The modulation of tumour-versus-host response in lung, colon, and breast cancer patients: implications for adjuvant immunochemotherapy.

Major advances in the understanding of clinical tumour biology occurred with the appreciation that tumour-associated substances circulated in the blood of cancer patients. In this study their origin and immunogenic function have been investigated. Whole tumour cells (WTC) and cancer cell membrane fractions (CMF) of 24 patients with lung, colon, and breast cancer were investigated for their antigenic effect upon the patients' own lymphocytes and upon healthy allogeneic ones. The antigenicity of whole lung and breast cancer cells to stimulate lymphocyte DNA synthesis, and the ineffectiveness of colon cells were confirmed. CMF had little stimulating effect upon autologous lymphocytes; however, they were able to augment lymphocyte response to PPD and PHA in high dilution and to suppress it in high concentration. The serum of cancer patients exerted similar biphasic activity upon PPD and PHA stimulated lymphocytes ("lymphosuppressive-stimulatory factors", or LSSF). Sephadex studies confirmed that LSSF activity in cancer serum correlated with circulating CMF. These substances modulate lymphocyte nucleic acid synthesis in vitro; it is likely that they similarly modulate the patient tumour-host cell relationship.