Nontuberculous mycobacterial infections in cancer patients in a medical center in Taiwan, 2005–2008

Effect of coexisting advanced extrapulmonary solid cancer on progression of Mycobacterium avium complex lung disease

Objective:

Although Mycobacterium avium complex (MAC) lung disease has been shown to be associated with lung cancer and hematologic malignancies, there have been few studies of its relationships with other types of cancer. The aim of this study was to assess the effect that coexisting advanced extrapulmonary solid tumors have on the progression of MAC lung disease.

Methods:

This was a retrospective study of patients diagnosed with MAC lung disease, on the basis of the American Thoracic Society (ATS) criteria, between October of 2005 and March of 2019. The patients were divided into three groups: those with advanced-stage cancer (A-SC group); those with early-stage cancer (E-SC group); and those without cancer (control group). Progression of MAC lung disease was defined as exacerbation seen on imaging. Patient characteristics and the time to progression were compared among the three groups.

Results:

A total of 286 patients met the ATS diagnostic criteria for MAC lung disease, and 128 of those were excluded. Of the remaining 158 patients, 20 (7.0%) were in the A-SC group, 36 (12.6%) were in the E-SC group, and 102 (35.7%) were in the control group. The median time to progression in the A-SC, E-SC, and control groups was 432, 3,595, and 2,829 days, respectively (p < 0.01). A proportional hazards model showed that the significant predictors of MAC lung disease progression were advanced-stage cancer (hazard ratio [HR] = 6.096; 95% CI: 2.688-13.826; p < 0.01), cavitary lesions (HR = 2.750; 95% CI: 1.306-5.791; p < 0.01), and a high Nodule-Infiltration-Cavity-Ectasis score (HR = 1.046; 95% CI: 1.004-1.091; p = 0.033).

Conclusions:

A coexisting advanced extrapulmonary solid tumor could hasten the progression of MAC lung disease.

Mycobacterium szulgai Lung Disease or Breast Cancer Relapse-Case Report

Cancers are one of the risk factors of non-tuberculous mycobacterial (NTM) lung disease. The majority of data in this group of patients concern infections caused by Mycobacterium avium—the most prevalent NTM species worldwide. In contrast, limited information can be found regarding the uncommon NTM such as Mycobacterium szulgai. We present the case of M. szulgai lung disease in a patient with a history of breast cancer. Coexistence of NTM lung disease and breast cancer lung metastasis as well as primary lung cancer was suspected. Finally, neoplastic disease was ruled out based on negative results of endobronchial biopsy and negative tumor markers for lung and breast cancer. M. szulgai lung disease was successfully treated with rifampicin, ethambutol and clarithromycin.

Clinical relevance and diagnosis of nontuberculous mycobacterial pulmonary disease in populations at risk

The lungs are the most common disease site of nontuberculous mycobacteria (NTM). However, the isolation of NTM in a respiratory specimen does not indicate lung disease (LD). Differentiation between NTM colonization and NTM-LD remains challenging. In this brief review, we summarize the clinical impact of NTM-LD on morbidity and mortality in high-risk populations. The diagnosis criteria for NTM-LD-including clinical features, radiological presentations, and microbiological evidence-are also reviewed, according to the latest American Thoracic Society (ATS)/Infectious Disease Society of America (IDSA) guideline and the British Thoracic Society (BTS) guideline. However, the diagnosis of NTM-LD does not necessitate the initiation of anti-NTM treatment. Both environmental, host, and bacterial factors should be considered to identify patients that require NTM-LD treatment.

Pulmonary non-tuberculous mycobacterial infections: current state and future management

Currently, there is a trend of increasing incidence in pulmonary non-tuberculous mycobacterial infections (PNTM) together with a decrease in tuberculosis (TB) incidence, particularly in developed countries. The prevalence of PNTM in underdeveloped and developing countries remains unclear as there is still a lack of detection methods that could clearly diagnose PNTM applicable in these low-resource settings. Since non-tuberculous mycobacteria (NTM) are environmental pathogens, the vicinity favouring host-pathogen interactions is known as important predisposing factor for PNTM. The ongoing changes in world population, as well as socio-political and economic factors, are linked to the rise in the incidence of PNTM. Development is an important factor for the improvement of population well-being, but it has also been linked, in general, to detrimental environmental consequences, including the rise of emergent (usually neglected) infectious diseases, such as PNTM. The rise of neglected PNTM infections requires the expansion of the current efforts on the development of diagnostics, therapies and vaccines for mycobacterial diseases, which at present, are mainly focused on TB. This review discuss the current situation of PNTM and its predisposing factors, as well as the efforts and challenges for their control.

