Postmastectomy Radiation Research Articles

Abstract PO3-02-14: The Safety of Breast Reconstruction: The Impact of Breast Reconstruction Surgery on Postoperative Adjuvant Therapy for Breast Cancer

Abstract Background: Postoperative adjuvant therapy is very important in treating breast cancer, and increasing numbers of patients are undergoing immediate breast reconstruction (IBR) at the same time as breast cancer surgery. However, the impact of breast reconstruction surgery on adjuvant therapy is controversial. In this multicenter cohort study led by the Japanese Breast Cancer Society, we examined the impact of reconstructive surgery on postoperative adjuvant therapy in breast cancer patients who underwent IBR. Methods: We examined the association between adjuvant therapy and complications of reconstructive surgery in 4726 patients with primary breast cancer who underwent IBR during the period from January 1, 2008 to December 31, 2016. Statistical analysis employed the χ2 test. Results: Of the 995 patients who received adjuvant chemotherapy, the median time from the date of surgery to the start of chemotherapy was 51.0 days, with 63 patients (6.2%) starting more than 90 days after surgery. Eighty-four IBR complications required surgery (8.4%), including infections and tissue expander (TE) removal. Of the 63 patients for whom chemotherapy was initiated 90 days or more after surgery, 10 patients (15.9%) had complications requiring surgery, significantly more than the 74 patients (7.9%) in the < 90 days group (P = 0.028). Post-mastectomy radiation therapy (PMRT) was performed after breast cancer surgery in 359 cases: 69 cases received autologous tissue irradiation, 46 TE irradiation, 241 silicone breast implant (SBI) irradiation, and 3 artificial material removal before irradiation. 5 cases given autologous tissue irradiation and 26 receiving artificial material irradiation (22 of whom the artificial material was removes) required surgery within 1 year after the cancer surgery due to complications of IBR. There was no significant difference in the frequency of complications requiring surgery between autologous tissue irradiation and artificial material irradiation (P=0.632). There were 33 complications (9.2%) requiring surgery in the irradiated group, significantly more than the 129 cases (3.0%) in the non-irradiated group (P< 0.001). Conclusion: Adjuvant chemotherapy was generally not delayed, but complications requiring surgery related to IBR were more frequent in those with delay beyond 90 days, suggesting that postoperative complications from breast reconstruction may have influenced the delay in initiating chemotherapy. Therefore, in cases for whom postoperative chemotherapy is anticipated, complications from breast reconstruction may have impacted outcomes, making preoperative risk assessment even more important. There was no difference in the frequency of reconstructive complication surgery according to whether autologous tissue irradiation or artificial material irradiation had been used, but further investigation is needed. Citation Format: Naomi Nagura, Akiko ogiya, Hiroko Nogi, Kazutaka Narui, Hiroki Mori, Shinsuke Sasada, Makoto Ishitobi, Naoto Kondo, Chikako Yamauchi, Ayaka Shimo, Miho Saiga, Hirohito Seki, Teruhisa Sakurai, Tadahiko Shien. The Safety of Breast Reconstruction: The Impact of Breast Reconstruction Surgery on Postoperative Adjuvant Therapy for Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-02-14.

Abstract PO3-04-09: Prognoses of Patients with Hormone Receptor-Positive andHuman Epidermal Growth Factor Receptor 2-Negative BreastCancer Receiving Neoadjuvant Chemotherapy before Surgery:A Retrospective Analysis

Abstract Abstract: Purpose: To evaluate the clinical characteristics, pathological response, and prognostic significance of hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR+/HER2−) breast cancer (BC) after neoadjuvant chemotherapy (NAC). Methods: A survival analysis was performed to detect the factors related to recurrence and death in 3070 consecutive patients with HR+/HER2− BC who received NAC from 2011 to 2022. All patients received current “standard of care” following neoadjuvant therapy based on guidelines, including surgery and adjuvant endocrine therapy. HER2-low was defined as immunohistochemistry (IHC) 1+ or IHC 2+ and fluorescence in-situ hybridization-negative. Results: The complete pathological response (pCR) (ypT0/is ypN0) rate was 14.5%. The clinical tumor size (cT), ER scores, PR status, and Ki67 levels were related to pCR. The 5-year disease-free survival (DFS) and overall survival (OS) rates were 82.6% and 90.4%, respectively. PR, Ki67 levels, and postmastectomy radiotherapy were independent factors for DFS and OS, and the extranodal extension (ENE) correlated with DFS. However, pCR and HER2 status were related to OS. The pCR rate in PR negativity BC was significantly higher than that in PR positivity BC (21.1% vs. 12.2%, p = 0.000), but PR negativity BC had a poorer prognosis than PR positivity BC. HER2-low BC showed high ER scores (over 50%), PR positivity, large ypT, ENE, and lymphovascular invasion but a lower pCR rate than HER2-zero BC. Patients with HER2-low BC had shorter OS than those with HER2-zero BC (p = 0.037). However, there was no difference in DFS. Conclusions: Depending on PR status and HER2 status, patients with ER positivity and HER2 negativity exhibit different pathologic complete response rates to neoadjuvant chemotherapy and long-term outcomes, especially patients with PR negativity or HER2-low status. Keywords: breast cancer; neoadjuvant chemotherapy; survival; prognosis; PR; HER2-low Citation Format: Jin Zhang, Yan Liu, Shichao Zhang. Prognoses of Patients with Hormone Receptor-Positive andHuman Epidermal Growth Factor Receptor 2-Negative BreastCancer Receiving Neoadjuvant Chemotherapy before Surgery:A Retrospective Analysis [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-04-09.

