Impact Of Adjuvant Radiotherapy Research Articles

Abstract 1108: The impact of adjuvant radiotherapy (ART) and survival prediction by machine learning in intracranial hemangiopericytoma (HPC)

Abstract Background: Intracranial HPC is a rare brain tumor that accounts for less than 1% of all primary central nervous system malignancies. Surgery is the primary treatment, and while radiation may reduce the risk of local recurrence, its overall effectiveness remains uncertain. Therefore, it is crucial to develop reliable predictions for personalized care and improved management. In this study, we used machine learning (ML) techniques to predict the survival of patients with intracranial HPC. Methods: Data were obtained from the Surveillance, Epidemiology, and End Results (SEER) database (2000-2019). Patients with other malignancies or lack of pathological diagnosis were excluded. T-tests and chi-square tests compared variables, while Kaplan-Meier, log-rank tests, and Cox regression identified prognostic factors for overall survival (OS) and cancer-specific survival (CSS). Patient records were randomly divided into training (80 %) and validation (20 %) sets. Univariate Cox regression and least absolute shrinkage and selection operator were used to identify the significant factors linked to survival, which were used to establish a nomogram for predicting the 3- and 5-year OS and CSS. Results: Of the 367 included patients, 121 underwent surgery and 246 underwent surgery + ART. The median survival time was 54 months. Patients who underwent surgery had 5-year OS rates of 61% and 86% for CSS, while those treated with surgery + ART had 81% and 96% survival rates, respectively. The two treatment groups showed significant differences in the OS and CSS (p<0.022 and p<0.017, respectively). Age ≥ 50 years was a poor prognostic factor for OS, whereas ART, localized stage and regional stage were good prognostic factors. No significant factors were associated with CSS. To construct the OS Nomogram, three predictors, age, stage, and treatment method, were chosen. In the training and validation sets, the C-indices are 0.799 and 0.736, respectively. The receiver operating characteristic curves (AUCs) for the 3- and 5-year OS in the training set were 0.594 and 0.617, respectively, whereas those in the validation set were 0.56 and 0.59. For the CSS nomogram, two factors, age and stage, were utilized. The C-indices for the training and validation sets are 0.814 and 0.774, respectively. In the training set, the AUCs for 3- and 5-year CSS were 0.585 and 0.605, respectively, and 0.563 in the validation set. The most important risk factor was the distant stage, while the most important protective factor was age less than 50 years. Conclusion: This study shows that ART has a significant impact on the treatment of Intracranial HPC and provides better survival outcomes. ML has been used to create prediction models to support personalized patient care. These findings provide valuable insights into the management of this rare brain tumor and the potential of data-driven approaches to improve treatment and outcomes. Citation Format: Sakhr Alshwayyat, Anas Alaa Al-Khalili, Ayah Erjan, Haya Kamal, Tala Abdulsalam, Mustafa Alshwayyat. The impact of adjuvant radiotherapy (ART) and survival prediction by machine learning in intracranial hemangiopericytoma (HPC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1108.

32LBA (PB-013) LBA Poster - The impact of adjuvant radiotherapy on immediate prepectoral implant-based breast reconstruction

32LBA (PB-013) LBA Poster - The impact of adjuvant radiotherapy on immediate prepectoral implant-based breast reconstruction

