Background: Differentiated thyroid cancer is a common endocrine malignancy with an indolent course and a high overall survival rate. With more cases diagnosed early, survivors of this cancer live longer and hence are at risk of second primary cancers. In patients with known primary malignancy, work-up often focuses on the primary disease, so that coexistence of another primary malignant lesion can be missed.

Case Presentation: We report a case of a 78 year-old Filipino male diagnosed to have papillary thyroid cancer with nodal metastases presenting with an incidental rectosigmoid cancer on pre-operative workup.

Treatment and Outcome: Patient eventually underwent complete surgical removal of both malignancies. He is currently on levothyroxine suppression therapy with no evidence of tumor recurrence for both malignancy and is on close follow-up for cancer recurrence surveillance.

Conclusion: Clinical vigilance for cancer screening and surveillance is mandatory for patients diagnosed with any type of primary malignancy to reduce the rate of missing secondary primary malignancy simultaneously present in the same patient. Early cancer detection might improve cancer patient’s overall prognosis and eventually proved to be life-saving.

Keywords: Multiple Primary Malignant Neoplasms, Papillary Thyroid Cancer, Colon Cancer  

1. Gilliland FD, HuntWC, Morris DM & Key CR. Prognostic factors in thyroid carcinoma. A population-based study of 15 698 cases from the surveillance, epidemiology and end results (SEER) program 1973–1991. Cancer 1997 79 564–573.
2. Dos Santos Silva I, Swerdlow AJ. Thyroid cancer epidemiology in England and Wales: time trends and geographical distribution. British Journal of Cancer. 1993. 67:330–340
3. Reynolds RM, Weir J, Stockton DL, et.al. Changing trends in incidence and mortality of thyroid cancer in Scotland. Clinical Endocrinology (Oxford) 2005. 62:156–162
4. Schlumberger MJ. Papillary and follicular thyroid carcinoma. New England Journal of Medicine 1998 338 297–306.
5. Sandeep TC, Strachan MWJ, Reynolds RM, et.al. Second Primary Cancers in Thyroid Cancer Patients: A Multinational Record Linkage Study. The Journal of Clinical Endocrinology and Metabolism. 2006. 91(5): 1819-1825
6. Cancer survivors: living longer, and now, better. Lancet. 2004. 364: 2153-2154.
7. Cercato MC, Colella E, Ferraresi V, et.al. Report of Two Cases of Quintuple Primary Malignancies and Review of Literature. Anticancer Research. 2008. 28:2953-2958.
8. Zubaidi A. Multiple Primary Cancers of the Colon, Rectum and the Thyroid Gland. Saudi Journal of Gastroenterology. 2008. 14(4):202-205.
9. Brown AP, Chen J, Hitchcock YJ, Szabo A, Shrieve DC & Tward JD. The risk of second primary malignancies up to three decades after the treatment of differentiated thyroid cancer. Journal of Clinical Endocrinology and Metabolism. 2008 93 504–515.
10. Billroth T: Die Allgemeine Chirurgische Pathologie und Therapie in 51 Vorlesungen. In: Handbuch fur Studierende and Artze, 14. Berlin: Auflage, 1889 p. 908.
11. Warren S and Gates O: Multiple primary malignant tumors. A survey of the literature and a statistical study. American Journal of Cancer 1932. 16:1358-1414.
12. Moertel CG: Multiple primary malignant neoplasms: historical perspectives. Cancer 1977. 40: 1786-1792.
13. Crocetti E, Buiatti E, Falini P and the Italian Multiple Primary Cancer Working Group: Multiple primary cancer incidence in Italy. European Journal on Cancer. 2001. 37: 2449-2456.
14. Reingold SR, Neugut AI & Meadows AT. Second cancers: incidence, risk factors and management. In Cancer Medicine, pp 2399–2406. Eds JF Holland, E Frei, RE Pollock, RR Weichselbaum, RC Bast & DW Kufe : Hamilton, ON, Canada, 2000.
15. Duchateau CSJ & Stokkel MPM. Second primary tumors involving non-small cell lung cancer: prevalence and its influence on survival. Chest 2005 127 1152–1158.
16. Cybulski C, Gorski B, Huzarski T, et.al. CHEK2 is a multiorgan cancer susceptibility gene. American Journal of Human Genetics 2004 75 1131–1135
17. Dong C, Hemminki K. Second primary neoplasms among 53 159 haematolymphoproliferative malignancy patients in Sweden, 1958-1996: A search for common mechanisms. British Journal of Cancer. 2001;85:997–1005.
18. Ueno M, Muto T, Oya M, et.al. Multiple primary cancer: An experience at the Cancer Institute Hospital with special reference to colorectal cancer. International Journal in Clinical Oncology. 2003;8:162–7
19. Kim C, Bi X, Pan D, et.al. The Risk of Second Cancers After Diagnosis of Primary Thyroid Cancer Is Elevated in Thyroid Microcarcinomas. Thyroid 2013;23(5):575-82.
20. Lu CH, Lee KD, Chen PT, et.al. Second primary malignancies following thyroid cancer: a population-based study in Taiwan. European Journal of Endocrinology 2013;169:577-85.
21. Subramanian S, Goldstein DP, Parlea L, et.al. Second primary malignancy risk in thyroid cancer survivors: a systematic review and meta-analysis. Thyroid 2007;17(12):1277-88.
22. Cho YY, Lim J, Oh CM et.al. Elevated risks of subsequent primary malignancies in patients with thyroid cancer: a nationwide, population-based study in Korea. Cancer 2015;121(2):259-68.
23. Evans HS, Moller H, Robinson D, Lewis CM, Bell CM, Hodgson SV. The risk of subsequent primary cancers after colorectal cancer in southeast England. Gut. 2002;50:647–52