Page 30 - HKSEMR2020 Programme book

Poster Presentation (Clinical) Abstracts

Thyroid immune-related adverse events in cancer patients treated

with anti-PD1/anti-CTLA4 immune-checkpoint inhibitor combination

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David Tak Wai Lui , Chi Ho Lee , Vikki Tang , Carol Ho Yi Fong , Joanne Wing Yan Chiu ,
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Roland Ching Yu Leung , Gerry Gin Wai Kwok , Bryan Cho Wing Li , Tan To Cheung , Yu
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Cho Woo , Karen Siu Ling Lam , Thomas Yau 1
1. Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China; 2. Department
of Surgery, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China
Introduction / Background / Objectives: hepatocellular carcinoma, a cancer of increased prevalence
in Asians. 47.2% of patients had prior anti-PD1 exposure, and
Thyroid immune-related adverse events (irAEs) have been reported
to carry prognostic significance among cancer patients treated 17.1% were on concurrent tyrosine kinase inhibitors (TKIs) with
with anti-PD1 and anti-PDL1 monotherapies. However, there combination immune-checkpoint inhibitors. Upon a median follow-
are scanty data in the literature about the clinical course and up of 7.4 months, 27 patients (22.0%) developed thyroid irAEs at a
prognostic significance of thyroid irAEs in the routine clinical use median of 17.4 weeks (inter-quartile range 5.1-36.4). Among them,
of combination anti-PD1/anti-CTLA4 treatment in advanced cancer 6 (22.2%) initially presented with hyperthyroidism, and 21 (77.8%)
patients. We aimed to describe the clinical course of thyroid irAEs, initially presented with hypothyroidism. Eventually, 14 (51.9%) of
identify the potential predictors of thyroid irAEs, and evaluate these 27 patients who developed thyroid irAEs required thyroxine
the potential relationship between thyroid irAEs and outcomes of replacement in the long run. Systemic steroid was not required
advanced cancer patients treated with combination anti-PD1/anti- in all cases. The number of cycles of combination anti-PD1/anti-
CTLA4. CTLA4 and concurrent TKI use independently predicted incident
thyroid irAEs. Multivariable Cox regression analysis revealed that
occurrence of thyroid irAEs was independently associated with
Methods: better OS (adjusted hazard ratio 0.530, 95% CI 0.286-0.982).
We conducted a territory-wide study and identified advanced
cancer patients who received at least one cycle of combination Conclusion:
anti-PD1/anti-CTLA4 from 1 January 2015 to 31 December 2019
in Hong Kong. Thyroid function tests (TFTs) were monitored every Our current study suggested the potential prognostic significance
three weeks. Thyroid irAE was defined by at least two abnormal of thyroid irAEs among advanced cancer patients treated with
TFTs after initiation of combination anti-PD1/anti-CTLA4 in the combination anti-PD1/anti-CTLA4. In routine clinical practice,
absence of other causes. Overall survival (OS) was calculated from thyroid irAEs are common among cancer patients treated with
the date of initiation of combination anti-PD1/anti-CTLA4 to the combination anti-PD1/anti-CTLA4. The concurrent use of TKIs
date of death or the last follow-up. Events were censored on 30 increases the risk of thyroid irAEs. Regular monitoring of TFTs is
June 2020. advised for timely treatment of thyroid irAEs to prevent potential
complications associated with untreated thyroid disorders.

Results / Outcomes:
One hundred and twenty-three patients were included (mean
age 57.6±11.4 years; 75.6% men). Over 50% of patients had

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