Tumour markers: Importance in Asia’s health monitoring

Asian countries in general and China and India in particular, have been countries of economic interest for the last few years. Economic development has encouraged lifestyle changes which have resulted in a shift in disease prevalence more typically seen in richer Western Countries. With improved sanitation, widespread availability of antibiotics and immunization, there has been a drop in communicable disease incidence and a corresponding rise in the incidence of non communicable diseases such as cancer suspected to be due dietary changes, increased sedentary lifestyle, and exposure to pollution amongst other factors. China has seen the pronounced shift at relatively faster rate than India consistent with the more advanced stages of economic development.

Cancer claimed the lives of approximately 7.9 million people worldwide in 2007 (13% of all deaths), according to World Health Organization. A substantial majority of experts have converged upon the view that the optimal cancer management practice that offers the greatest potential to saves lives, is inevitably, early detection of cancer. Early detection of cancer enables a higher probability of effective treatment options prior to the spread or metastasis of the tumour at which point organ damage is usually irreversible and treatments become substantially more burdensome on the patient in terms of adverse side effects. This article will introduce the growing importance of tumour markers and the tale they tell of the economy.

Clearstate Pte. Ltd, a Singapore based healthcare consultancy has conducted nationwide studies in China and India on the volume of tumour marker tests carried out in hospitals and laboratories in both countries.

The report indicates that tumour marker CA-125 has recorded highest number of tests performed for both India and China. CA-125 is a mucinous glycoprotein and is known to be elevated in ovarian cancer patients (80% chance of returning a true positive in ovarian cancer patients). Its current usage is early detection followed by monitoring treatment response or recurrence of the cancer. Although ovarian cancer is the second leading gynaecological cause of death in women, after breast cancer, it is not a leading cancer in China and India. Despite this the study shows that many Chinese and Indian women have been advised by their physicians to undergo CA-125 tests.

Another particular marker of interest would be total PSA tests; a tumour marker used for screening for prostate cancer in men. Prostate cancer is known to be more common in developed countries due to dietary factors and longer life span. Based upon these factors alone expectation would suggest China, being a more developed country, to have recorded a higher number of total PSA tests carried out. However, India recorded 100% more total PSA tests carried out than China.

Tumour markers CA19-9 and CA15-3, used for early detection of colon cancer and breast cancer respectively are both reported at significant higher percentages performed in China as compared to India. The increased performance of both of these tumour marker tests also continue to demonstrate the trends seen in more developed economies as colon cancer and breast cancer have been postulated to be associated with dietary factors, in particular obesity, high alcohol intake and diabetes; traits that are seen more commonly in developed nations. Specifically CA15-3, which is used to monitor response to treatment of breast cancer have been associated with women who have children at a later age and the prolonged intake of birth control pills, very much applicable to China and the ruling of one child per family in the country.

Another tumour marker that is worth the mention is pepsinogen I/II. There have been studies suggesting the usage of pepsinogen I/II as a screening test for and a monitor of recurrence to stomach cancer. Stomach cancer is highly prevalent in countries like Japan, Korea and China with half the global death toll for stomach cancer accounted in China, a startling proportion, what with stomach cancer being recorded as world’s second most common cause of cancer death. The incidence rate of stomach cancer in China is approximately 90.9 per 100 000 population.

Reflecting the high prevalence rate of stomach cancer in East Asian countries, there is the likelihood of substantial growth in pepsinogen I/II testing in the years to come.

Tumour markers will continue to play a critical role in the screening and monitoring of cancer. There will continue to be substantial investment in the development of other promising biomarkers as well. With the persistent trend towards preventive medicine as oppose to the traditional reactive medicine, this sector is anticipated to experience high growth rates in the near future.