Incidence, comorbidities, and treatment patterns of nontuberculous mycobacterial infection in South Korea

Nontuberculous mycobacteria (NTM) are important pathogens in humans, and hospital-based studies have shown an increased incidence of NTM infection. However, little is known about the treatment pattern of NTM infection with respect to the number of cases per population in South Korea. This study evaluated the trends in the incidence of NTM infection, respiratory comorbidities, and treatment patterns in South Korea.National claims data from the Health Insurance Review and Assessment service database for the years 2009 to 2015 were reviewed, and codes related to NTM infection, respiratory comorbidities occurring from one year before NTM infection and associated treatments were identified.In total, 52,551 patients were included in the study and the average annual incidence per 100,000 person-years was 12.8. The annual incidence was found to have increased from 6.6 to 26.6 per 100,000 persons. Accompanied comorbidities were tuberculosis (33.7%), followed by bronchial asthma (33.2%), chronic obstructive pulmonary disease (25.6%), and lung cancer (5.8%). A total of 76.6% of patients did not receive any combination treatment within one year after the diagnosis of NTM infection. Macrolide-based treatment was administered to 18.8% of patients.A dramatic increase in the incidence of NTM infection was noted in the population of South Korea. Approximately three-fourth of the patients with NTM infection were clinically observed without treatment for at least 1 year after the identification of NTM infection and most patients who treated NTM infection received macrolide-based combination therapy.

Risk of mycobacterial disease among cancer patients: A population-based cohort study in a TB endemic area

OBJECTIVES

Tuberculosis (TB) and nontuberculous mycobacteria (NTM) disease have similar symptoms, which makes them difficult to distinguish clinically and leads to the danger of NTM disease being neglected. The aim of this study was to assess the risk of developing mycobacterial disease among cancer patients.

METHODS

We conducted a retrospective cohort study using a population-based database. The multivariable Cox proportional hazards model was adjusted to identify independent factors contributing to the development of mycobacterial disease in the cancer cohort.

RESULTS

The results showed that the increased risk of developing TB and NTM disease was 1.84-fold and 4.43-fold, respectively, in cancer patients compared with the general population. Advanced age (≥65years) and being male were risk factors for developing TB disease. There was a 4.09-fold significantly increased risk of TB disease within six months of a cancer diagnosis. Hematological cancer patients were most likely to develop mycobacterial disease. Younger hematological cancer patients (< 45years) had a higher risk of NTM disease development.

CONCLUSION

There is an increasing risk of mycobacterial disease in cancer patients. We suggest that the possibility of mycobacterial disease in cancer patients should be assessed during the period of cancer therapy, particularly in those who have risk factors.

Mycobacterium avium: an overview

Mycobacterium avium is an environmental microorganism found in soil and water sources worldwide. It is the most prevalent species of nontuberculous mycobacteria that causes infectious diseases, especially in immunocompromised individuals. This review discusses and highlights key topics about M. avium, such as epidemiology, pathogenicity, glycopeptidolipids, laboratory identification, genotyping, antimicrobial therapy and antimicrobial resistance. Additionally, the main comorbidities associated with M. avium infection are discussed.

The impact of cancer development on the risk of mycobacterial diseases among rheumatoid arthritis patients

Mycobacterial diseases are prevalent in cancer and rheumatoid arthritis (RA) patients, especially those receiving tumor necrosis factor-α inhibitor (TNFi). However, the impact of cancer development on the risk of mycobacterial diseases among RA patients is unknown. Data from the Taiwan National Health Insurance Research Database were used to conduct a retrospective study to assess the occurrence of mycobacterial diseases in RA patients developing cancer (cancer-positive), those using TNFi (TNFi-exposure), those with cancer and using TNFi (cancer-TNFi-comb), and those without cancer and not using TNFi (cancer-TNFi-free). Cancer and TNFi exposure were time-dependent, and independent risk factors of mycobacterial diseases were assessed by Cox regression. Among 1344 RA patients diagnosed during 2000–2013, 68 (5·1%) developed cancer before their end points. The incidence rates of mycobacterial diseases in the cancer-positive (n = 56), TNFi-exposure (n = 290), cancer-TNFi-comb (n = 12), and cancer-TNFi-free (n = 986) subgroups were 6·7, 2·0, 7·6, and 1·3 per 1000 person-years, respectively. As compared with the cancer-TNFi-free group, the risk for mycobacterial diseases increased for the TNFi-exposure group (adjusted HR = 3·6, 95% confidence interval (95% CI) 1·1–11·5, P = 0·032) and remained high for cancer-positive (adjusted HR = 14·6, 95% CI 3·3–63·7, P < 0·001) after adjustment. This study suggested that cancer development increased the risk of mycobacterial diseases in RA patients, and risk assessment for this subgroup should be considered.

Characteristics of Mycobacterium avium complex (MAC) pulmonary disease in previously treated lung cancer patients

Introduction

Mycobacterium avium complex (MAC) is responsible for a large portion of non-tuberculous mycobacterial (NTM) infections worldwide. Host factors such as active malignancy, immunosuppression, chronic obstructive pulmonary disease (COPD) and bronchiectasis increase the risk of MAC infection. However, the relationship between previously treated lung cancer with subsequent development of MAC pulmonary disease and treatment outcomes have not been previously studied.

