De-intensification Of Therapy Research Articles

Challenging Conventional Care: Ethical Considerations of De-intensification of Therapy in IBD.

Challenging Conventional Care: Ethical Considerations of De-intensification of Therapy in IBD.

Proton pencil beam scanning radiotherapy in the postoperative treatment of p16 positive squamous cell tonsillar cancer – evaluation of toxicity and effectivity

PurposePatients with p16 positive tonsillar cancer (p16 + TC) have an excellent prognosis and long-life expectancy. Deintensification of therapy is a prevalent topic of discussion. Proton radiotherapy is one way to reduce radiation exposure and thus reduce acute and late toxicity. The aim is to evaluate treatment outcomes and toxicity of postoperative treatment with intensity-modulated proton therapy (IMPT).MethodsBetween September 2013 and November 2021, 47 patients with p16 + TC were treated postoperatively with IMPT. Median age was 54.9 (38.2–74.9) years, 31 were males and 16 were females. All patients had squamous cell carcinoma and underwent surgery as a primary treatment. Median dose of radiotherapy was 66 GyE in 33 fractions. Bilateral neck irradiation was used in 39 patients and unilateral in 8. Concomitant chemotherapy was applied in 24 patients.ResultsMedian follow-up time was 4.2 (0.15–9.64) years. Five-year overall survival, relapse free survival and local control were 95.7%, 97.8% and 100%. The most common acute toxicities were dermatitis and mucositis, with grade 2 + in 61.7% and 70.2% of patients. No acute percutaneous gastrostomy insertion was necessary and intravenous rehydration was used in 12.8% of patients. The most common late toxicity was grade 1 xerostomia in 70.2% of patients and grade 2 in 10.6% of patients. Subcutaneous fibrosis of grades 2 and 3 occurred in 17.0% and 2.1% of patients, respectively. One patient developed late severe dysphagia and became PEG-dependent.ConclusionIMPT for the postoperative treatment of p16 + TC is feasible with excellent efficiency and acceptable acute and late toxicity.

Children and young adults with newly diagnosed rhabdomyosarcoma metastatic to bone treated on Children's Oncology Group studies.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Despite bone metastases being present in 5% of patients at diagnosis, there are limited studies examining these outcomes. We sought to define the prognostic factors, clinical courses, and outcomes of children treated on Children's Oncology Group (COG) clinical trials with RMS metastatic to bone at diagnosis. We performed a retrospective analysis of patients diagnosed with bone metastatic RMS enrolled on COG RMS clinical trials (D9802, D9803, ARST0431, or ARST08P1) between 1997 and 2013. RMS metastatic to bone was identified in 154 patients at a median age of 14.9years at diagnosis. Fifty-eight percent of patients were male, 90% had metastases at additional sites, 74% had alveolar histology, and extremity was the most common primary site (31%). Eighty-six percent of patients (n=133) received radiation therapy. The 3- and 5-year event-free survival (EFS) was 15.4% and 14.5%, respectively. The 3- and 5-year overall survival (OS) was 30.4% and 18.0%, respectively. We identified alveolar histology, FOXO1 fusion presence, unfavorable primary location, higher Oberlin score, and lack of radiation as poor prognostic characteristics for both EFS and OS in univariate analysis. Lack of radiation was not significant when excluding patients with events prior to 20weeks. This study is the largest analysis of patients with bone metastatic RMS, and defines the poor overall outcomes and negative prognostic factors for these patients. They may be eligible for therapy deintensification for improved quality of life or pursuit of novel treatments/approaches, which are desperately needed.

MDB-53. SALVAGE CRANIOSPINAL IRRADIATION FOR RELAPSED WNT-PATHWAY MEDULLOBLASTOMA PATIENTS TREATED WITH UPFRONT FOCAL CONFORMAL RADIOTHERAPY AND CHEMOTHERAPY AT INITIAL DIAGNOSIS: LONG-TERM AND MATURE OUTCOMES FROM A PROSPECTIVE DE-INTENSIFICATION STUDY

