Lower Risk Of Locoregional Recurrence Research Articles

Surgical treatment outcomes of solitary fibrous tumors in the head and neck: A retrospective study

The aim of this study was to better characterize head and neck solitary fibrous tumors (SFTs) and to evaluate surgical treatment.This retrospective study included patients who presented with head and neck SFTs. Clinical, radiological, and histological information and data regarding the treatments performed were collected. The risk of locoregional and distant metastases was calculated, and for orbital SFTs a specific classification was used.Overall, 34 patients were included. The majority of the SFTs were found in the oral cavity (n = 10), followed by the neck region (n = 8). The mean time to recurrence was 67.4 months. All patients underwent primary surgical resection. Recurrence was observed in five patients with a low risk of locoregional recurrence and distant metastasis.The treatment of choice is complete resection. Recurrence seems to be highly correlated with positive surgical margins. The safety margin should be increased when removing the lesion, and long-term follow-up should be performed.

Population-based Long-term Outcomes for Squamous Cell Carcinoma of the Nasal Cavity.

This study evaluates population-based outcomes of patients with squamous cell carcinoma (SCC) of the nasal cavity treated in British Columbia. A retrospective review of nasal cavity SCC treated from 1984 to 2014 was performed (n = 159). Locoregional recurrence (LRR) and overall survival (OS) were evaluated. The 3-year OS was 74.2% for radiation alone, 75.8% for surgery alone, and 78.4% for surgery and radiation ( P = 0.16). The 3-year LRR was 28.4% for radiation alone, 28.2% for surgery alone, and 22.6% for surgery and radiation ( P = 0.21). On multivariable analysis, surgery and postoperative radiation relative to surgery alone was associated with a lower risk of LRR (hazard ratio: 0.36, P = 0.03). Poor Eastern Cooperative Oncology Group status, node-positive, orbital invasion, smoking, and advanced age were associated with worse OS (all P <0.05). In this population-based analysis, multimodality treatment with surgery and adjuvant radiation were associated with improved locoregional control for SCC of the nasal cavity.

Abstract GS4-03: Validation of Profile for the Omission of Local Adjuvant Radiotherapy (POLAR) in a meta-analysis of three randomized controlled trials of breast conserving surgery +/- radiotherapy

Abstract Background: There are currently no commercially available tests to identify early stage breast cancer patients treated with breast conserving surgery (BCS) and systemic therapy at low risk of locoregional recurrence (LRR) for whom postoperative radiotherapy (RT) may be safely omitted. Profile for the Omission of Local Adjuvant Radiotherapy (POLAR) is a 16-gene molecular signature developed to identify invasive breast cancer patients who may be candidates for RT omission after BCS. In this work, we seek to validate POLAR in a meta-analysis of three RCTs of BCS +/- RT: SweBCG91RT, Scottish Conservation Trial (SCT) and Princess Margaret Hospital (PMH). Methods: A patient-level meta-analysis was performed in 623 node-negative breast cancer patients with ER+/HER2-negative tumors who were enrolled in the three RCTs and for whom primary tumor material was available for analysis. Contributions from each cohort were as follows: SweBCG91RT N=354 (57%), SCT N=137 (22%), and PMH N=132 (21%). Numbers of LRR events in each cohort were as follows: SweBCG91RT N=72 (20%), SCT N=28 (20%), and PMH N=16 (12%). There was a mix of systemic therapy used (no systemic therapy for SweBCG91RT, chemotherapy or adjuvant endocrine therapy, but not both, in SCT, and tamoxifen but no chemotherapy for PMH). Median follow-up time for the patients who did not have LRR was 13.3 years for SweBCG91RT, 21.1 years for SCT, and 8.6 years for PMH. A multivariable Cox proportional hazards model on time to LRR, including the continuous standardized POLAR score, RT, and interaction, stratified by cohort, was used to test the interaction between the continuous POLAR score and RT. Additional Cox models tested the association between treatment arms separately for patients with a low and high POLAR score using a pre-specified cut point. Cumulative incidences were computed, with distant metastasis and death without recurrence considered as competing events. Results: The test for interaction between RT treatment and POLAR was statistically significant (p = 0.022). Patients with a high POLAR score (N=429 [69%]) had a large benefit from RT (10-year cumulative incidence of LRR: 20% [15%-26%] for those not treated with RT vs 7% [4%-11%] for those treated with RT; hazard ratio for RT vs no RT: 0.37 [0.23-0.60], p &amp;lt; 0.001), whereas there was no evidence of benefit from RT for patients with a low POLAR score (N=194 [31%], 10-year cumulative incidence of LRR: 5% [2%-11%] for those not treated with RT vs 7% [3%-14%] for those treated with RT; hazard ratio for RT vs no RT: 0.92 [0.42-2.02], p = 0.832). Conclusions: To our knowledge, POLAR is the first genomic classifier that is not only prognostic for LRR but also predictive, showing a significant interaction between RT and the classifier. Patients with a high POLAR score should be recommended radiotherapy while patients with a low score may be candidates for omission of radiotherapy after breast conserving surgery. Citation Format: Per Karlsson, Anthony Fyles, S. Laura Chang, Bradley Arrick, Frederick Baehner, Per Malmström, Mårten Fernö, Erik Holmberg, Martin Sjöström, Fei-Fei Liu, David A. Cameron, Linda J. Williams, John MS Bartlett, Joanna Dunlop, Jacqueline Caldwell, Joseph F. Loane, Elizabeth Mallon, Tammy Piper, Wilma J. Jack, Ian Kunkler, Felix Y. Feng, Corey W. Speers, Lori Pierce, John Bennett, Karen J. Taylor. Validation of Profile for the Omission of Local Adjuvant Radiotherapy (POLAR) in a meta-analysis of three randomized controlled trials of breast conserving surgery +/- radiotherapy [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS4-03.