Abstract PS18-07: Trends in Guideline Concordant Care for Inflammatory Breast Cancer: An analysis of the National Cancer Database

Abstract Background: Inflammatory breast carcinoma (IBC) is an aggressive form of breast cancer associated with worse survival outcomes compared with other subtypes of breast cancer. Black patients with IBC have worse survival outcomes than White patients. Trimodality treatment (TMT) which includes neoadjuvant chemotherapy (NCT) followed by modified radical mastectomy without immediate reconstruction (MRM), and postmastectomy radiotherapy (PMRT), has been associated with improved survival outcomes for patients with IBC. Whether receipt of TMT varies by race, ethnicity, and insurance status and its impact on survival is largely unknown. Methods: Adult female patients with non-metastatic IBC treated from 2010-2018 were identified from the NCDB. Guideline concordant care (GCC) was defined as TMT administered in the correct sequence. In addition, clinical tumor/nodal stage, age, race, ethnicity, facility type, patient location, insurance status, and pathologic complete response (pCR) were examined for each patient. Additional quality metrics of GCC examined included time to initiation of NACT < 60 days (TTNC) and proper surgical care defined as complete axillary lymph node dissection (>6 lymph nodes removed) at the time of MRM without reconstruction. Univariate and multivariate mixed methods were performed to determine association between patient, treatment, and facility-level factors and receipt of GCC, TTNC < 60 days, and proper surgical care. OS was estimated using the Kaplan-Meier method, and the log-rank test was used to compare groups. Results: 7,374 women with non-metastatic IBC were included. 78% were White, 17% Black, and 2.5% Asian/Pacific Islander patients; 7.7% identified as Hispanic and 92% as non-Hispanic. The majority had private insurance (51%), 29% Medicare, 14% Medicaid, 4.9% uninsured, and 1.3% other government insurance.Only 2,418 patients (32.7%) received GCC with only 29% undergoing MRM without reconstruction.Receipt of GCC was more common among patients age >50 years, patients with higher clinical nodal burden and those treated from 2010-2013 (p=0.001).Receipt of GCC did not differ by race, ethnicity, insurance status, or location.92% (6,005/7,374 patients) received NAC within 60 days of diagnosis. Both Black (OR 0.58, 95% CI 0.46-0.74, p= < 0.001) and Asian (OR 0.52, 95% CI 0.30-0.90, p= < 0.001) patients with IBC were less likely to have TTNC < 60 days when compared to White patients. Non-Hispanic patients (OR 2.24, 95% CI 1.65-3.03, p= < 0.001) and those with private insurance (OR 1.82, 95% CI 1.23-2.68, p= < 0.001) were more likely to have TTNC within 60 days of diagnosis. Patients with lower clinical nodal burden(cN0) were less likely to undergo proper surgery compared to patients with higher nodal burden(cN1-3) (p < 0.001). In addition, patients treated in a more contemporary cohort (2014-2018) were less likely to undergo proper surgery compared to patients treated earlier (2010-2013) (OR 0.82, 95% CI 0.73-0.92, p< 0.001).Among IBC patients receiving GCC, Black patients had significantly worse overall survival compared to White patients (p < 0.001) Conclusions: The majority of patients with IBC do not receive GCC and GCC has decreased since 2014 with fewer patients undergoing appropriate surgical treatment. The very low level of GCC indicates a need for multidisciplinary education, while improvement in TTNC may improve outcomes among racial/ethnic minorities. Citation Format: Brian Diskin, Audree Tadros, Varadan Sevilimedu, Amy Xu, Perri Vingan, Jonas Nelson, Yoshiko Iwai, Monica Morrow, Oluwadamilola (Lola) Fayanju. Trends in Guideline Concordant Care for Inflammatory Breast Cancer: An analysis of the National Cancer Database [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS18-07.

