WATERLOO, Sierra Leone — Although the rainy season was coming on fast, Zainabu Sesay was in no shape to help her husband. Ditches had to be dug to protect their cassava and peanuts, and their mud hut’s palm roof was sliding off.

But Mrs. Sesay was sick. She had breast cancer in a form that Western doctors rarely see anymore — the tumor had burst through her skin, looking like a putrid head of cauliflower weeping small amounts of blood at its edges.

“It bone! It booonnnne lie de fi-yuh!” she said of the pain — it burns like fire — in Krio, the blended language spoken in this country where British colonizers resettled freed slaves.

No one had directly told her yet, but there was no hope — the cancer was also in her lymph glands and ribs.