Impact of Regional Nodal Irradiation for Breast Cancer Patients with Supraclavicular and/or Internal Mammary Lymph Node Involvement: A Multicenter, Retrospective Study (KROG 16-14)

Clinical outcomes after post-operative radiotherapy for breast cancer patients presenting with ipsilateral supraclavicular metastasis: considerations on the cranial border of irradiation field

BACKGROUND

Disease recurrence at lower neck adjacent to ipsilateral supraclavicular (SCV) region represents a concern in locally advanced breast cancer patients presenting with SCV metastasis at diagnosis. This study aims to report the outcomes following post-operative radical radiation therapy and discuss the reasonable cranial border of the irradiation field for N3c patients.

METHODS

Between July 2016 and January 2022, a total of 268 patients were eligible for analysis. The endpoints included in-field and out-field cervical failures, local-regional recurrence-free survival (LRRFS), SCV recurrence-free survival (SRFS), distant metastasis-free survival (DMFS), relapse-free survival (RFS), and overall survival (OS).

RESULTS

During a median follow-up of 37 months (range 3-89 months), 17 patients (6.3%) developed local-regional recurrence as the first recurrence event, with 13 having concomitant distant-metastasis (DM); 56 patients (20.9%) had DM alone. The 3-year rates of LRRFS, SRF, DMFS, RFS, and OS were 92.3%, 94.5%, 74.5%, 73.0%, and 90.0%, respectively. 89.2% of patients received RT with the cranial border at the top of hyoid bone, and 95.1% of patients received a boost not exceeding the level of cricoid cartilage. A total of 11 patients (4.1%) developed ipsilateral SCV failure, and 3 patients (1.1%) experienced cervical failure, including 2 in-field failures and 1 out-field failure. Neoadjuvant systemic therapy (NST) was administered to 234 patients (87.3%). In the multivariate analysis, non-ypN0, triple-negative subtype and cT4 at diagnosis were predictors of worse SRFS and RFS in NST subgroup.

CONCLUSION

Our findings suggest that radical RT with cranial border of irradiation field at the hyoid bone level lead to excellent local-regional control, and out-field cervical failure was rare. The irradiation field might not extend to mastoid process.

Oncological outcomes in patients with residual triple-negative breast cancer after preoperative chemotherapy

PURPOSE

This study aimed to evaluate the clinical outcomes and prognostic implications of regional nodal irradiation (RNI) after neoadjuvant chemotherapy (NAC) in patients with residual triple-negative breast cancer (TNBC).

MATERIALS AND METHODS

We analyzed 152 patients with residual TNBC who underwent breast-conserving surgery after NAC between December 2008 and December 2017. Most patients (n = 133; 87.5%) received taxane-based chemotherapy. Adjuvant radiotherapy (RT) was administered at a total dose of 45-65 Gy in 15-30 fractions to the whole breast, with some patients also receiving RT to regional nodes. Survival was calculated using the Kaplan-Meier method, and prognostic factors influencing survival were analyzed using the Cox proportional-hazards model.

RESULTS

During a median follow-up of 66 months (range, 9 to 179 months), the 5-year disease-free survival (DFS) rate was 68.0%. The 5-year locoregional recurrence-free survival, distant metastasis-free survival, and overall survival rates were 83.6%, 72.6%, and 78.7%, respectively. In the univariate analysis, the cN stage, ypT stage, ypN stage, axillary operation type, and RT field were associated with DFS. Multivariate analysis revealed that higher ypT stage (hazard ratio [HR] = 2.0; 95% confidence interval [CI] 1.00-3.82; p = 0.049) and ypN stage (HR = 4.7; 95% CI 1.57-14.24; p = 0.006) were associated with inferior DFS. Among clinically node-positive patients, those who received RT to the breast only had a 5-year DFS of 73.7%, whereas those who received RNI achieved a DFS of 59.6% (p = 0.164). There were no differences between the DFS and RNI.

CONCLUSION

In patients with residual TNBC, higher ypT and ypN stages were associated with poorer outcomes after NAC. RNI did not appear to improve DFS. More intensive treatments incorporating systemic therapy and RT should be considered for these patients.

The optimal regional irradiation volume for breast cancer patients: A comprehensive systematic review and network meta-analysis of published studies

Background

Currently, the optimal adjuvant regional nodal irradiation (RNI) volume for breast cancer (BC) remained controversial. We aimed to define the optimal RNI treatment volume for BC by using a comprehensive network meta-analysis (NMA) of published studies.

