Recent advances in systemic therapy involve the biochemical modulation of fluorouracil. New trials combining either leucovorin or N-(phosphonoacetyl)-L-aspartate (PALA) with fluorouracil have demonstrated increased response rates. Recent trials of interferon-alpha with fluorouracil have not confirmed the high response rates reported in previous trials. Advances in regional therapy include the addition of either leucovorin or systemic therapy to fluorodeoxyuridine. Some adjuvant trials of portal vein infusion have shown increased survival, though the incidence of liver metastases was not decreased. A large adjuvant trial in rectal cancer demonstrated improved survival and decreased local recurrences when fluorouracil and methyl-CCNU were added to radiation therapy.