Abstract PO3-20-06: TRUDI: A phase II study of neoadjuvant TRastuzumab derUxtecan and Durvalumab for stage III HER2-expressing Inflammatory breast cancer

Abstract Background: Despite being a rare presentation of breast cancer, inflammatory breast cancer (IBC) is responsible for up to 10% of all breast cancer-related deaths. Most IBCs express HER2, with up to 40% of all IBCs being HER2-positive and 40% being HER2-low. Additionally, IBC more often exhibits PD-L1 expression compared to non-IBC, suggesting a preeminent role for immune evasion in the development and progression of IBC. No systemic treatment approaches have been yet developed specifically for IBC, and standard treatments commonly lead to poor outcomes. Trastuzumab deruxtecan (T-DXd) is an anti-HER2 antibody-drug conjugate currently approved for patients with pretreated HER2-positive and HER2-low metastatic breast cancer. Early-phase data highlighted the safety and potential synergy of combining T-DXd with the immune checkpoint inhibitor durvalumab. The aim of TRUDI is to evaluate the clinical activity and safety of neoadjuvant T-DXd with durvalumab among patients with HER2-expressing IBC. Trial Design: TRUDI is an ongoing, open label, multicenter, two cohort investigator-initiated phase II neoadjuvant trial for patients with stage III HER2-expressing IBC. The trial was activated in May 2023, with enrollment ongoing. Eligible participants are women and men with previously untreated, stage III (T4d, any N) breast cancer, clinically determined to be IBC. Patients will be included in two cohorts, depending on the locally determined HER2 status (with any hormone receptor [HR] status): Cohort 1 (n=36) for patients with HER2-positive disease (HER2 IHC 3+ or 2+/ISH amplified); Cohort 2 (n=27) for patients with HER2-low disease (HER2 IHC 1+ or 2+/ISH not amplified). Patients will receive eight cycles of T-DXd (5.4 mg/kg IV every 21 days) combined with durvalumab (1125 mg IV every 21 days), followed by modified radical mastectomy and post-mastectomy radiation. Post-surgical systemic treatment will follow local standards. Tumor tissue will be collected at baseline, cycle 1 day 8, and at surgery; blood will be collected at baseline, cycle 4 day 1, cycle 7 day 1 and at surgery; stool will be collected at baseline, after 3-6 weeks of treatment and surgery. The primary endpoint is pathologic complete response (pCR; ypT0/Tis ypN0). Patients in each cohort will be enrolled based upon Simon two-stage designs: in Cohort 1, if ≥8/20 patients with HER2-positive IBC experience pCR then a total of 36 patients will be enrolled. In Cohort 2, if ≥1/18 patients with HER2-low IBC experience pCR then a total of 27 patients will be enrolled. Secondary endpoints include the residual cancer burden at surgery, event free survival, distant progression or distant disease-free survival, as well as safety of the regimen. Exploratory objectives will investigate biomarker analyses on tissue, blood, and microbiome to explore the association of HER2 expression, immune variables, and stool composition on the efficacy of T-DXd with durvalumab among patient with HER2-expressing IBC. To our knowledge, this is the first and only ongoing study testing the combination of an anti-HER2 antibody-drug conjugate with immunotherapy for the neoadjuvant treatment of patients with IBC. Clinical trial information: NCT05795101. Citation Format: Paolo Tarantino, Samuel Niman, Antonio Giordano, Faina Nakhlis, Jennifer Bellon, Wendy Woodward, Azadeh Nasrazadani, Sadia Saleem, Anthony Lucci, Michelle DeMeo, Naoto Ueno, Sara Tolaney, Vicente Valero, Meredith Regan, Rachel Layman, Filipa Lynce. TRUDI: A phase II study of neoadjuvant TRastuzumab derUxtecan and Durvalumab for stage III HER2-expressing Inflammatory breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-20-06.

Abstract PO2-22-05: A prospective phase I-II study of hypofractionated accelerated breast and nodal intensity modulated radiation therapy delivered in the prone position