Impact of adjuvant radiotherapy and chemotherapy on thymoma

PurposeThymoma is a rare tumour. The most common treatment for thymoma is surgical resection, while the use of radiotherapy and chemotherapy remains controversial. Patients and methodsWe conducted a monocentric observational study of 31 patients diagnosed with thymoma from June 2004 to July 2020 at cancer centre in Strasbourg, France. We analysed the outcomes of the patients. ResultsThe 2- and 5- year locoregional relapse-free survival rates were 96.3% (95% confidence interval [CI]: 76.5–99.5%) and 68.0% (95% CI: 43.8–83.5%), respectively. Radiotherapy and chemotherapy significantly improved local tumour control (P=0.0008 and 0.04, respectively), while a larger initial tumour size significantly worsened local control rates (P=0.04). The 5- and 10-year overall survival rates were 87.1% (95% CI: 69.2–95%) and 81.7% (95% CI: 60.3–92.2%), respectively. The median overall survival was not reached, and no favourable factor was retrieved. For relapsed patients, the median overall survival after relapse was 115 months. ConclusionDespite the inherent limitations of retrospective studies with a limited patient sample size, we demonstrated that chemotherapy and radiotherapy in addition to surgery were effective in achieving local control and contributed to improving patient outcomes in thymoma. Notably, an aggressive treatment strategy at the time of relapse resulted in favourable outcomes for retreated patients.

Analysis of demographics and the impact of adjuvant radiotherapy on a nationwide cohort of patients with high-grade spinal meningiomas.

Although typically benign, 5% of spinal meningiomas (SMs) present with higher-grade features (World Health Organization grades 2 and 3). High-grade SMs are poorly studied and the role of adjuvant radiotherapy in their management remains controversial. We hence aimed to study the demographic characteristics of this rare tumor and investigate the outcomes associated with the use of surgery with adjuvant therapy in contrast to surgery alone. The National Cancer Database was queried for patients with SMs from 2004 to 2017. Basic statistics were used to identify differences between low- and high-grade tumors in terms of baseline characteristics. Surgery with and without adjuvant radiotherapy were compared after (1:1) propensity-score matching. Kaplan-Meier survival analysis was conducted to study overall survival. All analyses were performed on R. A total of 13184 patients diagnosed with SMs were included, of whom only 5% (n = 669) had high-grade SMs. Patients with high-grade SMs presented at a younger median age (57 years [IQR: 44-68] versus 65 years [54-75]; P < .001) and were more commonly males (33% vs 20%; P < .001). After propensity-score matching, survival analysis revealed similar overall survival outcomes in patients with high-grade SM undergoing both surgery and radiotherapy as compared to those only receiving surgery (P = .19). This study reveals major demographic differences between high- and low-grade SMs. There were no benefits associated with the use of adjuvant radiotherapy. However, due to confounding, overall survival outcomes between patients receiving surgery alone and those receiving surgery with adjuvant radiotherapy are not causally interpretable.

Impact of Adjuvant Radiotherapy in Squamous Cell Carcinoma of the Oral Cavity with Perineural Invasion.

Current guidelines indicate postoperative radiotherapy (PORT) in oral squamous cell carcinoma (OSCC) with perineural invasion (PNI), however, its real benefit has never been proven. The aim of our study is to investigate the benefit of PORT in OSCC patients with PNI in terms of survival and disease control. The Pubmed/MEDLINE, Cochrane Library, and Scopus databases. Patients with PNI + OSCC treated with primary surgery were extracted from the included studies. The pooled logHR was calculated by comparing patients who underwent PORT to those who underwent only observation for overall survival (OS), disease-specific survival (DSS), disease-free survival (DFS), and locoregional control (LRC). About 690 patients with primary OSCC and PNI were included from nine studies. 374 (54.2%) patients underwent PORT, while 316 (45.8%) underwent observation. Analyses showed non-significant difference between the two groups for OS (HR: 1.01; 95% CI: 0.38-2.69), DSS (HR: 2.03; 95% CI: 0.54-7.56), and LRC (HR: 0.89; 95% CI: 0.53-1.50). They showed a significant difference in terms of DFS (HR: 0.86; 95% CI: 0.77-0.97). The real benefit of PORT in OSCC patients with PNI is still unclear, although it may have a positive impact on DFS. Clinicians should consider individual patient's characteristics, tumor factors, and treatment goals when deciding whether to recommend PORT. Further studies are needed to clarify which entity of PNI really benefits from PORT. NA Laryngoscope, 134:2019-2027, 2024.

The Impact of Adjuvant Radiotherapy on Clinical Performance Status in Patients With Grade II Spinal Cord Astrocytoma - A Nationwide Analysis by the Neurospinal Society of Japan.

