Oncologic Significance of Therapeutic Delays in Patients With Oral Cavity Cancer.

Importance: Oral cavity cancer often requires multidisciplinary management, subjecting patients to complex therapeutic trajectories. Prolonged treatment intervals in oral cavity cancer have been associated with poor oncological outcomes, but there has yet to be a study investigating treatment times in Canada. Objective: To report treatment delays for patients with oral cavity cancer in Canada and evaluate the outcomes of treatment delays on overall survival. Design, Setting, and Participants: This multicenter cohort study was performed at 8 Canadian academic centers from 2005 to 2019. Participants were patients with oral cavity cancer who underwent surgery and adjuvant radiation therapy. Analysis was performed in January 2023. Main Outcomes and Measures: Treatment intervals evaluated were surgery to initiation of postoperative radiation therapy interval (S-PORT) and radiation therapy interval (RTI). The exposure variables were prolonged intervals, respectively defined as index S-PORT greater than 42 days and RTI greater than 46 days. Patient demographics, Charlson Comorbidity Index, smoking status, alcohol status, and cancer staging were also considered. Univariate (log rank and Kaplan-Meier) and multivariate (Cox regression) analyses were performed to determine associations with overall survival (OS). Results: Overall, 1368 patients were included; median (IQR) age at diagnosis was 61 (54-70) years, and 896 (65%) were men. Median (IQR) S-PORT was 56 (46-68) days, with 1093 (80%) patients waiting greater than 42 days, and median (IQR) RTI was 43 (41-47) days, with 353 (26%) patients having treatment time interval greater than 46 days. There were variations in treatment time intervals between institutions for S-PORT (institution with longest vs shortest median S-PORT, 64 days vs 48 days; η2 = 0.023) and RTI (institution with longest vs shortest median RTI, 44 days vs 40 days; η2 = 0.022). Median follow-up was 34 months. The 3-year OS was 68%. In univariate analysis, patients with prolonged S-PORT had worse survival at 3 years (66% vs 77%; odds ratio 1.75; 95% CI, 1.27-2.42), whereas prolonged RTI (67% vs 69%; odds ratio 1.06; 95% CI, 0.81-1.38) was not associated with OS. Other factors associated with OS were age, Charlson Comorbidity Index, alcohol status, T category, N category, and institution. In the multivariate model, prolonged S-PORT remained independently associated with OS (hazard ratio, 1.39; 95% CI, 1.07-1.80). Conclusions and Relevance: In this multicenter cohort study of patients with oral cavity cancer requiring multimodal therapy, initiation of radiation therapy within 42 days from surgery was associated with improved survival. However, in Canada, only a minority completed S-PORT within the recommended time, whereas most had an appropriate RTI. An interinstitution variation existed in terms of treatment time intervals. Institutions should aim to identify reasons for delays in their respective centers, and efforts and resources should be directed toward achieving timely completion of S-PORT.

Thyroid Cartilage Compression Causing Bow Hunter's Syndrome.

OBJECTIVES AND METHODS: We report a unique case of Bow Hunter's syndrome with a dominant aberrantly coursing right vertebral artery (VA), presenting with persistent dizziness and syncope despite previous decompressive surgery at vertebral levels C5-C6. RESULTS: Re-evaluation with computed tomography-scan during provocation of dizziness by neck rotation revealed compression of the right VA at level C6 from against the ipsilateral posterior border and superior cornu of the thyroid cartilage. Laryngoplasty resulted in complete resolution of symptoms. CONCLUSION: This extremely rare cause of Bow's Hunter's syndrome should be considered, especially in refractory cases after neurosurgical decompression, and surgical management is straightforward and successful.

Vitamin D Supplementation for Benign Paroxysmal Positional Vertigo: A Systematic Review.

