This is the protocol for a review and there is no abstract. The objectives are as follows: To assess the effects of Coriolus versicolor and its extracts on adverse effects during cancer treatment (chemotherapy and radiotherapy). To assess effects due to Coriolus versicolor and its extracts on survival, recurrence, and disease progression. To evaluate the evidence in relation to the type of preparation of the mushroom (e.g. whole fresh, dried, or extract).