The impact of adjuvant radiotherapy on overall survival (OS) and progression-free survival (PFS) of patients with grade II spinal cord astrocytomas remains controversial. Additionally, the relationship between progression and clinical deterioration after radiotherapy has not been well investigated. This study included 53 patients with grade II intramedullary spinal cord astrocytomas treated by either subtotal, partial resection or open biopsy. Their clinical performance status was assessed immediately before operation and 1, 6, 12, 24, and 60 months after surgery by Karnofsky Performance Scale (KPS). Patients with and without adjuvant radiotherapy were compared. The groups with and without radiation comprised 23 and 30 patients with a mean age of 50.3 ± 22.6 years (range, 2-88 years). The mean overall disease progression rate was 47.1% during a mean follow-up period of 48.4 ± 39.8 months (range, 2.5-144.5 months). In the radiation group, 11 patients (47.8%) presented with progressive disease, whereas 14 patients (46.7%) presented with progressive disease in the group without radiation. There were no significant differences in OS or PFS among patients with or without adjuvant radiotherapy. KPS in both groups, especially radiation group, gradually decreased after operation and deteriorated before the confirmation of disease progression. Adjuvant radiotherapy did not show effectiveness regarding PFS or OS in patients with grade II spinal cord astrocytoma according to classical classification based on pathohistological findings.

The Impact of Adjuvant Radiotherapy on Immediate Prepectoral Implant-Based Breast Reconstruction.

Immediate prepectoral implant-based breast reconstruction (IBBR) rates have increased in recent years owing to improved cosmetic and psychological benefits. However, there is a lack of studies regarding complications rates following adjuvant radiotherapy (RT) among patients undergoing immediate prepectoral IBBR. We conducted a retrospective monocentric analysis of a cohort of consecutively treated patients who underwent NSM following immediate prepectoral IBBR at our institution between March 2017 and November 2021. Patient demographics, quality of life, complication rates, and oncological safety were evaluated in the RT and non-RT groups. Data analysis was performed using IBM SPSS Version 24 (IMB Corp., Armonk, NY, USA). A total of 98 patients were examined: 70 were assigned to have prepectoral IBBR without RT and 28 to the group who had prepectoral IBBR with RT. There was a statistically significant difference in overall capsular contracture rate between the RT and non-RT group (18% vs. 4.3%, p=0.04). The total implant loss in the cohort was 4% (10.7% vs. 1.4%, p=0.05). We obtained a high percentages of all BREAST-Q categories in both groups; however, satisfaction with the breast and sexual well-being was higher in the non-RT group. The three-year overall survivals were 97.4% in the RT group and 98.5% in the non-RT group. Our findings showed that patients in the RT group had a higher rate of capsular contracture and implant loss than those in the non-RT group. However, complication rates were within acceptable range and with accurate preoperative information patients have more benefits from immediate reconstruction showing excellent overall quality of life irrespectively of radiation. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Impact of adjuvant radiation therapy on survival and recurrence in patients with stage I-III Merkel cell carcinoma: A retrospective study of 312 patients

Impact of adjuvant radiation therapy on survival and recurrence in patients with stage I-III Merkel cell carcinoma: A retrospective study of 312 patients

Adjuvant Radiotherapy in Patients with Squamous Cell Carcinoma of the Oral Cavity or Oropharynx and Solitary Ipsilateral Lymph Node Metastasis (pN1)-A Prospective Multicentric Cohort Study.

