Competing risk: An illustration with aspiration pneumonia in head and neck cancer patients undergoing radical radiotherapy: A biostatistician’s perspective.

Interest in survival analysis is to look and capture the information about the occurrence of events, i.e., death. In human life different types of events may happen at the same time. Sometimes, few events completely interrupt or make subtle changes on the occurrence of an event of interest. The method to capture information about the specific event of interest along with other events is known as competing risk modeling. This paper is dedicated to explore the application of competing risk model in oncology practice. It is aimed in near future that more and more survival analysis will be performed through application of competing risk modeling instead of traditional survival analysis to generate robust statistical inference.

Efficacy of radical radiotherapy alone for functional preservation of larynx in laryngeal carcinoma: A retrospective analysis.

PURPOSE: Concurrent chemoradiation is the current standard of care in locally advanced head and neck cancer. But, in our setup, many patients of carcinoma larynx are treated with only radical radiotherapy because of poor general condition of the patients. This study was performed to assess the influence radical radiotherapy alone on functional preservation of larynx. MATERIALS AND METHODS: 110 previously untreated patients with invasive squamous cell carcinoma of larynx were treated with radical radiotherapy alone between January 2006 and June 2009. Conventional one daily fraction of 2 Gy with total doses of 60–66 Gy was used. Voice preservation and local control at median follow-up period of 2 years were analyzed. Several host, tumor, and treatment parameters were also analyzed. RESULTS: Among 110 patients, preservation of larynx was possible in 78 patients (71%). With radical radiotherapy alone, excellent preservation of larynx was achieved in stage I (88.9%) and stage II (75%) disease, while in advanced stages, results were not so encouraging. In stage III and stage IVA, larynx preservation was only 72.4% and 65.3%, respectively. Patients without any cartilage invasion had significantly better laryngeal preservation rate as compared to patients with cartilage invasion. (78.9% vs. 35.3%; P = 0.008). CONCLUSION: Though concurrent chemoradiation is the standard of care in preservation of voice in laryngeal cancer, definitive radiotherapy alone may also be a good option in terms of preservation of larynx in patients of laryngeal cancer in community practice in the developing world where most of the patients cannot tolerate concurrent chemoradiation.

Effect of DENA induced hepatocarcinogenesis on neuroendocrine levels in male rats.

Hepatocarcinogenesis was induced in Sprague Dawley rats by injecting diethylnitrosamine (DENA); 150 mg/kg body weight, ip, a well known liver carcinogen and a mutagenic agent. Concurrent with the induction of hepatocarcinoma, psychological stress was also elicited from the changes in brain neurotransmitters. Noradrenaline and dopamine, the neurotransmitters of sympathetic system were estimated from the whole brain and corresponding hormones T3, T4 and prolactin were estimated from the blood of such rats. The neuroendocrine cascade and the marker enzyme gamma glutamyl transferase were estimated at 7, 14, 21 and 30 weeks. A direct relationship between noradrenaline, T3 and T4 and a reciprocal relationship between dopamine and prolactin were observed, which may be correlated to the carcinogenic effect of DENA.

A study on the effects of diclofenac sodium and etoricoxib in the treatment of osteoarthritis.

Diclofenac sodium, a non-selective cyclo-oxygenase inhibitor and etoricoxib, a selective cyclo-oxygenase-2 inhibitor have been widely used in treatment of patients with osteo-arthritis. Five hundred and eighty-five patients with uncomplicated knee osteo-arthritis were randomly allocated into 3 equal groups and received either diclofenac sodium, etoricoxib or placebo in a double-blind manner. The response in both the drug groups was comparable and much more than placebo group. The study shows that etoricoxib provides better clinical efficacy and gastro-intestinal tolerability in osteo-arthritis in comparison to diclofenac sodium presumably due to the selective inhibition of cyclo-oxygenase-2 by etoricoxib.

Effect of calcium-channel blocking drugs on focal ventricular arrhythmias induced by sub-epicardial epinephrine infusion in cats.

Sub-epicardial infusion of epinephrine (EP) in the dose of 3 x 10(-3) M in 2.5 x 10(-3) M CaCl2-0.9% NaCl (calcium-saline vehicle) at the rate of 10 microliters in the right ventricular myocardium of mongrel cats weighing between 2.8 and 3.3 kg, produced uniform, reversible and reproducible focal ventricular arrhythmia (VA) of varrying intensity and duration. Infusion of two calcium-channel blocking agents, verapamil (VP) and nifedipine (ND) at the site of arrhythmogenesis, in equimolar concentration of 3 x 10(-3) M alongwith EP in the same vehicle reduced the incidence, duration, peak and mean frequencies of arrhythmias while, the latent period of onset of arrhythmias increased significantly. Verapamil in equimolar concentration of 3 x 10(-3) M was found to be more effective than nifedipine in antagonizing EP-induced ventricular arrhythmias.

Role of 5-hydroxytryptamine in toxaemia of pregnancy.

5-HT concentration in blood of 24 randomly selected pregnant women presenting with signs and symptoms of toxaemia of pregnancy were estimated and compared with 30 normal pregnant women. As such 5-HT level increases with the progress of pregnancy and in toxaemia group in comparison to normal pregnancy. A change in the degree of oedema from moderate to severe could bring a statistically significant change in blood pressure and serum 5-HT level. Increased 5-HT plays a role in toxaemia as well as in normal pregnancy and some of the toxic effects observed in toxaemia of pregnancy are due to the effects of 5-HT.

Effect of lidocaine and quinidine on focal ventricular arrhythmias induced by subepicardial epinephrine in cats.

Subepicardial infusion of epinephrine (EP) in the dose of 3 x 10(-3) M in 2.5 x 10(-3)M CaCl2-0.9% NaCl (calcium-saline vehicle) at the rate of 10 microliters/min in the right ventricular myocardium of mongrel cats weighing between 2.7 and 3.3 kg produced uniform reversible and reproducible focal ventricular arrhythmias of varying intensity and duration. Infusion of two antiarrhythmic agents, lidocaine (LD) and quinidine (QD) in the same site of arrhythmogenesis in equimolar concentration of 3 x 10(-3) M along with EP in the same vehicle reduced incidence, duration, peak and mean frequencies of arrhythmias while the latent period of onset of arrhythmias increased significantly. In present study, quinidine, in equimolar concentration of 3 x 10(-3) M was found to be more effective than lidocaine in antagonizing EP-induced ventricular arrhythmias.