Adverse cardiac effects during induction chemotherapy treatment with cis-platin and 5-fluorouracil

Ventricular late potentials: another expression of cardiotoxicity of cytostatic drugs in children?

With the aim of finding a sensitive method to detect early anthracycline-induced myocardial damage ultimately resulting in cardiomyopathy, we studied the occurrence of ventricular late potentials, using a signal averaged electrocardiogram, in 68 children with cancer during or after chemotherapy. Ten (15%) of the children showed late potentials; in addition, patients treated with cytostatic drugs had significantly lower voltages of the last 40 ms of the QRS complex (RMS40) and a longer duration of low amplitude signals in the terminal QRS (LAS) than control patients. The occurrence of late potentials was not significantly correlated with anthracycline therapy or dosage, nor with the presence of echocardiographic abnormalities; in none of the patients we found late potentials during therapy with anthracyclines. We therefore conclude that late potentials are not helpful for early detection of myocardial injury. The occurrence of late potentials, however, does show another expression of cardiotoxicity not specifically related to anthracycline therapy. The occurrence of these late potentials may have prognostic significance with regard to the risk of ventricular arrhythmias during longer follow-up of these patients.

Cardiotoxicity of commercial 5-fluorouracil vials stems from the alkaline hydrolysis of this drug

The cardiotoxicity of 5-fluorouracil (FU) was attributed to impurities present in the injected vials. One of these impurities was identified as fluoroacetaldehyde which is metabolised by isolated perfused rabbit hearts into fluoroacetate (FAC), a highly cardiotoxic compound. FAC was also detected in the urine of patients treated with FU. These impurities were found to be degradation products of FU that are formed in the basic medium employed to dissolve this compound. To avoid chemical degradation of this antineoplastic drug, the solution of FU that will be injected should be prepared immediately before use.

Cisplatin and 5-FU combined with radiotherapy and surgery in the treatment of squamous cell carcinoma of the esophagus. Palliative effects and tumor response

The combination of cisplatin (90-120 mg/m2) and 5-fluorouracil (5-FU) (1,000 mg/m2/day in continuous infusion for five days) was given for 2-3 cycles, prior to combined radiotherapy and surgery, to 73 patients with esophageal squamous cell carcinoma, 60 with limited disease (LD), and 13 with extensive disease (ED) (i.e. with metastasis) of whom 3 had recurrent disease. Before preoperative radiotherapy among 60 LD patients, 12 (20%) had complete response, 21 (35%) partial response, 25 (42%) had stable disease, and 2 (3%) progressive disease. Swallowing was improved in 35/73 (48%) of the cases. In the resected specimens, no tumor was found in 8/53 (15%) of the cases, microscopic tumor in 18/53 (34%) and macroscopic tumor in 27/53 (51%). In the ED group, complete response of distant metastases was obtained in 6/13 (48%) of the patients, one of whom is still alive with no evidence of disease 62 months after the start of treatment.

Induction chemotherapy (cisplatin + 5-fluorouracil) and radiotherapy in advanced squamous cell carcinoma of the head and neck

A phase II study was made of 58 consecutive patients with previously untreated locally advanced squamous cell carcinomas of the head and neck. The induction chemotherapy consisted of 3 courses of cisplatin (100 mg/m2) and a subsequent 120-h infusion of 5-fluorouracil (1,000 mg/m2/24 h) repeated every 3 weeks. It was followed by radiotherapy to a median target dose of 66 Gy and surgery for residual tumour. A total of 91 per cent received all 3 courses of chemotherapy, which was well tolerated. Complete response (CR) was obtained in 20 patients (35%) after chemotherapy and in 40 patients (69%) after subsequent radiotherapy. The median observation time was 28 months (range 15-57). The actuarial survival at 2 years for complete responders to chemotherapy was 83 per cent, implying a prolonged survival (p = 0.002) compared to those with less than CR. Complete responders after chemotherapy had also a significantly longer recurrence-free survival, though 19 out of 20 did not undergo surgery. Complete response after this induction therapy is thus an important prognostic predictor.

Cardiotoxicity during chemotherapy treatment with 5-fluorouracil and cisplatin

Cardiotoxicity of 5-fluorouracil and cisplatin chemotherapy for esophageal, head and neck and gastric carcinoma was studied. Before treatment all patients had a cardiac evaluation and during treatment serial electrocardiographic (ECG) recordings were performed. In the pre-treatment evaluation signs of cardiovascular disease were found in 31(38.75%) patients. During treatment cardiotoxicity was observed in 12(15%) patients. The incidence of cardiotoxicity was not higher in patients with signs of cardiovascular disease than in those without in the pre-treatment evaluation. The most common signs of cardiotoxicity were chest pain, ST-T wave changes and arrhythmia. This study suggests that patients on 5-fluorouracil and cisplatin treatment should be under close supervision and that the treatment should be discontinued if chest pain and/or arrhythmias are observed.

Failure of preventing 5-fluorouracil cardiotoxicity by prophylactic treatment with verapamil

The most common cardiotoxic effects of 5-fluorouracil (5-FU) are chest pain and ischemic ECG abnormalities. Coronary vasospasm may be the underlying mechanism. If so, prophylactic treatment with calcium channel blockers might have a beneficial effect. In the present study, prophylaxis with verapamil (120 mg three times daily) was given to 58 patients with esophageal or advanced head and neck carcinoma during induction chemotherapy with cisplatin and continuous infusion with 5-FU. Signs of ischemia appeared in 12% of the patients as compared to 13% in a previously studied compatible group of patients not receiving prophylaxis. The study does not support the hypothesis that prophylactic treatment with verapamil reduces the incidence of ischemia in patients undergoing 5-FU treatment. Verapamil might, however, modify the adverse cardiac effects of 5-FU by preventing supraventricular tachyarrhythmia.