(1) Background: Evaluation of impact of adjuvant radiation therapy (RT) in patients with oral squamous cell carcinoma of the oral cavity/oropharynx (OSCC) of up to 4 cm (pT1/pT2) and solitary ipsilateral lymph node metastasis (pN1). A non-irradiated group with clinical follow-up was chosen for control, and survival and quality of life (QL) were compared; (2) Methods: This prospective multicentric comprehensive cohort study included patients with resected OSCC (pT1/pT2, pN1, and cM0) who were allocated into adjuvant radiation therapy (RT) or observation. The primary endpoint was overall survival. Secondary endpoints were progression-free survival and QL after surgery; (3) Results: Out of 27 centers, 209 patients were enrolled with a median follow-up of 3.4 years. An amount of 137 patients were in the observation arm, and 72 received adjuvant irradiation. Overall survival did not differ between groups (hazard ratio (HR) 0.98 [0.55-1.73], p = 0.94). There were fewer neck metastases (HR 0.34 [0.15-0.77]; p = 0.01), as well as fewer local recurrences (HR 0.41 [0.19-0.89]; p = 0.02) under adjuvant RT. For QL, irradiated patients showed higher values for the symptom scale pain after 0.5, two, and three years (all p < 0.05). After six months and three years, irradiated patients reported higher symptom burdens (impaired swallowing, speech, as well as teeth-related problems (all p < 0.05)). Patients in the RT group had significantly more problems with mouth opening after six months, one, and two years (p < 0.05); (4) Conclusions: Adjuvant RT in patients with early SCC of the oral cavity and oropharynx does not seem to influence overall survival, but it positively affects progression-free survival. However, irradiated patients report a significantly decreased QL up to three years after therapy compared to the observation group.

Molecular Signatures in Ductal Carcinoma In Situ (DCIS): A Systematic Review and Meta-Analysis

Adjuvant radiotherapy (RT) after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) is debated as benefits are inconstant. Molecular signatures for DCIS have been developed to stratify the risk of local recurrence (LR) and therefore guide the decision of RT. To evaluate, in women with DCIS treated by BCS, the impact of adjuvant RT on LR according to the molecular signature risk stratification. We conducted a systematic review and meta-analysis of five articles including women with DCIS treated by BCS and with a molecular assay performed to stratify the risk, comparing the effect of BCS and RT versus BCS alone on LR including ipsilateral invasive (InvBE) and total breast events (TotBE). The meta-analysis included 3478 women and evaluated two molecular signatures: Oncotype Dx DCIS (prognostic of LR), and DCISionRT (prognostic of LR and predictive of RT benefit). For DCISionRT, in the high-risk group, the pooled hazard ratio of BCS + RT versus BCS was 0.39 (95%CI 0.20-0.77) for InvBE and 0.34 (95%CI 0.22-0.52) for TotBE. In the low-risk group, the pooled hazard ratio of BCS + RT versus BCS was significant for TotBE at 0.62 (95%CI 0.39-0.99); however, it was not significant for InvBE (HR = 0.58 (95%CI 0.25-1.32)), Discussion: Molecular signatures are able to discriminate high- and low-risk women, high-risk ones having a significant benefit of RT in the reduction of invasive and in situ local recurrences, while in low-risk ones RT did not have a benefit for preventing invasive breast recurrence. The risk prediction of molecular signatures is independent of other risk stratification tools developed in DCIS, and have a tendency toward RT de-escalation. Further studies are needed to assess the impact on mortality.

Impact of adjuvant radiotherapy on patient-reported shortness of breath in patients with breast cancer using the ESAS

Background and purposeAs breast cancer radiotherapy (RT) has been shown to give rise to adverse pulmonary outcomes, such as radiation pneumonitis, trends in patient-reported shortness of breath (SOB) associated with RT were investigated. Adjuvant RT is commonly administered for local and/or regional control of breast cancer and was therefore included. MethodsThe Edmonton Symptom Assessment System (ESAS) was used to observe changes in SOB during RT, up to 6 weeks after RT completion, and one to three months post-RT. Patients with at least one completed ESAS were included in the analysis. Generalized linear regression analysis was performed to identify associations between demographic factors and SOB. ResultsA total of 781 patients were included in the analysis. There was a significant association between ESAS SOB scores and adjuvant chemotherapy when compared to neoadjuvant chemotherapy (p=0.0012). Meanwhile, loco-regional RT had no significant impact on ESAS SOB scores in comparison to local RT. SOB scores were stable over time (p>0.05) from baseline to follow-up appointments. ConclusionThe findings of this study suggest that RT was not associated with changes in SOB from baseline to 3 months post-RT. However, patients who underwent adjuvant chemotherapy reported significant higher SOB scores over time. Additional research is recommended to analyze the lasting effects of adjuvant breast cancer RT on SOB during physical activity.