Materials and methods

PubMed, Embase, Medline, and Cochrane Central Register of Controlled Trials were searched from database inception to 30 May 2022. Studies assessing different adjuvant RNI volumes for BC were eligible for inclusion. The primary outcome was overall survival (OS), and secondary outcome was disease-free survival (DFS) and distant-metastasis-free survival (DMFS).

Results

A total of 29,640 BC patients from twenty studies were included. The pooled hazard ratio demonstrated that internal mammary node irradiation (IMNI) in BC patients significantly improved OS giving HR (hazard ratio) of 0.87 (95%CI: 0.83-0.91, p<0.001), DFS with HR of 0.78 (95%CI: 0.68-0.90, p<0.01), and DMFS with HR of 0.87 (95%CI: 0.79-0.97, p<0.01) when compared to controls. Sub-group analysis indicated that RNI with IMNI significantly improved OS (HR 0.87, 95%CI: 0.81-0.93, p<0.01), DFS (HR 0.65, 95%CI: 0.56-0.77, p<0.01), and DMFS (HR 0.90, 95%CI: 0.82-0.98, p=0.02) when compared to RNI without IMNI. NMA showed that CW/WB (chest wall/whole breast) + RNI with IMNI significantly improved DFS (HR 0.93, 95%CI: 0.86-1.00) and DMFS (HR 0.90, 95%CI: 0.81-0.99), but not for OS (HR 0.93, 95%CI: 0.84-1.03) when compared to CW/WB alone. Based on the analysis of the treatment ranking, CW/WB+RNI with IMNI appeared as the best treatment approach for BC patients.

Conclusions

Our pooled results demonstrated that RNI with IMNI yielded a significant survival advantage for BC patients. NMA showed that CW/WB+RNI with IMNI was the optimal radiation volume for BC patients.

Clinical audit of breast cancer patients treated with helical tomotherapy for irradiation of the internal mammary chain

Aim:

To evaluate efficacy of helical tomotherapy (HT) for treatment of breast cancer with internal mammary lymph node involvement.

Methods:

This is a retrospective clinical audit of planning, dosimetry, toxicity and short-term survival of a cohort of 65 patients. Patients were treated between November 2014 and May 2019. The primary and nodal region was prescribed a dose of 50 Gray (Gy) in 25 fractions, while all cases of breast conserving surgery received a simultaneous integrated boost to a dose of 61 Gy in 25 fractions.

Results:

The 95% coverage for the primary, supraclavicular, internal mammary node and tumour bed was 93·4%, 96·8%, 90·7% and 98·3%, respectively. Mean dose to total lung, heart and contra-lateral breast was 10·6 Gy, 6·92 Gy and 4·32 Gy, respectively. None developed grade III skin or oesophageal toxicity. Twenty-one patients had progression; of which eighteen developed only distant failure while three also had loco-regional recurrence. At a median follow-up of 36 months, the 3-year loco-regional control, disease-free survival and overall survival were 93·5, 73·9 and 85·9%, respectively.

Conclusion:

We report encouraging clinical outcome for patients treated uniformly with HT. The predominant pattern of failure was distant metastases which suggests the need for systemic control intensification.

Locoregional Management and Prognostic Factors in Breast Cancer Patients with Ipsilateral Internal Mammary and Axillary Lymph Node Involvement

PURPOSE

Breast cancer patients with ipislateral axillary and internal mammary (IM) lymph node involvement (cN3b) often forego IM node resection. Therefore, radiation is important for curative therapy. However, prognosis is not well-described in the era of modern systemic therapy and limited data exist to guide optimal locoregional treatment recommendations.

METHODS

We retrospectively reviewed 117 patients with non-metastatic cN3b breast cancer treated at our institution between 2014-2019. Staging included ultrasound evaluation of all regional nodal basins. All patients received neoadjuvant chemotherapy (NAC), resection of the breast primary and axillary nodal dissection, followed by adjuvant radiation to the breast/chest wall and regional nodes. Institutional guidelines recommend a 10 Gy boost to radiographically resolved nodes, and 16 Gy boost to unresolved nodes. Overall survival (OS), recurrence (RFS), locoregional (LRRFS), internal mammary (IMRFS), and distant metastasis free survival (DMFS) were evaluated with Kaplan Meier analysis. A multivariable model for RFS was constructed.

