Sex differences and racial/ethnic disparities in the presentation and treatment of medullary thyroid cancer

Racial disparities in thyroid cancer outcomes: A systematic review

INTRODUCTION

Racial disparities in surgical outcomes are well described, but a paucity of literature exists examining trends in outcomes of thyroid cancer. We performed a systematic review of studies on thyroid cancer outcomes to better delineate the impact of race.

METHODS

A comprehensive search strategy was performed in several academic databases for articles on thyroid cancer and surgical outcomes in accordance with PRISMA guidelines. A total of 1771 abstracts were reviewed. Abstracts were screened by two independent reviewers with disagreements resolved by a third. Studies that were based in the United States, included single center, unique data, focused on outcomes of differentiated thyroid cancer, were performed on adults >18 years old, and reported race in their results were included. Chi square statistics with Yates correction were calculated on the compiled data. The protocol was registered on PROSPERO (CRD42022300021).

RESULTS

Twelve studies met inclusion criteria with data on 7,221patients. Among the included studies, our study consists of 67 ​% White patients, 22 ​% Black patients, 7 ​% Hispanic patients, and 3 ​% Asian patients. Extrathyroidal extension was observed in 8.4 ​% (n ​= ​13) of White patients. In comparison to White patients, Black (18.4 ​%, n ​= ​21, p ​= ​0.024) and Hispanic patients (28.3 ​%, n ​= ​30, p ​< ​0.001) had a higher incidence of extrathyroidal extension, while a similar incidence was observed in Asian patients (14.0 ​%, n ​= ​8, p ​= ​0.336). Compared to White patients (22.2 ​%, n ​= ​34), Black (12.4 ​%, n ​= ​13, p ​= ​0.065), Hispanic (16.0 ​%, n ​= ​15, p ​= ​0.301), and Asian (18.4 ​%, n ​= ​9, p ​= ​0.709) patients had a similar incidence of T1a stage. White patients had 10.1 ​% (n ​= ​54) recurrence rates, and Black (13.5 ​%, n ​= ​7, p ​= ​0.595), Hispanic (10.5 ​%, n ​= ​2, p ​= ​1.000), and Asian (11.1 ​%, n ​= ​3, p ​= ​1.000) patients had similar recurrence rates.

CONCLUSIONS

Race is seldom reported in outcomes on studies of thyroid cancer. From our analysis we conclude that non-White patients may have a higher risk of more advanced local disease at presentation. More data with granular detail on race is necessary to better understand racial disparities in thyroid cancer outcomes and how to alleviate them.

Critically evaluated key points on hereditary medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) accounts for only 3% of all thyroid carcinomas: 75% as sporadic MTC (sMTC) and 25% as hereditary MTC (hMTC) in the context of multiple endocrine neoplasia type 2 (MEN2). Early diagnosis is possible by determining the tumour marker calcitonin (Ctn) when clarifying nodular goitre and by detecting the mutation in the proto-oncogene RET in the MEN2 families. If the Ctn level is only slightly elevated, up to 30 pg/ml in women and up to 60 pg/ml in men, follow-up checks are advisable. At higher levels, surgery should be considered; at a level of > 100 pg/ml, surgery is always advisable. The treatment of choice is total thyroidectomy, possibly with central lymphadenectomy. In the early stage, cure is possible with adequate surgery; in the late stage, treatment with tyrosine kinase inhibitors is an option. RET A mutation analysis should be performed on all patients with MTC. During follow-up, a biochemical distinction is made between: healed (Ctn not measurably low), biochemically incomplete (Ctn increased without tumour detection) and structural tumour detection (metastases on imaging). After MTC surgery, the following results should be available for classification in follow-up care: (i) histology, Ctn immunohistology if necessary, (ii) classification according to the pTNM scheme, (iii) the result of the RET analysis for categorisation into the hereditary or sporadic variant and (iiii) the postoperative Ctn value. Tumour progression is determined by assessing the Ctn doubling time and the RECIST criteria on imaging. In most cases, "active surveillance" is possible. In the case of progression and symptoms, the following applies: local (palliative surgery, radiotherapy) before systemic (tyrosine kinase inhibitors).