Identification and Quantification of Radiotherapy-related Protein Expression in Cancer Tissues Using the Qupath Software and Prediction of Treatment Response.

BACKGROUND/AIM: Automated measurement of immunostained samples can enable more convenient and objective prediction of treatment outcome from radiotherapy. We aimed to validate the performance of the QuPath image analysis software in immune cell markers detection by comparing QuPath cell counting results with those of physician manual cell counting. PATIENTS AND METHODS: CD8- and FoxP3-stained cervical, CD8-stained oropharyngeal, and Ku70-stained prostate cancer tumor sections were analyzed in 104 cervical, 92 oropharyngeal, and 58 prostate cancer patients undergoing radiotherapy at our Institution. RESULTS: QuPath and manual counts were highly correlated. When divided into two groups using ROC curves, the agreement between QuPath and manual counts was 89.4% for CD8 and 88.5% for FoxP3 in cervical cancer, 87.0% for CD8 in oropharyngeal cancer and 80.7% for Ku70 in prostate cancer. In cervical cancer, the high CD8 group based on QuPath counts had a better prognosis and the low CD8 group had a significantly worse prognosis [p=0.0003; 5-year overall survival (OS), 65.9% vs. 34.7%]. QuPath counts were more predictive than manual counts. Similar results were observed for FoxP3 in cervical cancer (p=0.002; 5-year OS, 62.1% vs. 33.6%) and CD8 in oropharyngeal cancer (p=0.013; 5-year OS, 80.2% vs. 47.2%). In prostate cancer, high Ku70 group had worse and low group significantly better outcome [p=0.007; 10-year progression-free survival (PFS), 56.0% vs. 93.8%]. CONCLUSION: QuPath showed a strong correlation with manual counting, confirming its utility and accuracy and potential applicability in clinical practice.

A Japanese multi-institutional phase II study of moderate hypofractionated intensity-modulated radiotherapy with image-guided technique for prostate cancer.

BACKGROUND: The aim of this multi-institutional phase II study was to confirm the safety and the potential efficacy of moderately hypofractionated intensity-modulated radiotherapy (IMRT) with prostate-based image-guidance for Japanese patients. METHODS: Patients with low- or intermediate-risk localized prostate cancer were eligible. Patients with a part of high risk (having only one of the following factors, cT3a, 20 < PSA ≤ 30, or GS = 8 or 9) were also included. Hypofractionated IMRT using daily image-guided technique with prostate matching was performed with a total dose of 70 Gy in 28 fractions. Neoadjuvant hormonal therapy for 4-8 months was mandatory for patients with intermediate or high-risk prostate cancer. RESULTS: From 20 institutions, 134 patients enrolled. The median follow-up was 5.16 years (range, 1.43-6.47 years). The number of patients with low, intermediate, and high-risk prostate cancer was 20, 80, and 34, respectively. The 5-year overall, biochemical failure-free, and clinical failure-free survival was 94.5%, 96.0%, and 99.2%, respectively. The 5-year biochemical failure-free survival for patients with low-, intermediate-, and high-risk disease was 94.1%, 97.4%, and 93.9%, respectively. The incidences of grade 2 gastrointestinal (GI) and genitourinary (GU) late toxicities at 5 years were 5.3% and 5.3%, respectively. There are no acute or late toxicities ≥ grade 3. Of 124 patients who were followed for up to 5 years, the grade 2 late GU or GI toxicities were 10.5% (90% confidence intervals, 6.3-16.2%, p = 0.0958). CONCLUSION: The safety and efficacy of moderately hypofractionated IMRT with prostate-based image-guidance was confirmed among Japanese patients with prostate cancer.

Notch signaling genes and CD8+ T-cell dynamics: Their contribution to immune-checkpoint inhibitor therapy in oral squamous cell carcinoma: A retrospective study.

BACKGROUND: Aberrant Notch signaling pathway has been related with the tumorigenesis in head and neck region, involving oral cavity. Here, we report the correlation between mutations in the Notch signaling pathway and CD8+ T-cell infiltration via PD-L1, which lead to enhanced antitumor immunity and may target for immune-checkpoint inhibitors (ICIs) therapy. METHODS: This retrospective study analyzed the results of immunohistochemical staining for PD-L1 and CD8+ T-cell infiltration in 10 patients and whole-exome sequencing (WES) was conducted on five of these patients to identify frequently mutated genes. RESULTS: Four of 10 patients were positive for PD-L1 and CD8+ T. By analyzing WES in three of these four patients, we notably identified the mutations of NOTCH1, FBXW7, and noncoding RNA intronic mutation in NOTCH2NLR in two of these three patients. This study may enable better selection of ICI therapy with CD8+ T-cell infiltration via PD-L1 expression for oral squamous cell carcinoma patients with mutations in Notch signaling pathway.