Impact of adjuvant radiation therapy after definitive surgery in senior adults >80 years old with advanced head and neck squamous cell carcinoma on overall survival.

BackgroundAdjuvant radiotherapy (RT) following surgical resection confers a survival benefit for adult patients with locally advanced head and neck squamous cell carcinoma (HNSCC). We aim to investigate if adjuvant RT provides a similar survival advantage to patients ages 80+ through a national curated database.MethodsThis retrospective cohort study queried the National Cancer Database (NCDB) for all cases of HNSCC between 2004-2016. Patients treated with surgical resection alone were compared to those treated with surgery plus adjuvant RT. Overall survival (OS) was compared within adult (age <80 years) and senior adult (age ≥80 years) cohorts using Kaplan-Meier analysis. Hazard ratios (HR) were assessed using Cox proportional hazards to account for differences in patient characteristics, primary site, and HNSCC stage.ResultsNCDB identified 16,504 locally advanced HNSCC treated with definitive surgery with 9,129 (55.3%) also receiving adjuvant RT. The mean age was 63.8 years (SD = 12.0) with 88.7% of patients ages <80 years and 11.3% ages ≥80 years. In the adult cohort, adjuvant RT was associated with a significant increase in OS compared to surgery alone at 1 year (88.4% vs. 83.8%, p=<0.001), 3 years (64.0% vs. 59.2%, p=<0.001) and 5 years (52.8% vs. 47.2%, p=<0.001). Treatment with surgery alone remained a significant predictor of mortality risk at 1 year (HR 1.48, 95% CI 1.35-1.64, p<0.001), 3 years (HR 1.25, 95% CI 1.18-1.33, p<0.001), and 5 years (HR of 1.23, 95% CI 1.17-1.30, p=<0.001). In the senior adult cohort, there were no significant differences in OS between treatment groups at 1 year (73.4% vs. 74.8%, 0.296), 3 years (45.8% vs. 41.8%, p=0.465), or 5 years (28.2% vs. 27.7% p=0.759). Treatment with surgery alone was not a significant predictor of mortality risk at 1 year (HR 1.11, 95% CI 0.90-1.36, p=0.316), 3 years (HR 0.94, 95% CI 0.81-1.08, p=0.423), or 5 years (HR 0.95, 95% CI 0.83-1.08, p=0.476).ConclusionThe addition of adjuvant RT in senior patients (age ≥80 years) may not provide a similar OS benefit to that observed in younger patients. Further research is needed to best guide shared-decision making in this population.

PD-0412 Impact of adjuvant radiotherapy on biochemical recurrence rates for pn1 prostate cancer patients

PD-0412 Impact of adjuvant radiotherapy on biochemical recurrence rates for pn1 prostate cancer patients

Impact of Adjuvant Radiotherapy on Recurrence of Surgically Treated Atypical Meningiomas and Retrospective Analysis of Prognostic Factors.

