Publication: Breast cancer and autoimmune thyroid disease relationship: can hormonal factors or thyroglobulin gene polymorphism be the common factor?
Abstract
Amaç: Meme kanseri hastalarında otoimmun tiroid hastalıklarının (OİTH) sağlıklı populasyona oranla daha sık izlendiği saptanmıştır. Ancak bu ilişkinin nedeni henüz bilinmemektedir. Çalışmanın amacı meme kanserli hastalar ile sağlıklı kontroller arasında OİTH prevalansını karşılaştırmaktır. Çalışmada öngördüğümüz hipotez meme kanserli hastalarda OİTH prevalansının ve tiroglobulin (Tg) gen polimorfizminin meme kanseri ol- mayanlara oranla daha yüksek olduğudur. Yöntem ve Gereçler: Çalışma prospektif eşlikli-kohort olarak planlandı. Kontrol grubu katılımcılarının sayısı olgulara eşlikli 1:1 oranında belirlen- di. Marmara Ünivesitesi Hastanesi ne başvuran ardışık 100 meme kanseri hastası olgu grubunu, polikliniğe başvuran ve meme kanseri tanısı almamış 100 kişi de kontrol grubunu oluşturdu. Olgu ve kontrol grubundaki birey- lerden serum örneği alınarak tiroid otoantikor, tiroid hormon ve cinsiyet hormon düzeyleri ölçüldü. Sadece Tg gen polimorfizmi saptanmasında olgu grubundakilerden meme kanseri doku örneği alınırken, farklı kontrol grubu oluşturulacak şekilde hastane doku bankasından meme kanserli olgular ile eş yaş, cinsiyet ve ırkta bireyler seçilerek meme doku örnekleri kulanıldı. Bulgular: Olgu grubu (n=25) ile kontrol grubunda (n=18) OİTH saptanan kişi sayısı benzerdi. Tg geni ekson 33 ile beraber 10uncu ekson lokus 734 ve/veya 12nci ekson lokus 1028 polimorfizm prevalansları açısından da olgu grubu ile kontrol grubu arasında fark izlenmedi. Tüm kohortta östro- jen düzeyi OİTH olan kişilerde (89,75±84,4 pg/mL) OİTH olmayanlara (54,17±73,89 pg/mL) göre belirgin yüksek izlendi (p=0,01). Sonuç: Çalışmada meme kanserli hastalarda OİTH ve OİTHden so- rumlu Tg gen polimorfizminin daha sık görülmediği saptanmıştır. Ancak OİTHlilerde meme kanseri etyolojisinde rol aldığı düşünülen östrojen se- viyesinin yüksek olduğu görülmüştür.
Objective: Recent studies indicated an association between thyroid autoim- munity and breast cancer, but the causality still needed to be proven. The aim of this study was to compare the prevelance of autoimmune thyroid diseases (ATD) between breast cancer patients and the control group. We hypothesised that breast cancer patients have a higher ATD prevalance and higher thyroglobulin gene polymorphism rates than the control group. Materials and Methods: The study was designed as a prospective matched- cohort investigation. Control sample size was determined according to 1:1 matching with cancer cases. The study group included 100 consecutive breast cancer patients admitted to Marmara University Hospital , while the control group included 100 women admitted to outpatient clinics in whom breast cancer was ruled out. Thyroid autoantibody, thyroid and sex hormone levels were measured and compared between study and control groups. In order to compare Tg gene polymorphism rates between breast cancer and control groups, although cancer tissue samples were obtained from study patients, a different control group with the same age, sex and ethnicity with the study group was constituted from the hospital s tissue bank. Results: Autoimmune thyroid disease prevalances were similar between study (n=25) and control (n=18) groups. Tg gene polymorphism prevalences were also similar between the two groups. Estrogen levels were significantly higher in patients with ATD (89.75±84.4 pg/mL) when compared to those without (54.17±73.89 pg/mL). Conclusion: In conclusion, the prevalences of ATD and Tg polymorphism were similar between breast cancer cases and controls. As a significant find- ing, patients with ATD among all the cohort (with and without breast can- cer) had higher serum estrogen levels when compared to those without.
Objective: Recent studies indicated an association between thyroid autoim- munity and breast cancer, but the causality still needed to be proven. The aim of this study was to compare the prevelance of autoimmune thyroid diseases (ATD) between breast cancer patients and the control group. We hypothesised that breast cancer patients have a higher ATD prevalance and higher thyroglobulin gene polymorphism rates than the control group. Materials and Methods: The study was designed as a prospective matched- cohort investigation. Control sample size was determined according to 1:1 matching with cancer cases. The study group included 100 consecutive breast cancer patients admitted to Marmara University Hospital , while the control group included 100 women admitted to outpatient clinics in whom breast cancer was ruled out. Thyroid autoantibody, thyroid and sex hormone levels were measured and compared between study and control groups. In order to compare Tg gene polymorphism rates between breast cancer and control groups, although cancer tissue samples were obtained from study patients, a different control group with the same age, sex and ethnicity with the study group was constituted from the hospital s tissue bank. Results: Autoimmune thyroid disease prevalances were similar between study (n=25) and control (n=18) groups. Tg gene polymorphism prevalences were also similar between the two groups. Estrogen levels were significantly higher in patients with ATD (89.75±84.4 pg/mL) when compared to those without (54.17±73.89 pg/mL). Conclusion: In conclusion, the prevalences of ATD and Tg polymorphism were similar between breast cancer cases and controls. As a significant find- ing, patients with ATD among all the cohort (with and without breast can- cer) had higher serum estrogen levels when compared to those without.