Manifestations of local disease

cough cough is the most common symptom reported at
presentation by lung cancer patients. cough is present at diagnosis
in 50% or more of patients and eventually develops
in nearly all patients who are not cured. 10, 11 cough in lung
cancer may be related to many factors, including a central
tumor, obstructive pneumonia, multiple parenchymal metastases,
lymph node involvement, and pleural effusion. even
though cough is the most common symptom of lung cancer,
it accounts as the only cause in about 2% of patients with
chronic cough. 12
many lung cancer patients have underlying chronic obstructive
pulmonary disease (copd) and therefore may suffer
from a chronic cough. some smokers and former smokers also
have a chronic cough referred to as smoker ’ s cough. hence, the
patient or the patient’s physician may ignore a gradual change
in such a cough. a persistent change in the cough or acute
exacerbation of copd that fails to respond to therapy should
prompt performance of a chest radiograph or even a ct scan.
this evaluation is particularly important if the cough is not
associated with fever or symptoms of upper respiratory tract
infection or persists for longer than a week. some of these patients
are treated with multiple courses of antibiotics under the presumption of bronchitis or pneumonia, thereby delaying the
diagnosis of lung cancer.
treatment of cough is most successful if the underlying
etiology can be addressed. thus, tumor-specific therapy is
most successful in relieving lung cancer–related cough. in patients
with airway involvement by the tumor, patients may also
benefit from the addition of beta 2 -agonists such as albuterol.
many lung cancer patients continue to suffer from a persistent,
distressing cough despite appropriate tumor-specific
therapy. it is important to evaluate and treat other potential
causes of cough such as postnasal drip, gastroesophageal reflux,
and bronchospasm. opiates have been used with some success
for their antitussive properties. 9 there is no evidence that one
preparation of opiates is better than the other. other antitussives
such as guaifenesin, dextromethorphan, benzonatate, and
levodropropizine may be tried, but they have had variable success
in treating cancer-related cough. 13–16
inhaled lidocaine has been used to suppress cough. 13, 17–19
a starting dose of 5 ml of 2% lidocaine solution, via a nebulizer,
every 4 to 6 hours may be used. the dose may be increased
if required. generally, dosages greater than 15 ml of 2% lidocaine
solution are avoided to decrease the risk of seizures, from
systemic absorption of lidocaine through the airways. patients
should be warned about the potential for aspiration resulting
from oropharyngeal anesthesia. corticosteroids can also be helpful
in treating cough, particularly when the cough is related to
underlying bronchitis, radiation-induced lung damage, or lymphangitic
metastases. in addition, inhaled sodium cromoglycate
may help cough of lung cancer through the inhibition of afferent
unmyelinated c-fiber activation. c-fibers are involved
in cancer-related cough, probably from the release of bradykinin
by cancer cells and from the stimulation of the c-fibers by
the cancer.