Feasibility and clinical and implementation effectiveness of an adapted early warning signs and symptoms intervention for the early detection of childhood cancer in Cameroon and Kenya: protocol for a quasi-experimental, hybrid type 2 implementation effectiveness study. - Noh H; Chelva MP; Mbah Afungchwi G; Pondy A; Githanga J; Landis F; King'e M; Martiniuk AL; Ward N; Barwick M; Gupta S; Denburg A (BMJ open, 2025)