Stage-related correlations between immunoglobulins and complement components in preoperative sera from patients with gastric carcinoma

Pre-operative plasma levels of C-reactive protein, albumin and various plasma protease inhibitors for the pre-operative assessment of operability and recurrence in cancer surgery

Pre-operative levels of the acute phase protein C-reactive protein (CRP), albumin (assessing nutritional status), the tumour marker CEA and three plasma protease inhibitors, i.e. C1-esterase inhibitor, alpha-2-macroglobulin and antithrombin III, were prospectively studied in 183 patients with various solid cancers. First, the predictive value of abnormal levels for operability at the primary operation was studied. Secondly, the predictive value of abnormal levels for cancer recurrence and metastases was evaluated during 2 years of follow-up. The results show that malignancy induces increased CRP and C1-esterase inhibitor levels and decreased albumin levels in serum. These changes, as well as raised alkaline phosphatase and lowered haemoglobin levels, also correlate to the 'overall' tumour burden. The most important conclusion is, that increased pre-operative CRP levels (CRP > or = 10 mg/l; sensitivity, 79%; specificity, 71%) and/or low albumin levels (albumin <37 g/l; sensitivity, 94%; specificity, 54%) are seen in inoperable cancer patients compared with patients having operable cancers. The second main important conclusion is, that high pre-operative C1-esterase inhibitor levels (C1-esterase inhibitor >152%; sensitivity, 45%; specificity, 90%), and in some patients a high alkaline phosphatase level, are seen in patients exhibiting early cancer recurrence (within 2 years post-operatively).

The influence of the host on the course of gastric carcinoma

Immunoglobulins (Ig) and some complement components (C) were quantified in sera from patients with gastric carcinoma before surgery and at regular intervals during a 5-year follow-up. The preoperative concentrations of C1-INH and C4 were higher (P < 0.0005 and P < 0.005) and IgG lower (P < 0.0005) in 50 patients with recurrence than in 46 5-year survivors. The prognostic significant of C1-INH was superior to that of the extent of disease (F-values 37.1 and 26.1). The preoperative immune data classified 76% of the patients correctly as to recurrence and no recurrence. Also, the preoperative C1-INH concentration had a highly significant effect on time to recurrence of cancer (P = 0.0007), adjusting for age and disease extent. After surgery the mean IgG concentrations were within normal range and without difference between the two groups. On the other hand, the concentrations of C1-INH and C4 in the individual patients in both groups remained the same from before to after surgery and throughout the observation period (P = 0.34). Apparently, the serum levels of C1-INH and C4 do not reflect the bearing of cancer. We therefore suggest that these variables represent an independent immune state that is appropriate to the host. A comparison of our variables with those of healthy individuals seems to support this idea. This immune state has a significant influence on whether a resected gastric cancer will recur, and also on how soon recurrence may be manifest.

Serum C1-esterase inhibitor, an essential and independent prognosticator of gastric carcinoma

The preoperative concentrations of IgG were lower (P less than 0.002) and the concentrations of C4 and C1-INH higher (P less than 0.01 and P less than 0.001) in 29 patients with recurrence after potentially curative resection of gastric carcinoma, than in 31 patients alive and disease-free 5 years after surgery. These differences between the two groups of patients were consistent within each of six groups of disease extent. In each of the two groups of patients, the preoperative concentrations of IgG, C4 and C1-INH had no significant variation with the extent of disease (P greater than 0.05 or greater). Of our variables, C1-INH was the most potent prognosticator and discriminated between patients with and without recurrence with 80% accuracy. Furthermore, the predictive prognostic value of C1-INH at the time of surgery was superior to the prognostic value of the extent of disease (F values 27.00 and 12.69). Apparently, the preoperative C1-INH concentration is an essential and independent prognostic parameter of gastric carcinoma. We assume that C1-INH reflects an additional prognostic feature appropriate to the tumour or the host. Our finding that the interval between surgery and death from recurrence had an inverse relation to the preoperative C1-INH concentration also supports this assumption.

Plasma levels of secretory IgA in patients with gastric cancer

The levels of plasma secretory IgA were measured in patients with gastric cancer and found to be slightly higher (9.6 +/- 6.2 micrograms/ml) than those in healthy controls (7.0 +/- 2.6 micrograms/ml, 0.05 less than P less than 0.1). Secretory IgA levels in those with hepatic metastases (19.7 +/- 12.2 micrograms/ml) were significantly higher than those in patients without hepatic metastases (P less than 0.001). In the latter, there was no significant relationship between plasma secretory IgA levels and the deepest layer of cancerous invasion or lymph node metastases. The secretory IgA levels in cases of well differentiated tubular adenocarcinoma were significantly higher than those with poorly differentiated adenocarcinoma (P less than 0.05). Although there is small diagnostic value in the detection of gastric cancer by measuring the levels of secretory IgA, high levels of secretory IgA in gastric cancer patients may be indicative of the presence of hepatic metastases.