Affiliation:
1. Thyroid Research Institute, School of Medicine, Southern University of Science and Technology , Shenzhen, Guangdong 518055 , China
Abstract
Abstract
Context
The clinical relevance of the well-known association between thyroid cancer (TC) and breast cancer (BC) remains to be further defined.
Objective
This work aimed to investigate the effect of history of BC on the prognosis of TC.
Methods
This was a comparative cohort study of tumor behaviors and TC-specific mortality in 5598 patients with papillary thyroid cancer (PTC) and 604 patients with follicular thyroid cancer (FTC), all with a history of BC (TC-BC patients), and their propensity score–matched TC patients without a history of BC (TCnoBC patients) in Surveillance, Epidemiology and End Results (SEER) 18. The main outcome measure was TC-specific mortality.
Results
Lower TC distant metastasis rates of 2.4% vs 3.0% in PTC and 6.1% vs 9.1% in FTC and TC-specific mortality rates of 1.3% vs 2.6% in PTC and 5.8% vs 8.4% in FTC were found in TC-BC patients vs matched TCnoBC patients (all P < .05). Comparing TC-BC patients with matched TCnoBC patients, hazard ratios (HRs) for mortality were 0.472 (95% CI, 0.370-0.601) in PTC and 0.656 (95% CI, 0.461-0.934) in FTC (all P < .05). Such HRs for mortality in PTC were 0.397 (95% CI, 0.268-0.588; P < .001) when TC occurred before BC vs 0.607 (95% CI, 0.445-0.827; P = .002) when BC occurred before TC.
Conclusion
This study demonstrates a robust protective effect of a history of BC on TC-specific patient survival, which has strong implications for more precise prognostication of TC in such patients.
Funder
Guangdong Training Program of Science and Technology Innovation Cultivation Special Fund
Subject
Biochemistry (medical),Clinical Biochemistry,Endocrinology,Biochemistry,Endocrinology, Diabetes and Metabolism