Serum immunoglobulins in colorectal cancer.

Serum immunoglobulins (IgG, IgA and IgM) were measured in 75 patients with colorectal carcinoma. The levels of all three immunoglobulins were significantly higher in patients with recurrent colorectal carcinoma compared to those with resectable Duke's B or C colorectal carcinoma, particularly for IgM which was elevated above the normal range in 23 of 55 patients (41.8%). In recurrent disease there was no difference in serum immunoglobulin levels for multiple compared to single metastatic sites, or for patients with heaptic metastases compared to those with non-hepatic metastases. In recurrent colorecial carcinoma, serum alkaline phosphatase was normal in 23 of 55 patients, and serum IgM was elevated in 12 of these 23 patients. Serum carcinoembryonic antigen was normal in 3 of 18 patients, and serum IgM was elevated in two of these three patients. In patients who have had a colorectal cancer resected measurement of serum immunoglobulins, in combination with other screening tests, may be of value in the diagnosis of recurrent disease.