Which best summarises the relative lethality of first and subsequent primary cancers?
a) Initial primary cancers are more lethal because they tend to have more aggressive characteristics
b) Subsequent primary cancers are more lethal, possibly because some patients may have reached their maximum cumulative dose of effective drugs like doxorubicin during treatment of their first cancer
c) Subsequent primary cancers are less lethal because cancer survivors are able to recognize cancer-related symptoms and seek treatment promptly
d) Five year survival rates are similar for first and subsequent primary cancers