Cancer is a major health problem in developing countries, in many of which it is the second most common cause of death behind cardiovascular disease for all ages combined, and it will become of increasing importance in developing countries in the future as well. All of the major malignancies primarily affect the elderly, and the incidence of most common cancer types as well as of all tumors combined sharply increases with age.
The incidence of cancer at different sites shows extreme variations between populations and also strongly varies over time within populations. Furthermore, migrant studies have shown that migrants adopt cancer rates of the countries they are going to. Taken together, these patterns strongly support a major role of environmental, cultural and behavioral factors for the occurrence of different types of cancer. Although genetic factors undoubtedly also play a role, hereditary forms of cancer often account for small fractions of cancers only.
Prognosis of cancer patients strongly varies by cancer site, with 5-year survival rates ranging from almost 0% for patients with pancreatic cancer to almost 100%, for example, for patients with thyroid and prostate cancer, in some developed countries (Brenner, 2002; Brenner and Arndt, 2005). However, even for cancers of the same site, there is often strong variation of prognosis according to stage at diagnosis. For example, 5-year survival for patients with colorectal cancer nowadays exceeds 80% for patients with localized cancer, whereas it remains as low as 10% for patients with distant tumor spread. For that reason, there is much hope that the cancer burden can be strongly reduced by effective early detection programs. For some forms of cancer, such as cancer of the uterine cervix, early detection programs have been shown to be very effective indeed in lowering mortality. For other forms of cancer, such as colorectal cancer and breast cancer, the effectiveness of early detection measures has been demonstrated or is currently being assessed in large-scale clinical trials, and their implementation is likely to contribute to major reductions in mortality.
At the same time, progress in therapy will also continue to reduce cancer mortality. It certainly has contributed to major increases in survival of patients with a variety of cancers, including cancers of the breast, colon and rectum, testis and thyroid. Unfortunately, however, improvements have often been less pronounced for older adults, so that the age gradient in survival, which exists for many forms of cancer, has further increased in recent years (Brenner and Arndt, 2004). This is not too surprising, though, since older age groups, despite accounting for the majority of cancer patients, have often been and continue to be excluded from clinical trials evaluating new therapies (Hutchins et al., 1999), and older patients less often receive effective therapy (Bouchardy et al., 2003). With increasing expectations of survival, quality of life will become more and more important as an outcome measure for patients with cancer (Arndt et al., 2004 and 2005).
Probably the most powerful tool for reducing the cancer burden in the elderly would be primary prevention. For example, it is well established by large-scale epidemiologic studies that at least 20% of all cancers and more than 90% of lung cancers are attributable to smoking and could be prevented by reducing or eliminating this most harmful habit in the population. There also seems to be a large potential to reduce the cancer burden by a diet that is rich in vegetables and fruits. Although these facts have been well known for a long time, progress in primary prevention is slow and even absent in many countries of the world. Given the long latency period between tumor initiation and clinical cancer manifestation, primary prevention measures need to start early in life; many cancers in the elderly could be best prevented by primary prevention in childhood, adolescence and early and middle adulthood.
Was this article helpful?
Learning About 10 Ways Fight Off Cancer Can Have Amazing Benefits For Your Life The Best Tips On How To Keep This Killer At Bay Discovering that you or a loved one has cancer can be utterly terrifying. All the same, once you comprehend the causes of cancer and learn how to reverse those causes, you or your loved one may have more than a fighting chance of beating out cancer.