis in Excel. Version 2.015. BiostatXL, 2016. https://www.meta-analysis-made-easy.com ). There 2,105 studies were reviewed. Five studies covering a total of 828 subjects met the inclusion criteria and were included in the meta-analysis. Two hundred and ninety-eight (35.9%) patients were categorized as ECE+, of whom 54 (18.1%) survived at the end of follow-up. In the ECE-negative group, 257 patients (48.4%) survived by the end of follow-up. Thus, ECE status is associated with a significantly decreased survival rate: pooled RR 0.45 (95% CI 0.35-0.59), Q ₍₄₎ = 4.06, P _value = 0.39, and I ² = 68.00% (95 CI 0.00-79.55%). In conclusion, ECE has a significant impact on survival in NSCLC patients and should be considered in diagnostic and therapeutic decisions in addition to the current TNM staging. Postoperative radiotherapy may be an option in ECE-positive pN1 NSCLC patients.

Partial-breast radiotherapy after breast conservation surgery for patients with early breast cancer (UK IMPORT LOW trial): 5-year results from a multicentre, randomised, controlled, phase 3, non-inferiority trial

BACKGROUND

Local cancer relapse risk after breast conservation surgery followed by radiotherapy has fallen sharply in many countries, and is influenced by patient age and clinicopathological factors. We hypothesise that partial-breast radiotherapy restricted to the vicinity of the original tumour in women at lower than average risk of local relapse will improve the balance of beneficial versus adverse effects compared with whole-breast radiotherapy.

METHODS

IMPORT LOW is a multicentre, randomised, controlled, phase 3, non-inferiority trial done in 30 radiotherapy centres in the UK. Women aged 50 years or older who had undergone breast-conserving surgery for unifocal invasive ductal adenocarcinoma of grade 1-3, with a tumour size of 3 cm or less (pT1-2), none to three positive axillary nodes (pN0-1), and minimum microscopic margins of non-cancerous tissue of 2 mm or more, were recruited. Patients were randomly assigned (1:1:1) to receive 40 Gy whole-breast radiotherapy (control), 36 Gy whole-breast radiotherapy and 40 Gy to the partial breast (reduced-dose group), or 40 Gy to the partial breast only (partial-breast group) in 15 daily treatment fractions. Computer-generated random permuted blocks (mixed sizes of six and nine) were used to assign patients to groups, stratifying patients by radiotherapy treatment centre. Patients and clinicians were not masked to treatment allocation. Field-in-field intensity-modulated radiotherapy was delivered using standard tangential beams that were simply reduced in length for the partial-breast group. The primary endpoint was ipsilateral local relapse (80% power to exclude a 2·5% increase [non-inferiority margin] at 5 years for each experimental group; non-inferiority was shown if the upper limit of the two-sided 95% CI for the local relapse hazard ratio [HR] was less than 2·03), analysed by intention to treat. Safety analyses were done in all patients for whom data was available (ie, a modified intention-to-treat population). This study is registered in the ISRCTN registry, number ISRCTN12852634.

FINDINGS

Between May 3, 2007, and Oct 5, 2010, 2018 women were recruited. Two women withdrew consent for use of their data in the analysis. 674 patients were analysed in the whole-breast radiotherapy (control) group, 673 in the reduced-dose group, and 669 in the partial-breast group. Median follow-up was 72·2 months (IQR 61·7-83·2), and 5-year estimates of local relapse cumulative incidence were 1·1% (95% CI 0·5-2·3) of patients in the control group, 0·2% (0·02-1·2) in the reduced-dose group, and 0·5% (0·2-1·4) in the partial-breast group. Estimated 5-year absolute differences in local relapse compared with the control group were -0·73% (-0·99 to 0·22) for the reduced-dose and -0·38% (-0·84 to 0·90) for the partial-breast groups. Non-inferiority can be claimed for both reduced-dose and partial-breast radiotherapy, and was confirmed by the test against the critical HR being more than 2·03 (p=0·003 for the reduced-dose group and p=0·016 for the partial-breast group, compared with the whole-breast radiotherapy group). Photographic, patient, and clinical assessments recorded similar adverse effects after reduced-dose or partial-breast radiotherapy, including two patient domains achieving statistically significantly lower adverse effects (change in breast appearance [p=0·007 for partial-breast] and breast harder or firmer [p=0·002 for reduced-dose and p<0·0001 for partial-breast]) compared with whole-breast radiotherapy.

