Adjuvant immunotherapy with BCG in squamous cell bronchial carcinoma

Abstract

Fifty-four patients with evidence of locally advanced primary squamous cell bronchial carcinoma (SCC), and three patients with adenocarcinoma (AC) had lung resection to remove all visible tumour. After operation a randomly chosen group of 20 SCC patients received adjuvant BCG immunostimulation by scarifications (BCG-A). An additional group of 14 SCC patients, and three AC patients received intially intrapleural BCG treatment and subsequently scarifications (BCG-B). A control group of 20 SCC patients received no adjuvant treatment. Follow-up studies were done from three to 51 months. Immune reactivity was monitored in vivo with PPD skin tests in 33 treated and in 18 untreated patients. In both the BCG-treated SCC groups recurrence rates decreased statistically significant during follow-up (BCG-A; six to 51 months, p<0.001; BCG; 6-9 months, p<0.01 and nine to 24 months; p<0.001). However, no difference could be demonstrated between systemic and combined systemic and intrapleural treatment. The three BCG-treated Ac patients all relapsed within nine months of follow-up. A pronounced increase in skin reactivity to PPD was seen six months after surgery in the BCG-treated patients (BCG-A, p<0.001; BCG-B, p,0.01), whereas the control patients remained anergic after surgery. This improved immune reactivity went in parallel with a more favourable outcome of the individual patients (BCG-A, p<0.02; BCG-B, p<0.05). It is concluded that adjuvant BCG immunotherapy used in strongly selected patients with minimal residual squamous cell bronchial carcinoma improves the prognosis. Intrapleural treatment did not improve the prognosis further. A favourable clinical outcome was mirrored by an increase in cellular immune reactivity.