Factors affecting pretreatment immune competence in cancer patients

Summary The assessment of changes in immune competence due to cancer demands carefully controlled studies with simultaneous consideration of other factors such as age, sex, and general ill health. To determine the effect of each factor, immune competence was measured in 112 healthy individuals, 134 patients with benign disease, and 350 patients with cancer (breast, colorectal, and stomach) with a wide spectrum of parameters.In normal subjects, advancing age was associated with a significant reduction in percentage lymphocyte count (LC), absolute and percentage T cell counts, and responses to phytohaemagglutinin (PHA) and pokeweed mitogen (PWM). In patients with benign disease, advancing age was associated with depression of serum IgM levels, absolute and percentage LC, responses to PHA, and delayed cutaneous hypersensitivity (DCH) responses to tuberculin PPD (Mantoux), and dinitrochlorobenzene (DNCB), but elevation of serum IgA levels.No significant sex effects were demonstrated in either group of subjects.The effects of general ill health were determined by comparing individuals in good health (normal subjects and patients with minor benign breast disease) with those who had poor health (patients with significant benign gastrointestinal disease). The latter showed significant depression of DNCB sensitivity and lymphocyte reactivity to PHA, whereas total WBC and LC were significantly elevated.To determine the effects due to cancer, controls were matched for their general state of health and site of disease, in addition to completing all studies prior to any form of therapy. Age differences were corrected for by application of the findings of the above study. This age correction resulted in marked alterations in the significance of observed differences between cancer patients and controls. The previous significance of many differences either disappeared or was reduced, although in two instances significance was attained only after age correction. The only consistent immunodepression observed in the three types of cancer patient tested was impaired reactivity to DNCB. Responses were impaired even in early disease at all three sites.We have shown that the immunodepression exhibited by cancer patients is a summation of the effects due to age, general ill health, and malignancy. Some of the changes previously ascribed to cancer are due to these other factors.