Development and Validation of a Genomic Profile for the Omission of Local Adjuvant Radiation in Breast Cancer.

Adjuvant radiotherapy (RT) is used for women with early-stage invasive breast cancer treated with breast-conserving surgery. However, some women with low risk of recurrence may safely be spared RT. This study aimed to identify these women using a molecular-based approach. We analyzed two randomized trials of women with node-negative invasive breast cancer to ± RT following breast-conserving surgery: SweBCG91-RT (stage I-II, no adjuvant systemic therapy) and Princess Margaret (age 50 years or older, T1-T2, adjuvant tamoxifen). Transcriptome-wide profiling was performed (Affymetrix Human Exon 1.0 ST microarray). Patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative tumors and with gene expression data were included. The SweBCG91-RT cohort was divided into training (N = 243) and validation (N = 354) cohorts. A 16-gene signature named Profile for the Omission of Local Adjuvant Radiation (POLAR) was trained to predict locoregional recurrence (LRR) using elastic net regression. POLAR was then validated in the SweBCG91-RT validation cohort and the Princess Margaret cohort (N = 132). Patients categorized as POLAR low-risk without RT had a 10-year LRR of 6% (95% CI, 2 to 16) and 7% (0 to 27) in SweBCG91-RT and Princess Margaret cohorts, respectively. There was no significant benefit from RT in POLAR low-risk patients (hazard ratio [HR], 1.1 [0.39 to 3.4], P = .81, and HR, 1.5 [0.14 to 16], P = .74, respectively). Patients categorized as POLAR high-risk had a significant decreased risk of LRR with RT (HR, 0.43 [0.24 to 0.78], P = .0055, and HR, 0.25 [0.07 to 0.92], P = .038, respectively). An exploratory analysis testing for interaction between RT and POLAR in the combined validation cohort was performed (P = .066). The novel POLAR genomic signature on the basis of LRR biology may identify patients with a low risk of LRR despite not receiving RT, and thus may be candidates for RT omission.

Review for N2 Sub-staging in Non-small Cell Lung Cancer

Patients with N2 non-small cell lung cancer (NSCLC) were heterogeneous groups and required further stratification. The International Society for the Study of Lung Cancer (IASLC) divided N2 into three sub-stages: N2 at a single station without N1 involvement (N2a1), N2 at a single station with N1 involvement (N2a2), and N2 at multiple stations (N2b). These new descriptors significantly distinguished the overall survival (OS), disease-free survival (DFS), and recurrence pattern of patients with different N2 sub-stages. The OS and DFS of N2a1 were not sufficiently distinguished from N1 at multiple stations (N1b). The OS and DFS of N2a2 were intermediate between those of N2a1 and N2b. Current evidence did not support the further subdivision of the N2b. The main recurrence pattern of N2a1, N2a2 and N2b were distant metastasis, and the risks of distant metastasis increased successively. N2a1 patients were at low risk of locoregional recurrence, which could not be reduced by postoperative radiotherapy (PORT). N2a2 and N2b patients had a similar higher risk of locoregional recurrence, which could be reduced to a similar level of N2a1 patients by PORT. .