RESULTS

Median follow-up for 117 patients was 3.82 years. Median age at diagnosis was 46 years and 56 (48%) patients were receptor group ER+/HER2-. Mastectomy was performed in 96 (82%) of patients, 38 (32%) had biopsy confirmed IMC involvement, and 8 (7%) had IM node dissection. The median initial radiation dose was 50 Gy (range, 50-55) and IMC boost 10 Gy (range, 0-16). The 5-year OS, IMRFS, LRRFS, DMFS, and RFS were 74%, 98%, 89%, 68% and 67% respectively. On multivariable analysis, a clinical complete response (CR) of the IM nodes or pathologic ypN0 status had improved 5-year RFS with HR 0.24 (p=0.006) and HR 0.27 (p=0.05), respectively. Extranodal extension or lymphovascular invasion were associated with worse 5-year RFS with HR 4.13 (p=0.001) and HR 2.25 (p=0.04), respectively.

CONCLUSION

Multimodality therapy provides excellent locoregional control of 89% at 5 years for cN3b breast cancer patients. Adjuvant radiation yields a 5-year IMRFS of 98%. Clinical and pathologic response of IM nodes are independently prognostic for RFS.

Contemporary Outcomes After Multimodality Therapy in Patients With Breast Cancer Presenting With Ipsilateral Supraclavicular Node Involvement

PURPOSE

Patients with breast cancer and ipsilateral supraclavicular (SCV) node involvement at the time of diagnosis (TNM cN3c) have historically had poor outcomes. Radiation therapy (RT) has an important role because SCV nodes are not routinely surgically dissected. However, optimal locoregional management, contemporary outcomes, and prognostic factors are not well defined.

METHODS AND MATERIALS

We reviewed the data of patients with cN3c breast cancer treated at our institution between 2014 and 2019 with curative intent, including neoadjuvant chemotherapy, surgery, and adjuvant RT. All patients received comprehensive regional RT, including to the SCV nodes. Institutional guidelines recommend a 10-Gy or 16-Gy boost to resolved and unresolved N3 nodes, respectively. Overall survival (OS), recurrence-free survival (RFS), locoregional recurrence-free survival (LRRFS), and supraclavicular recurrence-free survival (SCRFS) were analyzed.

RESULTS

Data from 173 consecutive patients were analyzed with a median follow-up time of 2.8 years. The median age was 54 years, 76 patients (44%) were estrogen receptor positive/human epidermal growth factor receptor 2 negative, 100 patients (58%) had T3/4 disease, and 10 patients (6%) underwent a neck dissection. In addition, 156 patients (90%) received a cumulative SCV dose of ≥60 Gy. The 5-year OS, SCRFS, LRRFS, and RFS rates were 73%, 95%, 86%, and 50%, respectively. The 5-year OS rate for a cumulative SCV dose of ≥60 Gy versus <60 Gy was 75% versus 39% (P = .04). In the multivariable analysis, a cumulative SCV dose of ≥60 Gy, extranodal extension, receptor status, and Eastern Cooperative Oncology Group performance status were associated with OS. The 5-year SCRFS rates with and without neck dissection were 100% versus 95% (P = .57). Among patients with a postchemotherapy SCV node size of ≥1 cm without neck dissection, the 5-year SCRFS rate was 83%.

CONCLUSIONS

In one of the largest series of patients with cN3c breast cancer, multimodality therapy using adjuvant RT with a SCV boost resulted in a 5-year LRRFS rate of 86%. There is a limited role for neck dissection as the 5-year SCRFS rate was 95% overall and 83% for residual SCV disease ≥1 cm after chemotherapy with RT alone. A cumulative SCV dose of ≥60 Gy was associated with improved OS, but not SCRFS, LRRFS, or RFS. A SCV boost should be considered in these patients as treatment was well-tolerated. Despite advances in systemic therapy, nearly half of patients developed distant metastases, highlighting the need for close observation after treatment.

Dynamics of circulating tumor DNA during postoperative radiotherapy in patients with residual triple-negative breast cancer following neoadjuvant chemotherapy: a prospective observational study

BACKGROUND

This study was performed to evaluate circulating tumor DNA (ctDNA) kinetics during postoperative radiotherapy (PORT) in patients with residual triple-negative breast cancer (TNBC) at surgery following neoadjuvant chemotherapy (NAC).

METHODS

Stage II/III patients with post-NAC residual TNBC who required PORT were prospectively included in this study between March 2019 and July 2020. For 11 TNBC patients, next-generation sequencing targeting 38 genes was conducted in 55 samples, including tumor tissue, three plasma samples, and leukocytes from each patient. The plasma samples were collected at three-time points; pre-PORT (T0), after 3 weeks of PORT (T1), and 1 month after PORT (T2). Serial changes in ctDNA variant allele frequency (VAF) were analyzed.