Abstract Background In patients with breast cancer, prone radiotherapy (RT) has been shown to reduce heart and lung dose. Routinely used for whole breast (WB) RT, its use to treat regional lymph nodes (LNs) is not widespread. Methods In this phase I-II study (NCT02308488) patients treated with lumpectomy or mastectomy with 1-5 pathologically involved LNs underwent WBRT or post-mastectomy RT plus regional nodal RT using IMRT to the supraclavicular and level III axillary LNs. The prescription was 40.5Gy in 15 daily 2.7Gy fractions with a daily concomitant 0.5Gy tumor bed boost. Patients who underwent sentinel LN biopsy (SLNB) alone (no axillary dissection) had the level I-II axilla included in the RT field. The primary endpoints were incidence of >grade 2 acute toxicity per CTCAE v 3.0 and dosimetric feasibility. The secondary endpoint was late toxicity. Clinical outcomes were local recurrence (LR), disease free survival (DFS), distant recurrence free survival (DRFS) and overall survival (OS). Coverage constraints included planning target volume [PTV] V48Gy ≥ 98%, PTV breast V40.5Gy ≥ 95% and PTV nodes V38.5Gy ≥ 95%. Normal tissue constraints included heart V5Gy < 5%, ipsilateral lung V10Gy < 20%, contralateral lung V5Gy < 15%, ipsilateral brachial plexus (BP) maximal dose (Dmax) < 42Gy, spinal cord Dmax ≤ 3 7.5Gy, thyroid contralateral lobe Dmax ≤ 15Gy, esophagus V30Gy < 50% and Dmax ≤ 40.5Gy. Results From 2011-2016, 97 patients with stage IB-IIA breast cancer were enrolled. 66 underwent lumpectomy and 31 underwent mastectomy. 16 had SLNB alone. There were no grade 3 acute toxicities meeting the primary toxicity endpoint. Common acute low-grade toxicities included fatigue (grade 1: 65 [66.3%]; grade 2: 7 [7.1%]), esophagitis (grade 1: 7 [7.1%]; grade 2: 10 [10.2%]), dermatitis (grade 1: 82 [83.7%]; grade 2: 7 [7.1%]). At median and maximum follow up of 8.02 (IQR: 3.31) and 13.3 years, respectively, there were 2 LRs (2.1%). 8-year DRFS, DFS and OS were 88.1% (95% CI 81.3%, 95.4%), 85.7% (95% CI 78.4%, 94.6%) and 90.5% (95% CI 84%, 97.6%), respectively. Clinician-rated cosmesis (n=64) was excellent/good in 67.2% of cases and fair/poor in 6.3%. Patient- rated cosmesis (n=47) was excellent/good in 91.5% and fair/poor in 8.5%, with patients rating themselves more favorably than their physicians (p=0.0014). The incidence of maximum grade 1, 2 and 3 late toxicities were 49 (62.8%), 15 (19.2%), and 3 (3.8%), respectively. This included 2 grade 3 asymmetries,1 grade 3 pigmentation change, and 1 grade 2 pneumonitis. There was no brachial plexopathy. Among the 28 patients who underwent reconstruction, 17 were implant-based and 11 were autologous. Of the implant-based, 9 underwent RT to the tissue expander and 8 to the permanent implant. 11/28 patients had long-term plastic surgery follow up. There were 3 hospitalizations with reoperation post-RT (1 unplanned revision, 1 implant removal for threatened exposure, and 1 excision of fat necrosis). There was 1 incident of wound infection/cellulitis. With regard to dosimetric constraints, 54.3% of plans (95% CI 43.6%, 64.8%) met all constraints. 92% (95% CI 83%, 97%), 98% (95% CI 93%, 100%) and 89% (95% CI 80%, 94%) met the PTV tumor V48Gy, PTV breast V40.5Gy, and PTV nodes V38.5Gy coverage constraints, respectively. Heart, contralateral lung, spinal cord, and esophagus constraints were met by all patients. 95% (95% CI 88.6%, 98.4%) met the ipsilateral lung V10Gy and 99% (95% CI 94%, 100%) met the thyroid contralateral lobe constraint. The BP constraint was met in 73% (95% CI 63.0%, 81.0%) of plans with a mean increase of 1.61 Gy (SD 1.96 Gy) over target. Conclusion Toxicity was low and outcomes were excellent in this prospective trial of hypofractionated regional nodal RT in the prone position. Dosimetric constraints were only met in 54% of plans with the nodal coverage and the BP constraint as the most frequently unmet. These constraints may need to be modified and/or techniques refined to optimize hypofractionated prone nodal RT. Citation Format: Juhi Purswani, Olivier Maisonet, Julie Xiao, Jose R Teruel, Christine Hitchen, Xiaochun Li, Judith D. Goldberg, Carmen A. Perez, Silvia C. Formenti, Naamit K. Gerber. A prospective phase I-II study of hypofractionated accelerated breast and nodal intensity modulated radiation therapy delivered in the prone position [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-22-05.

Bilateral Implant-based Breast Reconstruction with Unilateral Radiotherapy: A Matched Cohort Study Comparing Nipple-sparing Mastectomy and Skin-sparing Mastectomy.

