Purpose: It is important to continually reevaluate the risk/bene t calculus of internal mammary node irradiation (IMNI) in the era of modern systemic therapy. We aimed to investigate the effect of IMNI on survival in node-positive breast cancer treated with mastectomy and anthracycline plus taxane-based chemotherapy.Methods and Materials: We analyzed 348 patients who underwent mastectomy and anthracycline plus taxane-based chemotherapy for node-positive breast cancer between January 2006 and December 2011. All patients received adjuvant radiotherapy with IMNI (n = 105, 30.2%) or without IMNI (n = 243, 69.8%).The bene t of IMNI for disease-free survival (DFS) and overall survival (OS) was evaluated using multivariate analysis and inverse probability of treatment weighting (IPTW) to adjust for unbalanced covariates between the groups.Results: After a median follow-up of 95 months, the 10-year locoregional recurrence-free survival rate, DFS, and OS in all patients were 94.8%, 77.4%, and 86.2%, respectively. The IPTW-adjusted hazard ratio (HR) for the association of IMNI (vs. no IMNI) with DFS and OS was 0.208 (95% con dence intervals (CI) 0.045-0.966) and 0.460 (95% CI, 0.220-0.962). In multivariate analysis, IMNI was a favorable factor for DFS (HR, 0.458; p = 0.021) and OS (HR 0.233, p = 0.018).Conclusions: IMNI was associated with improved DFS and OS in node-positive patients treated with mastectomy, post-mastectomy radiation therapy, and taxane-based chemotherapy, although the rate of locoregional recurrence was low.

Purpose To assess the safety and efficacy of gemcitabine and cisplatin as neoadjuvant chemotherapy followed by selective bladder preservation chemoradiotherapy in muscle-invasive bladder cancer (MIBC). Materials and Methods Patients with clinical T2-T4aN0M0 MIBC eligible for radical cystectomy and cisplatin-based chemotherapy were treated with gemcitabine 1,000 mg/m 2 on days 1, 8 and 15, and cisplatin 70 mg/m 2 on day 1 every 28 days for 3 cycles. After clinical re-staging with computed tomography scans and cystoscopy, patients with clinical complete response (CR) were eligible to proceed without cystectomy and receive bladder preservation chemoradiotherapy involving weekly cisplatin 10 mg/m 2 and up to 70.2 Gy of radiation. The primary endpoint of the present prospective phase II study was metastasis-free survival (MFS). Results Between Oct 2017 and Nov 2019, a total of 138 MIBC patients were enrolled and treated with neoadjuvant gemcitabine/cisplatin. Neoadjuvant chemotherapy was well-tolerated, with fatigue, nausea, and pruritus being the most commonly observed adverse events. After completion of planned neoadjuvant chemotherapy, 54 patients with a clinical CR and 10 patients who did not have CR but refused surgery received bladder preservation chemoradiotherapy. With a median follow-up duration of 34 months (95% confidence interval [CI], 32%–36%), the 3-year MFS rate in 64 chemoradiotherapy patients was calculated to be 70% (95% CI, 58%–82%). Conclusions Neoadjuvant chemotherapy followed by selective bladder preservation chemoradiotherapy based on the clinical CR was feasible and efficacious in the treatment of MIBC.

Background Postoperative radiotherapy (PORT) could be useful for pN1 breast cancer patients who have undergone breast-conserving surgery (BCS) or mastectomy. However, the value of regional nodal irradiation (RNI) for BCS patients, and the indications for post-mastectomy radiotherapy (PMRT) for pN1 breast cancer mastectomy patients, have recently been challenged due to the absence of relevant trials in the era of modern systemic therapy. “PORT de-escalation” should be assessed in patients with pN1 breast cancer. Methods The PORT-N1 trial is a multicenter, randomized, phase 3 clinical trial for patients with pN1 breast cancer that compares the outcomes of control [whole-breast irradiation (WBI) and RNI/PMRT] and experimental (WBI alone/no PMRT) groups. PORT-N1 aims to demonstrate non-inferiority of the experimental group by comparing 7-year disease-free survival rates with the control group. Female breast cancer patients with pT1-3 N1 status after BCS or mastectomy are eligible. Participants will be randomly assigned to the two groups in a 1:1 ratio. Randomization will be stratified by surgery type (BCS vs. mastectomy) and histologic subtype (triple-negative vs. non-triple-negative). In patients who receive mastectomy, dissection of ≥5 nodes is required when there is one positive node, and axillary lymph node dissection when there are two or three positive nodes. Patients receiving neoadjuvant chemotherapy are not eligible. RNI includes a “high-tangent” or wider irradiation field. This study will aim to recruit 1106 patients. Discussion The PORT-N1 trial aims to verify that PORT de-escalation after BCS or mastectomy is safe for pN1 breast cancer patients in terms of oncologic outcomes and capable of reducing toxicity rates. This trial will provide information crucial for designing PORT de-escalation strategies for patients with pN1 breast cancer. Trial registration This trial was registered at ClinicalTrials.gov (NCT05440149) on June 30, 2022.