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To evaluate the dosimetric benefits and clinical feasibility of deep inspiratory breath-hold (DIBH) combined with volumetric modulated arc therapy (VMAT) in left-sided postmastectomy radiotherapy (PMRT). Eligible patients with left-sided breast cancer undergoing DIBH-based PMRT were prospectively included. Chest wall, supra/infraclavicular fossa, and/or internal mammary node irradiation (IMNI) were planned with a prescription dose of 43.5 Gy in 15 fractions. VMAT plans were designed on free breathing (FB)—and DIBH-CT to compare dosimetric parameters in heart, left anterior descending artery (LAD) and lung. Cone-beam computed tomography (CBCT) was performed before and after treatment to evaluate inter- and intra-fractional setup errors. Heart position and dose variations during treatment were estimated by fusing CBCT with DIBH-CT scans.Twenty patients were included with 10 receiving IMNI. In total, 193 pre-treatment and 39 pairs pre- and post-treatment CBCT scans were analyzed. The Dmean, Dmax, and V5−40 of the heart, LAD, and left lung were significantly lower in DIBH than FB (p < 0.05 for all), except for V5 of LAD (p = 0.167). The cardiopulmonary dosimetric benefits were maintained regardless of IMNI. The inter- and intra-fractional setup errors were < 0.3 cm; and the overall estimated PTV margins were < 1.0 cm. During treatment, the mean dice similarity coefficient of heart position and the mean ratio of heart Dmean between CBCT and DIBH-CT plans was 0.95 (0.88–1.00) and 100% (70.6–119.5%), respectively. DIBH-VMAT could effectively reduce the cardiopulmonary doses with acceptable reproducibility and stability in left-sided PMRT regardless of IMNI. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the dosimetric advantages of the voluntary deep inspiration breath-hold technique assisted by optical surface monitoring system for whole breast irradiation in left breast cancer after breast-conserving surgery and verify the reproducibility and acceptability of this technique. Methods: Twenty patients with left breast cancer receiving whole breast irradiation after breast-conserving surgery were enrolled in this prospective phase II study. Computed tomography simulation was performed during both free breathing and voluntary deep inspiration breath-hold for all patients. Whole breast irradiation plans were designed, and the volumes and doses of the heart, left anterior descending coronary artery, and lung were compared between free breathing and voluntary deep inspiration breath-hold. Cone beam computed tomography was performed for the first 3 treatments, then weekly during voluntary deep inspiration breath-hold treatment to evaluate the accuracy of the optical surface monitoring system technique. The acceptance of this technique was evaluated with in-house questionnaires completed by patients and radiotherapists. Results: The median age was 45 (27-63) years. All patients received hypofractionated whole breast irradiation using intensity-modulated radiation therapy up to a total dose of 43.5 Gy/2.9 Gy/15f. Seventeen of the 20 patients received concomitant tumor bed boost to a total dose of 49.5 Gy/3.3 Gy/15f. Voluntary deep inspiration breath-hold showed a significant decrease in the heart mean dose (262 ± 163 cGy vs 515 ± 216 cGy, P <.001) and left anterior descending coronary artery (1191 ± 827 cGy vs 1794 ± 833 cGy, P <.001). The median delivery time of radiotherapy was 4 (1.5-11) min. The median deep breathing cycles were 4 (2-9) times. The average score for acceptance of voluntary deep inspiration breath-hold by patients and radiotherapists was 8.7 ± 0.9 (out of 12) and 10.6 ± 3.2 (out of 15), respectively, indicating good acceptance by both. Conclusions: The voluntary deep inspiration breath-hold technique for whole breast irradiation after breast-conserving surgery in patients with left breast cancer significantly reduces the cardiopulmonary dose. Optical surface monitoring system–assisted voluntary deep inspiration breath-hold is reproducible and feasible and showed good acceptance by both patients and radiotherapists. [ABSTRACT FROM AUTHOR]