Abstract P2-08-01: Validation of a 16-gene genomic signature to identify early-stage invasive breast cancer patients who may omit radiotherapy

Abstract Background While whole breast radiotherapy has been standard of care for invasive breast cancer patients treated with breast conserving surgery, not all women may benefit from radiotherapy. Recently, we demonstrated that a 16-gene signature named Profile for the Omission of Local Adjuvant Radiotherapy (POLAR) could identify breast cancer patients with HR+, HER2- tumors treated with breast conserving surgery alone with a 10-year locoregional recurrence risk of less than 10%. Methods In this study, we apply the signature to patients enrolled in the Princess Margaret Trial, a randomized trial where patients age 50 years or older were randomized to radiotherapy and tamoxifen or tamoxifen alone after breast conserving surgery. Tissue from 132 patients with HR+, HER2- tumors were available for gene expression analysis. Results For women treated with tamoxifen alone after breast conserving surgery, POLAR identified low risk women with a 7% risk of locoregional recurrence at 10 years. Comparison to POLAR-low patients treated with adjuvant radiotherapy did not demonstrate a significant benefit from radiotherapy (HR=1.5[0.14-16], p=0.74). POLAR-high patients not treated with radiotherapy had a 22% risk of locoregional recurrence at 10 years. Comparison to POLAR-high patients treated with adjuvant radiotherapy demonstrated a significant benefit from standard radiotherapy (HR=0.25[0.07-0.92], p=0.038). Conclusions These data suggest that the POLAR genomic signature may be used to identify patients with a low risk of locoregional recurrence without significant benefit from adjuvant radiotherapy. Patients with low POLAR scores may potentially be candidates for radiation therapy omission when treated with breast conserving surgery and tamoxifen. Citation Format: Anthony Fyles, S. Laura Chang, Katrina Rey-McIntyre, Wei Shi, Felix Feng, Corey Speers, Lori Pierce, David McCready, Fei-Fei Liu. Validation of a 16-gene genomic signature to identify early-stage invasive breast cancer patients who may omit radiotherapy [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-08-01.

Discovery and validation of a genomic signature to identify women with early-stage invasive breast cancer who may safely omit adjuvant radiotherapy after breast-conserving surgery.

512 Background: Adjuvant radiotherapy (RT) is currently the standard of care for women with early-stage invasive breast cancer (BC) treated with breast conserving surgery (BCS). However, some women may have very low risk of recurrence and could safely be spared RT. This study aimed to identify these women using a molecularly-based approach. Methods: We performed an analysis of the SweBCG91-RT cohort, a trial randomizing women with node-negative stage I-II invasive BC +/- RT following breast conserving surgery, with sparse use of adjuvant systemic therapy. Only patients with ER+, HER2- tumors, and not treated with adjuvant systemic therapy, were included in this analysis. Transcriptome-wide profiling of tumors was performed using the Affymetrix Human Exon 1.0 ST microarray. The SweBCG91-RT cohort was divided into a training cohort of 243 patients and a validation cohort of 354 patients. Biological gene sets and individual genes related to locoregional recurrence in patients not receiving RT of the training set were identified, and a 16-gene signature was trained using elastic net regression. The signature, named Profile for the Omission of Local Adjuvant Radiation (POLAR), was locked prior to validation. Results: In the validation cohort, POLAR was prognostic for locoregional recurrence (LRR) in patients not treated with RT (multivariable Cox model adjusting for age, grade, tumor size, and luminal A vs luminal B: HR = 1.7 [1.2,2.3], p &lt; 0.001). Patients categorized as POLAR low-risk had a 10-year locoregional recurrence rate of 7% in the absence of RT. Notably, there was no significant benefit from RT for these POLAR low-risk patients (HR = 1.1 [0.38,3.3], p = 0.83), whereas patients categorized as POLAR high-risk had a significant decreased risk of locoregional recurrence when treated with RT (recurrence rate without RT at 10-years 19%, HR = 0.43 [0.24,0.78], p = 0.0053). Conclusions: These data suggest that the novel POLAR genomic signature based on LRR biology can not only identify patients who have a low risk of LRR without adjuvant RT after BCS but who also would not benefit from RT, thus being prime candidates for RT omission.