Nipple-sparing mastectomy (NSM) preserves the natural nipple-areola complex and entire native breast skin, with the goal of better cosmetic outcomes in breast reconstruction. In bilateral TE/implant-based reconstruction requiring unilateral postmastectomy radiotherapy (PMRT), progressive radiation-induced fibrosis can lead to increasing nipple asymmetry with cosmetic dissatisfaction. Thus, PMRT may ultimately negate the intended positive cosmetic value of NSM compared with skin-sparing mastectomy (SSM). This study compares (1) surgical complications, (2) patient satisfaction, and (3) aesthetic outcomes between NSM versus SSM in bilateral implant-based reconstruction with unilateral PMRT. This retrospective matched cohort study included consecutive NSM patients with bilateral TE/implant breast reconstruction + unilateral PMRT matched 1:2 to SSM group. Patients completed PMRT and TE exchange to implants. Demographics, oncologic stage, comorbidities, and complications were collected. Patient satisfaction was evaluated by BREAST-Q. Aesthetic outcomes were assessed by blinded reviewers with a five-point Likert scale. Among 58 patients who underwent bilateral TE/implant reconstruction with unilateral PMRT, 17 NSM patients were matched to 41 SSM patients by age, body mass index, and comorbidities. No significant differences existed in overall surgical complications and individual BREAST-Q questionnaire scores between cohorts. However, aesthetic outcomes scores were higher in SSM compared with NSM. Although NSM is generally associated with superior cosmetic outcomes compared with SSM, it has far less impact in bilateral implant-based breast reconstruction with unilateral PMRT due to the negative postradiotherapy effect on nipple symmetry.

2010: Postmastectomy radiotherapy after immediate breast reconstruction: toxicities and control rate.

2010: Postmastectomy radiotherapy after immediate breast reconstruction: toxicities and control rate.

589: Pattern and Complication of Reconstructed Breast Cancer Patients with Postmastectomy Radiotherapy

589: Pattern and Complication of Reconstructed Breast Cancer Patients with Postmastectomy Radiotherapy

813: The treatment quality of SG-DIBH on postmastectomy left breast cancer radiotherapy patients

813: The treatment quality of SG-DIBH on postmastectomy left breast cancer radiotherapy patients

P8. Comparative Outcomes of Proton versus Photon Post-Mastectomy Radiation Therapy in Pre-pectoral Implant Based Breast Reconstruction

P8. Comparative Outcomes of Proton versus Photon Post-Mastectomy Radiation Therapy in Pre-pectoral Implant Based Breast Reconstruction

A Comparative Study of Cardiac Toxicity Analysis in Hypo-Fractionated Vs Conventionalfractionated Adjuvant Radiotherapy in Post-Mastectomy Leftbreast Carcinoma

Background: Post-mastectomy adjuvant radiotherapy improves long-term survival by reducing the risk of loco-regional recurrence in breast cancer patients with high-risk features. Considering radiation therapy to the left sided chest wall heart is an important organ at risk. Hypo-fractionated radiotherapy is increasingly being used due to involvement of fewer treatment sessions and is almost radio-biologically equivalent to conventionally fractionated radiotherapy. Objective: This study was conducted to evaluate cardiac toxicities between hypo and conventionally fractionated radiotherapy. Methods: This quasi-experimental study was done at the National Institute of Cancer Research and Hospital, Mohakhali, Dhaka from January 2019 to December 2019, 60 patients were purposively assigned into two groups and each group included 30 patients. Arm A: received Conventional fractionated radiotherapy (50Gy/25 fractions over 5 weeks, at 2Gy/fraction). Arm B: received Hypo- fractionated radiotherapy (40.05 Gy in 15 fractions over 3 weeks at 2.67 Gy/fraction). Echocardiography (ECHO), Electrocardiography (ECG) was performed to find the cardiac toxicities. Results: The mean age of the patients in arm A was 50.03 ± 6.82 years and that of arm B was 48.08 ± 5.08 years. No significant statistical difference was found between the two groups regarding socio-demographic variables and clinical presentations. Most of the patients in both arms showed grade 0 cardiac toxicity (arm A: 70% and arm B: 80%) & few showed grade 1 cardiac toxicity (arm A: 20% and arm B: 13.3%) and three patients (10.0%) in arm A and two patients (6.66%) in arm B had shown grade 2 cardiac toxicities six months after treatment. However, this difference was statistically not significant (p >0.05). Before treatment, the ejection fraction (EF) of arm A and arm B were 63.3 ± 5.621 and 64.7± 4.991. Six months after treatment the EF of both arms decreased (arm A 60.2 ± 4.051 & arm B 60.9 ± 5.121) but the difference was statistically not significant (p >0.05). Conclusion: Hypo-fractionated radiotherapy in the adjuvant setting for the treatment of left breast cancer has no additional cardiac toxicity in comparison to conventionally fractionated radiotherapy while maintaining same efficacy. J Bangladesh Coll Phys Surg 2024; 42: 169-175

Is there any radiation-induced brachial plexopathy after hypofractionated postmastectomy radiotherapy with helical tomotherapy?

