The UK's National Cancer Research Institute, a country-wide network of 23 cancer institutions covering the government, charity and industrial sectors, is ten years old this year. For seven of those years it has held an annual conference to showcase basic and clinical cancer research. The 2011 meeting, which opened yesterday (6 November) was the second to be held in the prestigious new BT Convention Centre in Liverpool's dockland. The opening session was quite a formal one, including the Cancer Research Award UK prize ceremony and presentation of the Cancer Research UK Lifetime Achievement in Cancer Research award to Chris Marshall of the Institute of Cancer Research for his work in cell signalling.

Dame Janet Husband, the NCRI's chair, was delighted to highlight one rather unusual aspect of a cancer research conference: an art exhibition. Two portrait artists had been invited to exhibit their work throughout the meeting. Harriet Barber, herself a breast cancer survivor, presented life drawings and paintings of 25 women in a similar situation, recruited from support groups near her home; Mark Gilbert presented portraits he had made during time as artist-in-residence at the Department of Oral and Maxillofacial Surgery at St. Bartholomew's and the Royal London Hospital, showing patients before, during and after surgery for tumours of the face.

The opening scientific session included contrasting plenary lectures by Hans Clevers of the Hubrecht Institute, Utrecht, The Netherlands and John Potter of the University of Washington, Seattle, USA and Massey University in New Zealand. Clevers used some stunning graphics to describe the mechanism through which the intestinal epithelium, the most rapidly self-renewing tissue in mammals, is formed from rapidly dividing stem cells in the base of intestinal crypts. These cells differentiate as they migrate out of the crypts onto the surface of villi; expression of the gene Lgr5 is necessary for stem cell activity.

The relevance of this elegant molecular and cell biology to the NCRI meeting, of course, lies in the fact that colon cancer originates with the stem cells in intestinal crypts. An early step in colon cancer formation is the loss of expression of the gene APC in these stem cells; APC- stem cells produce daughter cells that continue to proliferate without differentiation. Clevers described a group of interacting proteins in the Wnt signalling pathway, including Lgr5, that are essential for normal stem cell activity, and showed that co-culturing stem cells with Paneth cells, which neighbour them in the crypts, greatly improves their activity.

With Potter's talk, the focus moved from basic molecular biology to practical efforts to prevent cancer. The publication of a landmark report on nutrition and cancer in 1997 led to the now well known "five a day" rule for fruit and vegetable consumption. It was a small step from realising the role of these foods in cancer prevention to trials of natural products they contain as potential agents for chemoprevention. Yet almost all trials of these supplements have had disappointing results. Some were simply inconclusive, or showed no statistically significant effect. Others, however, seemed to show exactly the opposite result to the one they had been set up to prove. Beta-carotene, for instance, is, as its name implies, found in carrots, and was quite reasonably suggested as a source of the nutritional value of that vegetable. Yet several large trials have shown an undoubted increase in cancer risk in groups of high-risk subjects taking beta-carotene supplements compared to placebo.

Potter concluded that there are no single-agent supplements that have been shown to decrease cancer risk. There are ways of minimising cancer risk, however: the well-known and predictable set of good habits. Promoting a diet high in fruit and vegetables and low in fat, exercise and smoking cessation will not make anyone rich but it will, undoubtedly, prevent cancer. It might have been interesting to follow delegates through the reception and trade exhibition that followed the plenaries to see if they kept Potter's advice in mind.