Methods

We retrospectively identified all patients with lung cancer and MAC pulmonary disease documented in medical records at Mayo Clinic between January 2005 and October 2016. Patients who were diagnosed with MAC pulmonary disease before or at the time of lung cancer diagnosis were excluded. Patients meeting all inclusion criteria underwent chart review for prior oncologic treatments, clinical characteristics, and MAC treatment response.

Results

We identified 13 patients with MAC pulmonary disease and prior lung cancer, including 4 men and 9 women. Eight patients had structural lung disease that can predispose to MAC pulmonary disease, including bronchiectasis (23.0%) and COPD (46.2%). Four (30.8%) had no apparent immunosuppression or other risk factor(s) for MAC pulmonary disease. Primary pulmonary malignancies included pulmonary carcinoid, adenocarcinoma, and squamous cell carcinoma. Ten (76.9%) patients were started on antimicrobial treatment for MAC, and 8 (61.5%) patients completed MAC treatment with 6 (46.1%) patients achieving symptomatic improvement.

Conclusion

MAC pulmonary disease in previously treated lung cancer can occur without apparent risk factors for this NTM infection. Symptomatic improvement with MAC antimicrobial therapy appears to be lower than expected but comorbidities might influence outcomes in this patient population.

Nontuberculosis mycobacterial infections at a specialized tuberculosis treatment centre in the Republic of Korea

Background

The incidence of nontuberculous mycobacteria (NTM) infections is increasing worldwide, however formal evaluations of the epidemiology of NTM infections are limited. Understanding the trends and true prevalence of NTM is a major priority for optimizing infection control programmes and resources. The purpose of this study was to investigate the epidemiology, clinical manifestations, and radiologic findings in NTM-infected patients at specialized Tuberculosis (Tb) treatment centre in South Korea, which is endemic to Tb, and find solutions to control NTM infections.

Methods

A retrospective descriptive study was conducted among patients who were diagnosed with NTM from November 2011 to January 2016 at Seoul Metropolitan Government Seobuk hospital, Korea, using medical records and chest radiography results. Prevalence of NTM using national health insurance data was compared to the prevalence and incidence of Tb using National statistics data.

Results

The age- and sex- adjusted prevalence of NTM infection per 100,000 population increased between 2009 (9.4) and 2016 (36.1). However, the prevalence and incidence of Tb per 100,000 population decreased from 106.5 to 74.4, and 81.2 to 61.8, respectively. In total, 64 patients (37 [57.8%] men) were enrolled in the study. Among 33 (51.6%) patients with slowly growing nontuberculous mycobacteria (SGM) infection, 29 were detected with Mycobacterium avium complex (n = 13, M. avium; n = 16, M. intracellulare), and 4 with M. kansasii. Among 31 (48.4%) patients with rapidly growing nontuberculous mycobacteria (RGM) infection, 27 and 4 patients were detected with M. abscessus complex and M. fortuitum complex, respectively. RGM patients were more likely to have current Tb (P = 0.041), cough (P < 0.05), and sputum (P < 0.01) than SGM patients in the univariate analysis, but not in the multivariate analysis.

Conclusion

Given the increasing prevalence of NTM infections, precise epidemiological and surveillance data should be obtained by reporting NTM infections to public health authorities. Introducing nucleic acid amplification tests to differentiate between Tb and NTM in smear-positive specimens should be considered.

Mycobacterium avium Complex Disease

Despite the ubiqitous nature of Mycobacterium avium complex (MAC) organisms in the environment, relatively few of those who are infected develop disease. Thus, some degree of susceptibility due to either underlying lung disease or immunosuppression is required. The frequency of pulmonary MAC disease is increasing in many areas, and the exact reasons are unknown. Isolation of MAC from a respiratory specimen does not necessarily mean that treatment is required, as the decision to treatment requires the synthesis of clinical, radiographic, and microbiologic information as well as a weighing of the risks and benefits for the individual patient. Successful treatment requires a multipronged approach that includes antibiotics, aggressive pulmonary hygiene, and sometimes resection of the diseased lung. A combination of azithromycin, rifampin, and ethambutol administered three times weekly is recommend for nodular bronchiectatic disease, whereas the same regimen may be used for cavitary disease but administered daily and often with inclusion of a parenteral aminoglycoside. Disseminated MAC (DMAC) is almost exclusively seen in patients with late-stage AIDS and can be treated with a macrolide in combination with ethambutol, with or without rifabutin: the most important intervention in this setting is to gain HIV control with the use of potent antiretroviral therapy. Treatment outcomes for many patients with MAC disease remain suboptimal, so new drugs and treatment regimens are greatly needed. Given the high rate of reinfection after cure, one of the greatest needs is a better understanding of where infection occurs and how this can be prevented.