Benefit of adjuvant chemoradiotherapy in patients with pathologically lymph node-positive and locally advanced gastric cancer

Abstract Objective This study aimed to compare the effectiveness of adjuvant chemoradiotherapy (CRT) and adjuvant chemotherapy (ChT) for T3-4/N+ gastric cancer (GC) following D2/R0 dissection, and identify the specific subgroups that could benefit from adjuvant CRT. Methods All eligible patients were divided into the CRT group and ChT group. We assessed the survival outcomes and patterns of recurrence for each group, and determined the prognostic factors for survival by performing Cox proportional risk regression analyses. Results A total of 192 gastric cancer patients were included in the study. The estimated 3-year and 5-year disease-free survival (DFS) probabilities in the CRT and ChT groups were 52.9% vs. 36.7% (P = 0.024) and 41.2% vs. 31.1% (P = 0.148), respectively, and the estimated 3-year and 5-year overall survival (OS) probabilities were 82.4% vs. 70.0% (P = 0.044) and 52.0% vs. 35.6% (P = 0.022). Patients in the CRT group had a lower risk of locoregional recurrence than those in the ChT group (20.6% vs. 34.4%; P = 0.031). The subset analyses revealed that patients with stage N1-2 disease were more likely to benefit from adjuvant CRT than from adjuvant ChT (DFS: 53.1% vs. 36.4%; P = 0.039; OS: 53.1% vs. 38.6%; P = 0.036). Conclusion For locally advanced gastric cancer patients with LN+, adjuvant CRT showed superior survival benefits compared with adjuvant ChT alone. Patients with N1-2 achieved better survival from adjuvant CRT.

Post-Mastectomy Radiotherapy After Neoadjuvant Chemotherapy in Breast Cancer: A Pooled Retrospective Analysis of Three Prospective Randomized Trials.

The impact of locoregional radiotherapy (RT) after neoadjuvant chemotherapy (NACT) and mastectomy in breast cancer patients is currently unclear. Several publications have suggested that patients with a favorable response to NACT might not benefit from RT after mastectomy. A retrospective analysis of three prospective randomized NACT trials was performed. Information on the use of RT was available for 817 breast cancer patients with non-inflammatory breast cancer who underwent mastectomy after NACT within the GeparTrio, GeparQuattro, and GeparQuinto-trials. RT was administered to 676 of these patients (82.7%). The 5-year cumulative incidence of locoregional recurrence (LRR) was 15.2% (95% confidence interval [CI] 9.0-22.8%) in patients treated without RT and 11.3% in patients treated with RT (95% CI 8.7-14.3%). In the multivariate analysis, RT was associated with a lower risk of LRR (hazard ratio 0.51, 95% CI 0.27-1.0; p = 0.05). This effect was shown especially in patients with cT3/4 tumors, as well as in patients who were cN+ before neoadjuvant therapy, including those who converted to ypN0 after neoadjuvant therapy. In the bivariate analysis, disease-free survival was significantly worse in patients who received RT, however this was not confirmed in the multivariate analysis. Our results suggest that RT reduces the LRR rates in breast cancer patients who receive a mastectomy after NACT without an improvement in DFS. Prospective randomized controlled trials such as the National Surgical Adjuvant Breast and Bowel Project B-51/RTOG 1304 trial will analyze whether RT has any benefit in patients who have a favorable response after NACT.

Association of an intact E2 gene with higher HPV viral load, higher viral oncogene expression, and improved clinical outcome in HPV16 positive head and neck squamous cell carcinoma.

To assess the relationship of E2 gene disruption with viral gene expression and clinical outcome in human papillomavirus (HPV) positive head and neck squamous cell carcinoma, we evaluated 31 oropharyngeal and 17 non-oropharyngeal HPV16 positive carcinomas using two PCR-based methods to test for disruption of E2, followed by Sanger sequencing. Expression of HPV16 E6, E7 and E2 transcripts, along with cellular ARF and INK4A, were also assessed by RT-qPCR. Associations between E2 disruption, E2/E6/E7 expression, and clinical outcome were evaluated by Kaplan-Meier analysis for loco-regional recurrence and disease-specific survival. The majority (n = 21, 68%) of HPV16 positive oropharyngeal carcinomas had an intact E2 gene, whereas the majority of HPV16 positive non-oropharyngeal carcinomas (n = 10, 59%) had a disrupted E2 gene. Three of the oropharyngeal tumors and two of the non-oropharyngeal tumors had deletions within E2. Detection of an intact E2 gene was associated with a higher DNA viral load and increased E2/E6/E7, ARF and INK4A expression in oropharyngeal tumors. Oropharyngeal carcinomas with an intact E2 had a lower risk of loco-regional recurrence (log-rank p = 0.04) and improved disease-specific survival (p = 0.03) compared to tumors with disrupted E2. In addition, high E7 expression was associated with lower risk of loco-regional recurrence (p = 0.004) as was high E6 expression (p = 0.006). In summary, an intact E2 gene is more common in HPV16 positive oropharyngeal than non-oropharyngeal carcinomas; the presence of an intact E2 gene is associated with higher HPV viral load, higher viral oncogene expression, and improved clinical outcome compared to patients with a disrupted E2 gene in oropharyngeal cancer.

