Suppose a person developed a mutation in a somatic cell which diminishes the performance of the bodys natural cell cycle control proteins. this mutation resulted in cancer, but was effectively treated with a cocktail of cancer-fighting techniques. is it possible for this persons future children to inherit this cancer-causing mutation

Yes, it is probable for a person's future children to inherit this kind of mutation. There is a one in two possibility to inherit this. Cells that are already destroyed permanently by the cancer will divide further even though there is cancer fighting techniques or cocktails induced. The mutation may either be a recessive trait or a major trait depending on the genetic code of the mutation.