Screening for colorectal cancer: present, past and future

Review of the evidence for a colorectal cancer screening programme in elderly people

Colorectal cancer is a major public health issue, contributing to 16,000 UK deaths per year, most of these in the elderly population. A new NHS screening programme for colorectal cancer in people over 60 is being introduced across the country throughout 2009. The aim of this research was to review the current literature on colorectal cancer screening and determine how much of the evidence for screening is applicable to elderly people. MEDLINE database was searched for articles published between 1990 and 2007, using search terms of colorectal neoplasms, mass-screening, faecal occult blood, colonoscopy and sigmoidoscopy. Articles for inclusion were limited to those in English and those including older adults. The results showed that evidence for colorectal cancer screening in general has been well researched. However, little was found specifically on screening for elderly people, or looking at the different benefits and limitations in older people compared to younger people. Very few health agencies suggested an upper age limit for screening. In conclusion, there is very little research on screening for colorectal cancer specifically in elderly people, although many health authorities advise such screening. The health needs of an older population are different to those of middle-aged people and at present the screening programmes do not appear to reflect this.

Modeling and optimization in early detection programs with a single exam

The choice of timing of screening examinations is an important element in determining the efficacy of strategies for the early detection of occult disease. In this article, we describe a flexible decision-making framework for the design of early detection programs, and we investigate the choice of timing when each individual in the screening program is examined only once. We focus on the theoretical relation between the optimal examination time and the distributions of sojourn times in health-related states. Specifically, we derive closed-form solutions of the optimal age using two specifications of utility functions, discuss the effects of natural history and utility specifications on the optimal solution, and present an application to early detection of colorectal cancer by once-only sigmoidoscopy or colonoscopy.

Long-lasting reduction of risk of colorectal cancer following screening endoscopy

Several studies have suggested that incidence and mortality of colorectal cancer (CRC) may be strongly reduced for up to 10 years by endoscopic screening with removal of precancerous lesions, but so far there are no data on risk reduction beyond this period. We assessed long-term reduction of CRC risk following screening endoscopy in a statewide population-based case-control study in Saarland, Germany. Lifetime history of screening endoscopy was compared between 320 cases with CRC aged 45-80 and 263 controls with other forms of cancer recruited from the same population. Potential confounding factors were controlled for by multiple logistic regression. 11% of cases compared to 27% of controls had a history of endoscopy for screening purposes (adjusted odds ratio (OR) = 0.28, 95% confidence interval (CI): 0.16-0.48). This strong risk reduction was also seen (OR = 0.41, 95% CI: 0.19-0.89) in subjects who had their last screening endoscopy more than 10 years ago (median: 18.9 years). Long term (> 10 years since last screening) risk reduction appeared to be particularly strong for advanced (Dukes C or D) CRC (OR = 0.19, 95% CI: 0.06-0.64). We conclude that risk reduction by screening endoscopy is long lasting, in particular with respect to advanced CRC.

Early detection for colorectal cancer: new aspects in fecal occult blood screening

The authors report on promising diagnostic methods of occult intestinal bleeding and discusses the potential new strategy of early detection of colorectal carcinomas in respect to old and new diagnostic measures available. Because of the limited sensitivity and specificity of classical methods used for the demonstration of occult fecal blood, the authors recommend the introduction of new techniques and markers in screening practice. It is presumed that new discoveries in molecular biology will improve the accuracy of early colorectal cancer prevention. Their implementation into routine screening, however, will not take place in the near future. Until their realization, improved screening efficacy is expected from the use of more specific and sensitive blood tests.

Cancer surgery: the last 25 years

Surgery is, and always has been, the main treatment modality of solid tumours. For a long period, it consisted of a number of surgical procedures dictated by basic oncologic principles, most of which are still adhered to. Over the last few decades, increased understanding of the disease, new or improved diagnostic facilities, novel and perfected adjuvant treatments, improved surgical techniques and daring challenges to established dogmas have all contributed to the development of surgical oncology. The heritage from the past came under close scrutiny, and the fruits of basic and clinical science were added to an ever expanding body of knowledge. It is impossible to review all developments in surgical oncology of the last 25 years in one comprehensive paper. Therefore we have restricted ourselves to those items that appear most representative for the changes that have taken place, and those diseases that have the greatest numerical impact.