Clinicopathological parameters affecting nodal yields in patients with oral squamous cell carcinoma receiving selective neck dissection

IntroductionNodal yield has been demonstrated as a very promising marker for the prognostic outcome of patients with oral squamous cell carcinoma. However, studies on the importance of clinicopathological factors affecting the number of resected lymph nodes are rare, especially for patients without pathologically proven cervical lymph nodes. Material and methodsRetrospective chart review of 264 patients with treatment naive oral squamous cell carcinoma and histopathologically proven negative cervical lymph node status, who received selective neck dissection of levels I-III/IV. Exclusion criteria were neoadjuvant chemoradiotherapy, comprehensive or bilateral neck dissection, T4b classification, perioperative death, unresectable disease, synchronous malignancy, follow-up <3 months and inadequate information to correctly determine nodal yield. Statistical analysis was performed by using univariate and multivariate analysis. ResultsThe mean nodal yield was 22.31 with a standard deviation of 16.01 and a mean number of 17 nodes. Gender (p = 0.018), age (p = 0.03), tumor classification (p < 0.001) and perineural invasion (p = 0.012) were significantly associated with nodal yield. Multivariate analysis indicated T-classification (p = 0.049) and age (p = 0.020) as independent factors. Nodal yield was significantly associated with locoregional recurrence (p = 0.041; Cutoff value = 17). ConclusionAdvanced age and T-classification independently affect lymph node yields in patients with oral squamous cell carcinoma. Hence, they have to be considered for interpretation of both nodal yield and recommended minimum lymph node counts. Furthermore, resection of more than 17 lymph nodes is associated with a significantly lower risk of locoregional recurrence.

Prognostic Factors for Locoregional Recurrence in Patients with Thoracic Esophageal Squamous Cell Carcinoma Treated with Radical Two-Field Lymph Node Dissection: Results from Long-Term Follow-Up.

To aim of this study was to determine the clinical and biological prognostic factors for locoregional recurrence (LRR) in patients with thoracic esophageal squamous cell carcinoma (ESCC) undergoing radical two-field lymph node dissection (2FLD). A total of 462 patients diagnosed with thoracic ESCC underwent radical esophagectomy between March 2001 and May 2010 at Sun Yat-Sen University Cancer Center. Clinical characteristics, CD44 expression, and tumor-infiltrating lymphocyte (TIL) levels were evaluated in 198 patients who underwent R0 dissection with long-term follow-up. Partial Cox regression analysis with leave-one-out cross-validation was performed to validate the selected risk factors. With a median follow-up of 54months, the 5-year local failure-free survival (LFFS) rate of 198 patients was 62.5%. Multivariate analysis revealed that T stage (p=0.043), pathological positive tumor above the carina (p=0.000), CD44 expression level (p=0.045) and TIL level (p=0.007) were prognostic factors for LFFS, while the Cox model with risk scores had an area under the curve value of 83.6% for the prediction of 5-year LFFS. The best cut-off value (sum score=11.19) was used to determine the high- and low-risk groups, with patients at high risk having a significantly shorter 5-year LFFS than patients at low risk (p=0.000). The LRR pattern revealed significantly high incidences of recurrent disease at the supraclavicular and cervical sites, mediastinum (above the carina), and anastomosis. Our predictive model was able to distinguish between patients at high risk for LRR and patients at low risk for LRR. LRR primarily involved the upper thorax and this area must be considered in future study designs for radical trimodality treatment.

A prognostic index for locoregional recurrence after neoadjuvant chemotherapy.

