Relax. Take a deep breath.
Cancer is not generally infectious, AFAIK. Even though some cancers are know to be caused by infectious agents, they are not easily spread from person to person (require direct, intimate, contact).
If cancer was infectious we would see "clusters" of cancers in families and in groups that live in very close proximity (armed forces, colleges, nursing homes), but their is no evidence of this type of pattern.
The theory of most cancer is that the cells in the body are made to change through some exposure to something - not necessarily and infectious agent. But even it it were, you still have to be exposed to it in a manner than could cause disease.
I am very confident that the environment and belongings of a person who recently died of cancer are safe - provided, of course, that no toxic environmental agents remain (like radioactive substances or something).
Fear of cancer is common, because it's an unknown, and a painful disease. PM me if you want to discuss the specific cancer and how it might have been caused.
Cheers
Mick