Radiation-induced brachial plexopathy (RIBP) is one of the most concerning late radiation effects after hypofractionated postmastectomy radiotherapy (HF-PMRT) to the chest wall and regional lymph nodes. The purpose of this study was to investigate the RIBP events occurring in breast cancer patients after HF-PMRT using intensity-modulated radiation therapy (IMRT) by helical tomotherapy. Furthermore, the dosimetric parameters of the ipsilateral brachial plexus were reported. Breast cancer patients who underwent HF-PMRT using the IMRT via HT at our institute were included. In the first cohort, subjective RIBP symptoms were measured using a QuickDASH questionnaire, whereas objective RIBP events were assessed using a comprehensive physical evaluation in the second cohort. The ipsilateral brachial plexus from all eligible patients' treatment plans was contoured, and the dosimetric parameters were explored. From March 2014 to December 2022, 229 patients were enrolled; 107 and 72 individuals were in the first and second cohorts, respectively. The first cohort's median follow-up period was 27 months, and the second cohort was 31 months. In the first cohort, 80 patients (74.77%) had a normal function, 21 (19.63%) had a mild grade, and 6 (5.61%) had a moderate grade; no severe or very severe RIBP was observed. However, the comprehensive physical evaluation of the second cohort indicated no RIBP events. Dosimetric analysis revealed that the median maximum dose was 44.52, 44.52, and 44.60 Gy; the median mean dose was 33.00, 32.23, and 32.33 Gy; and the median dose at 0.03 cc was 44.33, 44.36, and 44.39 Gy for all patients, patients in the first and second cohort, respectively. Each dosimetric parameter was evaluated, and no statistically significant differences were detected. The absence of RIBP events supports the safety of employing HF-PMRT by HT for the chest wall and all regional lymph nodes. We propose that applying the ICRU Report 83 criteria for IMRT planning, which limit the maximum dose (107% of the prescribed dose) to less than 2% of the planning target volume and exclude the brachial plexus region from the maximal dose area, is a practical way to minimize the risk of RIBP from HF-PMRT.

Third national surgical consensus conference of the Italian Association of Breast Surgeons (ANISC) on management after neoadjuvant chemotherapy: The difficulty in reaching a consensus

IntroductionNeoadjuvant chemotherapy (NAC) has a profound impact on surgical management of breast cancer. For this reason, the Italian Association of Breast Surgeons (ANISC) promoted the third national Consensus Conference on this subject, open to multidisciplinary specialists. Materials and methodsThe Consensus Conference was held on-line in November 2022, and after an introductory session with five core-team experts, participants were asked to vote on eleven controversial issues, while results were collected in real-time with a polling system. ResultsA total of 164 dedicated specialists from 74 Breast Centers participated. Consensus was reached for only three of the eleven issues, including: 1) the indication to assess the response with Magnetic Resonance Imaging (79 %); 2) the need to re-assess the biological factors of the residual tumor if present (96 %); 3) the possibility of omitting a formal axillary node dissection for cN1 patients if a pathologic Complete Response (pCR) was confirmed with analysis of one or more sentinel lymph nodes (82 %). The majority voted in favor of mapping both the breast and nodal lesions pre-NAC (59 %), and against the omission of sentinel lymph node biopsy in cN0 patients in the case of pathologic or clinical Complete Response (69 %). In cases of cT3/cN1+ tumors with pCR, only 8 % of participants considered appropriate the omission of Post-Mastectomy Radiation Therapy. ConclusionThere is still a wide variability in surgical approaches after NAC in the “real world”. As NAC is increasingly used, multidisciplinary teams should be attuned to conforming their procedures to the rapid advances in this field.

Is postmastectomy radiotherapy necessary for breast cancer patients with clinically node-positive downstaging to ypN0 after neoadjuvant chemotherapy?

The significance of postmastectomy radiotherapy (PMRT) in breast cancer patients who initially have clinically node-positive (cN +) status but achieve downstaging to ypN0 following neoadjuvant chemotherapy (NAC) remains uncertain. This study aims to assess the impact of PMRT in this patient subset. Patients were enrolled from West China Hospital, Sichuan University from 2008 to 2019. Overall survival (OS), Locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and breast cancer-specific survival (BCSS) were estimated using the Kaplan-Meier method and assessed with the log-rank test. The impact of PMRT was further analyzed by the Cox proportional hazards model. Propensity score matching (PSM) was performed to reduce the selection bias. Of the 333 eligible patients, 189 (56.8%) received PMRT, and 144 (43.2%) did not. At a median follow-up period of 71months, the five-year LRFS, DMFS, BCSS, and OS rates were 99.1%, 93.4%, 96.4%, and 94.3% for the entire cohort, respectively. Additionally, the 5-year LRFS, DMFS, BCSS, and OS rates were 98.9%, 93.8%, 96.7%, and 94.5% with PMRT and 99.2%, 91.3%, 94.9%, and 92.0% without PMRT, respectively (all p-values not statistically significant). After multivariate analysis, PMRT was not a significant risk factor for any of the endpoints. When further stratified by stage, PMRT did not show any survival benefit for patients with stage II-III diseases. In the context of comprehensive treatments, PMRT might be exempted in ypN0 breast cancer patients. Further large-scale, randomized controlled studies are required to investigate the significance of PMRT in this patient subset.

