Compared with the remarkable success of the Pap smear in detecting and preventing cervical cancer, respiratory cytology (mostly sputum) has been a disappointment as a mass screening test for lung cancer. The problem is not lack of accuracy (sensitivity or specificity), but rather that even in high-risk patients (such as male smokers older than 45 years), it is not cost-effective, the diagnosis often comes too late (no increased survival), and difficult therapeutic choices arise when multifocal disease is detected in this vital organ.
Role of respiratory tract cytology
- tumor detection, confirmation, and typing of both primary and metastatic disease
- post therapeutic monitoring of patients with lung cancer, as a complementary procedure to radiologic examinations
- diagnosing a variety of benign diseases, and plays an important role in assessing the presence of opportunistic infections in immunocompromised hosts such as patients with AIDS and transplant recipients