To determine the factors that predispose the patient with lung cancer
to develop terminal pulmonary infections, we reviewed the case records
and autopsy data of 304 patients who died of lung cancer in the Kyush
u University Hospital between 1976 and 1990. The incidence of mycobact
erial infection was significantly higher among those treated with anti
neoplastic therapy and corticosteroids (group 3) than in those who rec
eived antineoplastic therapy alone (group 2). The incidence of nonbact
erial infection did not differ significantly between the two groups. I
n some group 3 patients, the administration of corticosteroids for rel
atively short periods (less than one month) led to fatal mycobacterial
infection. Among those patients with lymphocytopenia, the incidence o
f fatal mycobacterial infection was significantly higher in group 3 th
an in group 2, whereas the incidence of fatal nonbacterial infection w
as not. In group 3, the incidence of fatal mycobacterial and nonbacter
ial infections did not differ significantly among those with and witho
ut lymphocytopenia. Thus, in patients with lung cancer who were receiv
ing antineoplastic treatment, corticosteroids were more closely associ
ated with the development and exacerbation of mycobacterial infection
than was lymphocytopenia. The influence of corticosteroids on the deve
lopment of nonbacterial infection was not more marked than that of lym
phocytopenia. The incidence of common bacterial infections was no high
er among those patients who received no antineoplastic treatment or co
rticosteroid (group 1), group 2, and group 3. Therefore, the local and
systemic effects of the lung cancer itself are likely more important
in predisposing the patient to bacterial infections than are either an
tineoplastic agents or corticosteroids.