Impact of Radiation Therapy Modalities on Loco-regional Control in Inflammatory Breast Cancer

In inflammatory breast cancer, radiation therapy intensification is considered a standard of care by some teams, although the level of evidence remains low. We sought to analyze the impact of radiation therapy modalities on the risk of loco-regional and distant relapse. This retrospective multicenter study included patients with localized inflammatory breast cancer treated between 2010 and 2017. Standard postmastectomy radiation therapy consisted of daily fractions to a total dose of 50 Gy equivalent without a boost or bolus, while intensified radiation therapy referred to the use of a boost or bolus. The cumulative incidence curves of locoregional and distant recurrence were displayed using the competing risk method. Of the 241 included patients, 165 were treated with standard and 76 with intensified radiation therapy. There was significantly more nodal involvement in the intensified group. With a median follow-up of 40 months postradiation therapy, there was no difference between standard versus intensified radiation therapy regarding the cumulative incidence of locoregional (P = .68) or distant recurrence (P = .29). At 5 years, the risks of locoregional and distant recurrence were 12.1% (95% CI, 7.5; 17.7) and 29.4% (95% CI, 21.8; 37.3) for patients treated with standard radiation therapy and 10.4% (95% CI, 4.4; 19.3) and 21.4% (95% CI, 12.6; 31.9) for those treated with intensified radiation therapy. In multivariate analyses, triple-negative subtype and absence of complete pathologic response were associated with a higher risk of loco-regional recurrence. Radiation therapy intensification had no significant impact on locoregional and distant recurrence. For patients with a non-complete pathologic response (n = 172, 71.7%), no significant differences were observed between the 2 groups for loco-regional (P = .80) and distant (P = .39) recurrence. Severe toxicity rates were similar in both groups. Contrary to other important series, this large retrospective multicentric study did not show a locoregional or distant control benefit of intensified radiation therapy. Pooled prospective studies and meta-analyses of intensified radiation therapy are warranted to endorse this approach.

Prediction of Overall Disease Burden in (y)pN1 Breast Cancer Using Knowledge-Based Machine Learning Model.

We aimed to construct an expert knowledge-based Bayesian network (BN) model for assessing the overall disease burden (ODB) in (y)pN1 breast cancer patients and compare ODB across arms of ongoing trials. Utilizing institutional data and expert surveys, we developed a BN model for (y)pN1 breast cancer. Expert-derived probabilities and disability weights for radiotherapy-related benefit (e.g., 7-year disease-free survival [DFS]) and toxicities were integrated into the model. ODB was defined as the sum of disability weights multiplied by probabilities. In silico predictions were conducted for Alliance A011202, PORT-N1, RAPCHEM, and RT-CHARM trials, comparing ODB, 7-year DFS, and side effects. In the Alliance A011202 trial, 7-year DFS was 80.1% in both arms. Axillary lymph node dissection led to higher clinical lymphedema and ODB compared to sentinel lymph node biopsy with full regional nodal irradiation (RNI). In the PORT-N1 trial, the control arm (whole-breast irradiation [WBI] with RNI or post-mastectomy radiotherapy [PMRT]) had an ODB of 0.254, while the experimental arm (WBI alone or no PMRT) had an ODB of 0.255. In the RAPCHEM trial, the radiotherapy field did not impact the 7-year DFS in ypN1 patients. However, there was a mild ODB increase with a larger irradiation field. In the RT-CHARM trial, we identified factors associated with the major complication rate, which ranged from 18.3% to 22.1%. The expert knowledge-based BN model predicted ongoing trial outcomes, validating reported results and assumptions. In addition, the model demonstrated the ODB in different arms, with an emphasis on quality of life.

Anatomical assessment of local recurrence site in breast cancer patients after breast reconstruction and post-mastectomy radiotherapy: implications for radiation volumes and techniques.

