Until recently, there had only been one drug, 5-fluorouracil, to treat colorectal cancer but now there were three possibilities, said Dr David Cunningham (consultant medical oncologist, Royal Marsden hospital, London) on September 28. Speaking at a press conference marking the launch of Sanofi-Synthelabo's oxaliplatin (PJ, September 25, p504), Dr Cunningham said that the drugs were 5-fluorouracil and oxaliplatin (both licensed for first-line treatment of metastatic colorectal cancer) and irinotecan (introduced in 1997, with a licence for use where fluorouracil treatment has failed). This allowed different regimes to be used if one treatment was ineffective. However, further trials were needed to determine the order in which they should be used. The best order "remains to be seen".
Professor Andrew Miles (director of health services research, St Bartholomew's hospital, London) said that colorectal cancer accounted for 12 per cent of all cancer deaths in the UK, a figure second only to lung cancer. In 1997, there were 17,349 deaths in the UK as a result of colorectal cancer.
Dr Graham Hornett (general practitioner, Guildford, Surrey) said that it was difficult to see how funding for oxaliplatin would be found. Professor Miles said that only 1 per cent of the total NHS drug bill was spent on chemotherapy. This resulted in UK cancer survival rates inferior to those in the rest of Europe. The funding of oxaliplatin would be decided on a district and not national level.
Dr Clare Topham (consultant clinical oncologist, Royal Surrey County hospital) reported the results of a phase III randomised trial of oxaliplatin in 420 patients across Europe. Patients with metastatic colorectal cancer were given 5-fluorouracil plus folinic acid or oxaliplatin plus 5-fluorouracil/folinic acid. The addition of oxaliplatin gave a doubling of response rate. It also gave an increase in the progression-free survival time from six months to 8.2 months. The drug's main side effect was neurotoxicity, specifically cold-related dysaesthesia and paraesthesia.
Dr Topham said that oxaliplatin was a platinum compound which formed inter- and intra-strand crosslinks in DNA, inhibiting DNA synthesis. Discussing why oxaliplatin was effective for the treatment of colorectal cancer, while other platinum anticancer agents (cisplatin and carboplatin) were not, Dr Cunningham said that it could be related to the large size of the oxaliplatin molecule. Professor Jim Cassidy (professor of oncology, Institute of Medical Sciences, Aberdeen) added that cells were unable to repair the damage that oxaliplatin caused. Sanofi-Synthelabo says that studies are being conducted to test oxaliplatin's efficacy in treating other solid tumours.
Professor Cassidy emphasised that surgery was the treatment of choice for colorectal cancer. Chemotherapy could be used as an adjuvant to surgery to reduce the possibility of relapse or, where metastatic disease was already present, as a palliative treatment with the aim of reducing symptoms and prolonging life.