RESULTS

Somatic variants were found in the tumor specimens in 9 out of 11 (81.8%) patients. Mutated genes included TP53 (n = 7); PIK3CA (n = 2); and AKT1, APC, CSMD3, MYC, PTEN, and RB1 (n = 1). These tumor mutations were not found in plasma samples. Plasma ctDNA variants were detected in three (27.3%) patients at T0. Mutations in EGFR (n = 1), CTNNB1 (n = 1), and MAP2K (n = 1) was identified with ctDNA analysis. In two (18.2%) patients, the ctDNA VAF decreased through T1 and T2 while increasing at T2 in one (9.1%) patient. After a median follow-up of 22 months, no patient showed cancer recurrence.

CONCLUSION

Among patients with post-NAC residual TNBC, more than a quarter exhibited a detectable amount of ctDNA after curative surgery. The ctDNA VAF changed variably during the course of PORT. Therefore, ctDNA kinetics can serve as a biomarker for optimizing adjuvant treatment.

Combined Therapy Can Improve the Outcomes of Breast Cancer with Isolated Supraclavicular Lymph Node Involvement

Purpose

This study aimed to evaluate the efficacy of systemic combined with local therapies in isolated metachronous ipsilateral supraclavicular lymph node metastasis (mISLM) breast cancer patients.

Patients and Methods

We reviewed the data of mISLM patients admitted by Breast Disease Center of the Affiliated Hospital of Qingdao University, from January 2009 to July 2019. Ninety-nine patients were included and were divided into two groups: the systemic group, which referred to patients who received only systemic therapy, and the combined group, which referred to patients who received systemic therapy plus local therapy (including neck radiotherapy (RT) and/or supraclavicular lymph node dissection surgery). In the combined group, patients were further divided into systemic therapy plus: 1) neck RT, 2) supraclavicular lymph node dissection surgery, and 3) neck RT and supraclavicular lymph node dissection surgery.

Results

The median duration of follow-up was 36 months. The median PFS was 15 months, and the median OS was 35 months. Local control rates of 1 year, 2 years and 3 years were 92.9%, 86.9% and 84.8%, respectively. The combined group (n=56) had a significantly better PFS (P<0.001) and OS (P=0.001) than the systemic group (n=43). Compared with Group B (n=13) and Group C (n=14), Group A (n=29) had a significantly better PFS (P=0.007). Higher dose and conventional dose showed no significant differences regarding the local control rate (P=1.000), PFS (P=0.787) or OS (P=0.690) in the patients who received RT. In multivariate analysis, pN3 stage and combined therapy (systemic therapy plus local therapy) for mISLM affected PFS (P<0.001 and P=0.002, respectively). Neck RT was an independent parameter affecting OS (P=0.002).

Conclusion

In breast cancer patients with mISLM, systemic therapy combined with local therapy could improve PFS and OS. Based on systemic therapy, RT had a better effect on survival than surgery. However, more aggressive methods, such as systemic therapy combined with both RT and surgery or a higher dose of RT, may not be associated with improved PFS or OS in these patients.

Prognostic significance of the primary tumor site and immune indexes in patients with estrogen receptor-positive, human epidermal growth factor receptor-2-negative breast cancer

BACKGROUND

The ability to predict high risk factors for recurrence after neoadjuvant chemotherapy (NAC) is controversial. The purpose of the present study was to investigate the prognostic significance of tumor location, tumor-infiltrating lymphocyte (TIL) level, and pretreatment lymphocyte-to-monocyte ratio (LMR) in determining the survival of patients with estrogen receptor (ER)-positive, human epidermal growth factor receptor-2 (HER2)-negative breast cancer after treatment with NAC.

METHODS

The clinical data of 285 ER-positive, HER2-negative patients with clinical stage II-III breast cancer were analyzed from January 2009 to January 2015. To explore the prognostic factors for ER-positive, HER2-negative patients, we combined the conventional clinicopathological prognostic factors with tumor location, pretreatment LMR, and TIL. In addition, samples from 79 patients, who did not achieve pathological complete response (pCR) testing after NAC, were selected for hematoxylin-eosin (HE) staining to analyze the effect of TIL on prognosis.

