Development of immunotherapeutic strategies for the treatment of malignant neoplasms

Combination of Radiotherapy and Targeted Agents in Brain Metastasis: An Update

OPINION STATEMENT

The combination of radiation therapy and targeted agents (molecular inhibitors or immunotherapy) represents an opportunity to improve the outcomes of patients with brain metastases. The combination of whole-brain radiation therapy (WBRT) with targeted agents takes advantage of radiosensitization, while the combination with stereotactic radiosurgery (SRS) may allow one to substitute an effective systemic agent for adjuvant WBRT, the historical standard of care. This strategy may in turn allow the promotion of secondary prevention paradigms with possibly less cognitive toxicity. At present, the combination of targeted therapy with SRS rather than with WBRT is the more viable option although both avenues will likely have a role in the future management of brain metastases. Patients should be encouraged to enter clinical trials since the off-study use of these combinations will delay the advancement of the field. Caution is advised in the combination of radiation and targeted agents as unexpected toxicities can occur. Clinicians should avail themselves of clinical trials in order to offer patients these promising options and to move the field forward. In the absence of a clinical trial, we recommend the combination of SRS with targeted agents and deferred WBRT. Small, asymptomatic brain metastases may be best managed with single-modality targeted agents with deferred radiation therapy, preferably on a clinical trial. Advances in targeted therapies combined with radiation therapy will most likely improve local control and hopefully the quality of life and survival of patients with brain metastasis.

Cytokine-induced tumor immunogenicity: endogenous interleukin-1 alpha expressed by fibrosarcoma cells confers reduced tumorigenicity

A direct correlation between the constitutive expression of IL-1 alpha and reduced tumorigenicity of fibrosarcomas was observed. This was established in fibrosarcoma cell lines which produce IL-1 alpha 'spontaneously', possibly as an aberration of oncogene-mediated transformation or upon IL-1 alpha gene transfer. In fibroblasts intracellular or membrane-associated IL-1 alpha is expressed, whereas the secreted form of the cytokine (IL-1 beta) is absent. Studies on the mechanisms of tumor regression of the IL-1 alpha-positive fibroblastoid cell lines indicated that IL-1 alpha potentiates the development of tumor cell-specific CTLs, which are of importance for tumor eradication. Thus, IL-1 alpha induces enhanced helper T cell activity which provides auxiliary signals for the growth/development of CTLs. Non-adaptive effector cells, activated locally by IL-1 alpha-expressing fibrosarcoma cells, also contribute to the eradication of IL-1 alpha-expressing fibrosarcomas. Local IL-1 alpha expression potentiated antigen presentation, by the malignant fibroblasts as well as by tissue-resident antigen-presenting cells, thus further potentiating anti-tumor immune responses. Mice, in which IL-1 alpha-producing tumors were regressed, developed an immune memory and rejected a challenge with an IL-1 non-producing violent tumor cell line. Endogenous IL-1 alpha activates a cytokine cascade (i.e., IL-6, CSF), produced by the malignant cells and possibly also by stromal cells. However, IL-1 alpha expression is essential for fibrosarcoma eradication, while other cytokines possibly amplify and sustain its action.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between immunological parameters and survival of patients with liver metastases from breast cancer given immuno-chemotherapy

We treated 33 patients with liver metastases from breast cancer by immuno-chemotherapy including adoptive cell transfer between 1987 and 1992. In this study, we examined the change of immunological parameters in the peripheral blood lymphocytes and interleukin-2 (IL-2)-cultured lymphocytes, in primary vs. metastatic breast cancer patients and before vs. after treatment. Moreover, we examined their correlation with therapeutic response and survival after treatment. The immunological parameters used were in vitro natural killer cell activity (% lysis of K562), in vitro autologous tumor-killing activity (% lysis against autologous freshly isolated tumor cells), and proliferation of lymphocytes stimulated with IL-2 and autologous sonicated tumor extract antigen in mixed culture (IL-2-enhanced MLTR). When compared with primary breast cancer patients, patients with liver metastases showed a significant decrease in % lysis of K562 and autologous tumor cells. After treatment, the stimulation index in IL-2-enhanced MLTR increased significantly from the pretreatment level and correlated with survival after treatment. Moreover, non-specific immunological parameters (performance status, lymphocyte count, and transferred cell count and proliferation rate of cultured lymphocytes) were significantly associated with response and prognosis.