To the Editor:
I read with interest the article "Overview of the biochemical and genetic processes in
malignant mesothelioma", by Assis and Isoldi. (
11. Assis LV, Isoldi MC. Overview of the biochemical and genetic
processes in malignant mesothelioma. J Bras Pneumol. 2014;40(4):429-42.
http://dx.doi.org/10.1590/S1806-37132014000400012
https://doi.org/10.1590/S1806-3713201400...
) It is a comprehensive literature review of the mechanisms of tumorigenesis
in malignant mesothelioma (MM) and includes studies conducted by the authors themselves.
The topic is relevant because there is evidence of a gradual increase in the incidence
of MM in Brazil, particularly in southeastern Brazil,(
22. Pedra F, Tambellini AT, Pereira Bde B, da Costa AC, de Castro HA.
Mesothelioma mortality in Brazil, 1980-2003. Int J Occup Environ Health.
2008;14(3):170-5. http://dx.doi.org/10.1179/oeh.2008.14.3.170
https://doi.org/10.1179/oeh.2008.14.3.17...
) despite strong evidence of underreporting. Although the prognosis of MM is
extremely poor, MM is preventable, given that it is of occupational or environmental
origin in the vast majority of cases.
Although the title of the review article describes the scope of the study, the two-page introduction addresses general issues regarding MM and is the reason why the present letter was written.
First, I would like to comment on simian virus 40 (SV40). In the abstract of their
article,(
11. Assis LV, Isoldi MC. Overview of the biochemical and genetic
processes in malignant mesothelioma. J Bras Pneumol. 2014;40(4):429-42.
http://dx.doi.org/10.1590/S1806-37132014000400012
https://doi.org/10.1590/S1806-3713201400...
) the authors state that "the development of MM is strongly correlated with
exposure to asbestos and erionite, as well as to simian virus 40". At the end of the
sixth paragraph of the introduction, the statement is repeated, albeit in other words,
being accompanied by four references.
In the 1960s, some batches of polio vaccine were contaminated with SV40. Since then,
there has been interest in studying the consequences of this accidental inoculation in
individuals who received SV40-contaminated vaccines. More than 20 years ago, it was
hypothesized that SV40 played a role in the genesis of MM because of its potential to
cause mesothelioma in laboratory animals.(
33. Cicala C, Pompetti F, Carbone M. SV40 induces mesotheliomas in
hamsters. Am J Pathol. 1993;142(5):1524-33.
) Subsequent studies demonstrated the role of SV40 in a significant
proportion of MM cases.(
44. Jasani B, Jones CJ, Radu C, Wynford-Thomas D, Navabi H, Mason M, et
al. Simian virus 40 detection in human mesothelioma: reliability and significance of
the available molecular evidence. Front Biosci. 2001;6:E12-22.
http://dx.doi.org/10.2741/Jasani
https://doi.org/10.2741/Jasani...
,
55. Gazdar AF, Carbone M. Molecular pathogenesis of malignant
mesothelioma and its relationship to simian virus 40. Clin Lung Cancer.
2003;5(3):177-81. http://dx.doi.org/10.3816/CLC.2003.n.031
https://doi.org/10.3816/CLC.2003.n.031...
) However, epidemiological studies of populations exposed to contaminated
vaccines showed no increased incidence of cancer, including MM.(
66. Rollison DE, Page WF, Crawford H, Gridley G, Wacholder S, Martin J,
et al. Case-control study of cancer among US Army veterans exposed to simian virus
40-contaminated adenovirus vaccine. Am J Epidemiol. 2004;160(4):317-24.
http://dx.doi.org/10.1093/aje/kwh212
https://doi.org/10.1093/aje/kwh212...
) Two studies used multiple techniques for detecting SV40 in MM and normal
kidney tissue, avoiding cross-reactions with other polyomaviruses, and neither showed
the presence of SV40 in the samples analyzed.(
77. Manfredi JJ, Dong J, Liu WJ, Resnick-Silverman L, Qiao R, Chahinian
P, et al. Evidence against a role for SV40 in human mesothelioma. Cancer Res.
