BCG immunotherapy of lung cancer in a district oncology dispensary. I. Study of 860 patients with histologic diagnosis.

The investigation refers to lung cancer patients registered in an oncology dispensary from 1965 to 1975. The conventional treatment (surgery, radiotherapy and chemotherapy) has covered 35.9% of all patients, whereas immunotherapy with BCG or with its soluble fraction has been applied in 46.2% of them. Immunotherapy has mainly been applied to epidermoid carcinoma and large-cell carcinoma. Comparing the survival of immunotherapy treated with non-immunotherapy treated patients it was found that in Stage I-II group the difference in favor of immunotherapy was significant in the second year of observation and in Stage III group a significant difference was found in all observation periods (1-5 years). In Stage I-II the 5-year survival rate of immunotherapy treated patients (13.2%) was similar to the survival rate of operated patients (13.7%). Immunotherapy in large cell carcinoma showed significantly better results than immunotherapy in epidermoid carcinoma. Immunotherapy with BCG and F70 was applied as an independent treatment of lung cancer. When applied to patients primarily operated, radiation or chemotherapy treated, the survival was significantly higher than the survival of patients submitted to conventional treatment or to immunotherapy separately.

Survival of lung cancer patients treated with BCG and/or a soluble BCG fraction (F70) after surgery, radiotherapy and chemotherapy.

243 lung cancer patients treated with routine therapy (surgery 54, radiotherapy 46 and chemotherapy 143) in Plovdiv's District Oncologic Dispensary (PDOD) were submitted to an additional therapy with BCG or with its soluble fraction F70. The survival rate of these patients was compared with the survival rate of 305 lung cancer patients following routine therapy alone (surgery 78, radiotherapy 113 and chemotherapy 114). The two groups were not randomized. Between patients treated and non-treated with BCG(F70) a significant increase of the survival rate was found for patients submitted to BCG(F70) treatment after surgery or radiotherapy in the 2nd and 3rd year survival period and for patients submitted to BCG(F70) treatment after chemotherapy -- in the 1st year survival period of patients with limited disease only. The effect of the additional BCG(F70) treatment was less dependent on the preceding routine therapy than upon the clinical stage of the disease at the moment of BCG(F70) treatment beginning. More salient results were observed in patients with undifferentiated histological forms.

Investigations on the methods of clinical application of a soluble BCG fraction (F70) in lung cancer.

Several parameters for an optimal treatment scheme of a soluble BCG fraction (F70) were investigated. Among lung cancer patients treated with F70 a restricted selection was made of patients treated with small doses (5--10 U) every second or third month (sparing scheme) and of patients treated every month with sharply increasing doses up to tens of thousands units (aggressive scheme). It was found that the survival rate and the rate of marked X-ray regressions were higher in the former group. As it was previously established for lung cancer patients treated with living BCG, in the group of sparing scheme-treated patients the longest survival period pertained to patients treated once and patients treated twice or three times and an inverse correlation existed between the number of applications of F70 and the mean survival period. It was concluded that, as with living BCG, a sparing approach to the immunotherapy of lung cancer with F70 is to be preferred to an aggressive approach. Illustrative cases treated once, twice and three times are presented.

Analysis of the results of treament of lung cancer patients with BCG according to the scheme of application of the bacillus.

BCG has successfuly been applied in lymphoid and in myeloid leukemia but no positive results have been demonstrated in solid tumors except malignant melanoma after intratumoral injection. The authors' approach consists in applying BCG as an only antitumor treatment, much smaller doses and in much longer intervals between them than used by other investigators. The analysis of the treatment schemes of BCG, applied to 171 lung cancer patients showed that positive responses have been obtained only in patients without peripheral dissemination of the disease and that in doses from 0.0001 mg to 0.05 mg. The results obtained depended on the frequency of BCG application: the 5 years survival rate, the mean survival period and the rate of the marked X-ray regression have been found best in patients treated once, good in patients treated in intervals longer than 30 days between the applications of the mycobacteria and worse in patients treated in intervals shorter than 20 days. A direct inverse correlation has been discovered between the mean survival period of the treated patients and the number of the applications of BCG in the first 6 months of the treatment.