INTRODUCTION: Oral cancer is a major public health concern in India. Both conventional and altered fractionation radiotherapy schedules have been used in curative treatment of oral cancer. This study aimed to retrospectively evaluate the clinical profile and treatment outcomes of patients with carcinoma buccal mucosa who underwent treatment with definitive hypofractionated accelerated radiotherapy. METHODS: A total of 517 patients treated from January 2011 to December 2016 were eligible for the analysis. All patients were treated with definitive hypofractionated accelerated radiotherapy schedule of 5,250 cGy in 15 fractions over 3 weeks. Survival estimates were generated using the Kaplan-Meier method. RESULTS: At a median follow-up of 77.4 months, 473 (91.5%) patients attained complete remission with radiation therapy. The 5-year disease-free survival (DFS) and overall survival (OS) rates were 69% and 80.5%, respectively. The 5-year OS for stage I, II, III and IVa tumours was 80.3%, 84.4%, 81.4% and 73.7%, respectively, and the DFS was 75.7%, 73.2%, 69.6% and 60.2%, respectively. Age >50 years was found to be a significant factor affecting DFS ( P = 0.026) and OS ( P = 0.048) in multivariate analysis. Fifty-three (10.3%) patients developed osteoradionecrosis of the mandible. CONCLUSION Excellent outcome could be achieved in less-aggressive, low-volume carcinoma of the buccal mucosa with radical accelerated hypofractionated radiotherapy. A radiotherapy schedule over a 3-week period is useful in high-volume centres.
Humans ; Retrospective Studies ; Male ; Female ; Middle Aged ; Mouth Neoplasms/mortality* ; Mouth Mucosa/radiation effects* ; Treatment Outcome ; Aged ; Adult ; Radiation Dose Hypofractionation ; Disease-Free Survival ; India ; Kaplan-Meier Estimate ; Dose Fractionation, Radiation ; Aged, 80 and over

Our previous studies have shown that subthreshold concentrations of two platelet agonists exert synergistic effects on platelet aggregation. Here we studied the mechanism of synergistic interaction of 5-hydroxytryptamine (5-HT) and epinephrine mediated platelet aggregation. We show that 5-HT had no or little effect on aggregation but it did potentiate the aggregation response of epinephrine. The synergistic interaction of 5-HT (1-5 microM) and epinephrine (0.5-2 microM) was inhibited by alpha2-adrenoceptor blocker (yohimbine; IC50= 0.4 microM), calcium channel blockers (verapamil and diltiazem with IC50 of 10 and 48 mM, respectively), PLC inhibitor (U73122; IC50=6 microM) and nitric oxide (NO) donor, SNAP (IC50=1.6 microM)). The data suggest that synergistic effects of platelet agonists are receptor-mediated and occur through multiple signalling pathways including the activation PLC/Ca2+ signalling cascades.
Blotting, Western ; Calcium Channel Blockers/pharmacology ; Calcium Signaling* ; Drug Synergism ; Enzyme Activation ; Enzyme Inhibitors/pharmacology ; Epinephrine/pharmacology ; G-Protein, Inhibitory Gi/metabolism* ; GTP-Binding Proteins/metabolism* ; Human ; Phospholipase C/metabolism* ; Phospholipase C/antagonists & inhibitors ; Platelet Aggregation/physiology ; Platelet Aggregation/drug effects* ; Serotonin/pharmacology ; Signal Transduction