The Silent Seed: How Tuberculosis May Plant the Roots of Future Cancer

Can Tuberculosis Lead to Cancer? The Alarming Possibility

Tuberculosis (TB), once a leading cause of death worldwide, is now treatable and preventable. However, emerging research suggests that even after successful treatment, a past TB infection might carry a long-term risk: an increased chance of developing certain cancers. This revelation raises an important question: is your past TB putting you at risk for future cancer?

How Your Tuberculosis Increases Cancer Risk

Chronic Inflammation:

TB causes chronic inflammation, which can lead to tissue damage and DNA mutations, increasing the risk of cancer. This is particularly evident in lung cancer, where chronic pulmonary inflammation and fibrosis play a significant role in carcinogenesis.

Weekend Immune System:

TB can suppress the immune system, making it harder for the body to detect and destroy precancerous cells. Additionally, people with a history of TB may have residual immune system dysfunction, increasing their vulnerability to cancer.This is especially true for hematological malignancies, where immune suppression is a common factor.

Genetic Damage:

The bacteria causing TB can induce cellular DNA damage by increasing exposure to reactive oxygen and nitrogen species, further contributing to cancer risk.

Shared Risk Factors:

TB and certain cancers share common risk factors, such as smoking and alcohol use, which can independently increase cancer risk.

Which Cancers Are Linked to Past Tuberculosis?

Lung Cancer: TB is a significant risk factor for lung cancer, with studies indicating that individuals with a history of TB are 2-11 times more likely to develop lung cancer compared to those without TB. The chronic inflammation and tissue damage caused by TB can contribute to carcinogenesis in the lungs.

Hematological Cancers: Hematological malignancies, such as leukemia and lymphoma, have a higher incidence of TB due to compromised immune systems. These cancers also increase the risk of developing TB. The highest rates of active TB are observed in patients with hematological cancers.

Gynecological Cancers: TB has been associated with an increased risk of gynecological cancers, though the mechanisms are less clear compared to lung cancer.

Colorectal Cancer: There is evidence suggesting a higher incidence of colorectal cancer in individuals with TB, possibly due to shared risk factors like smoking and chronic inflammation.

Head and Neck Cancers: These cancers also have a higher incidence of TB, partly due to shared risk factors such as smoking and alcohol use.

Esophageal and Pancreatic Cancers: These cancers are noted for their association with future TB infections, indicating a complex interplay between cancer and TB.

Shared Risk Factor Reduction

Smoking Cessation: Smoking is a significant risk factor for both TB and cancer. Quitting smoking can reduce the risk of developing lung cancer and other malignancies.

Alcohol Reduction: Limiting alcohol consumption can also help mitigate shared risks for TB and cancer.

COPD Management: Managing chronic obstructive pulmonary disease (COPD) through lifestyle changes and medical interventions can reduce the risk of lung cancer in TB patients.

Preventive Measures for Cancer in Tuberculosis Patients

Monitoring Immune Status: Regularly assessing immune function in TB patients, especially those on immunosuppressive therapy, can help identify early signs of cancer or other infections.

Cancer Screening: Although there are no specific guidelines for cancer screening in TB populations, maintaining a high index of suspicion for cancer, particularly in the first year after TB diagnosis, is crucial. Early detection can improve cancer treatment outcomes.

Lifestyle Modifications: Maintaining a healthy diet and engaging in regular physical activity can support immune function and overall health, potentially reducing cancer risk.

Conclusion:

Dr. M.G. Giriyappagoudar, a senior radiation oncologist of North Karnataka and head of TumorBoard.Care, highlights the alarming yet often overlooked link between tuberculosis and cancer. He stresses that chronic inflammation, immune suppression, and shared risk factors like smoking significantly increase the likelihood of malignancies, particularly lung and hematological cancers. He also emphasizes the critical need for TB survivors to stay proactive by adopting a healthy lifestyle, quitting smoking, and undergoing regular cancer screenings. Early detection remains key to improving survival rates.

DR. M G GIRIYAPPAGOUDAR

DMRT, MDRT (CMC Vellore, TN)

Consultant Radiation Oncologist, Hubli