Effects of depression on parameters of cell-mediated immunity in patients with digestive tract cancers

To evaluate the effects of depression on parameters of cell-mediated immunity in patients with cancers of the digestive tract.

One hundred and eight adult patients of both sexes with cancers of the digestive tract admitted between March 2001 and February 2002 in the Department of Medical Oncology, First Affiliated Hospital of Xi'an Jiaotong University were randomly enrolled in the study. The Zung self-rating depression scale (SDS), Zung self-rating anxiety scale (SAS), numeric rating scale (NRS) and social support rating scale (SSRS) were employed to evaluate the degree of depression and their contributing factors. In terms of their SDS index scores, the patients were categorized into depression group (SDS> or =50) and non-depression group (SDS<50). Immunological parameters such as T-lymphocyte subsets and natural killer (NK) cell activities in peripheral blood were determined and compared between the two groups of patients.

The SDS index was from 33.8 to 66.2 in the 108 cases, 50% of these patients had a SDS index more than 50. Similarly, the SAS index of all the patients ranged from 35.0 to 62.0 and 46.3% of the cases had a SAS index above 50. Cubic curve estimation showed that the depression was positively correlated with anxiety and negatively with social support. Furthermore, the depression correlated with the tumor type, which manifested in a descending order as stomach, gallbladder, pancreas, intestine, esophagus, duodenum and rectum, according to their correlativity. Step-wise regression analysis suggested that hyposexuality, dispiritment, agitation, palpitation, low CD56 and anxiety were the significant factors contributing to depression. More severe anxiety (49.7 +/- 7.5 vs 45.3 +/- 6.9, P<0.05), pain (6.5 +/- 2.8 vs 4.6 +/- 3.2, P<0.05), poor social support (6.8 +/- 2.0 vs 7.6 +/- 2.1, P<0.05), as well as decline of lymphocyte count (0.33 +/- 0.09 vs 0.39 +/- 0.87, P<0.05) and CD56 (0.26 +/- 0.11 vs 0.29 +/- 0.11, P<0.05) were noted in the depression group compared with those of the non-depression patients. However, fewer obvious changes in CD4/CD8 ratio and other immunological parameters were found between the two groups.

Depression occurs with a high incidence in patients with cancers of the digestive tract, which probably is not the sole factor leading to the impairment of immunological functions in these cases. However, comprehensive measures including psychological support should be taken in order to improve the immunological function, quality of life and clinical prognosis of these patients.