Environmental Disease

COMMENTARY
Year
: 2018  |  Volume : 3  |  Issue : 3  |  Page : 55--56

Air pollution and liver cancer


Yu Ji1, Christopher Stone2, Xiaokun Geng3, Yuchuan Ding2,  
1 Department of Hepatobiliary Surgery, Beijing Luhe Hospital, Capital Medical University, Beijing, China
2 Department of Neurosurgery, Wayne State University School of Medicine, Detroit, Michigan, USA
3 Department of Hepatobiliary Surgery, Beijing Luhe Hospital, Capital Medical University, Beijing, China; Department of Neurosurgery, Wayne State University School of Medicine, Detroit, Michigan, USA

Correspondence Address:
Dr. Yuchuan Ding
Department of Neurosurgery, Wayne State University School of Medicine, Detroit, Michigan
USA




How to cite this article:
Ji Y, Stone C, Geng X, Ding Y. Air pollution and liver cancer.Environ Dis 2018;3:55-56


How to cite this URL:
Ji Y, Stone C, Geng X, Ding Y. Air pollution and liver cancer. Environ Dis [serial online] 2018 [cited 2022 Aug 14 ];3:55-56
Available from: http://www.environmentmed.org/text.asp?2018/3/3/55/243632


Full Text

Primary liver cancer poses, as the fourth leading cause of cancer death worldwide, a major and widespread burden of disease. The vast majority of primary liver cancers (approximately 75%–85%) are attributable to hepatocellular carcinoma (HCC),[1] the major risk factor for which is viral hepatitis secondary to hepatitis B and C infections.[2] Other prominent risk factors include hepatic cirrhosis, alcohol abuse, obesity, type 2 diabetes mellitus, and exposure to hepatotoxins.[1],[3],[4]

In addition to these established factors, recent studies have indicated that exposure to airborne particulate matter (PM) is also a risk factor for HCC. PM refers generally to microscopic solid or liquid matter suspended in the Earth's atmosphere.[5],[6] The deleterious effects of PM exposure on human health, particularly when particle diameters are below 2.5 μm (PM2.5), are well known. in addition to its designation by the International Agency for Research on Cancer as a Group 1 human carcinogen,[1],[2],[3] PM inhalation has been implicated in a range of other pathologic processes including asthma, lung cancer, cardiovascular disease, and cerebrovascular disease.[4],[7] The mechanisms by which PM2.5 exposure constitutes a risk factor for hepatic pathology seem to proceed through inflammatory, oxidative, and endoplasmic reticulum stress-mediated fibrosis.[8],[9]

Moreover, exposure to PM2.5 is every bit as ubiquitous as HCC, if not more so. a recent analysis concluded that over 87% of the world's population lives in areas that exceed the threshold set by the World Health Organization for safe annual average PM2.5 pollution.[10] It has, therefore, been possible to conduct analyses of PM2.5-mediated hepatic carcinogenesis on a large scale. In Taiwan, for instance, Wen-Chi Pan and his team recruited 23,820 participants with no history of HCC, and assessed the relationship between participants with HCC and PM2.5 exposure, finding both that long-term exposure was associated with dose-dependent elevations in baseline serum alanine aminotransferase, and that this exposure was positively associated with subsequent HCC risk at long-term follow-up.[11] Similarly, a study conducted by Huiyu Deng on 20,221 patients in the United States showed that PM2.5 exposure after HCC diagnosis was dose-dependently associated with shortened survival.[12]

It should be noted that PM2.5 is not the only modality of ambient pollution suspected to contribute to HCC pathogenesis. Roles have also been proposed for formaldehyde, the tumorigenic potential of which has earned it an EPA Group B1 carcinogen classification, and polycyclic aromatic hydrocarbons.[13] Further research is needed to elucidate the magnitude and mechanisms of the hepatic carcinogenic effect of these agents, however.

Surgical resection and transplantation of the liver are currently the main treatments for HCC, and percutaneous ablation may be employed for patients who cannot tolerate invasive surgery; interventional therapy, radiation therapy, and chemotherapy may be used as complementary treatments.[14] Since the 5-year survival rate of HCC remains, at <12%, distressingly low despite these treatments, primary prevention of HCC is essential.[15] This consideration, coupled with the pervasiveness of both HCC and the pollution that appears to precipitate it, underscores the ongoing need to conduct innovative, environmentally-focused, broad-based, and high-quality research in this field. Thus far, very little work of this kind has been conducted – an unfortunate state of affairs that our group hopes, in the coming years, to change.

References

1Bray F, Ferlay J, Soerjomataram I, Siegel RL, Torre LA, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin 2018.
2Parkin DM, Bray F, Ferlay J, Pisani P. Global cancer statistics, 2002. CA Cancer J Clin 2005;55:74-108.
3Davila JA, Morgan RO, Shaib Y, McGlynn KA, El-Serag HB. Hepatitis C infection and the increasing incidence of hepatocellular carcinoma: A population-based study. Gastroenterology 2004;127:1372-80.
4Dongiovanni P, Romeo S, Valenti L. Hepatocellular carcinoma in nonalcoholic fatty liver: Role of environmental and genetic factors. World J Gastroenterol 2014;20:12945-55.
5Guan L, Anand R, Ding Y. Is pm2.5a double-edged sword? Environ Dis 2017;2:97-8.
6Wang L, Qiao K, Zhang H, Zhang K. Chinese medicine and environmental disease. Environ Dis 2016;1:95-8.
7Anderson JO, Thundiyil JG, Stolbach A. Clearing the air: A review of the effects of particulate matter air pollution on human health. J Med Toxicol 2012;8:166-75.
8Zheng Z, Zhang X, Wang J, Dandekar A, Kim H, Qiu Y, et al. Exposure to fine airborne particulate matters induces hepatic fibrosis in murine models. J Hepatol 2015;63:1397-404.
9Zhang K. Environmental stressor, stress response, and disease. Environ Dis 2018;3:1-3.
10Brauer M, Freedman G, Frostad J, van Donkelaar A, Martin RV, Dentener F, et al. Ambient air pollution exposure estimation for the global burden of disease 2013. Environ Sci Technol 2016;50:79-88.
11Zhou YH. RE: Fine particle pollution, alanine transaminase, and liver cancer: A Taiwanese prospective cohort study (REVEAL-HBV). J Natl Cancer Inst 2017;109. pii: djw184.
12Deng H, Eckel SP, Liu L, Lurmann FW, Cockburn MG, Gilliland FD, et al. Particulate matter air pollution and liver cancer survival. Int J Cancer 2017;141:744-9.
13Cicalese L, Curcuru G, Montalbano M, Shirafkan A, Georgiadis J, Rastellini C. Hazardous air pollutants and primary liver cancer in Texas. PLoS One 2017;12:e0185610.
14Foerster F, Mittler J, Darstein F, Heise M, Marquardt JU, Wörns MA, et al. Recipient liver function before liver transplantation influences post-transplantation survival in patients with HCC. Eur J Intern Med 2018;55:57-65.
15El-Serag HB. Hepatocellular carcinoma. N Engl J Med 2011;365:1118-27.