BackgroundThe appropriate selection criteria for breast-conserving surgery (BCS) or mastectomy after neoadjuvant chemotherapy (NAC) are poorly defined. The aim of this study is to analyse the incidence and prognostic factors for locoregional recurrence (LRR) in patients with breast cancer (BC) treated with NAC to develop a prognostic score to help with clinical decision-making.Materials and methodsUsing our retrospective maintained BC database, we identified 730 patients treated with NAC (327 patients treated with BCS and 403 patients treated with mastectomy) between 1998 and 2014. To identify variables associated with an increased LRR rate, we performed firstly Kaplan–Meier curves, with comparisons among groups using log-rank test, and then, significant variables were included in a multivariate analysis using Cox proportional hazards. The prognostic index was developed by assigning score 0 (favourable) or score 1 (unfavourable) for each significant variable of multivariate analysis and was created separately for patients with BCS and mastectomy.ResultsAt a median follow-up of 72 months, the 6-year cumulative incidence of LRR was 7.2% ( ± 3%) for BCS and 7.9% ( ± 3%) for mastectomy.By univariate analysis, variables associated with an increased LRR were for BCS: HER2 positive, grade III, ductal carcinoma in situ (DCIS), No-pCR (ypTis, ypN0), and age < 40 years; and for mastectomy, HER2-positive, DCIS, No-pCR, and LVI. By multivariate analysis, variables associated with an increased LRR were for BCS: HER2 positive (HR: 11.1, p = 0.001), DCIS (HR: 3.1, p = 0.005), and age < 40 years (HR: 2.8, p = 0.02); and for mastectomy: HER2 positive (HR: 9.5, p = 0.03), DCIS (HR: 2.7, p = 0.01), No-pCR (HR: 11.4, p = 0.01), and age < 40 years (HR: 2.8, p = 0.006).The score stratified patients into three subsets with statistically different levels of risk for LRR. For BCS, the six-year LRR rates were 3%, 13%, and 33% for the low (score 0, n = 120), intermediate (score 1, n = 95) and high (score 2–3, n = 27) risk groups, respectively (p = 0.001). For mastectomy, the six-year LRR rates were 0%, 8%, and 27% for the low (score 0, n = 20), intermediate (score 1–2, n 191), and high (score 3–4, n = 30) risk groups, respectively (p = 0.001). Of note, 21 patients that had a LRR event were HER2 positive, all of them had received trastuzumab.ConclusionsPatients with a score of 0, which made up to 19% of the study population, had very low risk of LRR. The score enabled the identification of a small group (7%) of patients with very high risk of LRR, and who may benefit from alternative treatment.

The value of adjuvant radiotherapy on survival and recurrence in triple-negative breast cancer: A systematic review and meta-analysis of 5507 patients.

The value of adjuvant radiotherapy in triple negative breast cancer (TNBC) remains unclear. A systematic review and meta-analysis was conducted in TNBC patients to assess survival and recurrence outcomes associated with radiotherapy following either breast conserving therapy (BCT) or post-mastectomy radiotherapy (PMRT). Four electronic databases were searched from January 2000 to November 2015 (PubMed, MEDLINE, EMBASE and Web of Science). Studies investigating overall survival and/or recurrence in TNBC patients according to radiotherapy administration were included. A random effects meta-analysis was conducted using mastectomy only patients as the reference. Twelve studies were included. The pooled hazard ratio (HR) for locoregional recurrence comparing BCT and PMRT to mastectomy only was 0.61 (95% confidence interval [CI] 0.41-0.90) and 0.62 (95% CI 0.44-0.86), respectively. Adjuvant radiotherapy was not significantly associated with distant recurrence. The pooled HR for overall survival comparing BCT and PMRT to mastectomy only was 0.57 (95% CI 0.36-0.88) and HR 1.12 (95% CI 0.75, 1.69). Comparing PMRT to mastectomy only, tests for interaction were not significant for stage (p=0.98) or age at diagnosis (p=0.85). However, overall survival was improved in patients with late-stage disease (T3-4, N2-3) pooled HR 0.53 (95% CI 0.32-0.86), and women <40years, pooled HR 0.30 (95% CI 0.11-0.82). Adjuvant radiotherapy was associated with a significantly lower risk of locoregional recurrence in TNBC patients, irrespective of the type of surgery. While radiotherapy was not consistently associated with an overall survival gain, benefits may be obtained in women with late-stage disease and younger patients.

Do Recent Advances in Diagnostic and Therapeutic Procedures Negate the Benefit of Postmastectomy Radiotherapy in N1 Patients With a Low Risk of Locoregional Recurrence?