To clarify the effect of postmastectomy radiotherapy (PMRT) on pT 1-2 N 1 breast cancer patients with different molecular subtypes. We retrospectively analyzed the data of 5442 patients with pT 1-2 N 1 breast cancer treated using modified radical mastectomy in 11 hospitals in China. Univariate, multivariate, and propensity score matching (PSM) analyses were used to evaluate the effect of PMRT on locoregional recurrence (LRR). With a median follow-up duration of 63.8 months, the 5-year LRR rates were 4.0% and 7.7% among patients treated with and without PMRT, respectively (p < 0.001). PMRT was independently associated with reduced LRR after adjustments for confounders (p < 0.001). After grouping the patients according to the molecular subtype of cancer and conducting PSM, we found that the 5-year LRR rates among patients treated with and without PMRT (in that order) were as follows: luminal HER2-negative cancer, 1.9% and 6.5% (p < 0.001); luminal HER2-positive cancer, 3.8% and 13.7% (p = 0.041); HER2-overexpressing cancer, 10.2% and 15.5% (p = 0.236); and triple-negative cancer, 4.6% and 15.9% (p = 0.002). Among patients with HER2-overexpressing and triple-negative cancers, the LRR hazard rate displayed a dominant early peak, and was extremely low after 5 years. However, patients with luminal cancer continued to have a long-lasting high annual LRR hazard rate during follow-up. PMRT significantly reduced the LRR risk in patients with pT 1-2 N 1 luminal and triple-negative breast cancers, but had no effect on the LRR risk in patients with HER2-overexpressing cancer. Patients with different molecular subtypes displayed different annual LRR patterns, and the late recurrence of the luminal subtype suggests the necessity of long-term follow-up to evaluate the efficacy of PMRT. • PMRT reduces LRR of pT 1-2 N 1 luminal and triple-negative breast cancers. • PMRT has no effect on the LRR of HER2-overexpressing breast cancer. • Different molecular subtypes display different annual LRR patterns. • Late LRR beyond 5 years is observed in luminal breast cancers. [ABSTRACT FROM AUTHOR]

Purpose: To report patients' quality of life (QoL) at 1 year in a phase 2 randomized trial comparing partial breast irradiation (PBI) with whole-breast irradiation (WBI) after breast-conserving surgery (BCS) for breast cancer. Methods: Women aged ≥ 45 years with low-risk breast cancer after BCS were randomly assigned (1:1) to receive PBI (40 Gy in 10 fractions over 2 weeks) or WBI (43.5 Gy in 15 fractions over 3 weeks). The primary endpoint—the incidence of toxicities of grade 2 or higher—will be reported when participants complete 5 years of follow-up. QoL was assessed at baseline (T0), at the end of radiotherapy (RT) (T1), 6 months (T2) and 1 year (T3) after RT by using the EORTC QLQ-C30 and QLQ-BR23 questionnaires. We calculated the scores for all QOL subscales and differences in mean scores were compared. This study was registered at ClinicalTrials.gov (NCT03583619). Results: Between June 2017 and January 2019, 140 women were randomly assigned to receive PBI or WBI (n = 70 per group). Fifty-nine and 56 patients treated with PBI and WBI, respectively, were eligible for the QoL analysis. There were no significant differences in any subscale scores at T0, T1, T2, or T3 between the PBI and WBI arms. The scores for most QoL subscales that were influenced by RT recovered to a similar or better level relative to T0 scores within 1 year after RT, except for the scores of the dyspnea subscale. Longitudinal analysis showed that time since RT had a significant impact on physical functioning, role functioning, social functioning, fatigue, pain, dyspnea, financial difficulties, body image, and breast and arm symptoms. Conclusion: PBI using the intensity-modulated RT affords QoL comparable to that provided by WBI. Most QoL subscale scores that were influenced by RT recovered to a similar or better level relative to baseline scores within 1 year after RT. [ABSTRACT FROM AUTHOR]