INTERPRETATION

We showed non-inferiority of partial-breast and reduced-dose radiotherapy compared with the standard whole-breast radiotherapy in terms of local relapse in a cohort of patients with early breast cancer, and equivalent or fewer late normal-tissue adverse effects were seen. This simple radiotherapy technique is implementable in radiotherapy centres worldwide.

FUNDING

Cancer Research UK.

Hypofractionated Nodal Radiation Therapy for Breast Cancer Was Not Associated With Increased Patient-Reported Arm or Brachial Plexopathy Symptoms

PURPOSE

To determine whether nodal radiation therapy (RT) for breast cancer using modest hypofractionation (HF) with 2.25 to 2.5 Gy per fraction (fx) was associated with increased patient-reported arm symptoms, compared with conventional fractionation (CF) ≤2 Gy/fx.

METHODS AND MATERIALS

Two cancer registries were used to identify subjects who received computed tomography-planned nodal RT for pT1-3, pN0-2, M0 breast cancer, from 2007 to 2010 at 2 cancer institutions. After ethics approval, patients were mailed an explanatory letter and the Self-reported Arm Symptom Scale, a validated instrument with 8 questions about arm symptoms and 5 related to activities of daily living. Clinicopathologic characteristics and Self-reported Arm Symptom Scale scores were compared between HF/CF cohorts using nonparametric analysis, χ² analysis, and multivariate ordinal regression.

RESULTS

Of 1759 patients, 800 (45.5%) returned a completed survey. A total of 708 eligible cases formed the study cohort. Of these, 406 (57%) received HFRT (40 Gy/16 fx, 45 Gy/20 fx), and 302 (43%) received CFRT (45-50 Gy/25 fx, 50.4 Gy/28 fx). Median time interval after RT was 5.7 years. Forty-three percent and 75% of patients received breast-conserving surgery and chemotherapy, respectively. Twenty-two percent received breast boost RT, independent of fractionation. Median age at diagnosis was 59 years (HF) and 53 years (CF) (P<.001). The mean numbers of excised (n=12) and involved (n=3) nodes were similar between fractionation cohorts (P=.44), as were the mean sums of responses in arm symptoms (P=.17) and activities of daily living (P=.85). Patients receiving HF reported lower rates of shoulder stiffness (P=.04), trouble moving the arm (P=.02), and difficulty reaching overhead (P<.01) compared with the CF cohort. There was no difference in self-reported arm swelling or symptoms related to brachial plexopathy.

CONCLUSIONS

Nodal RT with hypofractionation was not associated with increased patient-reported arm symptoms or functional deficits compared with CF. Subjects treated with CF reported more disability in certain aspects of arm/shoulder function. These data support shorter fractionation utilization when regional nodes are within the therapeutic target.

Variability in axillary lymph node delineation for breast cancer radiotherapy in presence of guidelines on a multi-institutional platform

AIM

To quantify the variability between radiation oncologists (ROs) when outlining axillary nodes in breast cancer.

MATERIAL AND METHODS

For each participating center, three ROs with different levels of expertise, i.e., junior (J), senior (S) and expert (E), contoured axillary nodal levels (L1, L2, L3 and L4) on the CT images of three different patients (P) of an increasing degree of anatomical complexity (from P1 to P2 to P3), according to contouring guidelines. Consensus contours were generated using the simultaneous truth and performance level estimation (STAPLE) method.

RESULTS

Fifteen centers and 42 ROs participated. Overall, the median Dice similarity coefficient was 0.66. Statistically significant differences were observed according to the level of expertise (better agreement for J and E, worse for S); the axillary level (better agreement for L1 and L4, worse for L3); the patient (better agreement for P1, worse for P3). Statistically significant differences in contouring were found in 18% of the inter-center comparison. Less than a half of the centers could claim to have a good agreement between the internal ROs.

