Page 0096

DISEASE-SPECIFIC CANCER CONTROL

98 CANCER CONTROL 2015

region (3, 4). To place these figures in context, according to

Globocan data for The Gambia, HCC accounts for more than

half of all cancer in men (176 of 292 cases per year in 2012)

and 62 of 265 cases per year among women in 2012. In

comparison cervical cancer, another cancer associated with

viral infection, accounted for an estimated 98 of the 265

reported cases in 2012, whilst breast cancer accounted for an

estimated 40 cases (5). Aflatoxin is a powerful mycotoxin;

exposure through Aspergillus flavus-contaminated groundnut

consumption in many regions of SSA works synergistically

with HBV infection to increase cancer risk (6, 7).

Unfortunately, the natural history of HCC usually follows a

highly aggressive course and limited treatment options are

available, particularly in resource-poor settings such as SSA

(8). Furthermore, HBV-related HCC affects African patients

in their working and reproductive years (8), maximising the

negative socioeconomic effects of this disease. HBV

therefore represents a critical threat to health in the African

continent.

Early detection and treatment of HBV infection reduces

HCC incidence and mortality (primary prevention) (9, 10).

Furthermore, HCC survival is improved by early detection of

potentially treatable HCC by screening of at-risk patients

(secondary prevention) (11). However, limited access to

affordable medical care is a major limiting factor in hepatitis

and liver cancer management in SSA. Routine HBV and HCC

screening and surveillance programmes for the general

population are virtually non-existent in SSA and there is a

lack of infrastructure to support channelling of screened

patients into long-term treatment programmes

(http://www.who.int/csr/disease/hepatitis/global_report/en/;

accessed 21 November 2014). Safe and effective treatments

for HBV exist, but treatment access is severely limited in SSA

due to cost. Despite highly effective nucleoside analogues

such as tenofovir being available in most countries in SSA, at

no cost through the Global Fund, or at generic price for the

treatment of HIV, very few African countries offer publiclyfunded

HBV treatment (http://www.who.int/csr/disease/

hepatitis/global_report/en/; accessed 21 November 2014).

Treatment options for HCC are severely limited in SSA,

with percutaneous ethanol injection being the only modality

available at a small number of centres. Furthermore, this

modality is only effective for early stage HCC (8) and

limitations in access to screening and diagnostic services in

SSA mean most HCC cases are diagnosed when they are

already at an advanced stage and no longer amenable to

therapy.

Vaccination is the cornerstone of HBV prevention and is

most effective when given within 24 hours of birth (12, 13).

Multiple studies from SSA have demonstrated that HBV

vaccination of infants is both feasible and highly effective for

preventing chronic HBV carriage (14-16). Despite WHO

guidelines recommending HBV vaccination be commenced

within 24 hours of birth, the vaccine schedule of 6, 10 and 14

weeks has been adopted in most African countries to allow

the use of combination vaccines and to minimise costs and

logistic expenses by streamlining vaccination schedules (17).

There is limited data on the relative effectiveness of this

approach compared to birth dose vaccination in sub-Saharan

Africa. Data from The Gambia Expanded Programme on

Immunization, where complete delivery of the intended

intervention of birth dose vaccination was not always

achieved due to logistical constraints, suggested efficacy of

95% in preventing chronic HBV infection overall (18, 19).

However, the number of women in these studies who were

HBeAg positive with high viral load was small and vaccine

failure appeared much higher in this group (18).

Furthermore, in Africa there is incomplete HBV vaccine

coverage, widely ranging from 10% in Chad to 99% in The

Gambia, with the average less than 70% for Africa as a

whole) (20, 21) (http://www.who.int/csr/disease/hepatitis/

global_report/en/; accessed 21 Nov 2014; http://www.

afro.who.int/; accessed 21 November 2014).

Control of HBV prevalence is a major goal for the World

Health Organization (WHO) worldwide, with a key focus on

HBV prevention in African countries. In 2010, the World

Health Assembly (WHA) passed a resolution calling for

public health intervention to prevent and control viral

hepatitis. There is also a forthcoming WHA resolution

requesting the Global Health Fund to provide antiviral

medications for HBV mono-infected patients. However, until

greater global action for equitable treatment access is

achieved, there remains a significant burden from HBVrelated

liver disease and HCC in SSA, with little access to

life-saving screening and treatment. Importantly, there is a

significant lack of Africa-specific guidelines for HBV and

HCC screening and treatment.

Prevention of hepatitis B-related liver fibrosis and

cancer in Africa: The PROLIFICA study

Against the sombre backdrop of HBV-related liver disease in

SSA described above, the Prevention of Liver Fibrosis and

Cancer in Africa (PROLIFICA) project was established in

2011 to address some of the urgent HBV research needs in

three West African countries: Senegal, The Gambia and

Nigeria. This is an on-going five-year translational research

project funded by the European Union Framework 7

(www.prolifica.eu; EU-FP7 #265994) and represents a

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