Immunocompetence, immunosuppression, and human breast cancer. III. Prognostic significance of initial level of immunocompetence in early and advanced disease.

The prognostic significance of immunocompetence determined at diagnosis was analyzed in 158 operable breast cancer patients followed for 3--6 years, in terms of disease recurrence and of length of disease-free period (DFP) and in 52 patients with metastatic disease in terms of length of survival. In vitro lymphocyte stimulation by PPD and PHA were of higher predictive value with respect to probability of disease recurrence than in vivo cutaneous reactivity to PPD and DNCB. Conversely, length of DFP and of survival were found to correlate better with in vivo than within vitro parameters. Absolute number of peripheral blood lymphocytes (PBL) and percent of E-rosette-forming cells (E-RFC) proved devoid of prognostic value. Prognostic separation was best brought out upon analysis by integrated score of immunocompetence, comprising the four functional parameters. Probability of disease recurrence was 0.43 for all operable patients, as calculated by actuarial method 48 months postoperatively; it was 0.26 for optimal and 0.61 for suboptimal responders (P less than 0.0001). Separate analysis of Stage 1 (N0) and Stage II (N+) patients revealed prognostic segregation within each stage: probability of recurrence in Stage I was 0.06 for optimal vs. 0.41 for suboptimal responders (P less than 0.001) and in Stage II it was 0.45 vs. 0.79, respectively (P less than 0.01). These findings may prove valuable for a more selective patient allocation for post-mastectomy adjuvant therapy. Length of DFP was found inversely proportional to initial immunocompetence, with a mean of 23.5 months for good responders and 12.8 months for poor responders (P less than 0.01). Length of survival of metastatic patients was found to correlate with initial (pretreatment) levels of immunocompetence, mean survival being 29.5 months for those with preserved immune function and 12.3 months for the immunosuppressed (P less than 0.001). It was concluded that initial immunocompetence, determined by parameters of cell-mediated immunity, shows strong prognostic association with the subsequently observed course of human breast cancer.