In 111 patients with ACC we studied CEA, FP, CA-125 and CA 19.9 during therapy and follow-up. Marker determination was performed every two months. CEA was elevated (> 5 ng/ml) in 82%, alpha FP (> 15 ng/ml) in 0%, CA-125 (> 38 U/ml) in 37%, CA 19.9 (> 30 U/ml) in 64% of the patients. We did not find significant differences between the sensitivity of CEA alone and that of the combination of CEA + CA-125 (86%), CEA + CA 19.9 (87%), CA-125 + CA-19.9 (71%) and CEA + CA-125 + CA 19.9 (88%). We did not find any correlation between the level of positivity of the markers and the clinical parameters we examined. When serial determinations were carried out, CEA showed the best indication of response to treatment, followed by CA 19.9. In the evaluation of the response to chemotherapy we found that CA 125 presented significant percentages of false-positive (9%) (P < 0.008) and false-negative (8.1%) (P < 0.008) results, compared to CEA and CA 19.9. CA 125 did not demonstrate any utility for the follow-up of patients with colorectal cancer although increased values were found in 37%. We conclude that CEA is currently the best marker for the follow-up of patients with colorectal cancer. The combination of CEA and CA 19.9 had some utility in follow-up, without significantly improving CEA results.

We tried to study the protection of allopurinol (HPP) from the toxicity of 5-fluorouracil (5-FU). A total of 29 patients received 74 cycles of chemotherapy (16 colon adenocarcinomas, 7 head and neck, 3 breast cancers and 3 cancers of pancreas). HPP was given 900 mg/day p.o. 4 days prior to treatment, and continued with same dose throughout the course of 5-FU and for 12 days after completion of the treatment. 5-FU was administered in 24 hour intravenous infusions on days 1–5 (dose range 900–1,200 mg/m²/day). 5-FU was given alone or in combination with mitomycin-C 10 mg/m²/day (1st day), epirubicin 40 mg/m²/day (1st, 2nd day), cis-platinum 120 mg/m²/day (1st day). In comparison with other studies the toxicity was limited. We conclude that HPP can diminish the side effects, especially myelosuppression, allowing an increase in the maximum tolerated dose of 5-FU, even if combined with other cytostatic drugs. Control studies must be done to confirm our observations.