Differences in trends of lung carcinoma by histology type in Israeli Jews and Arabs, 1981-1995

[Diversity of incidence trend patterns: implications for carcinogenesis?]

OBJECTIVE

Cancers of the ENT, oesophagus and lungs are caused mainly by alcohol and/or tobacco consumption but have potentially heterogeneous latencies and dose-incidence relationships. The incidence of cancers having the same risk factors may vary in a similar way over time and space. The aim of the study was to identify groups of cancers with similar spatio-temporal incidence trends.

METHODS

Fifty thousand nine hundred and eighty cases of ten cancer types were collected between 1982 and 2002 in six French departments. The incidence levels and trends were assessed using an age-cohort random-effect model that took into account heterogeneity of incidence levels and trends between departments.

RESULTS

Three groups of cancer sites/types with similar spatio-temporal incidence trends were identified: (1) oral cavity, oropharynx, hypopharynx, larynx, oesophagus, and lung squamous cell carcinomas in which the incidence decreased similarly in time and space; (2) other types of lung cancer and lung adenocarcinomas whose incidence increased similarly; and (3) lung large- and small-cell carcinomas whose incidence trends were heterogeneous.

CONCLUSION

Using the tools of descriptive epidemiology different cancer groups with different temporal and spatial incidence trends were identified. This diversity suggests different latencies and different sensitivities of those groups to the main risk factors, alcohol and tobacco.

Increasing lung cancer incidence among Israeli Arab men reflects a change in the earlier paradox of low incidence and high smoking prevalence

Lung cancer in Israel has previously appeared to be less common than expected, relative to the prevalence of smoking. The objective is to examine trends in lung cancer rates and smoking prevalence in Israeli Arab and Jewish men compared with the United States. Age-adjusted lung cancer incidence and mortality rates in Israel were calculated for 1980-2004 using the National Cancer Registry, and compared with the United States' rates, on the basis of the Surveillance Epidemiology and End Results program. Smoking rates were obtained from national surveys carried out during the years 1970-2004. During the period 1980-2004, among Israeli Arab men, there was an increase in lung cancer incidence rates, particularly during 1990-2004, when they increased by 17.8%. During the latter period, the incidence of lung cancer among Israeli Jewish men and men in the United States declined by 5.2 and 22.8%, respectively. In 2003-2004, the age-adjusted smoking rates were 41.3 and 31.6% among Israeli Arab and Jewish men, respectively, and past smoking habits reflect higher rates among Arab men over the past three decades. The marked increase in the incidence of lung cancer among Israeli Arab men during the last decade, without any evidence of increased smoking prevalence, might reflect a gradual loss of some apparent protection in this subpopulation. The possible explanations are changes in lifestyle, particularly in dietary habits.

Time trends of lung cancer incidence by histologic types and smoking prevalence in Hong Kong 1983-2000

The gender difference in epidemiology of lung cancer has been postulated to be due to the higher susceptibility of women to risk factors especially tobacco smoking. Alternatively, such difference may also be explained by some unknown gender-specific etiological factors, which can have been masked if both the female and male prevalence of smoking are high. Hong Kong has a low female smoking prevalence rate and therefore the trend of the female incidence of lung cancer is particularly interesting because it can reflect the effects of the non-smoking related risk factors more clearly. The present study examined the trends of incidence rates for the major histologic types and smoking prevalence from 1983 to 2000 in Hong Kong with respect to gender. The prevalence of daily smokers decreased from 39.7% in 1982 to 22% in 2000 in males and from 5.6 to 3.5% in females. The time trends of the lung cancer incidence (overall or with respect to age and histology) were similar for both genders. The overall incidence decreased progressively throughout the study period, attributable to the decrease in squamous cell, small cell and large cell carcinoma. The decline occurred in all age groups but to a greater extent in the younger age groups. The incidence of adenocarcinoma increased until 1988-1990 and then stabilized. The initial increase was restricted to the older age groups. These temporal patterns suggested that the same etiological factors affected both genders to a different extent but manifested as similar changes in the direction of incidence over time. To confirm this hypothesis, further studies were needed to clarify the nature of these etiological factors for the non-smoking related lung cancer cases.