Recent advances in breast cancer management might make the use of postmastectomy radiotherapy (PMRT) redundant in the treatment of pT1/T2N1 patients. We investigated the impact of PMRT on disease-free survival (DFS) in these patients who have a low risk of locoregional recurrence (LRR) after contemporary multidisciplinary management.Between 1998 and 2011, 1123 patients underwent upfront surgery for pathologically diagnosed pT1/T2N1 breast cancer, at a single institution. A retrospective review was performed on 692 patients who had a mastectomy with axillary lymph node (LN) clearance. Most patients received adjuvant systemic chemotherapy and/or endocrine therapy. PMRT was administered to 17.8% of the patients. The median follow-up time was 98 months.The entire cohort was divided into 2 groups, the early-era (1998-2003) and late-era (2004-2011) cohorts. Grouping was based on the use of modern therapies since 2004 including sentinel LN (SLN) biopsy, anthracycline/taxane-based chemotherapy, and aromatase inhibitors. Late-era patients had a significantly lower 5-year LRR compared with early-era patients (3.2% vs 10.3%, respectively; P < 0.001). In late-era patients, although PMRT did not significantly reduce the 5-year LRR rate (1% vs 3.8%, respectively), it did improve the 5-year DFS rate (96.1% vs 87.5%, respectively). After controlling for all clinicopathological variables, PMRT was independently associated with improved DFS. In subgroup analysis, depending on the presence of micro- or macrometastasis in the axillary nodes, the benefit of PMRT was most apparent in patients with macrometastasis (hazard ratio, 0.19). In the late-era cohort with no PMRT, the 3-year distant metastasis risk increased according to LN tumor burden (0%, 5.2%, and 9.8% in micrometastasis, SLN macrometastasis, and non-SLN macrometastasis, respectively).Advanced surgical and systemic therapies might not negate the benefit of PMRT in recently diagnosed pN1 patients who have a very low risk for LRR. Our data indicate that the overall recurrence risk combined with the LRR should be considered for an indication of PMRT, and raises the question of whether the receipt of PMRT would improve outcome in patients with micrometastasis.

Rethinking the Local Therapy of Breast Cancer: Integration of Biology and Anatomy.

Local control has traditionally been considered a function of disease burden. Local control is now known to differ among biologic subtypes of breast cancer and is greatly improved with the use of systemic therapy. This offers opportunities for decreasing the morbidity of treatment and individualizing local therapy. The use of smaller margins in breast-conserving surgery and elimination of axillary dissection for some node-positive breast cancer patients are current examples of leveraging the benefits of systemic therapy to reduce surgery. Emerging evidence indicates that molecular profiling can identify patients at high and low risk for locoregional recurrence after surgery in a more accurate way than tumor burden, potentially allowing individualization of the use of postmastectomy and comprehensive node field irradiation. Future clinical trials should incorporate both disease burden and molecular profiling when examining treatment strategies.

Development and validation of a gene profile predicting benefit of postmastectomy radiotherapy in patients with high-risk breast cancer: a study of gene expression in the DBCG82bc cohort.

To identify genes predicting benefit of radiotherapy in patients with high-risk breast cancer treated with systemic therapy and randomized to receive or not receive postmastectomy radiotherapy (PMRT). The study was based on the Danish Breast Cancer Cooperative Group (DBCG82bc) cohort. Gene-expression analysis was performed in a training set of frozen tumor tissue from 191 patients. Genes were identified through the Lasso method with the endpoint being locoregional recurrence (LRR). A weighted gene-expression index (DBCG-RT profile) was calculated and transferred to quantitative real-time PCR (qRT-PCR) in corresponding formalin-fixed, paraffin-embedded (FFPE) samples, before validation in FFPE from 112 additional patients. Seven genes were identified, and the derived DBCG-RT profile divided the 191 patients into "high LRR risk" and "low LRR risk" groups. PMRT significantly reduced risk of LRR in "high LRR risk" patients, whereas "low LRR risk" patients showed no additional reduction in LRR rate. Technical transfer of the DBCG-RT profile to FFPE/qRT-PCR was successful, and the predictive impact was successfully validated in another 112 patients. A DBCG-RT gene profile was identified and validated, identifying patients with very low risk of LRR and no benefit from PMRT. The profile may provide a method to individualize treatment with PMRT.

Relationship between the prognostic and predictive value of the intrinsic subtypes and a validated gene profile predictive of loco-regional control and benefit from post-mastectomy radiotherapy in patients with high-risk breast cancer

