Studies on the role of cellular immunity and genetics in the etiology of rapidly progressing breast cancer in Tunisia.

It has been suggested that poussée évolutive (PEV) or rapidly progressing breast cancer (RPBC) represents a failure in the host immune system to control the proliferation of breast cancer cells. To evaluate this possibility, we have performed in vivo and in vitro assays of cellular immunity in Tunisian patients with breast cancer. Studies of delayed hypersensitivity using microbial antigens and in vitro including lymphocyte transformation tests and measurements of B and T cells indicated that RPBC patients had an immune response comparable to that of breast cancer patients without evidence of rapid progression. Normal Tunisians were more immunocompetent, however, an appeared to have a higher level of immune activity than normal individuals in the United States. In a second, independent series, an increased frequency of blood group A was found in RPBC patients, suggesting a genetic predisposition to this form of breast cancer. However HLA typing for A, B and DRW antigens revealed no specific RPBC-associated HLA antigen. Our studies clearly demonstrate that RPBC, or PEV, is not a reflection of immunodeficiency.