Quantitative and functional study of lymphoid cells infiltrating solid tumors

Abstract

Lymphocytes are a frequent component of inflammatory infiltrates that characteristically are present in certain human neoplasms. Although inflammatory cells may be sparse in spontaneously arising tumors, solid tumors such as carcinomas of the breast, lung, germinal-cell tumors, malignant melanoma, and primary liver cancer are characterized by a prominent lymphocytic infiltrate (12). The presence of inflammatory cells in and around tumors is a favorable prognostic sign in at least some tumors, and because of that, numerous analyses of the lymphoid cells in situ have been attempted in recent years. Still, the nature and function of mononuclear cells in tumors remain unclear, as does the precise relationship between mononuclear cell infiltrates and tumor growth. It is believed that certain of these infiltrating lymphoid cells sensitized to tumor antigens mediate lysis of tumor cells (i.e., cytotoxic T lymphocytes; CTL). Other lymphoid cells may mediate tumor-cell lysis in a nonspecific