Cryoimmunotherapy: Continuing studies toward determining a rational approach for assessing the candidacy of the prostatic cancer patient for cryoimmunotherapy and postoperative responsiveness an interim report

Cryosurgery (in situ freezing) is a recognized method for the controlled cryogenic destruction of benign and malignant tissues and has been efficaciously employed for the treatment of prostatic cancer. In situ freezing constitutes an antigenic stimulus capable of generating a specific immunologic response against autologous antigens of the tissue frozen, ergo, cryostimulation. The phenomenon of cryostimulation has, in light of 1 Results of this communication are derived from symposia on 'Immunological Considerations of Cryosurgery of the Prostate', 3rd International Congress of Cryosurgery, International Society of Cryosurgery, Valencia, Spain, 27-29 October, 1977; immunological Aspects of Cryosurgery*, 15th Annual Meeting, Society for Cryobiology, Tokyo, Japan, 6-10 August, 1978 and meetings of the Study Group Members in Valencia, Spain, October, 1977 and Tokyo, Japan, August, 1978. 2 Members of the Cryoimmunotherapeutic Study Group: Richard J. Ablin (Chairman), Chicago, 111.; Rolf Ackermantx, Wurzburg, Germany; Hermann Becker, Hamburg, Germany; Alfredo Tramoyeres Cases, Valencia, Spain; Jose Sanchez-Cuenca, Valencia, Spain; Gabriele Fontana (Vice Chairman), Turin, Italy;/u/ww Frick, Salzburg, Austria\Edgardo A. Giorgini, Buenos Aires, Argentina; Patrick D. Guinan, Chicago, III.; Horst Haschek, Vienna, Austria; Burkhard Helpap, Bonn, Germany; Patrick Le Pivert, St.-Etienne, France; Augustino Pu gliese, Turin, Italy; Hans J. Reutert Stuttgart, Germany; Giovanni Riggi, Turin, Italy; Georges Rigondet, Montlucon, France; Panos Rouvalis, Athens, Greece; Giovanni Sesia, Turin, Italy and Shigeo Tanaka, Naganoken, Japan. reports of metastatic tumour destruction, suggested that cryosurgery may he applicable not only for ablation of the primary tumour, but also as a means of augmenting or inducing host resistance to the tumour, ergo, cryoinimunothcrapy. For cryosurgery to be effectual as a means of immunotherapy, several factors, categorically referred to as “cryoscnsilivity”. must be fulfilled. “Cryosensitivity” is presently suggested to be reflective of the immunogenicity of [lie prostate and the immunocompetence of the host. The majority of prostatic cancer patients possess varying degrees of immunocompetence. Immunotherapy under such conditions may. rather than augmenting or inducing host resistance to the tumour, act in an antagonistic manner resulting in enhancement of the tumour. This knowledge has directed initial efforts of this study group toward establishment of critical criteria to evaluate the immunocompetency of the prospective cryosurgical patient. Once the degree of immunoeompetency Ii3s been established, this may serve as a means of staging this patient immunologically, i.e., 'immunostage*. Similar to traditional staging of the anatomic spread and histological grade of the tumour to aid in selecting therapy and predicting outcome, 'immunostaging' may provide adjunctive criteria toward determining a patient's suitability for cryoimmu no therapy. Directed toward improving criteria on which to 'immunostage' patients, our initial recommendations for assessment of tumour-host immunologic respon- siveness have been redefined. The principal objective being the elimination, for the most part, of non-specific correlates and the maintenance and addition of specific correlates of humoral- and cell-mediated tumour-directed immunity. Preliminary studies suggest a pos- sible relationship between a patient's 'immunostage' and the intensity of immunologic responsiveness following cryosurgery. But. more important, the direction of the immune response, i.e., tumouricidal versus tumour enhancing. Together with observations of the association of humoral immunity with enhancement of tumour metastases and cellular immunity with regression of tumour, reports of the ajunctive utilization of modulators of the immunologic effects of cryostimulation hold promise for the more effective clinical utilization of cryoimmu notherapy.