RESULTS

An LMR >5.2 was correlated with better 5-year disease-free survival (DFS) and overall survival (OS; P<0.001 and P<0.001, respectively). Patients with lower-inner/central quadrant tumors had lower 5-year DFS and OS than patients with tumors in the other quadrants (P=0.012 and P=0.048). Patients with a lower TIL level (≤10%) had better 5-year DFS than patients with a higher TIL level (P=0.010). According to the results of the multivariate analyses, tumor location was an independent prognostic factor for 5-year DFS (P=0.021). Pretreatment LMR was associated with both 5-year DFS and OS (P<0.001 and P<0.001, respectively). In the subgroup analysis stratified by TIL level, the TIL level and the initial clinical stage were associated with 5-year DFS (P=0.027 and P<0.001, respectively).

CONCLUSIONS

We explored the prognostic significance of the tumor site, TIL level, and pretreatment LMR level for ER-positive, HER2-negative patients. We concluded that the lower-inner/central quadrant tumors, TIL >10%, and pretreatment LMR level ≤5.2 were correlated with a poor prognosis. More aggressive NAC and/or endocrine therapy with internal mammary node radiotherapy (IMN-RT) should be administered to address the relatively poor prognosis of patients with breast carcinoma presenting the aforementioned adverse factors.

Supraclavicular lymph node dissection with radiotherapy versus radiotherapy alone for operable breast cancer with synchronous ipsilateral supraclavicular lymph node metastases: a real-world cohort study

Background

The role of supraclavicular lymph node dissection (SCLD) in the treatment of breast cancer with ipsilateral supraclavicular lymph node metastasis (ISLM) remains controversial. We evaluated the role of SCLD in the treatment of breast cancer with ISLM and identified patients who may benefit from SCLD.

Methods

Data on patients presenting with breast cancer to the Breast Disease Center, Southwest Hospital, The Army Medical University from January 2004 and December 2017 were retrospectively screened. The median duration of follow-up was 36 months (2-175 months). 305 patients who were recently diagnosed with ISLM were eligible for the analysis.

Results

Overall, 9,236 women presented with breast cancer during the study period. Among the patients included, 146 and 159 received SCLD with radiotherapy (RT) and RT alone, respectively. Synchronous ISLM without distant metastases were present in 3.6% cases. The 3- and 5-year overall survival (OS) and disease-free survival (DFS) rates were 79.5% and 73.9%, respectively, and 67.5% and 54.8%, respectively. However, SCLD with RT was not associated with superior survival on both univariate and multivariate analyses. On stratified analyses, patients with non-luminal A tumors with 4-9 positive axillary lymph nodes who underwent SCLD with RT had both superior OS (HR =5.296; 95% CI: 1.857-15.107; P=0.001) and DFS (HR =5.331; 95% CI: 2.348-12.108; P<0.001) compared with those who received RT alone.

Conclusions

SCLD may not beneficial in improving survival for unselected breast cancer patients with ISLNM. There is less of a tendency to perform SCLD in the luminal A group.

Cervical Lymph Node Involvement above the Supraclavicular Fossa in Breast Cancer: Comparison with Stage IIIC (KROG 18-02)

Purpose

We aimed to analyze the treatment outcomes of ipsilateral cervical lymph node (CLN)-positive breast cancer without other distant metastasis and compare the outcomes with those of supraclavicular lymph node (SCL)-positive breast cancer.

Methods

Seventy-eight patients with breast cancer and ipsilateral CLN metastasis above the supraclavicular fossa (CLN[+] group) were treated at 7 institutions (2000–2014). Seventy-four patients received systemic chemotherapy and breast surgery followed by locoregional radiotherapy. Outcomes of the CLN(+) group were compared with those of the SCL(+) group, which included 183 patients with SCL involvement.

Results

The median follow-up duration was 55.9 months. Twenty-two regional failures were found in 15 patients—axillary lymph node (LN) in 8, SCL in 6, internal mammary LN in 3, previously involved CLN in 4, and previously uninvolved ipsilateral CLN in one patient. The 5-year overall survival (OS), disease-free survival (DFS), locoregional relapse-free survival (LRRFS), and distant metastasis-free survival (DMFS) rates were 68.6%, 46.7%, 68.4%, and 57.0%, respectively. Neck dissection did not improve LRRFS and DFS (p = 0.86 and p = 0.26, respectively). Multivariate analysis showed that hormone receptor negativity and the presence of extracapsular extension were prognostic factors for poor DFS. On comparison with stage IIIC using propensity score matching, survival outcomes of the CLN(+) and SCL(+) groups were not different (5-year OS, p = 0.75; DFS, p = 0.88; LRRFS, p = 0.86; and DMFS, p = 0.45).

