[1] Amer Canc Soc, Surveillance & Hlth Serv Res, Atlanta, GA 30329 USA
[2] African Canc Registry Network, INCTR African Registry Programme, Oxford, England
[3] Ctr Hosp Univ Treichville, Serv Cancerol, Abidjan, Cote Ivoire
[4] Ctr Hosp Univ Brazzaville, Serv Carcinol & Radiotherapie, Brazzaville, Rep Congo
[5] Univ Oxford, Nuffield Dept Populat Hlth, Clin Trials Serv Unit, Oxford OX3 7LF, England
[6] Univ Oxford, Nuffield Dept Populat Hlth, Epidemiol Studies Unit, Oxford OX3 7LF, England