Prediction of late adverse events in pelvic cancer patients receiving definitive radiotherapy using radiation-induced gamma-H2AX foci assay.

Radiation can induce DNA double-stranded breaks, which are typically detected by the fluorescence of phosphorylated histone H2AX. In this study, we examined the usefulness of the dynamics of radiation-induced gamma-H2AX foci of peripheral blood lymphocytes (PBLs), as a marker of DNA repair ability, in predicting late adverse events from radiotherapy. A total of 46 patients with cervical, vaginal and anal canal cancers treated with radical radiotherapy between 2014 and 2019 were included in this analysis. Concurrent chemotherapy was administered in 36 cases (78.3%). Peripheral blood was obtained before treatment, and then irradiated ex vivo with 1 Gy X-ray. The ratio of radiation-induced gamma-H2AX foci in PBLs measured at 30 min and at 4 h was defined as the foci decay ratio (FDR). With a median follow-up of 54 months, 9 patients (19.6%) were observed to have late genitourinary or gastrointestinal (GU/GI) toxicity. The FDR ranged from 0.51 to 0.74 (median 0.59), with a significantly higher incidence of Grade 1 or higher late adverse events in the FDR ≥ 0.59 group. In multivariate analysis, FDR ≥ 0.59 and hypertension also emerged as significant factors associated with the development of late toxicities. Overall, our results suggest that measurement of radiation-induced gamma-H2AX foci in PBLs may predict the risk of late GU/GI toxicities from chemoradiotherapy, which can enable tailoring the radiation dose to minimize adverse effects.

Immunohistological evaluation of patients treated with intra-arterial chemoradiotherapy and surgery for oral cancer.

Preoperative intra-arterial chemoradiotherapy (IACRT) can improve the outcome and reduce the extent of surgery in patients with advanced oral cancer. However, the response to this regimen varies among patients, which may be related to the immune status of the tumor. We investigated the effects of proteins involved in tumor immunity on the outcomes of combined IACRT and surgery for oral cancer. We examined CD8 + and FoxP3 + tumor-infiltrating lymphocytes (TILs) and programmed death ligand 1 (PD-L1) expression on immune cells and tumor cells in pretreatment biopsy samples from 69 patients diagnosed with oral cancer treated with IACRT at our institution during 2000-2020. Patients with abundant CD8 + TILs had significantly better 5-year disease-specific survival (DSS) compared to that of patients with less infiltration of these cells (P = 0.016). Patients with higher FoxP3 + T-cells invasion had significantly better DSS compared to that of less FoxP3 (P = 0.005). Patients with high PD-L1 expression in tumor cells and immune cells had significantly better DSS than that of patients with low PD-L1 expression in these cells (P = 0.009 and P = 0.025, respectively). Collectively, these results suggest that the tumor immune microenvironment could affect outcomes of IACRT treatment in oral cancer.

Virtual clinical trial based on outcome modeling with iteratively redistributed extrapolation data.

Virtual clinical trials (VCTs) can potentially simulate clinical trials on a computer, but their application with a limited number of past clinical cases is challenging due to the biased estimation of the statistical population. In this study, we developed ExMixup, a novel training technique based on machine learning, using iteratively redistributed extrapolated data. Information obtained from 100 patients with prostate cancer and 385 patients with oropharyngeal cancer was used to predict the recurrence after radiotherapy. Model performance was evaluated by developing outcome prediction models based on three types of training methods: training with original data (baseline), interpolation data (Mixup), and interpolation + extrapolation data (ExMixup). Two types of VCTs were conducted to predict the treatment response of patients with distinct characteristics compared to the training data obtained from patient cohorts categorized under risk classification or cancer stage. The prediction models developed with ExMixup yielded concordance indices (95% confidence intervals) of 0.751 (0.719-0.818) and 0.752 (0.734-0.785) for VCTs on the prostate and oropharyngeal cancer datasets, respectively, which significantly outperformed the baseline and Mixup models (P < 0.01). The proposed approach could enhance the ability of VCTs to predict treatment results in patients excluded from past clinical trials.