The phase 3 NCT00793962 trial demonstrated that postmastectomy hypofractionated radiation therapy (HFRT) was noninferior to conventional fractionated radiation therapy (CFRT) in patients with high-risk breast cancer. This study assessed the cost-effectiveness of postmastectomy HFRT vs CFRT based on the NCT00793962 trial. A Markov model was adopted to synthesize the medical costs and health benefits of patients with high-risk breast cancer based on data from the NCT00793962 trial. Main outcomes were discounted lifetime costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER). We employed a time-dependent horizon from Chinese, French and USA payer perspectives. Model robustness was evaluated with one-way and probabilistic sensitivity analyses. Patients receiving CFRT versus HFRT gained an incremental 0.0163 QALYs, 0.0118 QALYs and 0.0028 QALYs; meanwhile an incremental cost of $2351.92, $4978.34 and $8812.70 from Chinese, French and USA payer perspectives, respectively. Thus CFRT versus HFRT yielded an ICER of $144,281.47, $420,636.10 and $3,187,955.76 per QALY from Chinese, French and USA payer perspectives, respectively. HFRT could maintain a trend of >50% probabilities of cost-effectiveness below a willingness-to-pay (WTP) of $178,882.00 in China, while HFRT was dominant relative to CFRT, regardless of the WTP values in France and the USA. Sensitivity analyses indicated that the ICERs were most sensitive to the parameters of overall survival after radiotherapy. Postmastectomy HFRT could be used as a cost-effective substitute for CFRT in patients with high-risk breast cancer and should be considered in appropriately selected patients. • HFRT is a cost-effective substitute for CFRT for women with high-risk breast cancer. • The incremental cost-effectiveness ratio varied in a time-dependent manner and increased with the time horizon. • Overall survival were the most influential parameter on the incremental cost-effectiveness ratio. [ABSTRACT FROM AUTHOR]

Background and Purpose: Optimal radiation target volumes for breast cancer patients with their first isolated chest wall recurrence (ICWR) after mastectomy are controversial. We aimed to analyze the regional failure patterns and to investigate the role of prophylactic regional nodal irradiation (RNI) for ICWR. Materials and Methods: Altogether 205 patients with ICWR after mastectomy were retrospectively analyzed. Post-recurrence progression-free survival (PFS) and overall survival (OS) rates were calculated by Kaplan-Meier method and the differences were compared with Log-rank test. Competing risk model was used to estimate the subsequent regional recurrence (sRR) and locoregional recurrence (sLRR) rates, and the differences were compared with Gray test. Results: The 5-year sRR rate was 25.2% with median follow-up of 88.6 months. Of the 52 patients with sRR, 30 (57.7%) recurred in the axilla, 29 (55.8%) in supraclavicular fossa (SC), and five (9.6%) in internal mammary nodes. Surgery plus radiotherapy was independently associated with better sLRR and PFS rates (p<0.001). The ICWR interval of ≤ 4 years was associated with unfavorable sRR (p=0.062), sLRR (p=0.014), PFS (p=0.001), and OS (p=0.005). Among the 157 patients who received radiotherapy after ICWR, chest wall plus RNI significantly improved PFS (p=0.004) and OS (p=0.021) compared with chest wall irradiation alone. In the 166 patients whose ICWR interval was ≤ 4 years, chest wall plus RNI provided the best PFS (p<0.001) and OS (p=0.022) compared with chest wall irradiation alone or no radiotherapy. Conclusion: Patients with ICWR have a high-risk of sRR in SC and axilla. Chest wall plus RNI is recommended. [ABSTRACT FROM AUTHOR]