Background. Breast cancer is characterized by great molecular heterogeneity demonstrated, e.g. by the intrinsic subtypes. Administration of post-mastectomy radiotherapy (PMRT) does, however, not reflect this heterogeneity. A gene profile (DBCG-RT profile) has recently been developed and validated, and has shown prognostic impact in terms of loco-regional failure and predictive impact for PMRT. Reports have also shown predictive value in terms of benefit of PMRT from intrinsic subtypes and derived approximations. The aim of this study was to examine: 1) the agreement between various methods for determining the intrinsic subtypes; and 2) the relationship between the prognostic and predictive impact of the DBCG-RT profile and the intrinsic subtypes.Material and methods. Intrinsic subtypes and the DBCG-RT profile was determined from microarray analysis based on fresh frozen tissue from 191 patients included in the Danish Breast Cancer Cooperative Group (DBCG) 82bc trial. Corresponding formalin-fixed, paraffin-embedded tissue was available from 146 of these patients and from another 890 DBCG82bc patients. Estrogen receptor, progesterone receptor, HER2, CK5/6, Ki-67 and EGFR were combined into immunohistochemical approximations of the intrinsic subtypes. Endpoint considered was loco-regional recurrence (LRR).Results. The DBCG-RT profile identified a group of patients with low risk of LRR and no additional benefit from PMRT among all subtypes. Combining six immunohistochemical markers identified a subgroup of triple negative patients with high risk of LRR and significant benefit from PMRT. Agreement in the different assignments of tumors to the subtypes was suboptimal, and the clinical outcome and predicted benefit from PMRT varied according to the method used for assignment.Conclusion. The prognostic and predictive information obtained from the DBCG-RT profile cannot be substituted by any approximation of the tumors intrinsic subtype. The predictive value of the intrinsic subtypes in terms of PMRT was influenced by the method used for assignment to the intrinsic subtypes.

Locoregional Recurrence Risk for Patients With T1,2 Breast Cancer With 1-3 Positive Lymph Nodes Treated With Mastectomy and Systemic Treatment

Postmastectomy radiation therapy (PMRT) has been shown to benefit breast cancer patients with 1 to 3 positive lymph nodes, but it is unclear how modern changes in management have affected the benefits of PMRT. We retrospectively analyzed the locoregional recurrence (LRR) rates in 1027 patients with T1,2 breast cancer with 1 to 3 positive lymph nodes treated with mastectomy and adjuvant chemotherapy with or without PMRT during an early era (1978-1997) and a later era (2000-2007). These eras were selected because they represented periods before and after the routine use of sentinel lymph node surgery, taxane chemotherapy, and aromatase inhibitors. 19% of 505 patients treated in the early era and 25% of the 522 patients in the later era received PMRT. Patients who received PMRT had significantly higher-risk disease features. PMRT reduced the rate of LRR in the early era cohort, with 5-year rates of 9.5% without PMRT and 3.4% with PMRT (log-rank P=.028) and 15-year rates 14.5% versus 6.1%, respectively; (Cox regression analysis: adjusted hazard ratio [AHR] 0.37, P=.035). However, PMRT did not appear to benefit patients treated in the later cohort, with 5-year LRR rates of 2.8% without PMRT and 4.2% with PMRT (P=.48; Cox analysis: AHR 1.41, P=.48). The most significant factor predictive of LRR for the patients who did not receive PMRT was the era in which the patient was treated (AHR 0.35 for later era, P<.001). The risk of LRR for patients with T1,2 breast cancer with 1 to 3 positive lymph nodes treated with mastectomy and systemic treatment is highly dependent on the era of treatment. Modern treatment advances and the selected use of PMRT for those with high-risk features have allowed for identification of a cohort at very low risk for LRR without PMRT.

Mastectomy Scar Boost Results in Low Risk of Locoregional Recurrence in the Setting of Close or Involved Surgical Margins

Background: Several Phase III randomized trials have demonstrated improved local control and survival for post-mastectomy radiotherapy in patients with high-risk pathologic features. Close or involved surgical margins were not included as high-risk in these protocols, but have been associated with increased risk of local failure; however, the impact of a boost dose following chestwall radiotherapy in this setting remains to be determined. Methods: Retrospective single-institution outcomes analysis for patients with close or involved surgical margins treated with post-operative radiotherapy is followed by a boost. Results: Between 2003 and 2011, 34 patients were identified for inclusion in the present study. The median chestwall dose was 5040 cGy (range 5000 - 5040) and median boost dose was 1080 cGy (900 - 1620). At a median follow-up of 38.4 months (10.2 - 115.6; with 29% more than 5 years), 28 patients were alive without evidence of recurrence, 3 were alive with recurrent disease (1 chestwall), and 3 had died (none with recurrent disease). The 3-year local control, disease-free survival, and overall survivals were 96.9%, 93.9%, and 93.1%, respectively. Conclusion: Chestwall radiotherapy plus boost results in low risk of early locoregional recurrence for women with close or involved surgical margin(s) at mastectomy. Further investigation of PMRT with or without boost in this setting is warranted.