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Fluorescence spectroscopy of the bladder mucosa of dogs given the bladder carcinogen 2-aminonaphthalene revealed the presence of a fluorescent metabolite displaying maxima at 400 mμ and 440 mμ at 340 mμ excitation. Control dog bladder mucosa displayed a single maximum of lower intensity at 440 mμ. The same fluorescence spectrum was obtained after the in-vitro interaction of the 2-amino-1-naphthyl sulfate with control dog bladder mucosa. However, other 2-amino-1-naphthol derivatives displayed the same fluorescence maxima under these conditions. The fluorescence is completely removed by dialysis of the bladder mucosa and also disappears if the ingestion of the 2-aminonaphthalene is discontinued for a few days. The metabolite was identified as 2-amino-1-naphthyl sulfate by paper chromatography. No other metabolites of 2-aminonaphthalene were detected.

A study of the effect of bladder lavage with isotonic fluid at 45 degrees C on proliferative transitional cell carcinoma has shown definite cancericidal changes. These early studies suggest that further investigation of hyperthermia on a larger scale would be worth while.

This paper presents the results of a random clinical trial designed to contrast megavoltage (4 MV linear accelerator) with conventional therapy (300–500 KV) in the radical treatment of bladder cancer. Two hundred and thirty-four patients were included in the trial and allocation to treatment was on a true random selection basis in accordance with the principles set out in Part 1 of this series of papers (Paterson 1958). It is concluded that subject to qualitative differences there is no strong evidence to suggest that the MV treatment is superior to the KV treatment.

Summary A bladder cancer conference sponsored by the U.I.C.C. and others was held in Leeds in September 1971, and considered both the clinical and scientific aspects of the disease. The more purely scientific contributions have been summarised elsewhere (European Journal of Cancer 1972). The papers of clinical interest emphasised the occupational hazards in the tailoring industry, in hairdressers, in nurses, in the leather industry and in certain Japanese silk painters. It seems likely that the overall incidence of bladder tumours is gradually increasing and that there is likely to be an association with smoking. Emphasis was given to the importance of medical surveillance not only of workers in the dye industry but also of those using the finished products. The role of bilharzia in the production of bladder cancer was considered and it is believed that this is associated with an increase in squamous but not in transitional cell carcinomas. The immunological consequences of radiotherapy were discussed and evidence was produced that high-energy radiation reduces the cellular response for the period of irradiation, though cytotoxic lymphocytes develop again soon after treatment ceases. If the cytotoxic response decreases again following radiotherapy it is usually associated with the appearance of metastases or local recurrence. Patients who maintain high levels of cytotoxicity remain clinically tumourfree. The clinical papers emphasised the diverse nature of the treatments available. In terms of 5-year survival they highlighted again the fact that many forms of treatment can be used to control the superficial (stage T1) tumours whilst, for the advanced (stage T4) lesions, no treatment is effective. The 3- and 5-year survivals for stage T2 and stage T3 lesions are so similar, despite the different forms of treatment used, that it seems likely that it is impossible clinically to differentiate these 2 stages. Since the 5-year survival following the different forms of treatment is so similar it may be thought unlikely that any of the treatments used significantly modifies the natural course of the disease. There is certainly no strong evidence to suggest that primary cystectomy for stage T, lesions when compared with the results following a radical course of high-energy radiation, justifies the high immediate surgical mortality and long-term morbidity. On the other hand, if the results following pre-operative radiotherapy and cystectomy reported by Bloom are maintained in a larger series, the picture may well change. In our opinion the results presented at the conference suggest that the best form of primary treatment yet available for invasive tumours of the bladder is external and/or interstitial radiotherapy, with the exception of those patients presenting with bilateral ureteric obstruction. One notable feature of this conference was the lack of any contribution relating to the use of cytotoxic chemotherapy in the management of bladder tumours.

Although the chief purpose of this paper is to deal with interstitial radiotherapy for carcinoma of the bladder it would seem desirable to first say something about the subject of bladder cancer in general in order to try and place this method of treatment in its proper perspective. The past 10 to 15 years have seen major advances in the whole field of bladder tumours, but perhaps the most important basic contribution from the clinician's point of view has been towards a better understanding of the natural history of the disease. As a result, more accurate methods of classification have been developed based upon the extent of the tumour and its histological type and grade. These have enabled prognosis to be assessed more accurately and have provided a guide for the individual surgeon or radiotherapist as to the most suitable treatment for a particular type of case. If only general agreement could now be obtained as to precisely which classification to adopt, we would be in a better position to study the r...

Recent development of the methodology of occupational cancer research was reviewed, in regard to the experimental and epidemiological approach. The author's attention was directed toward the evaluation of the results of animal experiment, particularly toward the standardization of carcinogenic potency, presented by Horton and Denman. Concerning the epidemiological methods, a paper prepared by the Committee on Occupational Cancer of Council of Industrial Health, U.S.A. 1948 was chiefly introduced. A result obtained by the present author was also quoted, comparing the date which showed about a double high "relative frequency" of lung cancer among workers in chromium and nicickel industries in comparison with the expected, to the other which resulted in the same conclusion by means of the computation of age adjusted death rates from the same material. In the latter, the observed lung cancer deaths were compared to the expected, calculated from the population record in the same year, and showed again significantly a higher figure (p=0.01) in the above mentioned industries. The result implies that the "relative frequency" would be useful when the denominator for computing a death rate is not available, although there are some limitations. Biochemical studies on the induction of the bladder cancer, developed by Bonser, Boyland and others were discussed, with ultimate hope that ideas akin to this in the study of occupational cancer would lead to the elucidation of other "natural cancers" among human beings. Finally the author did not forget to add that studies in this field be much more vigorously promoted in this country in light of rapid development of industrialization.

In discussing the treatment of bladder cancer by irradiation and diathermy, it has seemed fitting to include in the series of cases on which this paper is based those cases which were treated by excision of the tumor. By including the latter, there is given a possible standard for the comparison of results obtained by the different methods of treatment. Fifty cases, in all of which operation was performed within the last ten years, have been studied. In forty-seven, the diagnosis of carcinoma was made by microscopic examination of tissue removed. In two cases, the piece removed was too small or too necrotic for a satisfactory pathologic diagnosis. In both these cases, however, the tumor was of the infiltrating type and was obviously malignant. In another case, while the piece removed was reported to be a papilloma, other tumors were broad-based and necrotic, and were characteristically papillary carcinoma. Of the