Effect of gap length and position on results of treatment of cancer of the larynx in Scotland by radiotherapy: a linear quadratic analysis.

PURPOSE: This paper reports on the analysis of the effect of the length and position of unplanned gaps in radiotherapy treatment schedules. MATERIALS AND METHODS: Data from an audit of the treatment of carcinoma of the larynx are used. They represent all newly diagnosed cases of glottic node-negative carcinoma of the larynx between 1986 and 1990, inclusive, in Scotland that were referred to one of the five Scottish Oncology Centres for primary radical radiotherapy treatment. The end-points are local control of cancer of the larynx in 5 years and the length of the disease-free period. The local control rates at > or =5 years, Pc were analyzed by log linear models and Cox proportional hazard models were used to model the disease-free period. RESULTS: Unplanned gaps in treatment are associated with poorer local control rates and an increased hazard of a local recurrence through their effect on extending the treatment time. A gap of 1 day is potentially damaging but the greatest effect is at treatment extensions of 3 or more days, where the hazard of a failure of local control is increased by a factor of 1.75 (95% confidence interval 1.20-2.55) compared to no gap. The time factor for the actual time was imprecisely estimated at 2.7 Gy/day with a standard error of 13.2 Gy/day. Among those cases who had exactly one gap resulting in a treatment extension of 1 day, there is no evidence that gap position influences local control (P = 0.17). The treatment extension as a result of the gap is more important than the position of the gap in the schedule. CONCLUSIONS: Gaps in the treatment schedule have a detrimental effect on the disease-free period. A gap has a slightly greater effect than an increase in the prescribed treatment time. Any gap in treatment is potentially damaging. The position of the gap in the schedule was shown to be not important.

Early closure of a randomized trial: surgery and postoperative radiotherapy versus radiotherapy in the management of intra-oral tumours.

Tumours of the oral cavity/oropharynx occur relatively infrequently in the UK. The management of such lesions, especially the squamous cell carcinomas, is still a little controversial. Some centres advocate radiotherapy while others adopt surgery and radiotherapy. In an attempt to resolve the question of which approach gives the better results, a multicentre randomized trial was established to compare surgery plus postoperative radiotherapy with radical radiotherapy alone. It was anticipated that 350 patients would be required to give a statistically significant result, but, after 35 patients had been entered, the trial was closed prematurely with a marked difference in overall survival in favour of the combination arm (P = 0.0006). At this analysis, carried out 23 months after trial closure, the survival difference between the two arms remains statistically significant for all causes of mortality (P = 0.001; relative death rate = 0.24; 95% CI 0.10-0.59).

The role of post-operative radiotherapy in non-small-cell lung cancer: a multicentre randomised trial in patients with pathologically staged T1-2, N1-2, M0 disease. Medical Research Council Lung Cancer Working Party.

The role of post-operative radiotherapy for patients with non-small-cell lung cancer (NSCLC) is unclear despite five previous randomised trials. One deficiency with these trials was that they did not include adequate TNM staging, and so the present randomised trial was designed to compare surgery alone (S) with surgery plus post-operative radiotherapy (SR) in patients with pathologically staged T1-2, N1-2. M0 NSCLC. Between July 1986 and October 1993, 308 patients (154 S, 154 SR) were entered from 16 centres in the UK. The median age of the patients was 62 years, 74% were male, > 85% had normal or near normal levels of general condition, activity and breathlessness, 68% had squamous carcinoma, 52% had had a pneumonectomy, 63% had N1 disease and 37% N2 disease. SR patients received 40 Gy in 15 fractions starting 4-6 weeks post-operatively. Overall there was no advantage to either group in terms of survival, although definite local recurrence and bony metastases appeared less frequently and later in the SR group. In a subgroup analysis, in the N1 group no differences between the treatment groups were seen, but in the N2 group SR patients appeared to gain a one month survival advantage, delayed time to local recurrence and time to appearance of the bone metastases. There is, therefore, no clear indication for post-operative radiotherapy in N1 disease, but the question remains unresolved in N2 disease.

Referral patterns within Scotland to specialist oncology centres for patients with testicular germ cell tumours. The Scottish Radiological Society and the Scottish Standing Committee of the Royal College of Radiologists.

Details of 1123 patients registered in Scotland between 1983 and 1990 for testicular cancer under the Scottish Cancer Registration Scheme were obtained and compared with registrations within the five Scottish oncology centres. Some registration discrepancies were identified. Twenty-eight cancer registrations (2.5%) were coded to the wrong site, 29 patients seen at oncology centres had no cancer registration and 14 cancer registrations had the wrong histology. Five hundred and twenty-seven patients with testicular non-seminomatous germ cell tumours (NSGCT) and 567 with testicular seminoma were identified. Referral rates to specialist oncology centres for testicular germ cell tumours were measured by period and health board area of residence. For the whole study period 92% of NSGCT and 93% of seminoma patients were referred to specialist centres for treatment. Referral rates for different health board areas of residence were not significantly different. This study shows that within Scotland the majority of patients with testicular NSGCT and seminoma are referred to specialist centres, and suggests referral rates of around 92% are underestimates. Access is not related to area of residence.

A Scottish national mortality study assessing cause of death, quality of and variation in management of patients with testicular non-seminomatous germ-cell tumours. The Scottish Radiological Society and the Scottish Standing Committee of the Royal College of Radiologists.

A detailed casenote review was performed on 55 patients registered with testicular non-seminomatous germ cell tumours (NSGCT) between 1983 and 1988 under the Scottish Cancer Registration Scheme and who had died by 1992. Details of all aspects of clinical management relating to their NSGCT and death details were extracted and summarised. An assessment was made on whether the patients' management had been optimal. An analysis of 5 year survival rates by the five Scottish oncology centres demonstrated significant differences between centres (range 70.4-94.2; chi 2 = 14.46, d.f. = 4, P = 0.006). Some patients in all centres were assessed as having received suboptimal treatment, but two centres performed less well than the other three. There is a suggestion that the number of patients treated suboptimally decreases with increasing number of patients seen, but this does not reach statistical significance.

Cancer of larynx in west of Scotland. A review of results and a consideration of new therapeutic approaches.

A recent epidemiological study carried out by the Cancer Intelligence Unit in Glasgow has shown: 1) there has been an increase in consumption of tobacco products and alcohol in Scotland over the past 25 years; and 2) the mortality rate from cancer of the larynx has been unchanged over that time (Fig. 1). Ayrshire, a county in the west of Scotland, has a population of 360,000 which is remarkably similar in age structure, sex and urban/rural mix to Scotland as a whole. The incidence of carcinoma of the larynx in this region has been unchanged over the 20-year period 1959-1978. The results of treatment for the period 1958-1968 were reported recently by Quayum. In this report the results of treatment of carcinoma of the larynx by radiotherapy in Ayrshire and district over the decade 1968-1978 are presented and compared with those of the previous decade. The overall survival is unchanged over the two decades 1958-68 and 1968-78. This confirms the findings of the Cancer Registry. The survival of certain stages has improved, though this may be due to changes in criteria for staging introduced in 1974. All cases in this report were staged retrospectively. Recent innovations in treatment which may improve overall survival are considered.