CONCLUSIONS

The overall intra-institute and inter-institute agreement was moderate. Central lymph-node levels were the most critical and variability increased as the complexity of the patient's anatomy increased. These findings might have an effect on the interpretation of results from multicenter and even mono-institute studies.

Standardization of nodal radiation therapy through changes to a breast cancer clinical pathway throughout a large, integrated cancer center network

BACKGROUND

Studies demonstrate safety of omitting axillary nodal dissection for early-stage breast cancer with positive sentinel lymph node (+SLN) biopsy, although trial designs differed in radiation therapy (RT) fields. Regional nodal irradiation was separately shown to improve outcomes in high-risk patients. This led to lack of consensus in RT volumes. Clinical pathways (CPs) standardize care where practice varies unnecessarily. We evaluated the impact of changes to a CP guiding postoperative RT in women with +SLNs on practice patterns throughout a network.

METHODS AND MATERIALS

We implemented a CP for management of breast cancer with postoperative RT designed to promote uniform nodal treatment. The CP recommended modified tangents (MTs) including level I/II nodes for women with micrometastases (pN1mi). For women with macrometastases (pN1a), CPs recommended including level I/II LN in MT and a third supraclavicular node (SCN) LN ± internal mammary nodes for women with adverse factors present.

RESULTS

RT fields of 233 women undergoing breast-conserving surgery with +SLN but not axillary nodal dissection were retrospectively reviewed: 25% had pN1mi disease and 75% pN1a. Of 127 women treated before CP changes, 35% with pN1mi and 22% with pN1a were treated with whole-breast irradiation alone. Following CP changes, 106 women were treated: 5% with whole-breast irradiation alone, 58% with MT, and 38% with MT + SCN field. Utilization of MT was associated with CP changes. Utilization of a third SCN field was associated with CP changes, pN stage, extracapsular extension, and total number of adverse factors.

CONCLUSIONS

CPs translate published data and institutional experience into management plans that promote evidence-based care and eliminate unnecessary practice variations. Recognizing that postoperative RT treatment volumes were heterogeneous, we modified the CP based upon the latest evidence for regional nodal irradiation, after which we found increased compliance and consistency with quality guidelines, which will also aid in tracking outcomes in future investigations.

Prognostic Impact of Elective Supraclavicular Nodal Irradiation for Patients with N1 Breast Cancer after Lumpectomy and Anthracycline Plus Taxane-Based Chemotherapy (KROG 1418): A Multicenter Case-Controlled Study

Purpose

This study was conducted to evaluate the impact of supraclavicular lymph node radiotherapy (SCNRT) on N1 breast cancer patients receiving post-lumpectomy whole-breast irradiation (WBI) and anthracycline plus taxane-based (AT) chemotherapy.

Materials and Methods

We performed a case-control analysis to compare the outcomes of WBI and WBI plus SCNRT (WBI+SCNRT). Among 1,147 patients with N1 breast cancer who received post-lumpectomy radiotherapy and AT-based chemotherapy in 12 hospitals, 542 were selected after propensity score matching. Patterns of failure, disease-free survival (DFS), distant metastasis-free survival (DMFS), and treatment-related toxicity were compared between groups.

Results

A total of 41 patients (7.6%) were found to have recurrence. Supraclavicular lymph node (SCN) failure was detected in three patients, two in WBI and one in WBI+SCNRT. All SCN failures were found simultaneously with distant metastasis. There was no significant difference in patterns of failure or survival between groups. The 5-year DFS and DMFS for patients with WBI and WBI+SCNRT were 94.4% versus 92.6% (p=0.50) and 95.1% versus 94.5% (p=0.99), respectively. The rates of lymphedema and radiation pneumonitis were significantly higher in the WBI+SCNRT than in the WBI.

Conclusion

We did not find a benefit of SCNRT for N1 breast cancer patients receiving AT-based chemotherapy.