Abstract BACKGROUND Excellent long-term outcomes (5-year overall survival >90%) in WNT-pathway medulloblastoma (MB) patients have prompted systematic attempts at de-intensification of therapy to mitigate treatment-related toxicities. Mature outcomes of a prospective study (FOR-WNT) treating low-risk WNT-MB children with focal conformal radiotherapy (RT) and adjuvant systemic chemotherapy omitting upfront craniospinal irradiation (CSI) are being reported herein. METHODS Seven children with rigorously-defined low-risk WNT-MB were treated with post-operative focal conformal RT to the index tumor-bed (54Gy/30 fractions) followed by 6-cycles of adjuvant systemic chemotherapy after written informed consent/assent. Survival outcomes were computed using Kaplan-Meier method and reported as point estimate with 95% confidence intervals (CI). The trial was terminated prematurely due to unacceptably high risk of neuraxial failures. RESULTS One child succumbed to chemotherapy-related toxicity while 3 of 7 children were detected with leptomeningeal relapse on surveillance neuro-imaging within 2-years of index diagnosis. Full-dose salvage CSI (35Gy/21 fractions) at relapse followed by further chemotherapy led to excellent clinico-radiological response in all 3 children; however, one child developed further local recurrence and leptomeningeal metastases and succumbed to recurrent/progressive disease despite further aggressive salvage therapy. Five of 7 children including the other two treated with salvage CSI and systemic chemotherapy are alive and continue to remain in remission on long-term follow-up. At a median follow up of 61 months, the 5-year Kaplan-Meier estimates of event-free survival, relapse-free survival, and overall survival were 42.9% (95%CI: 18.2-100%), 50.0% (95%CI: 22.5-100%), and 71.4% (44.7-100%) respectively. CONCLUSIONS Omission of upfront CSI in low-risk WNT-MB is associated with unacceptably high-risk of neuraxial failure. Although full-dose salvage CSI achieves excellent response, remissions are not durable resulting in sub-optimal long-term overall survival. Judicious de-escalation with upfront low-dose CSI (18Gy) is currently being tested in a successor study (FOR-WNT 2).

MDB-05. PERSONALIZED, RISK ADAPTED THERAPY FOR PEDIATRIC PATIENTS WITH MEDULLOBLASTOMA – A SINGLE CENTER 8-YEAR RETROSPECTIVE REVIEW

Abstract BACKGROUND Clinically relevant risk stratification and optimal therapies for pediatric medulloblastoma molecular subgroups are still being investigated. METHODS We reviewed host/disease characteristics, patient/tumor specific risk adapted therapy and outcomes of patients treated for medulloblastoma at UC Davis since 2016. RESULTS Fifteen patients (age 1-19 years, 12 male, 3 with Li Fraumeni Syndrome (LFS), 2 with spinal cord disease) were included in our review. Tumor histologies included: Classic (n=8), Desmoplastic-Nodular (n=6), Anaplastic (n=1). Tumor genomic profiles were SHHP53WT(n=5), SHHP53 mutated (n=4), Group4 (n=3), NWNSHH (n=2), WNT (n=1). Gross total resection was achieved in 9 patients. Patients with post resection residual tumor, high risk genomic features or disseminated disease were stratified as high risk. We treated all radiation eligible patients (n=13) per COG ACNS0332 maintenance chemotherapy regardless of risk group with 12/13 receiving radiosensitization (Vincristine/Carboplatin) and either 23.4 Gy/36 Gy CSI (two patients treated per Headstart3D2 and ACNS0334 respectively). 2 patients with spinal cord disease were treated with intrathecal topotecan and liposomal cytarabine respectively. During ACNS0332 maintenance bacteremia, weight loss and hypomagnesemia were frequent complications. 5 patients required chemotherapy dose reductions (4 Vincristine/1 Cisplatin). Two patients with LFS developed glioblastoma/undifferentiated pleomorphic sarcoma following ACNS0332 therapy. Two patients (with WNT and NWNSHH subgroup tumors) experienced medulloblastoma relapse. These patients were treated using LITT/Intrathecal chemotherapy and ACNS0821 chemotherapy. Both are alive and one patient is NED off therapy. All patients who have not developed secondary malignancies (n=13) are alive. (follow up 7-72 months). All attend school with support, 10 have hearing impairment and 5 receive endocrine supplements. CONCLUSIONS Utilizing patient specific risk adapted therapy we have achieved favorable clinical outcomes in our patient cohort. Therapy deintensification for patients with WNT medulloblastomas should be approached with caution. Patients with LFS might require radiation sparing therapeutic protocols for longer term benefit.