Predictive value of an exosomal microRNA-based signature for tumor immunity in cervical cancer patients treated with chemoradiotherapy.

Resistance of cervical cancer to radiotherapy with concurrent chemotherapy (CCRT) results in a poor prognosis. To identify new biomarkers for predicting the treatment response and prognosis, we explored exosomal microRNA (miRNA) expression signatures associated with the outcome of cervical cancer patients treated with CCRT. Exosomes were isolated from the plasma of 45 patients prior to CCRT during 2014-2020, and miRNA analysis was performed by next-generation sequencing. At a median follow-up of 38 months, 26 patients were recurrence free, 15 patients had died of the disease, and 4 patients received salvage chemotherapy due to distant metastasis. Of the 2522 miRNAs detected, 9 (miR-148a-5p, 1915-3p, 3960, 183-5p, 196b-5p, 200c-3p, 182-5p, 374a-5p, and 431-5p) showed differential expression between the recurrence-free and recurrence groups. Patients were divided into high- and low-risk groups according to the cutoff of the miRNAs-based risk score calculated from respective expression levels. The high-risk group had significantly worse disease-specific survival than the low-risk group (p < 0.001). In addition, miR-374a-5p and miR-431-5p expression showed a weak inverse correlation with tumor-infiltrating CD8+ and FOXP3+ T cells, suggesting a potential inhibitory effect on CCRT by suppressing tumor immunity. This miRNA signature could improve non-invasive monitoring and personalized treatment for cervical cancer.

Combined chemoradiotherapy and programmed cell death-ligand 1 blockade leads to changes in the circulating T-cell receptor repertoire of patients with non-small-cell lung cancer.

Combined chemoradiotherapy (CRT) and programmed cell death-ligand 1 (PD-L1) blockade is a new care standard for unresectable stage III non-small-cell lung cancer (NSCLC). Although this consolidation therapy has improved the overall survival of patients with NSCLC, the synergistic action mechanisms of CRT and immunotherapy on T cells remain unclear. In addition, there is a paucity of reliable biomarkers to predict clinical responses to therapy. In this study, we analyzed T-cell receptor (TCR) sequences in the peripheral blood of five patients with NSCLC. T-cell receptor analysis was undertaken before treatment, after CRT, and after PD-L1 blockade. Notably, we observed the expansion and alteration of the dominant T-cell clonotypes in all cases with a complete response. In contrast, neither expansion nor alteration of the TCR repertoire was observed in cases with progressive disease. T cell expansion was initiated after CRT and was further enhanced after PD-L1 blockade. Our findings suggest the systemic effect of CRT on circulating T cells in addition to the curative effect on limited tumor sites. Dynamic changes in circulating T-cell clonotypes could have a prognostic significance for combined CRT and PD-L1 blockade.

Clinical and histopathologic effects of neoadjuvant intra-arterial chemoradiotherapy with cisplatin in combination with oral S-1 on stage III and IV oral cancer.

OBJECTIVE: The aim of this study was to examine the clinical and histopathologic effects of neoadjuvant intra-arterial chemoradiotherapy (IACRT) using cisplatin in combination with oral S-1 (tegafur/gimeracil/oteracil potassium) on stage III and IV oral squamous cell carcinoma. STUDY DESIGN: Thirty patients received infusions of superselective intra-arterial cisplatin 60 mg/m2 by the Seldinger method and conventional external beam radiotherapy (total 40 Gy) combined with oral S-1 on the day of irradiation. Curative surgery and neck dissection were performed 4 to 6 weeks after IACRT. The clinical response of the primary lesion was evaluated approximately 4 weeks after IACRT. The surgically resected specimens were examined for histologic features according to the grading system for histologic evaluation and for residual tumor grade (RGrades). RESULTS: Histopathologic evaluation of the therapeutic effect was grade 2 in 10 patients and grade 3 in 16 patients. According to the distribution of RGrades, the remaining tumor cells were mostly in the central area of the primary lesion, as seen in 24 patients. CONCLUSIONS: These findings indicate that neoadjuvant IACRT with cisplatin and oral S-1 was an effective treatment, suggesting the possibility of reducing the extent of curative surgery based on RGrades.

Radiotherapy for HPV-related cancers: prediction of therapeutic effects based on the mechanism of tumor immunity and the application of immunoradiotherapy.

