Active Tuberculosis Risk Associated with Malignancies: A 4-Year Retrospective Study in a Tertiary Care Hospital

Background Tuberculosis (TB) remains an important public health problem worldwide. Risk of acquiring TB in patients diagnosed with cancers remains high and can result due to reactivation or reinfection. We share the experience in a large tertiary care hospital. Materials and Methods Clinical samples from presumptive TB patients while on cancer therapy were tested by smear Ziehl-Neelsen (ZN) staining, GeneXpert MTB/RIF (Gx), TB polymerase chain reaction (PCR), and liquid culture (MGIT 960) from January 1, 2019, to December 31, 2022. Statistical Analysis Stata 14.0 software was used for statistical analysis. The p-value calculation was done by Pearson's chi-square test. Results Of 906 patients investigated, 42 (4.64%) tested positive for TB. Seven (1.37%) tested positive by ZN staining, 10 patients (6%) had culture positive by MGIT, 20 (10.53%) and 5 (13.51%) samples were positive by Gx and PCR, respectively. Maximum number of TB-positive patients were found to be suffering from carcinoma lung (28%) followed by leukemia (25%), gastrointestinal cancer (13%), and genitourinary cancer (13%), respectively. Seven of the 42 patients succumbed to the disease; the cases belonged to Hodgkin's lymphoma (75% mortality), leukemia (30% mortality), and genitourinary cancer (20% mortality). Conclusion The incidence of active TB is high in cancer patients, especially lung cancer, leukemia, gastrointestinal, and genitourinary cancers. Mortality was high in Hodgkin's lymphoma patients who developed TB. Screening for TB at the time of diagnosis of a high TB risk cancer would help initiate early treatment. We recommend targeted screening for TB in patients with these high-risk cancers, at the time of diagnosis and periodically through cancer treatment.