Background and Purpose: We investigated the locoregional effect of trastuzumab, and determined whether patients with human epidermal growth factor receptor (HER)2-positive breast cancer (BC) treated with trastuzumab could achieve comparable efficacy to that of patients with HER2-negative BC. Materials and Methods: This was post hoc analyses of data of 793 BC patients from a randomized controlled trial comparing post-mastectomy hypofractionated radiotherapy with conventional fractionated radiotherapy. Survival rates were analyzed by the Kaplan–Meier method and compared by the log-rank test. Results: Patients were classified into three groups: HER2-negative (HER2−; n = 547), HER2-positve with trastuzumab (HER2+ + T; n = 136), and HER2-positive without trastuzumab (HER2+ − T; n = 110). The HER2+ + T group had significantly lower locoregional recurrence (LRR, 6.0% vs. 13.9%), distant metastasis (DM, 17.4% vs. 33.8%) and higher disease-free survival (DFS, 81.2% vs. 61.9%) at 5 years than that of the HER2+ − T group (P <.05). The HER2− group had significantly lower LRR (6.8% vs. 13.9%), DM (22.4% vs. 33.8%) and higher DFS (76.1% vs. 61.9%) at 5 years than that of the HER2+ − T group (P <.05). The difference in LRR, DM and DFS at 5 years was not significant between the HER2+ + T group and HER2− group (P >.05). Different annual LRR patterns was found among groups according to HR status. Conclusion: Trastuzumab reduces LRR in patients with locally advanced HER2-positive BC who have received post-mastectomy radiotherapy. It provides comparable DFS to that with patients with HER2-negative BC. [ABSTRACT FROM AUTHOR]

Background: The role of postmastectomy radiotherapy (PMRT) in women with pT1-T2N1 breast cancer is controversial. The authors developed a nomogram that was predictive for overall survival (OS) and identified patients who derived no benefit from PMRT.Methods: The authors retrospectively evaluated 4869 patients with pT1-T2N1 breast cancer who were treated with mastectomy between 2000 and 2014 in 11 Chinese hospitals. Rates of locoregional recurrence and distant metastasis were calculated using competing risk analysis, and disease-free survival and OS rates were calculated using the Kaplan-Meier method. Based on the risk factors identified from Cox regression analysis in 3298 unirradiated patients, a nomogram predicting OS was developed. The benefit of PMRT was evaluated in different risk groups stratified by the nomogram model.Results: After a median follow-up of 65.9 months, the 5-year OS, disease-free survival, locoregional recurrence, and distant metastasis rates were 93.3%, 84.3%, 5.2%, and 8.3%, respectively. A total of 1571 patients (32.3%) underwent PMRT. On multivariable analyses, PMRT was found to increase OS significantly (hazard ratio, 0.61; P = .002). An OS prediction nomogram evaluated the effect of age; tumor location; tumor size; positive lymph node ratio; estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 status; and treatment with trastuzumab. Based on nomogram scores, the entire patient cohort was classified into 3 risk groups. PMRT significantly improved the OS of patients in the intermediate-risk (P < .001) and high-risk groups (P = .004), but not in the low-risk group (P = .728).Conclusions: The authors developed a nomogram that is predictive of OS among women with pT1-T2N1 breast cancer after mastectomy. This nomogram may help to select a subgroup of patients with a good prognosis who will not benefit from PMRT. [ABSTRACT FROM AUTHOR]

Purpose: To map supraclavicular fossa-involved lymph nodes (SCF-LNs) in patients with nonmetastatic breast cancer, evaluate the coverage of widely adopted atlases, and propose modified borders for individualized regional irradiation.Methods and Materials: M0 patients with biopsy-proven SCF-LNs who were SCF treatment-naïve were included. The SCF was spatially divided into subregions, with each node mapped on the original images. The geographic misses after the borders of multiple atlases were evaluated and factors affecting SCF-LNs' spread pattern were analyzed.Results: From 1998 to 2022, 209 patients with 1242 SCF-LNs were eligible. Patients had a median of 4 nodes. At least 537 nodes (43.2%) in 147 patients (70.3%) were lateral to the sternocleidomastoid muscle (SCM), and 403 nodes (32.4%) in 127 patients (60.8%) were dorsal to the anterior scalene muscle (ASM). In the 88 patients with ≤3 SCF-LNs, at least 66 nodes (39.1%) in 40 patients (45.5%) were lateral to the SCM, and 34 nodes (20.1%) in 29 patients (33.0%) were dorsal to the ASM. These nodes were not covered by the Radiation Therapy Oncology Group (RTOG) atlas and partly within the Radiotherapy Comparative Effectiveness atlas. One hundred four patients (49.8%) had 432 SCF-LNs (34.8%) beyond the upper border of the European Society for Radiotherapy and Oncology (ESTRO) atlas. In multivariate regression, nodal sizes were associated with wider spread in the primary group. Being triple-negative (TN) subtype was associated with less spread in the recurrent group. Situation-based clinical target volumes (CTVs) were theorized, in which for a sequential spread, the posterior border could be the posterior scalene muscle or even be more constringent; otherwise, it should touch the anterior trapezius surface.Conclusions: SCF-LNs tend to spread laterally and dorsally beyond the RTOG borders, even in M0 stages with ≤3 SCF-LNs. The ESTRO upper border does not guarantee coverage with multiple SCF-LNs. Nodal burden and non-TN types are predictive of wider dissemination. A situation-based CTV is possibly feasible. Deciphering the SCF-LN spread route is needed. [ABSTRACT FROM AUTHOR]

