Fighting chance

He seemed to be doing everything right for a healthy life: he did not drink or smoke, and had been running and swimming every day for the past decade. But Lai, 46, a policeman, was diagnosed with first-stage nasopharyngeal cancer in 2006.

The next two months of radiotherapy went well, destroying all his cancer cells. But seeing people around him suffer a relapse after successful treatment, Lai is worried the cancer will strike again.

'A colleague of mine got his nasopharyngeal cancer successfully treated in 2006, but it spread to his lungs in 2011,' he says.

But recent advances in cancer vaccines provide hope for Lai and millions of other sufferers worldwide. Immunotherapy, in particular, holds promise. Oncology experts are manipulating cancer-causing viruses to develop vaccines that trigger the immune system to attack cancerous cells.

Globally, a host of cancer vaccines are in the pipeline. According to a University of Michigan Health System report published in November, the types of cancer with the highest number of active clinical trials worldwide last year were melanoma (40), breast (34), lung (30), prostate (22) and brain (20). Unlike common vaccines for diseases such as polio and measles, which are given to healthy people for lifelong immunity, these vaccines are for those already afflicted with cancer.

Professor Anthony Chan Tak-cheung, director of the Hong Kong Cancer Institute and the Sir Y.K. Pao Centre for Cancer at Chinese University, is at the forefront of research on using the Epstein-Barr virus (EBV) to treat nasopharyngeal cancer, which strikes 1,000 new victims every year in Hong Kong.