The role of adjuvant radiotherapy after surgery for atypical meningiomas remains controversial. The present study was designed to investigate the recurrence rate of atypical meningiomas after surgery (with or without adjuvant radiotherapy) and determine which factors were related with recurrence. Data obtained from 83 patients who underwent surgery and histopathologically diagnosed with atypical meningioma at a single institution between January 2009 and June 2019 were retrospectively reviewed. Then, the patients were divided into two groups: the surgery-only (n = 43) and surgery + adjuvant radiotherapy (n = 40) groups. The mean age of the patients was 53.5 ± 14.6 years. Among them, 51 (61.4%) were female and 32 (38.6%) were male. The recurrence rates were 30.2% (n = 13) in the surgery-only group and 17.5% (n = 7) in the surgery + adjuvant radiotherapy group. A statistically significant decrease in the recurrence rate was observed after adjuvant radiotherapy application (p = 0.046). Moreover, adjuvant radiotherapy significantly increased progression-free survival (p = 0.042). Peritumoral edema, sinus invasion, brain invasion, subtotal tumor resection, and complications were significant predictors of tumor recurrence, and the main risk factors for the recurrence of atypical meningiomas were brain invasion (p = 0.019) and subtotal tumor resection (p = 0.006). Progression-free survival and overall survival of the study group were 45.50 ± 27.56 and 56.69 ± 28.17 months, respectively. The parameters examined in the study, except for tumor recurrence, did not show a statistically significant influence on overall survival. This study revealed that the important prognostic factors for tumor recurrence are subtotal tumor resection and brain invasion. Moreover, adjuvant radiotherapy in addition to surgical resection reduces the recurrence rate of atypical meningiomas and improves progression-free survival of the patients. However, adjuvant radiotherapy did not show a significant influence on overall survival.

The Impact of Adjuvant Radiotherapy on Immediate Implant-based Breast Reconstruction Surgical and Satisfaction Outcomes: A Systematic Review and Meta-analysis.

Background:Adjuvant radiotherapy could be a necessary step in the oncological treatment for breast cancer. However, radiotherapy may have negative effects on implant-based immediate breast reconstruction. The aim of this study was to determine the impact of adjuvant radiation therapy on surgical results and patient-reported satisfaction outcomes in women undergoing immediate implant-based breast reconstruction.Methods:A systematic search in PubMed was conducted on September 2019 and updated on April 2021. The risk of bias of the included studies was assessed using the Newcastle-Ottawa Quality Assessment Form for Observational Studies. RevMan 5 was used for statistical analysis. We obtained relative risks to determine the complication incidence and mean differences for 2-year BREAST-Q scores.Results:Fourteen studies were included. A total of 11,958 implant-based immediate reconstructions were performed, 2311 received postmastectomy radiation therapy, and 9647 were considered as control group. Surgical complications, reoperation rates, and reconstruction failure were significantly higher among irradiated breasts. Significantly lower BREAST-Q scores were reported by irradiated women receiving radiotherapy.Conclusions:This systematic review and meta-analysis combines reconstruction complication rates with aesthetic and patient-reported satisfaction outcomes. Adjuvant radiotherapy is consistently associated with greater complication rates and poorer aesthetic and satisfaction outcomes. The magnitude of association is significantly lower when the reconstruction is based on autologous tissues.

Impact of Adjuvant Radiotherapy in Patients with Central Neurocytoma: A Multicentric International Analysis.

Simple SummaryCentral neurocytoma is a rare tumor accounting for <0.5% of all intracranial tumors. We analyzed 33 patients treated with surgical resection with or without radiotherapy from ten closely cooperating institutions in Germany, Egypt, and Jordan. Patients who received radiotherapy had longer progression-free survival with an acceptable toxicity profile.Background: Central neurocytoma (CN) is a rare tumor accounting for <0.5% of all intracranial tumors. Surgery ± radiotherapy is the mainstay treatment. This international multicentric study aims to evaluate the outcomes of CNs patients after multimodal therapies and identify predictive factors. Patients and methods: We retrospectively identified 33 patients with CN treated between 2005 and 2019. Treatment characteristics and outcomes were assessed. Results: All patients with CN underwent surgical resection. Radiotherapy was delivered in 19 patients. The median radiation dose was 54 Gy (range, 50–60 Gy). The median follow-up time was 56 months. The 5-year OS and 5-year PFS were 90% and 76%, respectively. Patients who received radiotherapy had a significantly longer PFS than patients without RT (p = 0.004) and a trend towards longer OS. In addition, complete response after treatments was associated with longer PFS (p = 0.07). Conclusions: Using RT seems to be associated with longer survival rates with an acceptable toxicity profile.

