A bird's eye view of the air pollution-cancer link in China / 癌症

Air pollution in China comes from multiple sources, including coal consumption, construction and industrial dust, and vehicle exhaust. Coal consumption in particular directly determines the emissions of three major air pollutants: dust, sulfur dioxide (SO(2)), and nitrogen oxide (NOx). The rapidly increasing number of civilian vehicles is expected to bring NOx emission to a very high level. Contrary to expectations, however, existing data show that the concentrations of major pollutants [particulate matter-10 (PM10), SO(2), and nitrogen dioxide (NO(2))] in several large Chinese cities have declined during the past decades, though they still exceed the national standards of ambient air quality. Archived data from China does not fully support that the concentrations of pollutants directly depend on local emissions, but this is likely due to inaccurate measurement of pollutants. Analyses on the cancer registry data show that cancer burden related to air pollution is on the rise in China and will likely increase further, but there is a lack of data to accurately predict the cancer burden. Past experience from other countries has sounded alarm of the link between air pollution and cancer. The quantitative association requires dedicated research as well as establishment of needed monitoring infrastructures and cancer registries. The air pollution-cancer link is a serious public health issue that needs urgent investigation.

Active and passive smoking with breast cancer risk for Chinese females: a systematic review and meta-analysis / 癌症

Previous studies suggested that smoking and passive smoking could increase the risk of breast cancer, but the results were inconsistent, especially for Chinese females. Thus, we systematically searched cohort and case-control studies investigating the associations of active and passive smoking with breast cancer risk among Chinese females in four English databases (PubMed, Embase, ScienceDirect, and Wiley) and three Chinese databases (CNKI, WanFang, and VIP). Fifty-one articles (3 cohort studies and 48 case-control studies) covering 17 provinces of China were finally included in this systematic review. Among Chinese females, there was significant association between passive smoking and this risk of breast cancer [odds ratio (OR): 1.62; 95% confidence interval (CI): 1.39-1.85; I2 = 75.8%, P < 0.001; n = 26] but no significant association between active smoking and the risk of breast cancer (OR: 1.04; 95% CI: 0.89-1.20; I2 = 13.9%, P = 0.248; n = 31). The OR of exposure to husband's smoking and to smoke in the workplace was 1.27 (95% CI: 1.07-1.50) and 1.66 (95% CI: 1.07-2.59), respectively. The OR of light and heavy passive smoking was 1.11 and 1.41, respectively, for women exposed to their husband's smoke (< 20 and ≥ 20 cigarettes per day), and 1.07 and 1.87, respectively, for those exposed to smoke in the workplace (< 300 and ≥ 300 min of exposure per day). These results imply that passive smoking is associated with an increased risk of breast cancer, and the risk seems to increase as the level of passive exposure to smoke increases among Chinese females. Women with passive exposure to smoke in the workplace have a higher risk of breast cancer than those exposed to their husband's smoking.

SNP rs16917496 within SET8 3'UTR is associated with the age of onset of breast cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>We have identified a SNP within the seed-binding region for miR-502 in the 3'-UTR of the SET8 gene that codes for a methyltransferase for histone H4. SET8 methylates TP53 and thus regulates cell proliferation and genome stability. This study is to investigate the role for this SNP and its interaction with the TP53 codon 72 SNP in the age of onset of breast cancer.</p><p><b>METHODS</b>We conducted a case-only study of 1, 110 breast cancer cases. PCR-RFLP was used for SNP genotyping. Ages of onset of breast cancer among different genotypes were analyzed using SAS software.</p><p><b>RESULTS</b>Our analysis revealed that the SET8 CC and TP53 GG genotypes were independently associated with earlier age of onset of breast cancer in an allele-dose dependent manner. Moreover, individuals with both SET8 CC and p53 GG genotypes developed cancer at age of 47.74 years, compared with 54.55 years for individuals with both SET8 TT and TP53 CC genotypes.</p><p><b>CONCLUSIONS</b>miR-502-binding SNP in SET8 may modulate SET8 expression and contribute to early development of breast cancer either independently or together with the TP53 codon 72 SNP.</p>

Single-nucleotide polymorphisms among microRNA: big effects on cancer / 癌症

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the transcriptional or posttranscriptional level. Many miRNAs are found to play a significant role in cancer development either as tumor suppressor genes or as oncogenes. Examination of tumor-specific miRNA expression profiles in diverse cancers has revealed widespread deregulation of these molecules, whose loss and overexpression respectively have diagnostic and prognostic significance. Genetic variations, mostly single-nucleotide polymorphisms (SNPs) within miRNA sequences or their target sites, have been found to be associated with many kinds of cancers. In this review, we summarize the current knowledge of miRNAs including their biogenesis and role in cancer development, and finally, how SNPs among miRNAs affect miRNA biogenesis and contribute to cancer.

Epidemiological trend of gastric cancer in Tianjin, 1981-2002 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the secular trend in incidence and mortality rate of gastric cancer in Tianjin and to provide evidence and reference for making prevention and control strategy for gastric cancer.</p><p><b>METHODS</b>Data derived from Tianjin cancer registry system were analyzed by descriptive epidemiological method and Joinpoint model. A total of 17990 gastric cancer cases reported in Tianjin from 1981 to 2002, including 12755 males and 5235 females were studied.</p><p><b>RESULTS</b>The annual percent change (APC) of crude incidence rate for males and females was -0.92% (Z = -3.85, P = 0.001) and -0.79% (Z = -2.67, P = 0.015), while the APC of standard incidence rate was -3.55% (Z = -13.52, P = 0.000) and -3.47% (Z = -12.85, P = 0.000). There was a descending trend of incidence rate in males and females above 45-years-old, however, in male under 45 years it showed an increased trend and in females it kept stable. The APC of crude mortality rate was -1.66% ( Z = -5.79, P = 0.000) for males and -1.84% (Z = -6.02,P = 0.000) for females, while the APC of standard mortality rate was -4.60% ( Z = -15.79, P = 0.000) for females and -5.36% ( Z = -8.28, P = 0.000) for males during 1989-2002. Mortality and incidence ratio also indicated a downward trend.</p><p><b>CONCLUSION</b>Despite its declining trend in Tianjin, gastric cancer still remains an important public health problem in facing of the aging society and many risk factors.</p>