2005;65(7):2602-9. http://dx.doi.org/10.1158/0008-5472.CAN-04-2461
https://doi.org/10.1158/0008-5472.CAN-04...
,
88. López-Rios F, Illei PB, Rusch V, Ladanyi M. Evidence against a role
for SV40 infection in human mesotheliomas and high risk of false-positive PCR results
owing to presence of SV40 sequences in common laboratory plasmids. Lancet.
2004;364(9440):1157-66. Erratum in: Lancet. 2005;366(9503):2086.
http://dx.doi.org/10.1016/S0140-6736(04)17102-X
https://doi.org/10.1016/S0140-6736(04)17...
) In contrast, in one study, indirect ELISA demonstrated a higher prevalence
of serum antibodies to SV40 in patients with MM than in healthy controls.(
99. Mazzoni E, Corallini A, Cristaudo A, Taronna A, Tassi G, Manfrini M,
et al. High prevalence of serum antibodies reacting with simian virus 40 capsid
protein mimotopes in patients affected by malignant pleural mesothelioma. Proc Natl
Acad Sci U S A. 2012;109(44):18066-71.
http://dx.doi.org/10.1073/pnas.1213238109
https://doi.org/10.1073/pnas.1213238109...
)
Recently, the International Agency for Research on Cancer (IARC) published a comprehensive review of the carcinogenicity of polyomaviruses, concluding that there is inadequate evidence in humans for the carcinogenicity of SV40, which was therefore classified as a Group 3 carcinogen,( 1010. IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Malaria and some polyomaviruses (SV40, BK, JC, and Merkel Cell Viruses) In: IARC Monographs on the evaluation of carcinogenic risks to humans. International Agency for Research on Cancer. World Health Organization. Vol. 104. Lyon, France: World Health Organization. 2013. p. 133-204. ) meaning that SV40 is not classifiable as to its carcinogenicity to humans. In the aforementioned review,( 1010. IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Malaria and some polyomaviruses (SV40, BK, JC, and Merkel Cell Viruses) In: IARC Monographs on the evaluation of carcinogenic risks to humans. International Agency for Research on Cancer. World Health Organization. Vol. 104. Lyon, France: World Health Organization. 2013. p. 133-204. ) the reasons for conflicting results across studies are discussed. On the basis of the available evidence, it is incorrect to state that MM is strongly correlated with SV40. What is even worse is that the statement as it is misleads readers to believe that SV40 and asbestos have the same potential to cause MM.
Second, I would like to comment on the statement that "there is considerable debate
regarding the role of chrysotile asbestos in the genesis of MM". The authors continue by
stating that "there are reports that chrysotile asbestos cannot cause MM in humans",
without providing any reference to support this assertion. That is not the consensus!
According to the IARC, chrysotile is a Group 1 carcinogen to human mesothelial
cells.(
1111. IARC Working Group on the Evaluation of Carcinogenic Risks to
Humans. Arsenic, metals, fibres, and dusts. In: IARC Monographs on the evaluation of
carcinogenic risks to humans. International Agency for Research on Cancer. World
Health Organization. Vol. 100C. Lyon, France: World Health Organization. 2012. p.
11-465.
) The potential of chrysotile asbestos to cause MM has been reported to be
one order of magnitude lower than that of amphibole asbestos.(
1212. Hodgson JT, Darnton A. The quantitative risks of mesothelioma and
lung cancer in relation to asbestos exposure. Ann Occup Hyg. 2000;44(8):565-601.
http://dx.doi.org/10.1093/annhyg/44.8.565
https://doi.org/10.1093/annhyg/44.8.565...
)
Assis and Isoldi are experts in the biochemical and genetic processes associated with MM, as evidenced by the references to studies conducted by the group. Their review of the genes and biochemical pathways involved in MM is excellent; however, the introduction of the article mars their work by including poorly substantiated or incorrect statements regarding the potency of MM-inducing agents and the causal relationships between human exposure to those agents and the development of MM (all of which have been widely discussed in the literature), presenting readers with recurrent misconceptions.