Over-irradiation

Decreasing the burden of radiation therapy (RT) for breast cancer includes, next to complete omission, several ways to tailor the extent of RT. Possible options for this include lowering of the total dose, such as selective omission of the boost, hypofractionated RT to shorten the duration of treatment, the selective introduction of partial breast irradiation and anatomy based target volume contouring to decrease the size of the irradiated volumes. Elective regional nodal irradiation showed in several randomised trials and meta-analyses to significantly impact on local-regional control, disease-free survival, breast cancer mortality and overall survival. The generalisability of these results remains complex in the light of the decreasing use of axillary lymph node dissection, the use of more effective adjuvant systemic therapy, the increasing use of primary systemic therapy and continuously improving RT techniques. In general, the use of RT compensates for the decreasing extent of surgery to the breast and the axillary lymph nodes, eliminating residual tumour cells while maintaining better aesthetic and functional results. In some occasions, however, the indications for the extent of RT have to be based on limited pathological staging information. Research is ongoing to individualise RT more on the basis of biological factors including gene expression profiles. When considering age, treatment decisions should rather be based on biological instead of formal age. The aim of this review article is to put current evidence into the right perspective, and to search for an appropriate appreciation of the balance between efficacy and side effects of local-regional RT.

Lymph Node Ratio as a Risk Factor for Locoregional Recurrence in Breast Cancer Patients with 10 or More Axillary Nodes

PURPOSE

We analyzed the association of lymph node ratio (LNR) wth locoregional control (LRC) in breast cancer patients with ≥10 involved axillary lymph nodes who underwent multimodality treatment.

METHODS

We retrospectively analyzed 234 breast cancer patients with ≥10 involved axillary lymph nodes between 2000 and 2011. All patients received adjuvant chemotherapy and radiotherapy (RT) after radical surgery. The cutoff value of LNR was obtained using receiver operating characteristic curve analysis. The majority of patients (87.2%) received chemotherapeutic regimen including taxane. RT consisted of tangential fields to the chest wall or intact breast, delivered at a median dose of 50 Gy, and a single anterior port to the supraclavicular lymph node area, delivered at a median dose of 50 Gy. For patients who underwent breast-conserving surgery, an electron boost with a total dose of 9 to 15 Gy was delivered to the tumor bed.

RESULTS

Within a median follow-up period of 73.5 months (range, 11-183 months), locoregional recurrence (LRR) occurred in 30 patients (12.8%) and the 5-year LRC rate was 88.8%. After multivariate analysis, LNR ≥0.7 was the only independent factor significantly associated with LRC (hazard ratio, 2.06; 95% confidence interval, 0.99-4.29; p=0.05).

CONCLUSION

An aggressive multimodal treatment approach showed favorable locoregional outcome in patients with ≥10 involved axillary lymph nodes. However, patients with a high LNR ≥0.7 still had an increased risk for LRR, even in the setting of current local treatments.

Sentinel lymph node identification using superparamagnetic iron oxide particles versus radioisotope: The French Sentimag feasibility trial

BACKGROUND AND OBJECTIVES

The French Sentimag feasibility trial evaluated a new method for the localization of breast cancer sentinel lymph node (SLN) using Sienna+®, superparamagnetic iron oxide particles, and Sentimag® detection in comparison to the standard technique (isotopes ± blue dye).

METHODS

We conducted a prospective multicentric paired comparison trial on 115 patients. SLN localization was performed using both the magnetic technique and the standard method. Detection rate and concordance between magnetic and standard tracers were calculated. Post-operative complications were assessed after 30 days.

RESULTS

Results are based on 108 patients. SLN identification rate was 98.1% [93.5-99.8] for both methods, 97.2% [92.1-99.4] for Sienna+® and 95.4% [89.5-98.5] for standard technique. A mean of 2.1 SLNs per patient was removed. The concordance rate was 99.0% [94.7-100.0%] per patient and 97.4% [94.1-99.2] per node. Forty-six patients (43.4%) had nodal involvement. Among involved SLNs, concordance rate was 97.7% [88.0-99.9] per patient and 98.1% [90.1-100.0] per node.

CONCLUSIONS

This new magnetic tracer is a feasible method and a promising alternative to the isotope. It could offer benefits for ambulatory surgery or sites without nuclear medicine departments. J. Surg. Oncol. 2016;113:501-507. © 2016 Wiley Periodicals, Inc.