Survivorship Care Plans Improve the Identification of Post-radiation Hypothyroidism After Head and Neck Cancer Treatment

Background/aim: Survivorship care programs (SCPs) educate patients on post-treatment side-effects, which may lead to earlier identification and mitigation of their impact. This study assessed the impact of SCP on identification and management of post-treatment hypothyroidism in a head and neck cancer population and evaluated socio-demographic factors in the effectiveness of SCPs.

Patients and methods: A retrospective analysis was performed of sociodemographic and clinical characteristics of patients with head and neck cancer treated with radiation therapy between January 2011 and January 2019 at a large community cancer institution. Development of hypothyroidism was defined as elevated thyroid-stimulating hormone (TSH) or initiation of supplementation post-treatment. Cumulative incidence of hypothyroidism was analyzed with Gray's method.

Results: Of 608 patients, 483 (79%) had post-treatment TSH surveillance. A total of 203 (42%) of those patients developed hypothyroidism; 53 (11%) patients completed SCPs. The median follow-up was 1.4 (interquartile range=0.7-2.6) years with a median time until diagnosis of hypothyroidism of 1.2 (interquartile range=0.7-2.1) years. The median time to diagnosis was 12.0 months with SCP versus 14.2 months without. Race and insurance status were not associated with differences in thyroid surveillance. Patients with laryngeal cancer were at greatest risk of developing hypothyroidism (hazard ratio=1.92, confidence interval=1.44-2.56; p<0.077). Cumulative incidence of post-treatment hypothyroidism was higher in patients managed with SCP, 65.4% at 4 years, compared to those without (49.0%). Receipt of SCP was independently associated with an increased incidence of hypothyroidism detection (hazard ratio=1.51, confidence interval=1.04-2.20; p=0.030).

Conclusion: In our experience, SCP utilization was independently associated with a diagnosis of hypothyroidism. This study supports implementation of a survivorship program for identification and management of post-treatment sequelae.