Locally Advanced Primary and Recurrent Rectal Cancer : Surgical experience after Multimodality Treatment at the Norwegian Radium Hospital

GENERAL INTRODUCTION Epidemiology of rectal cancer Colorectal cancer is one of the most common cancers in Norway. The incidence rate is highest in North America, Australia/ New Zealand and Western Europe. In 2006 1686 new tumours of colon, rectum and anus were diagnosed in Norway in males and 1767 in females. 569 men and 435 women were diagnosed this year with adenocarcinomas less than 20 cm from anal verge1. Cancer incidence has been monitored in Norway since 1953. Data (2006) from the Cancer registry of Norway shows an age-adjusted incidence rate (per 100 000) of 14.0 for males and 9.3 for women (Cancer Registry of Norway 2007). Over the last 50 years there has been an increase in incidence but the rate of annual increase has slowed recently. Colorectal tumours may be divided into proximal and distal tumours in relation to the splenic flexure due to different biological and clinical characteristics identified in the lesions of proximal and distal colon (Bufill 1990). Distal tumours are in the majority of cases aneuploid, rarely display microsatelite instability, but contain a higher frequency of allelic losses and mutations in the p53 gene and KRAS mutation in 20-30% of patients (Lothe et al. 1993). At the end of 2006, 6.8% of the inhabitants in Norway were 75 years of age or older. The elderly will represent an increasingly larger proportion of the population of Norway in the next quarter of a century, predominantly as a result of prolonged life expectancy. In 2030 it is expected that 20% will be 65 years or older. Rectal cancers diagnosed in Norway 1997-2001 have a total 5-year relative survival rate of 58.5% in males and 60.5% in women (Larønningen 2008). This is more than a 50% improvement during the last 30 years