In the course of running two clinical trials between 1966 and 1985, data became available for 1315 patients, 713 in the first trial and 602 patients in the second trial, which has allowed comparison between histological findings in laryngeal and hypopharyngeal carcinoma, the observed survival and the tumour-free rates for these patients who were followed for up to 10 years. Extensive histopathology reviews have revealed over 98% agreement on tumour cell type between the initial report and that of the reviewer. Highly significant differences have been found for squamous cell carcinoma between the observed survival and the tumour-free rates for patients with well-differentiated and with anaplastic lesions. There was a statistically significant greater proportion of patients with well-differentiated tumours at larynx sites and in stage 1 when compared with patients with anaplastic tumours, but even when this was taken into account, multivariate analyses showed that tumour grading still made an independent significant contribution to the prediction of prognosis. For squamous cell carcinoma only very simple and rapidly assessed histopathological features need to be identified to classify tumours into the two grades employed in this study. The analyses have confirmed the prognostic significance of tumour grading in squamous cell carcinoma in the larynx and hypopharynx.

In a randomized controlled clinical trial of hyperbaric oxygen in the radiotherapy of advanced carcinoma of the uterine cervix a total of 320 cases were contributed by four radiotherapy centres in the United Kingdom. The use of hyperbaric oxygen resulted in improved local control and survival. The benefit was greatest in patients under the age of 55 who presented with stage III disease. There was a slight increase in radiation morbidity but it seemed that the benefit of hyperbaric oxygen outweighed this increase in morbidity and that there was a true improvement in the therapeutic ratio.

In a randomized controlled clinical trial of hyperbaric oxygen in the radiotherapy of carcinoma of the bladder a total of 241 cases were contributed by four radiotherapy centres in the United Kingdom. In this trial where in each centre identical radiotherapy was employed for both oxygen and air cases, no benefit was shown with the use of hyperbaric oxygen.

The second British Institute of Radiology trial of dose fractionation in radiotherapy compared two groups of prospectively randomized patients with squamous carcinoma of the laryngo-pharynx; one group was treated in a short (less than or equal to 4 weeks) and the other in a long (greater than 4 weeks) overall time. Treatment in any one centre could be given, with no planned gap in the course of treatment, either as a conventional, daily (5 fractions per week regime) or as 3 fractions per week. A total of 611 patients were allocated to treatment, of whom nine have had to be excluded from the analysis for a lack of information. Patients were admitted to the trial from January 1976 to December 1985 and were followed up for a maximum of 10 years and a minimum of 3 years. A reduction in total dose was made for use in the short compared with the long treatment regime. This reduction in total dose varied between 18% and 22% depending on whether 5 fractions or 3 fractions per week regimes were used. Overall, no statistically significant differences have been found between the two arms of the trial. The patients treated with 5 fractions per week in a short overall treatment time showed fewer late normal tissue effects. An analysis based on stratification by age, stage and anatomical site gave a relative risk (short/long overall treatment time) for deaths of 1.23 with a 95% confidence interval from 0.96 to 1.59. Analyses stratified for stage and site gave relative risks with 95% confidence intervals of 1 x 10 (0.84-1.44) for local recurrences/tumour persistence, and 1.01 (0.70-1.45) for laryngectomies.

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