Our objective was to assess the incidence and risk factors of radiation-induced hypothyroidism (RHT) after adjuvant hypofractionated radiation therapy (RT) in patients with breast cancer. Eligible patients with breast cancer who were treated with hypofractionated RT were prospectively evaluated. Thyroid function tests were performed before and at regular times after RT. RHT was defined as twice elevated serum thyroid-stimulating hormone (TSH) with decreased or normal free thyroxin after RT. The patient, tumor, and treatment factors were evaluated for possible associations with the risk of RHT. Five hundred patients were analyzed. All patients underwent chest wall/breast with or without regional nodal irradiation. Among them, 369 (73.8%) patients received supraclavicular nodal radiation (SCRT). Eighty-two (16.4%) patients had elevated TSH before RT. At a median follow-up of 21.9 months, 131 (26.2%) patients developed RHT, and 59 (11.8%) patients received thyroid hormone-replacement therapy. Patients with SCRT had a significantly increased 2-year cumulative incidence of RHT compared with patients without SCRT (31.5% and 11.4%, P <.001). The peak incidence of RHT occurred around 6 to 12 months after RT. Multivariate analysis revealed that elevated baseline TSH and increased thyroid mean dose (Dmean) were independent risk factors for developing RHT. After adjusted for baseline TSH, there was a nonlinear relationship between thyroid Dmean and the risk of RHT. Dmean >21 Gy was the threshold value for predicting RHT (hazard ratio, 2.2; P <.001). The incidence of RHT was high in patients with breast cancer. Thyroid function test should be started no later than 6 months after RT. We recommend that the Dmean of the thyroid should be kept lower than 21 Gy for hypofractionated RT. [ABSTRACT FROM AUTHOR]

• This is a post hoc analysis of 628 patients from a phase III, randomized trial with long-term follow-up of 110.8 months. • Radiation-induced lymphopenia in breast cancer patients after BCS tends to be mild. • The lower pre-RT PLC predicted poorer survival. • Neither nadir PLC during RT nor the recovery of PLC after RT was independently associated with survival. To evaluate the prognostic value of peripheral lymphocyte count (PLC) in the breast cancer patients after breast-conserving surgery (BCS) with radiotherapy (RT). This post hoc analysis was performed using data of 628 patients from a phase III, randomized controlled trial comparing hypofractionated RT (HFRT) with conventional fractionated RT (CFRT) after BCS. PLCs were obtained before, during, and after RT until the 1-year follow-up. The optimal cut-off PLCs were determined using the maxstat package in R. Survival rates were estimated using the Kaplan-Meier method and compared with the log-rank test. A total of 275 (46.1 %) patients developed lymphopenia during RT, among them, 17 (2.8 %) had grade 3 lymphopenia and no one developed grade 4 lymphopenia. With a median follow-up of 110.8 months, patients with pre-RT PLCs of < 1.77 × 109/L had a significantly lower 10-year breast cancer-specific survival (BCSS) rate (P = 0.013) and overall survival (OS) rate (P = 0.026). Patients with a nadir PLC of < 1.35 × 109/L had a significantly poorer 10-year OS rate (P = 0.048). Multivariate analysis showed that a pre-RT PLC of < 1.77 × 109/L was an independent factor influencing BCSS and OS, while the effect of the nadir PLC did not remain significant. Neither PLC nor lymphopenia recovery at post-RT 1, 3, and 6 months and 1 year was associated with survival. Radiation-induced lymphopenia in patients with breast cancer after BCS tends to be mild. The lower pre-RT PLC predicted poorer survival. [ABSTRACT FROM AUTHOR]

