For years, clinicians treating thyroid cancer have recognized that anxiety can influence treatment preferences, including decisions about the extent of surgery. A newly validated instrument, the Thyroid Cancer Modified Anxiety Scale (TC-MAX), developed by investigators at Cedars-Sinai Cancer, provides a thyroid cancer-specific measure of patient-reported anxiety that may help inform shared decision-making [1].
Key Takeaways
- TC-MAX is a validated instrument designed specifically to measure thyroid cancer-related anxiety, tested in more than 1,150 patients across development and validation cohorts [1].
- The 18-item scale measures three domains: general cancer-related anxiety, anxiety associated with surveillance ultrasound, and fear of cancer progression or recurrence [1].
- Anxiety scores were associated with treatment choice, including active surveillance, hemithyroidectomy, and total thyroidectomy [1].
- The instrument demonstrated high internal consistency, test-retest reliability, and correlations with established measures of distress and quality of life in both internal and external validation cohorts [1].
- Clinically meaningful differences in TC-MAX scores were identified between patients choosing active surveillance versus surgery, and between patients choosing hemithyroidectomy versus total thyroidectomy [1].
A Diagnosis That Can Produce Significant Anxiety
Thyroid cancer differs from many other solid tumors in its clinical course. In most cases, particularly small papillary thyroid carcinomas, tumors grow slowly and have an excellent long-term prognosis. For appropriately selected patients with low-risk disease, active surveillance, involving regular clinical and ultrasound monitoring rather than immediate surgery, is an established management approach.
Onco’Zine has previously reported on a Cedars-Sinai-led clinical trial in which patients with low-risk thyroid cancer who selected active surveillance experienced less anxiety over time than patients who underwent immediate surgery [2].
Despite the favorable prognosis associated with many thyroid cancers, patients can experience substantial anxiety after diagnosis. That anxiety may influence treatment preferences and decisions about surgery. General distress instruments, including the Distress Thermometer and Hospital Anxiety and Depression Scale (HADS), measure broader psychological distress but were not developed specifically for thyroid cancer. TC-MAX was designed to address thyroid cancer-related concerns, including anxiety surrounding surveillance and the possibility of recurrence or progression [1].
Building and Testing TC-MAX
The Cedars-Sinai research team, led by senior author Allen S. Ho, MD, professor of Surgery and co-director of the Thyroid Cancer Program at Cedars-Sinai Cancer, developed TC-MAX in four stages [1]. The first stage included a systematic literature review, input from a four-member expert panel, and ten patient focus groups to identify factors contributing to thyroid cancer-specific anxiety. The second stage refined the questionnaire through pilot testing in 59 patients, additional expert review, and patient feedback. The instrument was then internally validated in 148 patients and externally validated in a separate cohort of 1,002 patients. All participants had papillary thyroid cancer, the most common thyroid cancer subtype [1].
TC-MAX contains 18 items organized into three subscales:
- Collective Anxiety, which measures general cancer-related anxiety.
- Ultrasound Anxiety, which measures anxiety associated with surveillance imaging.
- Fear of Recurrence/Progression, which measures concern about cancer returning or progressing.
Scores range from 0 to 100, with higher scores indicating greater anxiety [1]
Psychometric Performance
In the internal validation cohort, TC-MAX demonstrated high internal consistency, with a Cronbach’s α of 0.93, and strong test-retest reliability, with an intraclass correlation coefficient of 0.86 [1]. The instrument also correlated with established measures of psychological distress and quality of life. Correlations were 0.56 with the Distress Thermometer, 0.52 with HADS, and −0.50 with the Functional Assessment of Cancer Therapy-General (FACT-G), indicating that higher TC-MAX scores were associated with lower quality of life [1]. Exploratory and confirmatory factor analyses supported the three-subscale structure.
The external validation cohort of 1,002 patients produced similar results. Internal consistency was 0.94, test-retest reliability was 0.87, and correlations with the Distress Thermometer, HADS, and FACT-G were 0.54, 0.67, and −0.62, respectively [1]. The findings support the reliability and construct validity of TC-MAX across both the original and external validation cohorts.
Score Categories and Clinically Meaningful Differences
The investigators also established score categories of low (0–26), moderate (26–43), and severe (43–100). Agreement between the internal and external cohorts was high, with a weighted κ of 0.84 [1]. The study also examined minimal clinically important differences (MCIDs), defined as the smallest change in score considered meaningful to patients. These differences were anchored to treatment decisions observed in the study population.
