Immunopathologic changes in patients with cutaneous malignant melanoma following intratumoral inoculation BCG: correlation with cell-mediated immunity

Augmentation of antitumor immune responses by multiple intratumoral inoculations of replication-conditional HSV and interleukin-12

Intratumoral inoculation with a herpes simplex virus (HSV) mutant, G207, as an in situ cancer vaccine has been shown to inhibit tumor growth by inducing tumor-specific immune responses. Here, as a step toward the clinical application of this therapeutic approach, we evaluated different protocols for enhancing the antitumor effect. First, in a bilaterally established tumor model with CT26 colon carcinoma, we demonstrated that multiple intratumoral inoculations with G207 induced a greater antitumor effect on both the inoculated and distant tumors than did 1 or 2 inoculations. Second, to boost this antitumor effect, we developed 2 strategies: multiple in situ cancer vaccines with G207 in combination with systemic administration of recombinant interleukin-12 (rIL-12) (G207/systemic rIL-12) or local administration of rIL-12 (G207/local rIL-12). The antitumor effects in both the inoculated and distant tumors by the combined treatments were significantly greater than by either G207 or rIL-12 treatment alone. G207/systemic rIL-12 and G207/local rIL-12 mediated the complete regression of both the inoculated and distant tumors in 67% and 79% of the animals, respectively. These results indicate that multiple intratumoral inoculations of G207 and systemic or local rIL-12 administration work synergistically to facilitate tumor regression and that this combination of treatments may have potential for treating cancer metastasis.

Comparison of the response to PHA and suppressor macrophage function in different age groups of cancer patients and healthy controls

The mitogenic response of peripheral blood lymphocytes was examined in 37 healthy individuals and in 44 patients with various malignant neoplasms. Tested individuals were divided into three major age groups (20-40; 40-60; and over 60 years of age). There was a significant decrease in Phytohemagglutinin (PHA) response with age in the normal controls, but no significant change with age was observed in the cancer patients. Comparison between the various age groups of cancer patients and their corresponding normal controls did not reveal a significant difference in mitogenic response of the young and middle age groups. However, the older cancer patients responded significantly better compared with their corresponding older normal controls. The reduced responsiveness of older normal controls was partially explained by a high activity of suppressor macrophages observed in this group. Reduction of the proportion of phagocytic cells improved their response to PHA. On the other hand, the activity of suppressor macrophages in the older cancer patients was much less prominent. These observations emphasize the importance of appropriate age grouping when immune function tests in cancer patients are compared with those performed in normal individuals and suggest the possibility of higher mitogen responsiveness in certain age groups of cancer patients.

Immunologic responsiveness of the breast cancer patient

Lymphocytic infiltration of the primary breast cancer and sinus histiocytosis of the axillary lymph nodes are indications of a favorable prognosis. Similarly, skin test responsiveness such as with DNCB or with tumor extracts correlates in general with stage of disease. This presentation will bring forth preliminary data on cellular immunity of breast cancer patients. Circulating lymphocytes (PBL) were stimulated with mitogens and a breast cancer antigen. PBL from patients with a primary tumor less than 2.4 cm in size reacted as though no immune stimulus existed. PBL from patients with a lump from 2.5 to 5.0 cm in size showed evidence of immune stimulation. An increase in size of the primary tumor over 5 cm and an increase in the number of axillary lymph nodes with metastasis were associaed with a diminution in cellular immunity. However, data from an adjuvant immunotherapy program show that cellular immunity can be improved in certain patients by immunization. Such patients continued to remain disease free, while patients whose cellular immunity was poor or not improved by adjuvant immunotherapy tended to develop recurrent disease.

Abnormal "activated" rosette formation in patients with gastrointestinal cancer

The mean percentage of peripheral blood lymphocytes forming fast spontaneous rosettes with sheep red blood cells was estimated in 40 patients presenting with gastrointestinal symptoms suggestive of cancer. Patients who were eventually diagnosed as having cancer had significantly lower numbers (P less than 0.01 Mann Whitney Test) of rosette forming cells than patients who had gastrointestinal tumours successfully removed, or patients with other gastrointestinal diseases. The use of this test as an aid to the diagnosis of gastrointestinal malignancy and its possible application to the detection of recurrences of cancer after surgery are discussed.