7
June 2005
Cancer
prevention: The Chinese University of Hong Kong and Hong Kong Cancer
Fund
collaborate on a screening and surveillance study on hepatitis B
virus carriers
for early detection of liver cancer
¡@¡@Liver cancer (hepatocellular carcinoma) is one of the most common
cancers in Hong Kong. It ranked as the 3rd commonest cancer in men.
Over the past 10 years, an average of 1,600 new cases are diagnosed
and 1,300 patients die each year.
¡@¡@Hepatitis
B virus, being the major cause of liver cancer in Hong Kong, contributes
to over 70% of all cases. Over 10% of our population are chronic
carriers of the hepatitis B virus and they are at risk of developing
cirrhosis and liver cancer. Carriers are at more than 100 folds
higher risk than non carriers. Majority of patients are asymptomatic
at the early stage of their illness and do not seek medical attention.
Consequently, when they present with symptoms, only 10 to 20% of
patients can undergo surgical resection with the prospect of cure.
The remainders are diagnosed at an advanced stage that curative
resection is not possible. Early detection holds the only promise
to improvement of survival for HCC patients.
¡@¡@"One
of our major work is to promote cancer awareness in Hong Kong through
large scale public education campaigns. This year we have organized
campaigns on cervical cancer, skin cancer, breast cancer as well
as an anti-smoking campaign. We also continue to fund cancer screening
programmes such as the hereditary colorectal cancer registry and
this liver cancer screening and surveillance study. All these efforts
are important as they could save lives. We are also bringing the
message to the public that they could cut their risk of getting
cancer by adopting a healthier lifestyle and be more aware of their
health in general," said Agatha Hu, Operations Director of The Hong
Kong Cancer Fund.
¡@¡@The
Department of Clinical Oncology of The Chinese University of Hong
Kong received a competitive grant from the Hong Kong Cancer Fund
in 1997 to conduct a large scale screening and surveillance study
on hepatitis B carriers for early detection of liver cancer. 1,018
hepatitis B carriers enrolled in the programme between 1997 and
2000 and were screened by serum alfa-fetoprotein (AFP) and abdominal
ultrasound (AUS). Patients with either AFP>20ng/dl or abnormal AUS
were enrolled to an intensive programme that screened patient with
one or more hepatic angiogram plus lipiodol CT scan, followed by
AFP/AUS every 3 months for 2 years then every 6 months. Patients
with normal AFP/AUS were followed routinely with AFP every 6 months
and AUS repeated at the end of 2 years. All suspicious lesions were
confirmed by biopsy or surgery. (Refer to Figure 1)
¡@¡@One
hundred and seventy-one patients with abnormal screening test(s)
were enrolled to the intensive surveillance programme. After a median
follow-up of 4.4 years we detected 47 liver cancers (15 at enrollment
and 32 during follow-up), giving an annual risk of 6.8%. Out of
the 847 patients with normal AFP/AUS for 2 years, 9 patients were
eventually diagnosed of liver cancer, giving a much lower annual
rate of 0.3%. These statistical results confirmed that intensive
screening and surveillance programme had significant impact on the
early detection of liver cancer.
¡@¡@Mean
tumor size of the 47 liver cancer detected in the intensive screening
programme was 2.98 cm, and the mean tumor size of the 9 liver cancer
outside the intensive screening programme was 4.82cm. There was
a significant difference between the two groups. Surgical resection
was feasible for only 17 patients (36.2%) from the programme. The
main reasons for non-surgical intervention included poor liver function,
small cirrhotic liver, multi-focal disease, and patient refusal.
However, an additional 14 patients (29.8%) were able to receive
loco-regional ablative therapy which attained a similar survival
as the resected cases in our project.
¡@¡@Professor
Tony Mok Shu-kam, principal investigator of the study, concluded,
"Our intensive screening and surveillance programme is successful
in detection of small liver cancer. We achieved the objective of
identifying early disease but concurrent presence of advanced cirrhosis
prevents patients from curative surgery. Further development in
treatment modalities including novel loco-ablative therapy is required
to improve the survival outcomes of these patients."
¡@¡@Mrs.
Sally Lo, Chairman of The Hong Kong Cancer Fund, commented, "We
are delighted to see the encouraging results from this surveillance
study. We have always promoted the importance of Early Detection
Saves Lives, and an early diagnosis of cancer will significantly
improve the chances of recovery. We believe that the success of
this study will encourage further research on early detection methods
and will pave the way to a cancer controlled future."
¡@¡@Professor
Anthony Chan, Chairman of the Department of Clinical Oncology and
Director of the Sir YK Pao Center for Cancer, commented, "Major
progress has been made in the early diagnosis for cancers of the
cervix and breast, where multi-disciplinary treatment of early stage
disease results in very high cure rates. Effort is increasingly
focused on early detection of cancers with high mortality including
lung cancer and liver cancer, and this current study represents
a significant step forward in achieving the aim of early diagnosis
of liver cancer."
¡@¡@Professor
Fok Tai-fai, Dean of Faculty of Medicine of the Chinese University,
expressed gratitude on behalf of the Faculty to the Hong Kong Cancer
Fund for the fruitful partnership that has made possible the undertaking
of research projects such as this one in the early detection of
liver cancer, and an ongoing study testing a novel immunotherapy
approach which also involves partnership with Cancer Research UK.
From left: Mr Fok Ma Tai, Prof Tony Mok, Mrs Sally Lo, Prof
Fok Tai Fai and Prof Anthony Chan
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