Conclusion

The comparable clinical outcomes indicate that patients with breast cancer who have ipsilateral CLN metastasis without other distant metastasis may benefit from locoregional treatment of the ipsilateral breast and systemic therapies, as do those with N3c disease.

Adjuvant regional nodal irradiation did not improve outcomes in T1-2N1 breast cancer after breast-conserving surgery: A propensity score matching analysis of BIG02/98 and BCIRG005 trials

Aim

To determine whether the addition of regional nodal irradiation (RNI) to whole-breast irradiation (WBI) would improve outcomes over WBI alone in T1-2N1 breast cancer after breast-conserving surgery (BCS) and adjuvant systematic therapy.

Methods

Data were obtained from two randomized controlled trials (NCT00174655 and NCT00312208). Univariate and multivariate Cox-regression analysis were performed to investigate predictors for overall survival and disease-free survival. A 1:1 propensity score matching (PSM) analysis was applied to eliminate selection bias.

Results

With median follow-up 80 months (range: 3–155 months), the 5-year local regional recurrence in the WBI group was 2% vs. 5% (p = 0.28) in the WBI + supraclavicular radiotherapy, and the rate of 5-year distant metastasis in the WBI group was 7% vs. 13% in the WBI + supraclavicular radiotherapy (p = 0.0748); In addition, the 5-year local regional recurrence in the WBI group was 3% vs. 9% (p = 0.19) in the WBI + internal mammary irradiation (IMI); However, the rate of 5-year distant metastasis in the in the WBI group was significantly lower than that in the WBI + IMI (8% vs. 24%, p = 0.036). After PSM, cox-regression analysis indicated that neither RNI nor IMI in combination with WBI in T1-2N1 breast cancer was associated with an improved overall survival and disease-free survival when compared to WBI alone.

Conclusion

The addition of RNI to WBI in T1-2N1 breast cancer after BCS and adjuvant systematic therapy did not improve outcomes in comparison with WBI alone. Further studies are still needed to identify patients who would most benefit from RNI in this patient population.

•

The addition of RNI to WBI in unselected T1-2N1 breast cancer after BCS and adjuvant systematic therapy does not significantly improve outcomes in comparison with WBI alone.

•

Early stage (pT1-2N1) breast cancer after BCS represents a diverse population.

•

An individualized risk analysis based on clinical-genomic models is recommended to identify patients who would benefits or omit from RNI in further prospective studies.

Aggressive Surgical Excision of Supraclavicular Lymph Node Did Not Improve the Outcomes of Breast Cancer With Supraclavicular Lymph Node Involvement (KROG 16-14)

INTRODUCTION

The purpose of this study was to evaluate the outcomes of upfront surgery followed by radiation therapy (RT) for ipsilateral supraclavicular (SCN) and/or internal mammary (IMN) node-positive breast cancer.

MATERIALS AND METHODS

One hundred fifty-eight patients were included; among these, 91 patients were SCN-positive, 54 were IMN-positive, and 13 were SCN- and IMN-positive. Patients underwent breast conserving surgery (n = 74) or mastectomy (n = 84) followed by systemic therapy, and adjuvant RT to whole breast/chest wall with or without regional nodal RT. Regarding regional treatments for SCN and IMN, SCN excision was performed in 59 (37.3%) patients, IMN excision in 10 (6.3%) patients, SCN RT in 143 (90.5%) patients, and IMN RT in 68 (43.0%) patients.

RESULTS

The median duration of follow-up was 72 months (range, 7-182 months). There were 20 locoregional recurrences and 45 distant metastases. In-field failure was observed only in SCN (n = 8), and 6 of these patients initially underwent SCN excision. The 5-year locoregional recurrence-free survival, disease-free survival (DFS), and overall survival rates were 87.3%, 71.6%, and 89.7%, respectively. Neither SCN excision nor SCN RT dose ≥ 54 Gy improved locoregional control (P = .927 and P = .693, respectively) or DFS (P = .394 and P = .686, respectively). Having ≥ 10 involved axillary lymph nodes was the only independent prognosticator for DFS after adjusting for covariates (P = .003).

CONCLUSION

Regional control rate in initially involved SCN and/or IMN was acceptable in patients treated with upfront surgery followed by systemic therapy plus adjuvant RT. More aggressive regional therapy such as SCN excision did not improve locoregional control or survival.