Reactivation of pulmonary tuberculosis in malignancy

Deterioration of immunity due to local or systemic effects of the tumor itself and/or administered chemotherapeutics or radiotherapy may play roles in the reactivation of tuberculosis, increasing the mortality in patients with various malignancies. In a country with a high prevalence of tuberculosis such as Turkey, most people have inactive tuberculous lesions and tuberculin test positivity. Therefore, a prospective study was carried out to investigate the frequency of tuberculosis reactivation in patients with a malignancy.

Seventy-three patients with a malignancy and undergoing diagnostic fiberoptic bronchoscopy were enrolled in the study during a 2-year period (1993-1995). Bronchoscopic biopsies and cytologic materials were obtained. Bronchoalveolar lavage fluids, bronchial washings, and pre- and postbronchoscopic sputum specimens were also evaluated for acid-fast bacilli. A diagnosis of tuberculosis was based on smear and/or culture positivity for acid-fast bacilli.

The mean age of the patients was 56.2 +/- 13.6 years, with a male/female ratio of 69/4. The biopsy proven malignancies were as follows: primary lung carcinoma (n = 66, 90.4%), lymphoma (n = 5, 6.8%), metastatic breast adenocarcinoma (n = 1, 1.4%), and acute myelocytic leukemia (n = 1, 1.4%). Thirty-one of all patients had findings compatible with tuberculosis on radiology. The sputa and bronchial washing specimens were smear negative in all patients. Acid-fast bacilli were grown on culture in 6 patients (8%) (primary lung cancer, n = 5; non-Hodgkin lymphoma, n = 1). Four of these 6 patients had positive radiology for tuberculosis. These subjects were treated with a three- or four-drug anti-tuberculosis regimen. Two months later, smears remained acid-fast bacilli negative, or no bacilli were grown on culture.

The possibility of coexisting tuberculosis should be kept in mind in patients with a malignancy, especially those with lung carcinoma in countries with a high prevalence of tuberculosis. Pulmonary infections encountered in such patients should raise the suspicion of tuberculosis reactivation, and in addition to direct microscopic evaluation, sputum specimens and materials obtained by fiberoptic bronchoscopy should be cultivated for tuberculosis. Three-four-drug anti-tuberculosis regimens should be given, especially in countries with high drug-resistance rates for eradicating tuberculosis.