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Endocrine Care: Thekkepat C. Sandeep, Mark W. J. Strachan, Rebecca M. Reynolds, David H. Brewster, Ghislaine Scélo, Eero Pukkala, Kari Hemminki, Aage Anderson, Elizabeth Tracey, Søren Friis, Mary L. McBride, Chia Kee-Seng, Vera Pompe-Kirn, Erich V. Kliewer, Jon M. Tonita, Jon G. Jonasson, Carmen Martos, Paolo Boffetta, and Paul Brennan Second Primary Cancers in Thyroid Cancer Patients: A Multinational Record Linkage Study J Clin Endocrinol Metab 2006; 91: 1819-1825 [Abstract] [Full text] [PDF]

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E-Letter to the Editor: Second primary cancers after thyroid cancer

William L Harper, Asma Ali, Ahmed Al-Nemer   (11 December 2006)

E-Letter to the Editor: Second primary cancers after thyroid cancer 11 December 2006
William L Harper, Medical Doctor, Endocrinologist, Assistant Professor of Medicine McMaster University, Hamilton, Ontario, Canada, Asma Ali, Ahmed Al-Nemer Send letter to journal: Re: E-Letter to the Editor: Second primary cancers after thyroid cancer harperw{at}hhsc.ca William L Harper, et al.	We read with great interest the report of Sandeep et al. (1) regarding second primary cancers in thyroid cancer patients based on multinational record linkage. From their data, it is clear that there are several cancers that share a bidirectional association with thyroid cancer, raising a strong possibility of shared genetic and/or environmental risk factors. However, there also appear to be far more unidirectional associations for thyroid cancer arising after other primary cancers (esophagus, liver, pancreas, larynx, lung, melanoma, cervix, corpus uteri, ovary, testis, and Hodgkin's) than there were for other cancers arising after thyroid cancer (prostate, pharynx, small intestine). Given the large number of different cancers analyzed (34) one would expect a unidirectional statistically significant standardized incidence ratio for at least one, if not two, of the cancers that were studied. Notwithstanding the limitations of this type of analysis, we believe their data supports not only the concept of shared risk factors between thyroid cancer and several other second primary cancers, but also either 1) an effect of cancer treatment(s) to induce thyroid cancers or 2) a bias of ascertainment arising from thyroid cancer detection in patients monitored for other malignancies. Reference 1. Sandeep TC, Strachan MWJ, Reynolds RM, Brewster DH, Scélo G, Pukkala E, Hemminki K, Anderson A, Tracey E, Friis S, McBride ML, Kee-Seng C, Pompe-Kirn V, Kliewer EV, Tonita JM, Jonasson JG, Martos C, Boffetta P, Brennan P. 2006. Second Primary Cancers in Thyroid Cancer Patients: A Multinational Record Linkage Study J Clin Endocrin Metab 91:1819-1825