Liver cancer tumours found to differ across patients, prompts customised approach to treatment

SINGAPORE - Researchers from the National Cancer Centre Singapore (NCCS) and the Genome Institute of Singapore (GIS) have made a discovery that could transform the treatment of one of the world's most lethal cancers.

They found that the genetic characteristics of liver cancer tumours can vary widely, not only across different patients but also within a single tumour.

This suggests that treatment needs to be customised to each patient, a concept called precision medicine.

Until today, people have assumed that any given case of liver cancer was caused by a single type of genetic mutation, and have been wondering why Sorafenib, the standard drug used for liver cancer, has been ineffective in preventing recurrence in most patients after the tumour has been removed by surgery, said the researchers.

In fact, the tumour can contain several mutations - which differ widely across patients - and the key to successful treatment may lie in identifying and targeting those mutations responsible for recurrence.

This was not previously realised because the cancer has traditionally been diagnosed with a single biopsy, a procedure which extracts a single tissue sample from the liver.

GIS' Dr Zhai Weiwei, the study's lead author, likened it to the well-known analogy of touching one part of an elephant and thinking it is something else.

Only when the researchers examined slices of surgically removed tumours did they discover that tumours are more complicated than they seem. Their findings were published in February in the journal Nature Communications.

They are now looking for existing drugs used for other cancers that might work on liver cancer, since some of the mutations they found are also present in other cancers.

The study's principal investigator, NCCS' Professor Pierce Chow, said the study sets the scientific basis for clinical trials of new treatments, which he expects to take place within five years.

They are also expanding their study to more patients in collaboration with scientists in other Asia-Pacific countries, with funding from Singapore's National Medical Research Council, in the quest to collect more data to better understand and more effectively treat liver cancer across different ethnic groups.

Currently, if detected in its early stages, the median five-year survival rate for liver cancer is 65 per cent. It is the second deadliest cancer in the world, after lung cancer.