References
-
1Assis LV, Isoldi MC. Overview of the biochemical and genetic processes in malignant mesothelioma. J Bras Pneumol. 2014;40(4):429-42. http://dx.doi.org/10.1590/S1806-37132014000400012
» https://doi.org/10.1590/S1806-37132014000400012 -
2Pedra F, Tambellini AT, Pereira Bde B, da Costa AC, de Castro HA. Mesothelioma mortality in Brazil, 1980-2003. Int J Occup Environ Health. 2008;14(3):170-5. http://dx.doi.org/10.1179/oeh.2008.14.3.170
» https://doi.org/10.1179/oeh.2008.14.3.170 -
3Cicala C, Pompetti F, Carbone M. SV40 induces mesotheliomas in hamsters. Am J Pathol. 1993;142(5):1524-33.
-
4Jasani B, Jones CJ, Radu C, Wynford-Thomas D, Navabi H, Mason M, et al. Simian virus 40 detection in human mesothelioma: reliability and significance of the available molecular evidence. Front Biosci. 2001;6:E12-22. http://dx.doi.org/10.2741/Jasani
» https://doi.org/10.2741/Jasani -
5Gazdar AF, Carbone M. Molecular pathogenesis of malignant mesothelioma and its relationship to simian virus 40. Clin Lung Cancer. 2003;5(3):177-81. http://dx.doi.org/10.3816/CLC.2003.n.031
» https://doi.org/10.3816/CLC.2003.n.031 -
6Rollison DE, Page WF, Crawford H, Gridley G, Wacholder S, Martin J, et al. Case-control study of cancer among US Army veterans exposed to simian virus 40-contaminated adenovirus vaccine. Am J Epidemiol. 2004;160(4):317-24. http://dx.doi.org/10.1093/aje/kwh212
» https://doi.org/10.1093/aje/kwh212 -
7Manfredi JJ, Dong J, Liu WJ, Resnick-Silverman L, Qiao R, Chahinian P, et al. Evidence against a role for SV40 in human mesothelioma. Cancer Res. 2005;65(7):2602-9. http://dx.doi.org/10.1158/0008-5472.CAN-04-2461
» https://doi.org/10.1158/0008-5472.CAN-04-2461 -
8López-Rios F, Illei PB, Rusch V, Ladanyi M. Evidence against a role for SV40 infection in human mesotheliomas and high risk of false-positive PCR results owing to presence of SV40 sequences in common laboratory plasmids. Lancet. 2004;364(9440):1157-66. Erratum in: Lancet. 2005;366(9503):2086. http://dx.doi.org/10.1016/S0140-6736(04)17102-X
» https://doi.org/10.1016/S0140-6736(04)17102-X -
9Mazzoni E, Corallini A, Cristaudo A, Taronna A, Tassi G, Manfrini M, et al. High prevalence of serum antibodies reacting with simian virus 40 capsid protein mimotopes in patients affected by malignant pleural mesothelioma. Proc Natl Acad Sci U S A. 2012;109(44):18066-71. http://dx.doi.org/10.1073/pnas.1213238109
» https://doi.org/10.1073/pnas.1213238109 -
10IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Malaria and some polyomaviruses (SV40, BK, JC, and Merkel Cell Viruses) In: IARC Monographs on the evaluation of carcinogenic risks to humans. International Agency for Research on Cancer. World Health Organization. Vol. 104. Lyon, France: World Health Organization. 2013. p. 133-204.
-
11IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Arsenic, metals, fibres, and dusts. In: IARC Monographs on the evaluation of carcinogenic risks to humans. International Agency for Research on Cancer. World Health Organization. Vol. 100C. Lyon, France: World Health Organization. 2012. p. 11-465.
-
12Hodgson JT, Darnton A. The quantitative risks of mesothelioma and lung cancer in relation to asbestos exposure. Ann Occup Hyg. 2000;44(8):565-601. http://dx.doi.org/10.1093/annhyg/44.8.565
» https://doi.org/10.1093/annhyg/44.8.565
Publication Dates
-
Publication in this collection
Sep-Oct 2014