Human papillomavirus (HPV)-related cancer is one of the diseases entities for which the applications of radiotherapy have been increasing. Recently, the process of carcinogenesis from HPV infection and the mechanism of tumor immunity that develops during disease progression have been elucidated. In this review, we will describe the mechanism of tumor immunity and how chemoradiotherapy may overcome and improve the efficacy of tumor immunity. We will also discuss the usefulness of proteins involved with tumor immunity as a predictive marker of radiotherapy response, and present an overview of ongoing clinical trials of combinations of immune checkpoint inhibitors and radiotherapy to demonstrate the promising combination therapy that has been currently emerging.

Stiff coils enhance shape retention and pressure resistance in an aneurysm model even at low volume.

PURPOSE: To elucidate the characteristics of 3 D frame coils and identify the optimal coil for visceral aneurysms. MATERIAL AND METHODS: Using a vascular model, we compared the postembolization coil distribution and repulsive force of three coils: Guglielmi detachable coil (GDC; stock wire diameter, 0.004 in; primary diameter, 0.015 in), Target XL (0.003, 0.014), and Target XXL (0.003, 0.017). Additionally, the coil area, roundness, and center of gravity were quantitatively compared. The coil repulsive force was measured by compressing the postembolization vessel model with a digital force gauge. RESULTS: There were no significant differences in the coil area and roundness among the three coil types. Compared with the Target coils, the GDC deployed evenly along the vessel wall, its center of gravity was less displaced, and although it had the lowest embolic density, its repulsive force was greater regardless of the number of coils used. CONCLUSIONS: GDC coils with a larger stock wire diameter and a smaller primary diameter unfolded evenly along the wall and had a greater repulsive force. Coil stiffness contributes to coil stability and shape retention, indicating the possibility of preventing recurrence by selecting a frame coil with a focus on coil stiffness.

Prediction of treatment response from the microenvironment of tumor immunity in cervical cancer patients treated with chemoradiotherapy.

To supplement clinical decision-making in the management of cervical cancer, various prognostic factors, including tumor immune microenvironments, were examined in patients with cervical cancer treated with definitive chemoradiotherapy. We retrospectively analyzed the expression of CD8, FoxP3, HLA-1, PD-L1, and XRCC4 in 100 cases of cervical cancer. The observed tumor immune microenvironments were also classified into three types: inflamed, excluded, and cold type. Less FoxP3+ T cells and cold-type tumor were found to be poor prognostic factors in addition to non-SCC, large pre-treatment tumor volume, and three or less cycles of concurrent chemotherapy based on multivariate analysis. Cold-type tumors had significantly worse prognoses than the other two types, whereas inflamed- and excluded-type tumors showed similar 5-year disease-specific survival (P < 0.001; 0% vs. 60.3% vs. 72.3%). Radiotherapy could overcome the inhibitory immune microenvironment that occurs in excluded type. Individualized combination therapy adapted to pre-treatment tumor immunity may be necessary to improve radiotherapy outcomes in cervical cancer.

Association between cancer immunity and treatment results in uterine cervical cancer patients treated with radiotherapy.

OBJECTIVE: To evaluate proteins related to tumor immune response and treatment outcome from radiotherapy for uterine cervical cancer patients. METHODS: We performed a retrospective immunohistochemical staining of 81 patients with uterine cervical cancer who underwent definitive radiotherapy. We examined the expression of programmed death ligand 1, human leukocyte antigen class I, tumor-infiltrating CD8+, and forkhead box P3+ (FoxP3+) T cells in tumor tissues. RESULTS: In biopsy specimen, patients with a higher number of CD8+ T cells and FoxP3+ T cells had a better disease-specific survival than patients with a lower number of CD8+ T cells and FoxP3+ cells (P = 0.018 and P = 0.009). Multivariate analysis showed that equivalent dose in 2 Gy fractions (EQD2) of the minimum dose to 90% of the high-risk clinical target volume, FoxP3+ T cells and expression of human leukocyte antigen class I were significant prognostic factors. When the EQD2 is 70 Gy or more, a higher local control rate is obtained regardless of the number of CD8- or FoxP3-positive cells. When EQD2 is <70 Gy, the number of CD8-positive cells has a significant impact on treatment outcome: the recurrence rate (local recurrence rate + distant metastasis rate) was 46.2% in the group with a CD8 value of 230 or higher, whereas the recurrence rate was 75.7% in the group with a CD8 value of less than 230. CONCLUSION: The combination of CD8 or FoxP3 with EQD2 can be potentially useful to predict the treatment results of radiotherapy for cervical cancer, leading to individualized optimal selection of treatment for cervical cancer.