De-Intensification from Basal-Bolus Insulin Therapy to Liraglutide in Type 2 Diabetes: Predictive Value of Mean Glycaemia during Fasting Test.

Successful conversion from insulin therapy to glucagon-like peptide 1 receptor agonist (GLP-1RA) with basal insulin in well-controlled patients has already been demonstrated. However, the data concerning individuals with poor glycaemic control are scarce. The aim of this work was to assess the success rate of insulin therapy to liraglutide transition in poorly controlled diabetes in a real-world clinical setting and to define predictors of success. We are the first to present the method of a fasting test as a way to identify the patients at higher risk of failure after treatment de-intensification. The retrospective observational study analyzed data of 62 poorly controlled obese diabetic patients on high-dose insulin therapy, who were subjected to a 72 h fasting test during hospitalization and subsequently switched to liraglutide ± basal insulin therapy. During the fasting, all antidiabetic treatment was discontinued. Patients were classified as responders if they remained on GLP-1RA treatment after 12 months. Non-responders restarted the basal-bolus insulin (BBI) regimen. Development of glycated hemoglobin (HbA1c) and body weight in both groups, alongside with parameters associated with the higher risk of return to the BBI regimen, were analyzed. A total of 71% of patients were switched successfully (=responders). Responders had more significant improvement in HbA1c (-6.4 ± 19.7 vs. -3.4 ± 22.9 mmol/mol) and weight loss (-4.6 ± 7.1 vs. -2.5 ± 4.0). Statistically significant difference between groups was found in initial HbA1c (75.6 ± 17.9 vs. 90.5 ± 23.6; p = 0.04), total daily dose of insulin (67.6 ± 36.4 vs. 90.8 ± 32.4; p = 0.02), and mean glycaemia during the fasting test (6.9 ± 1.7 vs. 8.6 ± 2.2 mmol/L; p < 0.01). This study confirms that therapy de-intensification in poorly controlled patients with a BBI regimen is possible. Higher baseline HbA1c, total daily insulin dose, and mean glucose during fasting test are negative predictive factors of successful therapy de-escalation.

The IDEAL (Insulin therapy DE-intensificAtion with iglarLixi) Randomised Controlled Trial-Study Design and Protocol.

Multiple daily injection insulin regimen (MDI) represents the most intensive insulin regimen used in the management of people with type 2 diabetes (PwT2D). Its efficacy regarding glycaemic control is counterbalanced by the increased risk of hypoglycaemia, frequently observed tendency to weight gain and necessity for frequent glucose monitoring. Recent introduction of novel antidiabetic medications with pleiotropic effects reaching far beyond the reduction of glycaemia (HbA1c), such as the glucagon-like peptide 1 receptor agonist (GLP-1 RA), has significantly widened the therapeutic options available for management of T2D. Consequently, there is currently asubstantial number of PwT2D for whom the MDI regimen was initiated at a time when no other options were available. Yet, in present times, these individuals could benefit from simplified insulin regimens ideally taking advantage of the beneficial effects of the novel classes of antidiabetic medications. iGlarLixi (Suliqua®) is a once-daily fixed-ratio combination of basal insulin analogue glargine 100U/ml and a GLP-1 RA lixisenatide. Insulin therapy DE-intensificAtion with iglarLixi (IDEAL) is a six-centre, open-label, parallel-group, active comparator, phase IV randomised controlled trial with a 24-week active treatment period examining the efficacy and safety of MDI regimen de-intensification with once-daily administration of iGlarLixi versus MDI regimen continuation in PwT2D on a backgroud therapy with metformin ± sodium-glucose cotransporter 2 inhibitor. The primary objective is to compare the effects of MDI therapy de-intensification with iGlarLixi versus MDI regimen continuation regarding glycaemic control (HbA1c). Secondary objectives include detailed evaluation of the effects of MDI regimen de-intensification with iGlarLixi on glycaemic control using standardised continuous glucose monitoring (CGM) metrics and self-monitoring of plasma glucose. Furthermore, body weight and body composition analysis, quality of life and safety profile are evaluated. ClinicalTrials.gov, identifier NCT04945070.

Clinico-Radiological Outcomes in WNT-Subgroup Medulloblastoma.

