ATS 2012, SAN FRANCISCO – Tuberculosis independently predicts death from lung cancer in the elderly, according to a new study from researchers in Hong Kong.
"There is a high incidence of both tuberculosis and lung cancer among the elderly in Hong Kong," said lead author Chi Chiu Leung, MBBS, consultant chest physician in the Tuberculosis and Chest Service of the Department of Health of Hong Kong. "In our prospective follow-up study of a cohort of 61,239 subjects aged 65 years or older, we found that active tuberculosis was an independent predictor of lung cancer death after adjustment for a number of demographic and health-related factors."
The results will be presented at the ATS 2012 International Conference in San Francisco.
Study subjects were enrolled from 18 Elderly Health Centers of the Department of Health in Hong Kong between 2000 and 2003 and retrospectively cross-matched with 1993-2003 data from the tuberculosis notification registry. The cohort was followed prospectively through 2011 with causes of death ascertained through the territory-wide death registry.
Of 61,239 study subjects, 516 had active tuberculosis prior to study enrollment. During follow-up, there were 1,344 deaths from lung cancer, 910 deaths from other tobacco-related malignancies, and 2,003 deaths from non-tobacco-related malignancies.
After adjustment for gender, age, language spoken, education level, marital status, housing situation, public means-tested financial assistance status, ever-smoking status, passive smoking, alcohol use, body mass index, chronic obstructive pulmonary disease and/or asthma and family history of malignancy, having active tuberculosis before study enrollment was significantly associated with death from lung cancer but not with death form the other two categories of malignancies.
"The association between tuberculosis and lung cancer death in elderly patients in our study likely reflects the effect of tuberculosis on the occurrence of this cancer," said Dr. Leung. "Lung cancer mortality is increasing rapidly with the aging population in China and other Asian Countries. Our results call for greater attention to the possibility of lung cancer in patients with a history of tuberculosis and increased public health initiatives aimed at tobacco and tuberculosis control."
"With accumulating knowledge on risk factors other than cigarette smoking, attempts should be made to build a more comprehensive predictive model for lung cancer to target future screening activities," Dr. Leung concluded. "Further delineation of the underlying mechanisms may also help to identify potential drug targets for prevention and/or treatment of this important deadly disease."
"Tuberculosis Increases The Risk Of Lung Cancer Death In The Elderly" (Session B20, Monday, May 21, 9:30 a.m., Room 3005-3007, Moscone Center; Abstract 34214)
* Please note that numbers in this release may differ slightly from those in the abstract. Many of these investigations are ongoing; the release represents the most up-to-date data available at press time.
Abstract 34214
Tuberculosis Increases The Risk Of Lung Cancer Death In The Elderly
Type: Late Breaking Abstract
Category: 09.22 - Lung Cancer: Epidemiology (CP)
Authors: C.C. Leung1, L. Hui2, T.H. Lam3, W.W. Yew4, W.S. Law2, C.M. Tam2; 1Department of Health - Hong Kong/HK, 2Department of Health - Hong Kong/CN, 3The University of Hong Kong - Hong Kong/CN, 4Grantham Hospital - Hong Kong/CN
Abstract Body
Rationale: In Hong Kong, the annual tuberculosis notification rate exceeded 150/100,000 person-years among persons aged 65 or above. Lung cancer tops the list of all cancer deaths. With the high incidence of both conditions, a prospective follow-up study was therefore conducted to explore their relationship.
Methods: A cohort of clients aged 65 years or above, enrolled at 18 Elderly Health Centers of the Department of Health in Hong Kong from 2000 to 2003 was assembled and retrospectively cross-matched with the territory-wide tuberculosis notification registry from 1993 to 2003 for active tuberculosis notified before the enrollment, using the identity card number as unique identifier. The cohort was then followed up prospectively through linkage with the territory-wide death registry for causes of death till December 31, 2011. Lung cancer was defined as primary carcinoma of the lung with the corresponding International Classification of Disease (ICD) 9 codes of 162, or ICD 10 codes of C33-C34. Other tobacco-related malignancies included carcinoma of nasopharynx, larynx, lip, oral cavity, esophagus, stomach, pancreas, bladder, prostate, cervix, renal cell carcinoma and acute myeloid leukemia. All subjects with suspected or confirmed malignancy at enrollment and those who died within two years of follow-up were excluded.
Results: Out of 61239 included subjects, 516 had been notified for active tuberculosis before enrolment. After a total of 612,736 person-years of follow-up, 1344, 910 and 2003 deaths occurred from lung cancer, other tobacco-related malignancies and non-tobacco-related malignancies respectively. Active tuberculosis before enrollment was associated with lung cancer death (odds ratio: 2.38, 95% confidence level: 1.64.45, p<0.001) but not the other two categories of malignancies after stratification by gender in Mantel-Haenszel analysis. Consistent results were observed on examination of never-smokers alone. Active tuberculosis remained an independent predictor of lung cancer death (adjusted hazard ratio: 2.00, 95% confidence level: 1.39.88, p<0.001) after adjustment for gender, age, language spoken, education level, marital status, housing situation, public means-tested financial assistance status, ever-smoking status, passive smoking, alcohol use, body mass index, chronic obstructive pulmonary disease and / or asthma and family history of malignancy (Table and Figure).
Conclusion: Tuberculosis independently predicted death from lung cancer in the elderly, likely reflecting its effect on the occurrence of this high-mortality condition. With the rapidly aging population in China, heightened clinical alertness for the possibility of lung cancer in patients with history of tuberculosis is called for, alongside public health measures for tobacco and tuberculosis control.
Funded by: None reported