Sambo noted that there were many factors contributing to cancers and the disease process differs according to different sites.

He indicated that tobacco was the single most important preventable cause of cancer known to man, accounting for almost 30% of cancer-related deaths worldwide. It is estimated that about 30% to 40% of all cancers globally are related to unhealthy diet, physical inactivity and their associated conditions of obesity.

Harmful use of alcohol is another important risk factor for cancer.

A host of environmental exposures, some genetic predispositions and certain infections play an important role in carcinogenesis. Nearly 20% of cancers worldwide are caused by underlying chronic infections, according to the regional WHO for Africa.

“In the African Region, however, chronic infectious diseases account for almost 26% of cancer risk factors. As a significant number of human cancers are caused by persistent infection with viruses, bacteria or parasites, the implementation of appropriate preventive measures including vaccination and treatment can greatly reduce the burden of cancers caused by infections. For example, the prevention of HIV can reduce Kaposi sarcoma; vaccination against hepatitis B and Human Papilloma Virus reduces liver and cervical cancers respectively and effective early treatment of Helicobacter pylori and Schistosomiasis can reduce stomach and bladder cancers,” he said on a day to mark the 2010 World Cancer Day.

World Cancer Day provides an opportunity to draw public attention to the growing problem of Cancer in Africa. The theme for World Cancer Day 2010 “Cancer can be prevented too”. This theme underscores the importance of protecting individuals against cancer risk factors such as tobacco use, unhealthy diet, harmful use of alcohol, physical inactivity, overweight and infections that cause cancer.

Sambo is worried that despite the available preventive measures, many African have no access to such services and called for a more integrated response to cancer and other related illnesses.

He said: “For most cancers, preventive measures exist and are related to lifestyles such as cessation of tobacco use, avoiding excessive use of alcohol, undertaking regular physical activity, and adopting a healthy diet rich in fruits and vegetables. Effective techniques and treatment regimens have been developed for prevention, early diagnosis and adequate management. Unfortunately, these measures are not readily accessible to everyone.”

According to the World Cancer Report 2008, new cancer cases are expected to rise from 13 million to nearly 27 million annually by 2030. By then, cancer will be killing some 17 million people every year.

In Africa, there were an estimated 667 000 new cases of cancer in 2008 affecting 314 000 males and 353 000 females and causing 518 000 deaths involving 252 000 males and 266 000 females.

The report added that cancer situation in Africa was worsening in several countries and many patients remained unscreened, undiagnosed and inadequately treated.