Medulloblastoma (MB) comprises four broad molecular subgroups, namely wingless (WNT), sonic hedgehog (SHH), Group 3, and Group 4, respectively, with subgroup-specific developmental origins, unique genetic profiles, distinct clinico-demographic characteristics, and diverse clinical outcomes. This is a retrospective audit of clinical outcomes in molecularly confirmed WNT-MB patients treated with maximal safe resection followed by postoperative standard-of-care risk-stratified adjuvant radio(chemo)therapy at a tertiary-care comprehensive cancer centre. Of the 74 WNT-MB patients registered in a neuro-oncology unit between 2004 to 2020, 7 patients accrued on a prospective clinical trial of treatment deintensification were excluded, leaving 67 patients that constitute the present study cohort. The median age at presentation was 12 years, with a male preponderance (2:1). The survival analysis was restricted to 61 patients and excluded 6 patients (1 postoperative mortality plus 5 without adequate details of treatment or outcomes). At a median follow-up of 72 months, Kaplan-Meier estimates of 5-year progression-free survival and overall survival were 87.7% and 91.2%, respectively. Traditional high-risk features, large residual tumour (≥1.5 cm2), and leptomeningeal metastases (M+) did not significantly impact upon survival in this molecularly characterized WNT-MB cohort treated with risk-stratified contemporary multimodality therapy. The lack of a prognostic impact of conventional high-risk features suggests the need for refined risk stratification and potential deintensification of therapy.

Update for the ‘Watch’ Registry, a Real-World Observational Study Using Clonoseq® to Monitor MRD in Lymphoid Malignancies

Background: For patients with the most common B-cell malignancies, assessment of minimal/measurable residual disease (MRD) is routinely incorporated into clinical trials to evaluate patient response and NCCN guidelines include recommendations for incorporation of MRD assessment into clinical practice for ALL, CLL, and MM. Despite that, there is a desire for additional data that reflect the impact of MRD assessment in patient management in the real-world setting. The Watch Registry (NCT04545333) is a prospective, multicenter observational study being conducted in the US to collect data from health care providers who use the clonoSEQ MRD assay as part of routine care for their lymphoid malignancy patients. Data collection is focused on understanding broad practice patterns for clonoSEQ® MRD assessment, including assay timing and subsequent treatment decisions. The ultimate goal of the study is to describe the implementation and impact of the assay in patient management. Here we describe the latest updates from this ongoing study. Methods: Eligible patients are ≥ 18 years old, diagnosed with NHL, MM, ALL, or CLL, not enrolled in an interventional clinical study that dictates the frequency of their MRD testing, and whose treating physician is currently or planning to use clonoSEQ to monitor their MRD as part of their routine management. Patients may be in any phase of treatment at enrollment. Enrollment is now closed and follow-up will continue through December 31, 2024. Results: From October 2020 through data cutoff of June 21, 2023, 465 patients were enrolled across 18 academic and community sites (463 patients with reportable data). Enrollment by disease is 70 ALL, 109 CLL, 140 MM, 34 DLBCL, 27 MCL, 54 FL and 29 other lymphoid malignancies. Of these patients, 91 (20%) have discontinued the study; the most common reasons are death (35; 8%) and failure to detect trackable sequences by clonoSEQ (23; 5%). Other reasons include site closure and patient/physician decision to withdraw. Patients range in age from 18 to 92, 57% are male, and the mean lines of therapy (LOT) prior to enrollment is ~2. The median follow up period is 14 months. To date, 994 clonoSEQ MRD tests have been ordered and 74.5% of patients have received at least 1 MRD test (Table 1). The most frequent testing was reported for ALL patients (4.8 tests/pt) followed by CLL (2.9 tests/pt), MCL (3.3 tests/pt), other lymphoid malignancies (2.9tests/pt), DLBCL (2.6 tests/pt), FL (2.1 tests/pt) and MM (2.2 tests/pt). Across all disease cohorts, most MRD tests were ordered during remission (71.4%). In the ALL cohort, a larger proportion of tests were ordered at other treatment timepoints relative to other disease cohorts: end of induction (6%), pre-HSCT (6%), post-HSCT, including some post-HSCT monitoring (42%) and post-CAR-T (6%). Across all cohorts, 220 patients (48%) had multiple MRD tests ordered with the largest proportion observed in the ALL cohort (67%), followed by MCL (63%), DLBCL (50%), CLL (48%), other lymphoid malignancies (45%), MM (39%) and FL (35%). For patients tested during monitoring, the number of tests/pt was generally larger among patients with ≥1 prior LOT compared to patients with 0 prior LOT. With 979 test results reported (Table 2), there were 583 tests with residual sequences detected (59.5%) and 396 with no residual sequences detected (39.5%). Based on the presence of residual sequences, a change to a patient's treatment plan was reported 66 times (11.3%) and there were 52 separate reports (11.1%) of a change to the frequency of future MRD monitoring. Specific treatment changes included 56 instances of therapy intensification (9.6%) and 10 instances of therapy de-intensification (1.7%). In the case where no change was made based on the presence of residual sequences, reported reasons for not making a change (if reported) included decreasing MRD (24%) and low/stable disease (10.9%). Conclusions: Clinicians are using clonoSEQ to assess MRD across multiple lymphoid malignancies in routine care. In ALL, MRD testing was reported for multiple treatment timepoints whereas in other disease states (CLL, MM, NHL) reported use of the assay was predominantly for monitoring remission. The advent of therapeutic regimens for B-cell malignancies with higher relative response rates denotes the need for sensitive tools that can be used in clinical practice to better assess treatment response and monitor MRD to facilitate future treatment decisions.

