Misdiagnosis of Cancer as Tuberculosis in Low- to Middle-Income Countries: A Tip of the Iceberg!

To the Editor:

In their recent article in Journal of Global Oncology, Masamba et al[1] concluded that misdiagnosis of cancer as tuberculosis is a major concern in low- to middle-income countries (LMICs). However, in our practice and experience, it is only a tip of the iceberg in other parts of the world such as Southeast Asia.

The authors cited the incidence of tuberculosis in Malawi as 156 per 100,000. If we compare this incidence with other Southeast Asian countries and another African country, Nigeria, it seems that the incidence of cancer misdiagnosed as tuberculosis would be much higher. In fact, tuberculosis remains a major health care issue as compared with cancers as illustrated in Table 1.

Table 1

Incidence of Cancer and TB in LMICs

There is no doubt that tuberculosis is a major cause of morbidity and mortality in LMICs, but in our opinion, the incidence of misdiagnosis and mistreatment of cancer as tuberculosis is grossly under-reported. The authors stated that tuberculosis often complicates the diagnosis of lymphomas, but in reality, it complicates the diagnoses of other cancers as well, such as lung cancer, which is a potentially lethal disease as compared with lymphomas (lymphomas being curable). Only meager data are available from these countries, and they are limited to case reports and retrospective series.

Underdiagnosis or misdiagnosis of cancer is reported to be as high as 44% according to Burton et al,[4] who documented discrepancies between autopsy and clinical diagnosis. Singh et al[5] identified 14 patients who were treated with antituberculous therapy before review of diagnosis, which later proved to be lung cancer (12 non–small-cell lung cancer and two small-cell lung cancer). A high prevalence of tuberculosis in LMICs may justify the use of empirical antituberculous treatment; however, it needs vigilant monitoring, and if the patient does not respond in a maximum of 4 weeks, the diagnosis should be reviewed. It is not a matter of unavailability of advanced diagnostic facilities like CT or PET imaging; rather, it is an issue of the training of primary health care staff, who should have a high index of suspicion. The question is, how can we train that staff?

We suggest that well-developed cancer awareness campaigns, education, and training of health care staff regarding the possibilities of missed diagnoses and their effects on an individual patient’s mortality and morbidity can only decrease the incidence of this important health care issue. Nevertheless, there remains a need to properly use health care resources in primary care in LMICs to avoid missed or delayed diagnoses, and that issue also highlights the difference in cancer care between developed countries and LMICs.