Sequential
tumor biopsies from 9 patients with disseminated
cancers were obtained before, during, and
after treatment with
interleukin-2 (IL-2) with or without the adoptive transfer of lymphokine-activated killer (LAK) cells. Infiltrating lymphoid and
tumor cells were characterized in frozen sections by the use of
monoclonal antibodies and the
avidin-
biotin complex (ABC) immunoperoxidase technique. Five patients had objective
tumor regression (1 complete response of a
follicular lymphoma, 4 partial responses of
melanomas). Four patients (2
melanomas, 1
renal cell carcinoma, 1 breast carcinoma) were nonresponsive
after treatment.
After treatment, responsive
tumors showed a pronounced infiltration of T cells, mainly Leu-2+ (CD8, primarily cytotoxic/suppressor) cells. Macrophages, although increased, were fewer than the T cells, and Leu-7+ or Leu-11+ (NK and K) cells were virtually absent. In nonresponders, there was no significant increase in lymphoid cells after
therapy, and no differences were noted between groups before
therapy. In 4 of 5 responders,
tumor cells were positive for
HLA-DR before
therapy; and in the remaining responder, the
tumor became positive during treatment.
Tumor cells in all biopsy specimens from nonresponders were DR- before and after the start of
therapy. It is concluded that the expression of
HLA-DR by
tumor cells may play a role in the response to
IL-2 with or without LAK and that marked infiltration by T cells accompanies, and possibly mediates, such a response.