Prognosis of children and young adults with newly diagnosed rhabdomyosarcoma metastatic to bone marrow treated on Children's Oncology Group studies.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Metastatic disease occurs in 16% of all RMS cases and has a poor prognosis. There are limited studies examining the outcomes specific to patients with RMS metastatic to bone marrow despite an incidence of 6% at diagnosis. Our study aims to document the outcomes, prognostic factors, and clinical courses of children presenting with RMS metastatic to bone marrow treated on Children's Oncology Group (COG) cooperative trials. We performed a retrospective analysis of the patients diagnosed with RMS metastatic to bone marrow between 1997 and 2013 enrolled on one of four COG RMS clinical trials of D9802, D9803, ARST0431, and ARST08P1. We identified 179 cases with RMS metastatic to bone marrow. Patients had a median age of 14.8years, 58% were male, predominantly alveolar histology (76%), extremity was the most common primary site (32%), and 87% had metastatic disease to additional sites; 83% (n=149) received radiation as a treatment modality. The 3- and 5-year event-free survival was 9.4% and 8.2%, respectively. The 3- and 5-year overall survival was 26.1% and 12.6%, respectively. Age ≥10years, alveolar histology, FOXO1 fusion presence, unfavorable primary location, higher Oberlin score, and lack of radiation were identified as poor prognostic/predictive characteristics. This study represents the largest analysis of RMS metastatic to bone marrow, defining the poor prognostic outcome for these patients. These patients may be eligible for therapy deintensification or early pursuit of novel treatments/approaches that are desperately needed.

Noncanonical HPV carcinogenesis drives radiosensitization of head and neck tumors

We analyzed transcriptional data from 104 HPV+ (Human papillomavirus) HNSCC (head and neck squamous cell carcinoma) tumors together with two publicly available sources to identify highly robust transcriptional programs (modules) which could be detected consistently despite heterogeneous sequencing and quantification methodologies. Among 22 modules identified, we found a single module that naturally subclassifies HPV+ HNSCC tumors based on a bimodal pattern of gene expression, clusters all atypical features of HPV+ HNSCC biology into a single subclass, and predicts patient outcome in four independent cohorts. The subclass-defining gene set was strongly correlated with Nuclear factor kappa B (NF-κB) target expression. Tumors with high expression of this NF-κB module were rarely associated with activating PIK3CA alterations or viral integration, and also expressed higher levels of HPHPV E2 and had decreased APOBEC mutagenesis. Alternatively, they harbored inactivating alterations of key regulators of NF-κB, TNF receptor associated factor 3 (TRAF3), and cylindromatosis (CYLD), as well as retinoblastoma protein (RB1). HPV+ HNSCC cells in culture with experimental depletion of TRAF3 or CYLD displayed increased expression of the subclass-defining genes, as well as robust radio-sensitization, thus recapitulating both the tumor transcriptional state and improved treatment response observed in patient data. Across all gene sets investigated, methylation to expression correlations were the strongest for the subclass-defining, NF-κB-related genes. Increased tumor-infiltrating CD4+ T cells and increased Estrogen receptors alpha (ERα) expression were identified in NF-κB active tumors. Based on the relatively high rates of cure in HPV+ HNSCC, deintensification of therapy to reduce treatment-related morbidity is being studied at many institutions. Tumor subclassification based on oncogenic subtypes may help guide the selection of therapeutic intensity or modality for patients with HPV+ HNSCC.

