Disparities in breast cancer mortality trends between 30 European countries: retrospective trend analysis of WHO mortality database

Why victory in the war on cancer remains elusive: biomedical hypotheses and mathematical models

We discuss philosophical, methodological, and biomedical grounds for the traditional paradigm of cancer and some of its critical flaws. We also review some potentially fruitful approaches to understanding cancer and its treatment. This includes the new paradigm of cancer that was developed over the last 15 years by Michael Retsky, Michael Baum, Romano Demicheli, Isaac Gukas, William Hrushesky and their colleagues on the basis of earlier pioneering work of Bernard Fisher and Judah Folkman. Next, we highlight the unique and pivotal role of mathematical modeling in testing biomedical hypotheses about the natural history of cancer and the effects of its treatment, elaborate on model selection criteria, and mention some methodological pitfalls. Finally, we describe a specific mathematical model of cancer progression that supports all the main postulates of the new paradigm of cancer when applied to the natural history of a particular breast cancer patient and fit to the observables.

Rational and irrational issues in breast cancer screening

Evidence on the efficacy of breast screening from randomized controlled trials conducted in the last decades of the 1900s is reviewed. For decades, controversy about their results has centered on the magnitude of benefit in terms of breast cancer mortality reduction that can be achieved. However more recently, several expert bodies have estimated the benefits to be smaller than initially expected and concerns have been raised about screening consequences such as over-diagnosis and unnecessary treatment. Trials with substantial mortality reduction have been lauded and others with null effects have been critiqued. Critiques of the Canadian National Breast Screening Study are refuted. Extreme responses by screening advocates to the United States Preventive Services Task Force 2009 guidelines are described. The role vested interests play in determining health policy is clearly revealed in the response to the guidelines and should be more generally known. A general reluctance to explore unexpected results or to accept new paradigms is briefly discussed.

Effective biennial mammographic screening in women aged 40-49

BACKGROUND

The United Kingdom is currently moving the age limit for invitation in its national breast screening programme downwards from 50 to 47. In contrast, the US Preventive Services Task Force concluded that, because of borderline statistical significance on effectiveness of mammographic screening, the current evidence is insufficient to advise screening in women aged 40-49.

MATERIAL AND METHODS

We designed a case-referent study to investigate the effect of biennial mammographic screening on breast cancer mortality for women in their forties. In Nijmegen, the Netherlands, screening started in 1975. A total of 272 breast cancer deaths were identified, and 1360 referents aged 40-69 were sampled from the population invited for screening. Effectiveness was estimated by calculating the odds ratio (OR) indicating the breast cancer death rate in screened versus unscreened women.

RESULTS

In women aged 40-49, the effect of screening was OR = 0.50 (95% confidence interval (CI) = 0.30-0.82). This result is similar to those aged 50-59 (OR = 0.54; 95% CI = 0.35-0.85) and 60-69 (OR = 0.65; 95% CI = 0.38-1.13).

CONCLUSION

Our results add convincing evidence about the effectiveness of biennial mammographic screening in women aged 40-49.