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. 2022 Sep;195(2):209-221.
doi: 10.1007/s10549-022-06674-5. Epub 2022 Jul 31.

Cancer-specific mortality in breast cancer patients with hypothyroidism: a UK population-based study

Lauren McVicker  1 , Christopher R Cardwell  2 , Stuart A McIntosh  3   4 , Úna C McMenamin  2
Affiliations

Cancer-specific mortality in breast cancer patients with hypothyroidism: a UK population-based study

Lauren McVicker et al. Breast Cancer Res Treat. 2022 Sep.

Abstract

Purpose: Epidemiological studies have indicated a higher prevalence of hypothyroidism in breast cancer patients, possibly related to shared risk factors and breast cancer treatments. However, few studies have evaluated how hypothyroidism impacts survival outcomes in breast cancer patients. We aimed to determine the association between hypothyroidism and breast cancer-specific and all-cause mortality.

Methods: We conducted a population-based study using the Scottish Cancer Registry to identify women diagnosed with breast cancer between 2010 and 2017. A matched comparison cohort of breast cancer-free women was also identified. Using hospital diagnoses and dispensed prescriptions for levothyroxine, we identified hypothyroidism diagnosed before and after breast cancer diagnosis and determined associations with breast cancer-specific and all-cause mortality. Cox proportional hazards regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) adjusted for potential confounders.

Results: A total of 33,500 breast cancer patients were identified, of which 3,802 had hypothyroidism before breast cancer diagnosis and 565 patients went on to develop hypothyroidism after. Breast cancer patients had higher rates of hypothyroidism compared with cancer-free controls (HR 1.14, 95% CI 1.01-1.30). Among breast cancer patients, we found no association between hypothyroidism (diagnosed before or after) and cancer-specific mortality (before: HR 0.99, 95% CI 0.88-1.12, after: HR 0.97, 95% CI 0.63-1.49). Similar associations were seen for all-cause mortality.

Conclusion: In a large contemporary breast cancer cohort, there was little evidence that hypothyroidism, either at diagnosis or diagnosed after breast cancer, was associated with cancer-specific or all-cause mortality.

Keywords: All-cause mortality; Breast cancer; Cancer-specific mortality; Hypothyroidism; Population-based study.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Flow diagram outlining the number of breast cancer patients with hypothyroidism
Fig. 2
Fig. 2
Sub-group and sensitivity analyses for the risk of cancer-specific mortality in patients with hypothyroidism diagnosed before breast cancer compared to patients without hypothyroidism. ER oestrogen receptor, HRT hormone replacement therapy
Fig. 3
Fig. 3
Sub-group and sensitivity analyses for the risk of cancer-specific mortality in patients with hypothyroidism diagnosed after breast cancer compared to patients without hypothyroidism. ER oestrogen receptor, HRT hormone replacement therapy
See this image and copyright information in PMC

References

    1. Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, et al. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin. 2021;71(3):209–249. doi: 10.3322/caac.21660. - DOI - PubMed
    1. Carioli G, Malvezzi M, Rodriguez T, Bertuccio P, Negri E, La Vecchia C. Trends and predictions to 2020 in breast cancer mortality in Europe. Breast. 2017;36:89–95. doi: 10.1016/j.breast.2017.06.003. - DOI - PubMed
    1. Allemani C, Minicozzi P, Berrino F, Bastiaannet E, Gavin A, Galceran J, et al. Predictions of survival up to 10 years after diagnosis for European women with breast cancer in 2000–2002. Int J Cancer. 2013;132(10):2404–12. doi: 10.1002/ijc.27895. - DOI - PubMed
    1. Land LH, Dalton SO, Jørgensen TL, Ewertz M. Comorbidity and survival after early breast cancer. A review. Crit Rev Oncol Hematol. 2012;81(2):196–205. doi: 10.1016/j.critrevonc.2011.03.001. - DOI - PubMed
    1. Rao AV, Demark-Wahnefried W. The older cancer survivor. Crit Rev Oncol Hematol. 2006;60(2):131–43. doi: 10.1016/j.critrevonc.2006.06.003. - DOI - PubMed