A Pilot Study Omitting Radiation in the Treatment of Children with Newly Diagnosed Wnt-Activated Medulloblastoma.

Treatment of wingless (WNT)-activated medulloblastoma (WNT+MB) with surgery, irradiation (XRT), and chemotherapy results in excellent outcomes. We studied the efficacy of therapy de-intensification by omitting XRT entirely in children with WNT+MB. Tumors were molecularly screened to confirm the diagnosis of WNT+MB. Eligible children were treated within 31 days following surgery with nine cycles of adjuvant chemotherapy per ACNS0331. No XRT was planned. The primary endpoint was the occurrence of relapse, progression, or death in the absence of XRT within the first two years after study enrollment. Four events in the first 10 evaluable patients would result in early study closure. Fourteen children were prescreened, and nine met the protocol definition of WNT+MB. Six of the nine eligible patients consented to protocol therapy, and five completed planned protocol therapy. The first two children enrolled relapsed shortly after therapy completion with local and leptomeningeal recurrences. The study was closed early due to safety concerns. Both children are surviving after XRT and additional chemotherapy. A third child relapsed at completion of therapy but died of progressive disease 35 months from diagnosis. Two children finished treatment but immediately received post-treatment XRT to guard against early relapse. The final child's treatment was aborted in favor of a high-dose therapy/stem cell rescue approach. Although OS at 5 years is 83%, no child received only planned protocol therapy, with all receiving eventual XRT and/or alternative therapy. Radiotherapy is required to effectively treat children with WNT-altered medulloblastoma. See related commentary by Gottardo and Gajjar, p. 4996.

Human papillomavirus status and prognosis of oropharyngeal high-grade neuroendocrine carcinoma

BackgroundThe prognostic impact of human papillomavirus (HPV) infection or smoking on oropharyngeal high-grade neuroendocrine carcinoma (HG-NEC) is not established. MethodsRetrospective study with patients with oropharyngeal HG-NEC seen at MD Anderson Cancer Center from 1997 to 2020, and previously reported patients with oropharyngeal HG-NEC and known p16 and HPV status from the literature review. Survival was estimated with the Kaplan-Meier method, and survival differences assessed with the log-rank test and Cox proportional hazards models. ResultsThirty patients were included; most had a heavy (≥10 pack-years) smoking history (52%), locoregional disease (stage III-IVB; 77%), and p16-positive tumor (92%). HPV was positive in 65% of tested samples (15/23). Of 24 patients treated with curative intent, the objective response rates was 90% (9/10) and 81% (17/21), respectively, for induction chemotherapy and definitive radiotherapy. During follow-up, 54% (13/24) recurred, mostly (11/13) at distant sites. Median overall survival (OS) was 46 months (95% CI, 14.3 - NA). OS was not associated with HPV status (HR 0.73, P = 0.6) or smoking (HR 1.16, P = 0.8). Among 63 patients with known HPV status after the literature review (19 HPV- and 44 HPV + ), HPV status remained unassociated with OS (P = 0.92). ConclusionsThis is the largest retrospective cohort of oropharyngeal HG-NEC. Distant recurrence rate after curative treatment was high, suggesting that multimodality treatment including systemic therapy may benefit patients with locally advanced disease. HPV infection did not affect survival outcomes, therefore should not lead to therapy de-intensification for this histology.

The Prognostic and Predictive Value of Genomic Assays in Guiding Adjuvant Breast Radiation Therapy.

Many patients with non-metastatic breast cancer benefit from adjuvant radiation therapy after lumpectomy or mastectomy on the basis of many randomized trials. However, there are many patients that have such low risks of recurrence after surgery that de-intensification of therapy by either reducing the treatment volume or omitting radiation altogether may be appropriate options. On the other hand, dose intensification may be necessary for more aggressive breast cancers. Until recently, these treatment decisions were based solely on clinicopathologic factors. Here, we review the current literature on the role of genomic assays as prognostic and/or predictive biomarkers to help guide adjuvant radiation therapy decision-making.