OBJECTIVE: Benign paroxysmal positional vertigo (BPPV) is commonly attributed to displaced otoconia. These have been shown to have biomineralization close to that of bone, and vitamin D deficiency has been associated with BPPV. We aim to systematically review the available literature on vitamin D supplementation and BPPV intensity and recurrence in adults. DATABASES REVIEWED: PubMed, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Current Controlled Trials, and ClinicalTrials.gov. METHODS: We systematically reviewed the available literature from 1947 to April 2020. The study protocol was registered in the PROSPERO database (trial registration: CRD42020183195). RESULTS: A total of 179 abstracts were identified and screened by two independent reviewers. Based on inclusion and exclusion criteria, six studies were selected and subjected to a quality assessment. In one randomized clinical trial (RCT), vitamin D supplementation was found to reduce annual recurrence rate of vertigo in patient with BPPV and subnormal serum vitamin D levels compared with placebo (odds ratio, 0.69; 95% confidence interval, 0.54-0.90). Non-RCTs demonstrated the possibility of a null effect in the random effects model (odds ratio, 0.08; 95% confidence interval, 0.00-1.56). The RCT considered as low risk of bias. All of the nonrandomized studies were assessed as serious risk of bias. CONCLUSIONS: The intervention studies identified consistently demonstrated a decrease in BPPV recurrence with supplementation of vitamin D in patients with subnormal vitamin D levels. Although there is a paucity of high-quality studies, the present literature does highlight a role for optimization of vitamin D levels in patients with BPPV.

Rhinologic manifestations of Burkitt Lymphoma in a pediatric population: Case series and systematic review.

INTRODUCTION: Burkitt lymphoma (BL), an aggressive form of B-cell non-Hodgkin's lymphoma, arising from the nose and paranasal sinuses is relatively rare. It can present with various symptoms leading to potential misdiagnosis and delayed treatment. BL is fatal if left untreated, while early identification and treatment can improve prognosis. OBJECTIVES: 1) To review clinical presentations and sites of involvement of six cases of pediatric BL with rhinologic manifestations and compare these with the current literature. 2) To raise awareness on the variety of presentations of BL in this particular anatomic location. METHODS: A series of six cases of pediatric (0-18 years) BL with rhinologic manifestations is presented. Age, sex, ethnicity, symptoms, imaging, staging, treatment and outcome were recorded. A systematic review of literature was also conducted using PRISMA guidelines. The search strategy used keywords related to rhinologic manifestations of BL (nasal cavity, nasopharynx, paranasal sinus etc.; Burkitt etc.) and included studies published in English and French describing patients 0-18 years of age. RESULTS: 42 patients were included (six from case series and 36 from current literature). Most common presenting symptoms were: nasal obstruction (29%), facial swelling (24%), headache (21%) and proptosis (19%). Most frequent sites of presentation were: nasopharynx (40%), maxilla (40%) and sphenoid (33%). More than half (60%) had systemic involvement, of which the most common locations were: kidney (19%), pancreas (17%) and liver (17%). Mortality from BL in children from this study population was correlated with a longer duration of symptoms prior to presentation, as well as a misdiagnosis preceding the final diagnosis of BL. CONCLUSIONS: This study brings understanding to the numerous presentations of the same aggressive disease, promotes high clinical suspicion when evaluating common otolaryngologic symptoms and can guide healthcare providers in diagnosing pediatric BL with rhinologic manifestations.

CDK4 regulates cancer stemness and is a novel therapeutic target for triple-negative breast cancer.

Triple negative breast cancers exhibit very aggressive features and poor patient outcomes. These tumors are enriched in cancer stem cells and exhibit resistance to most treatments and chemotherapy. In this study, we found the cyclin-dependent kinase (CDK4) to act as a cancer stem cell regulator and novel prognostic marker in triple negative breast cancers. We found CDK4 to be highly expressed in these tumors and its expression to correlate with poor overall and relapse free survival outcomes, high tumor grade and poor prognostic features of triple negative breast cancer patients. Moreover, we found that blocking CDK4 expression or kinase activity, using a pharmacological inhibitor prevented breast cancer stem cell self-renewal. Interestingly, suppression of CDK4 expression or kinase activity reversed the basal-B TNBC mesenchymal phenotype to an epithelial- and luminal-like phenotype which correlates with better clinical prognosis. Finally, blocking CDK4 activity efficiently eliminated both normal and chemotherapy-resistant cancer cells in triple negative breast cancers, highlighting CDK4 as a promising novel therapeutic target for these aggressive breast tumors.