Cancer develops when cells begin to grow and spread uncontrollably throughout the body, as is often referred to as a malignant tumour. After invading surrounding tissues, cancerous tumours spread to different parts of the body and other organs with almost every part of the body as susceptible to cancer. According to the latest cancer statistics in Hong Kong, colorectal cancer has already surpassed lung cancer as the most common type of cancer, accounting for 17.3% of all cancer cases, pushing breast cancer back to the third most common cancer. In 2016, 31,468 new cancer cases had been recorded in Hong Kong, representing an increase of 3.8% and 1,150 cases from 2015^[1].

As cancer has become increasingly prevalent, great strides have been made in cancer treatment, thanks to the advances in medical technology. Early detection of cancerous tumours now enables more timely treatment through medical surgery, radiotherapy or chemotherapy that destroys cancer cells and facilitates full recovery. Taking lung cancer as an example, early-stage lung cancer, with appropriate treatment, can now achieve a survival rate of around 90%^[2]. For patients diagnosed with late-stage cancers, the increase in innovative treatments such as targeted therapy and immunotherapy have proven to effectively prolong their lives.