Addressing Clinical and Therapeutic Inertia Through Comprehensive Medication Review.

Avoiding clinical and therapeutic inertia, through pharmacist-led medication therapy management, can lead to avoidance of inappropriate medication use and adverse medication events. Clinical and therapeutic inertia are terms that have been used indistinctly. One definition is inertia that appears when clinicians do not initiate or intensify therapy appropriately when therapeutic goals are not reached. Another definition is failure to advance or deintensify treatment, and in a broader sense beyond escalation or deintensification of therapy; definitions include failure to screen, make appropriate referrals, manage risk factors, and complications. Failure of clinicians to address clinical and therapeutic inertia in office or hospital visits can contribute to patients using inappropriate medications, and lead to avoidable serious adverse events. Addressing therapeutic inertia may also be a means to minimize prescription costs and improve quality of life. This case illustrates the importance of identifying and addressing the therapeutic appropriateness of medications for an older person who has been prescribed numerous medications over a long period but now has complaints of dizziness as well as the inability to afford all medications.

Part Five: The Role of Deprescribing and Adjusting Glycemic Targets in Older People With Diabetes.

The prevalence of diabetes continues to increase across the general population, including older people. Because of the changing needs of older people, glycemic targets are often relaxed. Deintensification of therapy or deprescribing becomes important to reduce risk of adverse effects and ensure optimal quality of life. The use of continuous glucose monitoring can be highly effective in determining areas for concern and potential opportunities for deprescribing.

1069P An immune-based score for the prediction of clinical outcome in patients with metastatic non-small cell lung cancer treated with first-line immunotherapy

The first-line therapy for metastatic non-small cell lung cancer (mNSCLC), with the exception of oncogene-addicted NSCLC, is based on either immunotherapy (IT) or chemo-immunotherapy (CT-IT). These treatments revolutionized the therapeutic landscape, but responses are variable in clinical practice. For this reason, it would be fundamental to predict the clinical outcome from these therapies to get to more tailored therapeutic scenarios, such as the implementation of CT-IT or a therapy de-intensification.

The accuracy of clinical neck staging for p16-positive and negative oropharyngeal cancer and its therapeutic implications

PurposeOropharyngeal squamous cell carcinoma (OPSCC) may be treated with primary surgery or primary (chemo)radiation. While surgery with concurrent neck dissection provides definitive pathological staging of the neck, non-surgical treatment relies on clinical staging for treatment planning. To assess the accuracy of clinical neck staging, we compared clinical to surgical staging after primary surgery in patients with p16-negative and p16-positive OPSCC.MethodsRetrospective analysis of clinical, pathological, and oncologic outcome data of patients with OPSCC treated with primary surgery and bilateral neck dissection. Clinical and pathological nodal status were compared for p16-negative and p16-positive patients. Patients with occult metastatic disease were analyzed in detail.Results95 patients were included. 60.5% of p16-negative patients and 66.6% of p16-positive patients had pathologically confirmed metastatic neck disease. p16-positive patients had improved 24-month recurrence-free survival compared to p16-negative patients at 93.3% vs. 69.6%. Pathological N-status differed from clinical N-status in 36.8% of p16-negative patients vs. 31.6% of p16-positive patients. Occult metastatic disease was more common in p16-negative patients at 18.4% vs. 8.8% for p16-positive patients. Clinical detection sensitivity for extranodal extension was low overall; sensitivity was 27.3% and specificity was 91.6% for p16-negative patients vs. 61.5% and 80.0% for p16-positive patients, respectively.ConclusionOur data show a considerable degree of inaccuracy of clinical neck staging results in all OPSCC patients which needs to be taken into consideration during therapy planning. For p16-positive patients, these findings warrant attention in the context of therapy deintensification to avoid undertreatment.