Post-mastectomy radiotherapy (PMRT) improves local control rates and survival in patients with adverse prognostic features. The dose coverage to target volumes is critical to yield maximum benefit to treated patients, increasing local control and reducing risk of toxicity. This study aims to assess patterns of breast cancer relapse in patients treated with mastectomy, breast reconstruction and PMRT. Breast cancer patients treated with PMRT between 1992 and 2017 were retrospectively reviewed. Clinical and pathological characteristics of patients were collected. Recurrences were defined as "in field," "marginal" or "out of field." Survival analyses were performed in relation to progression-free survival (PFS) and overall survival (OS). Correlation between baseline features was explored. Data of 140 patients are collected. After a median follow-up time of 72 months, median PFS and OS of 63 and 74 months were detected, respectively. Neoadjuvant chemotherapy, lympho-vascular space invasion (LVI) and size of primary tumor were all significantly associated with worst PFS and OS. Ten patients developed local recurrence: 30% "in field," 30% marginal recurrences, 20% "out of field" and 20% both "in field" and "out of field." No recurrence was detected under the expander, 80% above the device and 20% patients relapsed on IMN chain. The mean distant relapse-free survival was 39 months. Overall, 39 of 140 patients developed distant metastases. The onset of local-regional relapses occurred mainly above the expander/prosthesis, underlying the importance of inclusion of the subcutaneous tissues within the target volume. In order to refine new contouring recommendations for PMRT and breast reconstruction, future prospective studies are needed.

Comparing Late Toxicity of Conventional versus Hypofractionated Postmastectomy Radiotherapy: Retrospective Analysis

Comparing Late Toxicity of Conventional versus Hypofractionated Postmastectomy Radiotherapy: Retrospective Analysis

Topical Fibronectin Improves Wound Healing in Postmastectomy Breast Cancer Radiation Therapy : A Review

Breast cancer is the most common cancer among women worldwide. Breast cancer provides an excellent example of how multidisciplinary management has improved patient outcomes. This paper synthesizes the complex and evolving evidence regarding the role of radiation therapy after mastectomy. Although substantial evidence indicates that radiation therapy can reduce the risk of locoregional failure after mastectomy. This therapy is known as PMRT. Postmastectomy radiotherapy (PMRT) is an essential component of combined therapy for early‐stage, high‐risk breast cancer. Breast reconstruction (BR) is often considered for patients with breast cancer who have undergone mastectomy. There has been a considerable amount of discussion about the optimal approach to combining PMRT with BR in the treatment of breast cancer. PMRT may increase the risk of complications and prevent good aesthetic results after BR, while BR may increase the complexity of PMRT and the radiation dose to surrounding normal tissues. The goal of a PMRT plan is to achieve optimal coverage of the target volume while minimizing the irradiation dose to normal tissues. The purpose of this review is to give a broad overview and summary of the current topical fibronectin improves wound healing in postmastectomy breast cancer radiation therapy. In summary, Exogenous fibronectin diminishes wound progression, by increasing angiogenesis & cell proliferation. This suggests that enhances healing by stimulating the appearance of fibroblasts into the wound site and development of granulation tissue. This acceleration of the repair process may have an important application in the healing of skin chronic wounds.

Newly Diagnosed Mental Health Disorders in Patients With Breast Cancer Receiving Radiation Therapy

ObjectivesPatients with a mental health disorder (MHD) have higher age-adjusted mortality compared to the general population. Few reports investigate factors contributing to MHD among breast cancer patients receiving radiotherapy. Here, we report the incidence of acquired MHD after the diagnosis of breast cancer and treatment with radiotherapy. MethodsUtilizing a single-institution, prospectively maintained database, we analyzed patients with breast cancer treated with radiotherapy between 2012 and 2017. We cross-referenced these patients with newly acquired ICD-10 MHD codes within 3 years post-breast cancer diagnosis. The study included baseline NCCN distress tool scores and area deprivation index (ADI). Univariate (UVA) and multivariable (MVA) Cox regression analyses were conducted to evaluate factors impacting new MHD onset. ResultsOf the 967 included patients, 318 (33%) developed an MHD after their breast cancer diagnosis, which were predominately anxiety (45.1%) and depression (20.1%) related, with a median (IQR) time to diagnosis of 30 (24–33) months. UVA showed lymph node-positive disease, receipt of chemotherapy, receipt of a mastectomy, high comorbidity index, divorced status, retired status, and fourth-quartile ADI as significant predictors. On MVA, only receipt of chemotherapy (HR=1.70, p=0.014) and divorced status (HR=2.04, p=0.009) remained significant. Fourth-quartile ADI, retired status, and high comorbidity index showed trends towards significance (HR=1.78, p=0.065; HR=1.46, p=0.094; HR=1.41, p=0.059, respectively). On MVA examining the effects of the radiotherapy type on MHD, whole breast with regional nodal irradiation (WBI+RNI) (HR=2.31, p=0.015) and post-mastectomy radiotherapy (PMRT) (HR=1.88, p=0.024) were both strong predictors of MHD development. Additionally, an NCCN distress tool score of >3 was also predictive of MHD onset. ConclusionIn this cohort, one in three patients with localized breast cancer developed a new MHD, predominantly related to anxiety and depression. MHD risk was higher among divorced patients, those receiving chemotherapy, and patients receiving PMRT or WBI+RNI. These findings highlight the importance of future studies and targeted interventions to support this vulnerable population.