Prediction of Results of Radiotherapy With Ku70 Expression and an Artificial Neural Network.

Background/Aim: Accurate prediction of radiotherapy results is indispensable for the individualized selection of treatment modalities of cancer. We examined the application of the artificial neural network (ANN) model in predicting radiotherapy results using clinical factors and immunohistochemical staining of Ku70 as inputs. Patients and Methods: We analyzed 79 prostate cancer patients with localized adenocarcinoma treated with radiotherapy between August 2001 and October 2010. We also analyzed 46 hypopharyngeal cancer patients with squamous cell carcinoma treated with radiotherapy between March 2002 and December 2009. The properly trained ANN analysis using a standard feedforward, back-propagation neural network was used to predict the radiotherapy treatment results. Results: The areas under the receiver-operating characteristic curve (AUC) were 0.939 for patients treated with intensity modulated radiotherapy (IMRT)+androgen deprivation therapy (ADT), 0.803 for IMRT alone, and 0.960 for 3D-conformal radiotherapy (CRT) alone in prostate cancer. Sensitivity and specificity were 85.7% and 90.4% for IMRT+ADT, 75.0% and 88.5% for IMRT alone, and 92.3% and 100% for 3D-CRT alone. The AUC was 0.901 for hypopharyngeal cancer. Sensitivity and specificity were 66.7% and 88.2%, respectively. Conclusion: We demonstrated a possibility to predict the radiotherapy treatment results in prostate and hypopharyngeal cancer using ANN in combination with Ku70 expression and clinical factors as inputs.

Evaluation of the urethral α/ß ratio and tissue repair half-time for iodine-125 prostate brachytherapy with or without supplemental external beam radiotherapy.

PURPOSE: To assess the correlation between postimplant dosimetric quantifiers and the genitourinary (GU) toxicity of low-dose rate brachytherapy for prostate cancer. METHODS AND MATERIALS: The minimum urethral dose (UD10, 30, and 90) and the percent volume of the urethra receiving the prescription dose (V100, V150) were calculated from the postimplant dose-volume histograms of 182 patients. We then calculated various urethral biologically equivalent doses (uBEDs) using different values of the α/ß ratio and tissue repair half-time (t1/2) and examined the correlations with GU toxicity. RESULTS: Common dosimetric quantifiers, such as UD90 (brachytherapy) + UD50 (external beam radiotherapy), showed no correlation with Grade ≥ 2 GU toxicity. There was a significant correlation between Grade ≥2 GU toxicity and uBED when the α/ß value was 0.5 or 1 Gy and t1/2 was 0.5-2.5 h. An uBED (α/ß = 1.0, t1/2 = 0.5) had the largest hazard ratio for GU toxicity, and it was also significantly correlated with Grade ≥ 2 GU toxicity according to multivariate analysis. CONCLUSIONS: We observed a significant correlation of uBED with GU toxicity when α/ß was 0.5 or 1.0 Gy and t1/2 was 0.5-2.5 h. As the simple formula we used has not been verified in basic experiments, more data are needed to validate our results.

Retrospective DVH analysis of point A based intracavitary brachytherapy for uterine cervical cancer.

Combining external beam radiotherapy (EBRT) with intracavitary brachytherapy (ICBT) is important for definitive treatment of cervical cancer. In cervical cancer patients receiving radiotherapy, we evaluated treatment outcomes in relation to dose-volume histogram parameters, including the computed tomography (CT)-based high-risk clinical target volume (HR-CTV) for ICBT. Between 2010 and 2015, 89 consecutive cervical cancer patients were mostly treated with 40 Gy of EBRT in 20 fractions and 18 Gy of ICBT prescribed to point A in 3 fractions. CT scans were obtained during ICBT. The HR-CTV D90 was calculated and the total doses of ICBT and EBRT were converted to the equivalent dose in 2 Gy fractions (EQD2). When the patients were divided into four groups according to EQD2 of the HR-CTV D90, the 3-year local recurrence-free survival rates were 95.2, 78.4, 52.7 and 42.9% for patients receiving >80 , 70-80 , 60-70 and <60 Gy, respectively. There was a significant negative correlation between EQD2 of the HR-CTV D90 and the HR-CTV volume at first ICBT (r = -0.713). Local recurrence was more frequent when the HR-CTV volume was ≥22 cc and EQD2 of the HR-CTV D90 was <70 Gy. Multivariate analysis showed that EQD2 of the HR-CTV D90 and concurrent chemotherapy (≥4 cycles) were significant determinants of overall survival. HR-CTV D90 was an important prognostic indicator for local recurrence. HR-CTV D90 >70 Gy is required for the better local control, especially in patients with a larger HR-CTV (≥22 cc at initial ICBT).

