If a pre-screening phase is used then the following happens:

itemization(
    it() If there's no tumor but the case's natural death occurs before the
tumor-induced death, then (tt(loop/pretumordeath.cc)) the case's simulation
ends, setting its status to tt(LEFT_PRE).

        If at this point there also happens to be an existing tumor then the
tumor's characteristics are determined as well (by tt(Tumor::characteristics),
cf. section ref(TUMOR)).


    it() On the other hand, if the complement of the above condition holds
true (i.e., there is a tumor and the tumor's self-dectected age is before the
case's natural death) the characteristics of the tumor are determined (see the
next section) resulting in the case leaving the simulation because the tumor
was self detected.
    )
