Specific LIF production in laryngeal cancer patients: evidence of suppressor activity exerted by adherent cells.

The specific tumor-induced LIF production in 30 laryngeal cancer patients has been investigated before and after the removal of adherent cells to evaluate the existence of a suppressor activity. LIF production, after challenging lymphocytes with 3 M KCI autologous tumor extracts, was significant in 16 patients and showed a further significant increase after removal of adherent cells. A conversion to significance when the adherent cells were removed was shown in 6 patients, with no previous significant LIF production. These data suggest the existence of a suppressor activity exerted by adherent cells on LIF production in laryngeal cancer patients.