Heart-related mortality after postoperative breast irradiation in patients with ductal carcinoma in situ in the contemporary radiotherapy era

Although radiation-induced cardiotoxicity has been addressed, its prognostic relevance to modern radiotherapy (RT) techniques is unclear. This study assessed the impact of adjuvant RT on heart-related deaths in patients with ductal carcinoma in situ. Patients who underwent adjuvant RT after breast-conserving surgery between 1988 and 2008 were identified from the Surveillance, Epidemiology, and End Results database. Kaplan‒Meier and competing risks analyses were conducted after propensity score-matching according to tumor laterality. A total of 41,526 propensity-matched patients were identified (n = 20,763 for either left- or right-sided tumor). In the analysis of the cumulative incidence of heart-related mortality events, there was a greater risk increment in the left-sided group over the first to second decades after RT in patients aged ≤ 50 years (P = 0.048). Competing risks analysis of the young patients showed that left-sided RT was associated with higher heart-related mortality rates (Grey’s test, P = 0.049). The statistical significance remained after adjusting for other covariates (subdistribution hazard ratio 2.35; 95% confidence interval 1.09‒5.10). Regarding the intrinsic effect of modern RT techniques, further strategies to reduce heart-related risks are needed for young patients. Close surveillance within an earlier follow-up period should be considered for these patients in clinics.

PO-0851: Impact of Adjuvant Radiation Therapy for Advanced Cutaneous Squamous Cell Carcinoma of Head and Neck

PO-0851: Impact of Adjuvant Radiation Therapy for Advanced Cutaneous Squamous Cell Carcinoma of Head and Neck

685 - Impact of adjuvant radiotherapy in patients with high burden lymph node metastases after radical prostatectomy

685 - Impact of adjuvant radiotherapy in patients with high burden lymph node metastases after radical prostatectomy

Indication of adjuvant chemoradiation post neoadjuvant chemotherapy in very locally advanced borderline resectable head and neck cancer.

e18505 Background: Adjuvant chemoradiation (ACRT) is indicated in the presence of margin positivity or extranodal extension. However, indications of ACRT post neoadjuvant chemotherapy (NACT) is not well defined. At our centre, ACRT is administered in the majority of patients who undergo NACT. This analysis was performed to identify indications for the avoidance of ACRT post NACT. Methods: 160 very locally advanced borderline resectable HNSCC who underwent surgery after NACT were selected. The adjuvant treatment administered was either radiation or chemoradiation at the discretion of the joint clinic. The post-surgical tumour and nodal specimen were graded in accordance with modified tumour regression grade (MTRG). Where grade 1 indicated a complete pathological response. The primary endpoint was disease-free survival (DFS). The patients were divided into 3 biological distinct classes. Group-1 had a pathological complete response (CR) in both tumour and nodes, Group-2 had pathological CR in either tumour or nodes and Group 3 had no pathological CR. Kaplan Meier method was used for the estimation of DFS. The stratified (for groups) log-rank test was used for evaluating the impact of adjuvant radiation. Stratified Cox regression analysis was used for the calculation of hazard ratio. A p-value of 0.05 was considered significant. Results: There were 56 patients (35%) in group 3, 75 (46.9%) in group 2 and 29 (18.1%) in group 1. The overall median DFS was 89.067 months (95%CI 15.345-162.788). The 5-year DFS was 22.1% in group 3, 75.4% in group 2 and 92.3% in group 1 ( P-value &lt; 0.0001). Adjuvant radiation was received by all patients and concurrent chemotherapy was received by 134 (83.8%) patients. Use of concurrent chemotherapy decreased the hazard of disease recurrence (HR-0.297 95%CI 0.135-0.656, P-value = 0.003). The stratified log-rank test p-value was 0.002. Conclusions: Adjuvant chemoradiation is needed after neoadjuvant chemotherapy in very locally advanced borderline resectable head and neck cancer