MEDB-27. Clinico-Radiological Outcomes in WNT-pathway Medulloblastoma: Retrospective Single Institutional Audit

BACKGROUND: Medulloblastoma (MB) is a heterogeneous disease comprising 4 molecular subgroups - wingless (WNT), sonic hedgehog, Group 3, and Group 4 tumors - with distinct developmental origins, diverse clinico-demographic characteristics, unique transcriptional profiles, and widely varying outcomes. WNT-MB is associated with the best outcomes (5-year survival >90%) prompting attempts at treatment de-escalation to reduce late toxicity. We undertook a clinical audit of WNT-MB patients treated at our tertiary-care comprehensive cancer centre. METHODS: Patients with molecularly confirmed WNT-MB treated with maximal safe resection followed by post-operative standard-of-care risk-stratified adjuvant radio(chemo)therapy were identified retrospectively via electronic search of the neuro-oncology database. Data regarding clinico-demographic characteristics, histo-molecular features, treatment details, patterns of failure, and survival outcomes was retrieved from electronic medical records and/or hospital case files. Time-to-event outcomes were analyzed using Kaplan-Meier methods and compared with the log-rank test. RESULTS: Between 2004 to 2018, a total of 65 patients of WNT-MB were registered at our institute. Five patients treated on a prospective clinical trial of therapy de-intensification were excluded leaving 60 patients that constitute the present study cohort. Median age at presentation was 12 years (inter-quartile range 9-18 years) with male preponderance (2:1). Six patients (1 post-operative mortality and 5 without adequate details of treatment or outcomes) were excluded from the survival analysis which was restricted to 54 patients. At a median follow-up of 66 months, Kaplan-Meier estimates of 5-year progression-free survival and overall survival were 87.9% and 92.8% respectively. Traditional high-risk features such as age, residual tumor (>1.5cm2) and leptomeningeal metastases (M+) did not emerge as significant prognostic factors for survival in this molecularly-characterized WNT-MB cohort. CONCLUSION: WNT-MB patients have excellent survival outcomes irrespective of traditional high-risk features suggesting the need for more tailored and refined risk-stratification with potential de-intensification of therapy. ACKNOWLEDGEMENTS: Brain Tumor Foundation (BTF) of India

Prospective Study of PET/MRI Tumor Response During Chemoradiotherapy for Patients with Low and Intermediate Risk p16-positive Oropharynx Cancers

<h3>Purpose/Objective(s)</h3> To compare the intratreatment PET/MRI tumor response in patients with low-risk (LR) and intermediate-risk (IR) p16-positive oropharynx cancer during chemoradiotherapy. <h3>Materials/Methods</h3> Patients with non-metastatic, p16-positive oropharynx cancer were treated with definitive chemoradiotherapy. LR disease was defined as cT0-3 and cN0-2b and </= 10 pack-years and IR disease as cT4 or cN2b-3 or > 10 pack-years. Patients underwent a PET/MRI scan pre-treatment and at fraction 10. PET/MRI data used for analysis of the primary tumor and largest node included changes in volume, SUVmax, SUVmedian, SUVpeak, and diffusion. Radiographic differences between LR and IR patients were compared using the standard t-test. Principal component analysis, with K-means and Euclidean distance functions were used for patient clustering. Silhouette width was used to determine the optimal number of clusters similarity of objects within each cluster. Linear regression was performed on all radiographic metrics using patient and disease characteristics. <h3>Results</h3> Twenty-four patients were enrolled with 7 LR and 11 IR patients available for analysis. Cluster analysis defined two cohorts that exhibited a similar intratreatment response. Cohort 1 contained 7 of 7 LR patients and 8 of 11 IR patients. Cohort 2 contained 3 of 11 IR patients. There was a trend for patients in Cohort 2 to be older (mean 68 years ± 5 versus 59 years ± 7; p = 0.057) and have a higher smoking history (mean 30 pack-years ± 40 s.d. versus 12 pack-years ± 17 s.d.; p = 0.2). Cluster 2 exhibited significant differences compared to cluster 1 in the change in primary tumor SUVpeak (0.46 mean ± 0.15 s.d. versus -0.22 mean ± 0.24 s.d.; p < 0.001) and largest lymph node SUVmedian (0.43 mean ± 0. s.d. versus -0.00 mean ± 0.9 s.d.; p = 0.001) after 10 fractions of chemoradiotherapy. <h3>Conclusion</h3> We demonstrate that intermediate-risk p16-positive oropharynx cancers exhibit heterogeneity in their radiographic response to chemoradiotherapy. These data support further study of intratreatment image response as a mechanism for identifying patients with intermediate-risk disease suitable for therapy de-intensification.