Active tuberculosis and malignance: a 5 year retrospective study

Abstract

There seems to be a higher risk of developing active tuberculosis (TB) in patients with cancer. Direct effects of malignancy (deterioration of immunity resulting from local and systemic effects) as well as the instituted therapies for their management may play a role.

The aim of this study was to characterize patients with cancer who developed TB.

Retrospective study conducted among adult patients from a Lisbon pulmonary diagnosis center newly diagnosed with active TB between 2017-2021 who had a concurrent or previous diagnosis of cancer. Demographic characteristics, TB location and outcomes where compared between cancer patients (CP) and general population (GP) with newly diagnosed TB. Data was collected from clinical records and national TB registry forms.

Total sample of 1381 patients, 3.8% (n=53) had cancer and TB simultaneously. CP were older (mean age 63y[21-89] vs 45y[18-96], p<0.001). The majority of CP (79%) had solid tumors, with head and neck, colon and breast being the most common; chronic lymphocytic leukemia was the main type of hematological cancer.

Regarding location of TB, there was not a difference between groups: pleural/pulmonary involvement was the most frequent (75.5% CP vs 72.1% GP); 3.8% CP and 3.4% GP presented with disseminated disease.

The majority of patients from both groups completed treatment (70.7% CP, 76.9% GP) but there a higher mortality from all causes in CP group (13.2% vs 3.8%, p<0.001).

TB and cancer clinically mimic one another and may present simultaneously in a patient, making the diagnosis challenging. It is of the utmost importance to be aware of both entities when evaluating a patient since patients with TB and cancer appear to have a worse prognosis.