Background: Mid-gut carcinoid tumours often present with liver metastases, and survival has then been less than 2 years in earlier reports. We have evaluated the effects of interferon therapy on clinical response and survival, with or without hepatic artery embolization in these patients.
Methods: In a prospective study 30 female and 12 male patients, aged 23 to 75 years, with mid-gut carcinoid tumours and liver metastases underwent surgery with removal of as much as possible of their primary tumour. If technically feasible, embolization of hepatic arteries was performed in the absence of contraindications. Seventeen patients were embolized, and all patients received interferon-alpha 2b treatment for 1 year. Response factors were computer tomography (CT) measurement of the largest liver metastasis and the 24-h urinary excretion of 5-hydroxyindoleacetic acid (5-HIAA). After 12 months patients with objective response or stable disease either continued or withdrew from interferon therapy. Survival was estimated when all patients had been observed for at least 36 months.
Results: Nine patients reduced the dose, and five withdrew from interferon treatment owing to side-effects the 1st year. Three patients died. Fifteen patients (39%) showed objective response 12 months after inclusion. Cumulative 5-year survival estimated from inclusion was 37.5% in all 42 patients but 71.4% in those who continued interferon therapy. The difference in survival between the interferon-treated and those who withdrew from interferon therapy at 12 months was significant when embolization was corrected for in a Cox model (p < 0.0125). The seemingly increased survival in embolized versus non-embolized patients did not reach statistical significance (p = 0.07).
Conclusion: Interferon induced an objective response in mid-gut carcinoid patients as judged by the 24-h urinary 5-HIAA excretion. Patients receiving continuous interferon therapy showed improved response and survival compared with patients who stopped the treatment. Regardless of medical therapy, more survivors and more responders, as evaluated from CT measurements, were found among the embolized patients than among the non-embolized. Embolization could, however, not be shown to have a significant effect on survival.