Does biomodulation of 5-fluorouracil improve results?

Optimal duration of a first-line palliative chemotherapy in disseminated colorectal cancer - a review of the literature from a developing country perspective

We still do not know whether the presently used protocol of the first-line palliative treatment of disseminated colorectal cancer (FOLFOX/FOLFIRI protocol) allows maximization of therapeutic response and minimization of side effects. No-one has verified whether continuation of the first-line chemotherapy despite the lack of progression is reflected by improved prognosis or significant risk of toxicity. This issue is of vital importance in the case of developing countries where targeted therapies are not available due to financial shortages. We have identified three potential strategies of the palliative therapy of disseminated colorectal cancer: 1) discontinuation of chemotherapy after a fixed number of cycles with its restart on progression (stop-and-go strategy), 2) intermittent protocol of chemotherapy, and 3) continuation of chemotherapy with discontinuation of the most toxic agent. None of the studies proved the superiority of the most commonly used standard, i.e. 12 cycles of the FOLFOX or FOLFIRI regimen. Although longer duration of this treatment may be associated with higher response rates and longer progression-free survival, these improvements frequently prove insignificant on statistical analysis.

Systemic chemotherapy of liver tumors

Primary and secondary liver tumors have a reputation for being resistant to chemotherapy and, in the absence of surgical resection, rapidly fatal. Until recently, such a reputation was well justified: response rates above 20% were not seen, and complete responses were distinctly rare. Over the past 5 years, the mood of those in the field has become rather more optimistic and a pattern of effective therapy is emerging. This involves combination therapy in patients with unresectable disease to increase the operative rates, and postoperative adjuvant therapy to decrease the high relapse rate which is so characteristic of both primary and secondary liver tumors. In the case of hepatocellular carcinoma, the combination therapy involves cytotoxic drugs and interferon. With secondary colorectal cancer (CRC), the combination of 5-fluorouracil (FU) and leucovorin, together with one of the new cytotoxic agents such as oxaliplatin or irenotecan, is producing much higher response rates and prolonged survival, and permitting a higher resection rate. Postoperative treatment is also showing promise in decreasing the relapse rate. With CRC metastatic to the liver, this involves hepatic artery infusion (HAI), systemic 5-FU, and leucovorin. Adjuvant systemic therapy of HCC has not yet been widely tested, but success with locoregional lipiodol iodine131 is proof of principle. The coming decade should see a significant improvement in the outlook of patients with malignant liver tumors as multimodality treatment becomes more widely investigated and practiced.

Achievements and future of chemotherapy

Although surgery and radiotherapy result in a cure in 40% of all cancer patients, the remaining 60% of the patients die as a result of metastatic disease. For those patients cancer has to be considered as a systemic disease and cure from cancer will likely come from some type of systemic treatment. This article gives a brief overview of the achievements in the development of chemotherapy over the last 50 years and the new potential targets for further drug development.