Purpose: We investigate the correlation of purified protein derivative (PPD) results before intravesical bacillus Calmette-Guerin (BCG) instillations with prognosis and complications of BCG.
Materials and methods: A total of 57 men and 4 women with proven intermediate or high risk superficial bladder cancer received 6 courses of intravesical BCG instillations following complete resection of tumors. Skin reactivity to a PPD derivative of Mycobacterium tuberculosis was tested before starting and 1 week after BCG. The test was considered positive if the induration was 10 mm. or more in diameter after 48 or 72 hours. The patients were grouped according to PPD responses and symptoms. The statistical analyses were performed between PPD positive and negative groups, and also between symptomatic and asymptomatic patients. The groups were compared for relapse rates, time to first recurrence, complication rates and clinical outcome.
Results: Most of the patients with systemic side effects were in the PPD positive group but only fever had a statistically significant difference and was more frequent in the positive group (p <0.05). The recurrence-free intervals after intravesical BCG therapy did not differ significantly between PPD positive and negative groups. However, the trend of longer recurrence-free survival was evident for symptomatic patients (p = 0.056). The numbers of tumor recurrences were 10 (52%) in the PPD negative group and 19 (51%) in the PPD positive group, which was statistically insignificant.
Conclusions: Patients with systemic reactions to BCG had the longest disease-free survival. It seems that patients with an augmented reaction to BCG probably have better antitumor activity. Furthermore, although larger groups of patients are mandatory for statistical analysis, this study shows that hypersensitivity reaction against tuberculin could alert physicians of severe complications.