Clinical importance of squamous metaplasia in invasive transitional cell carcinoma of the bladder.

One hundred cases of transitional cell carcinoma of the bladder were studied to determine whether squamous metaplasia and other histological features within the bladder can be of value in predicting outcome of treatment with radiotherapy. Sixty cases showed the changes of squamous metaplasia, and of this group 46 (78%) failed to respond to radiotherapy. A significant response rate of 90% was seen in the 40 tumours without squamous metaplasia. It is concluded that transitional cell carcinomas of the bladder showing squamous metaplasia are mainly resistant to radiotherapy and alternative treatment methods should be sought.