Association between radiotherapy-induced alteration of programmed death ligand 1 and survival in patients with uterine cervical cancer undergoing preoperative radiotherapy.

PURPOSE: To evaluate radiotherapy-induced changes in the expression of programmed death ligand 1 (PD-L1), programmed death 1 (PD-1), and human leukocyte antigen class I (HLA-1) in patients with uterine cervical cancer, as well as infiltration of CD8+ and Forkhead box P3+ (FoxP3+) T lymphocytes into tumor tissue and the prognostic value of these parameters. MATERIALS AND METHODS: We performed immunohistochemical analysis of pre-radiotherapy biopsies and corresponding post-radiotherapy resected tissues in 104 uterine cervical cancer patients undergoing preoperative chemoradiotherapy or radiotherapy alone. We scored the expression of various proteins to distinguish positive from negative samples. RESULTS: PD-L1-expressing tumor cells (PD-L1 TC) increased significantly after chemoradiotherapy (p = 0.043). CD8+ T cell infiltration (p = 0.002) and FoxP3+ T cell infiltration (p = 0.003) decreased significantly after chemoradiotherapy. Expression of PD­1, PD-L1-expressing immune cells (PD-L1 IC), and HLA­1 did not change after chemoradiotherapy. In biopsy specimens obtained before chemoradiotherapy or radiotherapy, greater infiltration of CD8+ T cells (p = 0.001) and FoxP3+ T cells (p = 0.003) were significant predictors of better overall survival (OS). In surgical specimens obtained after chemoradiotherapy or radiotherapy, greater infiltration of PD-L1 TC was the only significant predictor of better OS (p < 0.001) and was related to a significantly lower probability of out-of-field recurrence (p = 0.005). CONCLUSION: Chemoradiotherapy induced an immunologic shift that increased PD-L1 TC. Chemoradiotherapy has immunological effects that can influence the results of treatment for uterine cervical cancer.

Phase 2 Study of Neoadjuvant Treatment of Sequential S-1-Based Concurrent Chemoradiation Therapy Followed by Systemic Chemotherapy with Gemcitabine for Borderline Resectable Pancreatic Adenocarcinoma (HOPS-BR 01).

PURPOSE: Preoperative treatment is recommended for borderline resectable pancreatic ductal adenocarcinoma. However, the standard treatment has not yet been determined. We conducted a multicenter phase 2 study to investigate the efficacy of neoadjuvant treatment of sequential chemoradiation followed by chemotherapy. METHODS AND MATERIALS: All enrolled patients were treated by preoperative chemoradiation (a total dose of 50.4 Gy in 28 fractions and orally administered S-1 at 80 mg/m2 on the day of irradiation) followed by chemotherapy (administration of gemcitabine at 1000 mg/m2/dose on days 1, 8, and 15 in 3 cycles of 4 weeks) and attempted curative resection. The primary outcome was an R0 resection rate among patients who completed preoperative treatment and pancreatectomy. The threshold of the R0 resection rate was defined as 74% based on a previous study of up-front surgery. RESULTS: Forty-five patients were included. Twenty-one patients could not undergo pancreatectomy because of progressive diseases (n = 14), adverse events (n = 5), or consent withdrawal (n = 2), and 4 patients underwent additional resection after dropping out. The resection rates were 53.3% and 62.2% in the per-protocol set (PPS) and full analysis set (FAS) populations, respectively. The R0 resection rates were 95.8% (95% confidence interval, 78.9%-99.9%) and 96.4% (81.7%-99.9%) in the PPS and FAS populations, respectively. The median overall survival and progression-free survival of all the included patients were 17.3 and 10.5 months, respectively. The median survival time of the patients with pancreatectomy was significantly longer than that of the patients without pancreatectomy in the PPS (27.9 vs 12.3 months; P = .001) and FAS populations (32.2 vs 11.8 months; P < .001). CONCLUSIONS: This study revealed that a long duration of preoperative treatment of sequential chemoradiation followed by systemic chemotherapy provides a high rate of R0 resection and sufficient survival time in patients undergoing pancreatectomy.