Immunotherapy of bovine ocular squamous cell carcinoma by repeated intralesional injections of live bacillus Calmette-Guérin (BCG) or BCG cell walls.
Thirty cows of the Dutch Friesian and the Maas-Rijn-Ijssel breed with histologically confirmed ocular squamous cell carcinoma were treated by repeated intralesional injection of live bacillus Calmette-Guérin (BCG) (n = 14) or a BCG cell-wall vaccine (n = 16). Complete regression of the primary tumour was observed in 64% and 57% of the animals respectively. In the 2-year follow-up period there was no recurrence of primary tumours. This sharply contrasts with the recurrence frequency (40%-50%) after complete remission induced by a single intralesional injection with BCG, observed in an earlier study. In 1 animal a new primary tumour developed. At necropsy metastases were present in 33% of the treated animals: in 3 of 17 animals that showed complete regression of the primary tumour and in 7 of 13 animals with partial regression or progressive disease. This did not differ significantly from results obtained after a single treatment (27%). Delayed-type hypersensitivity to M. bovis purified protein derivative (PPD) was more persistent in animals showing regression of the primary tumour than in non-responding animals. Of the animals with a positive PPD response 6 months after treatment, 79% showed tumour regression. Regression was observed in only 28% of the animals not responding to PPD after the same period of time.


CONCLUSIONS
(a) recurrence of the primary tumour was not observed after repeated BCG treatment; (b) the frequency of metastases was not decreased compared to results obtained with a single treatment; (c) regression was correlated with a positive delayed-type hypersensitivity reaction to PPD (P less than 0.05) 6 months after treatment; (d) no significant differences were observed when the clinical results of treatment with live BCG and the BCG cell wall vaccine were compared.
Rutten
V P
VP
Department of Immunology, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands.
Klein
W R
WR
De Jong
W A
WA
Misdorp
W
W
Steerenberg
P A
PA
De Jong
W H
WH
Den Otter
W
W
Ruitenberg
E J
EJ
D000818:Animals; D001500:BCG Vaccine / Q000627:therapeutic use*; D002294:Carcinoma, Squamous Cell / Q000276:immunology / Q000628:therapy / Q000662:veterinary*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000628:therapy*; D002473:Cell Wall / Q000276:immunology; D005134:Eye Neoplasms / Q000276:immunology / Q000628:therapy / Q000662:veterinary*; D005260:Female; D006968:Hypersensitivity, Delayed / Q000276:immunology; D016233:Immunotherapy, Active; D015552:Injections, Intralesional
D001500:BCG Vaccine