• A novel nomogram was built for predicting LRR risk. • ypN stage and lymph node ratio have great impact on LRR. • The nomogram showed higher accuracy than the existing models. This study aimed to establish a nomogram for predicting locoregional recurrence (LRR) in breast cancer patients treated with neoadjuvant chemotherapy (NAC) and mastectomy. A total of 2368 patients who received NAC and mastectomy between 2000 and 2014 from 12 grade A tertiary hospitals in China were analyzed retrospectively. The nomogram was developed based on the patients treated in three cancer hospitals (training set, n = 1629) and validated based on patients from the other nine general hospitals (validation set, n = 739). Factors identified from Fine and Gray's competing risk analysis were used to establish the nomogram. The predictive performance of the nomogram model was compared with the cTNM stage, ypTNM stage, and the Neo-Bioscore model by using the area under the time dependent receiver operating characteristic curves (tAUC), calibration curve, and decision curve analysis (DCA). The nomogram incorporated six risk factors derived from multivariable analysis of the training set including age, ypT stage, ypN stage, lymph node ratio, postmastectomy radiotherapy, and endocrine therapy. In the training set, the AUC of the nomogram was 0.792, which was higher than the values of the cTNM stage (0.582), ypTNM stage (0.737), and the Neo-Bioscore prognosis model (0.658). In the validation set, the AUC of the cTNM (0.619); ypTNM (0.636); and Neo-Bioscore staging system (0.584) were also significantly lower than the AUC of the nomogram (0.705). Both in the training and validation sets, the calibration curve showed good agreement between the nomogram-based predictions and the actual observations. The novel nomogram provides a more accurate evaluation of LRR for breast cancer patients treated with NAC and mastectomy. [ABSTRACT FROM AUTHOR]

Purpose: The present study aimed to evaluate the effect of postmastectomy radiation therapy (PMRT) after neoadjuvant chemotherapy in patients with node-positive stage II to III (cT1-4N1-2M0) breast cancer.Methods and Materials: A total of 1813 patients from 12 institutions were retrospectively reviewed. Patients were classified into 1 of 3 groups based on the pathologic lymph node status after neoadjuvant chemotherapy: ypN0, ypN1, and ypN2-3. The role of PMRT was separately evaluated in each group. Locoregional control, disease-free survival, and overall survival (OS) were estimated using the Kaplan-Meier method. The effect of PMRT was assessed by propensity score-matched analyses and multivariate Cox analyses.Results: With a median follow-up of 72.9 months, 5-year locoregional control, disease-free survival, and OS rates were 86.3%, 68.4%, and 83.1% for the entire cohort, respectively. There were 490 (27.0%), 567 (31.3%), and 756 (41.7%) patients in the ypN0, ypN1, and ypN2-3 groups, respectively. PMRT significantly improved 5-year OS in the ypN2-3 group (74.2% vs 55.9%; P < .001) but had no effect on 5-year OS in the ypN0 group (93.1% vs 95.5%; P = .517) and ypN1 group (88.4% vs 87.8%; P = .549).Conclusions: With modern systemic therapy, PMRT significantly improved OS in the ypN2-3 group but not in the ypN0 and ypN1 groups. Whether PMRT can be safely omitted in the ypN0 and ypN1 groups should be addressed prospectively. [ABSTRACT FROM AUTHOR]

• Patients with synchronous ipsilateral supraclavicular LNM showed excellent supraclavicular nodal control after multimodality therapy. • Distant metastasis was the major failure pattern. • Supraclavicular lymph node dissection plus RT did not improve outcomes compared with RT alone. • Patients can be classified into three risk groups with different prognosis. To evaluate and compare the outcomes of supraclavicular lymph node dissection plus radiotherapy (RT) and RT alone for patients with synchronous ipsilateral supraclavicular lymph node metastasis. In all, 293 patients with synchronous ipsilateral supraclavicular lymph node metastasis across three centers were included. Of these, 85 (29.0%) received supraclavicular lymph node dissection plus RT (Surgery + RT) and 208 (71.0%) received RT alone. All patients received preoperative systemic therapy followed by mastectomy or lumpectomy and axillary dissection. Supraclavicular recurrence-free survival (SCRFS), locoregional recurrence-free survival (LRRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) were evaluated by using the Kaplan–Meier method and multivariate Cox models. Multiple imputation was used for missing data. The median follow-up duration of the RT and Surgery + RT groups were 53.7 and 63.5 months, respectively. For the RT and Surgery + RT groups, the 5-year SCRFS rates were 91.7% vs. 85.5% (P = 0.522), LRRFS rates were 79.1% vs. 73.1% (P = 0.412), DMFS rates were 60.4 vs. 58.8% (P = 0.708), DFS rates were 57.6% vs. 49.7% (P = 0.291), and OS rates were 71.9% vs. 62.2% (P = 0.272), respectively. There was no significant effect on any outcome when comparing Surgery + RT versus RT alone in the multivariate analysis. Based on four risk factors of DFS, patients were classified into three risk groups: the intermediate- and high-risk groups had significantly lower survival outcomes than the low-risk group. Surgery + RT did not improve outcomes of any risk group compared with RT alone. Patients with synchronous ipsilateral supraclavicular lymph node metastasis may not benefit from supraclavicular lymph node dissection. Distant metastasis remained the major failure pattern, especially for intermediate- and high-risk groups. [ABSTRACT FROM AUTHOR]

Background: Mammary adenoid cystic carcinoma (ACC) is a rare breast cancer. The aim of this retrospective study was to assess prognostic factors and patterns of failure, as well as the role of radiation therapy (RT), in ACC. Methods: Between January 1980 and December 2007, 61 women with breast ACC were treated at participating centers of the Rare Cancer Network. Surgery consisted of lumpectomy in 41 patients and mastectomy in 20 patients. There were 51(84%) stage pN0 and 10 stage cN0 (16%) patients. Postoperative RT was administered to 40 patients (35 after lumpectomy, 5 after mastectomy). Results: With a median follow-up of 79 months (range, 6–285), 5-year overall and disease-free survival rates were 94% (95% confidence interval [CI], 88%–100%) and 82% (95% CI, 71%–93%), respectively. The 5-year locoregional control (LRC) rate was 95% (95% CI, 89%–100%). Axillary lymph node dissection or sentinel node biopsy was performed in 84% of cases. All patients had stage pN0 disease. In univariate analysis, survival was not influenced by the type of surgery or the use of postoperative RT. The 5-year LRC rate was 100% in the mastectomy group versus 93% (95% CI, 83%–100%) in the breast-conserving surgery group, respectively (p = 0.16). For the breast-conserving surgery group, the use of RT significantly correlated with LRC (p = 0.03); the 5-year LRC rates were 95% (95% CI, 86%–100%) for the RT group versus 83% (95% CI, 54%–100%) for the group receiving no RT. No local failures occurred in patients with positive margins, all of whom received postoperative RT. Conclusion: Breast-conserving surgery is the treatment of choice for patients with ACC breast cancer. Axillary lymph node dissection or sentinel node biopsy might not be recommended. Postoperative RT should be proposed in the case of breast-conserving surgery. [ABSTRACT FROM AUTHOR]