Patients who selected surgery rather than active surveillance had a mean TC-MAX score of 42.6 compared with 25.9 among patients who selected active surveillance, a difference of 16.7 points [1]. Among patients choosing surgery, those who selected total thyroidectomy had a mean score of 50.5 compared with 33.6 among patients who selected hemithyroidectomy, a difference of 16.9 points [1]. These findings show that higher levels of thyroid cancer-related anxiety were associated with more extensive treatment choices in the study population.
Anxiety and Treatment Choice
The relationship between TC-MAX scores and treatment selection was also examined among patients for whom active surveillance, hemithyroidectomy, and total thyroidectomy were considered medically reasonable options [3] Patients with higher anxiety scores were more likely to select total thyroidectomy, patients with intermediate scores were more likely to select hemithyroidectomy, and patients with lower scores were more likely to select active surveillance [3].
This association does not establish that anxiety causes patients to choose more extensive surgery. Treatment decisions are influenced by multiple factors, including tumor characteristics, physician recommendations, patient preferences, perceived risk, and psychological distress. The findings do, however, provide a measurable association between thyroid cancer-related anxiety and treatment choice and support further study of how psychological factors contribute to management decisions in patients with clinically indolent disease.
What TC-MAX Does Not Yet Establish
TC-MAX is a measurement instrument, not a treatment intervention. The current study demonstrates that anxiety can be measured reliably and that TC-MAX scores are associated with treatment choice. It does not establish that administering the questionnaire changes treatment decisions or reduces unnecessary surgery.
Whether using TC-MAX before a treatment discussion can help patients make decisions that are more consistent with their clinical risk and personal preferences remains an open question. Prospective studies will be needed to determine whether measuring thyroid cancer-specific anxiety and addressing it during clinical encounters changes treatment selection.
The validation cohorts also consisted specifically of patients with papillary thyroid cancer. It remains uncertain how TC-MAX will perform in other thyroid cancer histologies or in patients with more advanced disease.
Clinical Trials Using TC-MAX
A prospective study is now evaluating TC-MAX as part of a structured pre-clinic education intervention. Registered on ClinicalTrials.gov as Pre-Clinic Visit Online Education for Thyroid Cancer (NCT07690839), the study administers the 18-item TC-MAX questionnaire at baseline, one day after, and 14 days after a clinic visit, together with the Decisional Conflict Scale [4]. The study is designed to evaluate whether pre-visit education affects patient anxiety and decision-making regarding thyroid cancer treatment [4]. Its results may help determine whether addressing anxiety earlier in the care pathway changes subsequent treatment decisions.
Related Onco’Zine Coverage
- Active Surveillance May be an Effective Option for Low-risk Thyroid Cancer. Onco’Zine. September 2022. Onco’Zine. Online. Last accessed on September 1, 2026
Clinical Trials
Pre-Clinic Visit Online Education for Thyroid Cancer – ClinicalTrials.gov ID NCT07690839
References
[1] Bastien AJ, Kim S, Zalt C, Cong I, Ng J, Marshall C, Almario CV, Liran O, Spiegel BMR, Mallen-St Clair J, Walgama ES, Scher KS, Jang JK, Chen Y, Zhang S, Bloom G, Chen MM, Peterson KL, Sacks WL, Zumsteg ZS, Ho AS. The Thyroid Cancer Modified Anxiety Scale (TC-MAX): Development and External Validation of a Thyroid Cancer Distress Instrument. Thyroid. 2026 Aug 11. doi:10.1177/10507256261475819. Online ahead of print. PMID: 42578929.
[2] Onco’Zine. Active Surveillance May be an Effective Option for Low-risk Thyroid Cancer. September 2022. Online. Last accessed on September 4, 2026.
[3] Cedars-Sinai Health Sciences University. Research Tip Sheet: Cancer, Brain and Microbiome Studies—New Tool Measures Thyroid Cancer Patients’ Anxiety. Press release, 2026. Online. Last accessed on September 4, 2026.
This article is intended for informational purposes for healthcare professionals and does not constitute medical advice. TC-MAX is a research and clinical assessment instrument; it is not a diagnostic test and does not itself determine treatment.
Featured image: Doctor explaining diagnosis to her female patient. © 2017 – 2026 Fotolia/Adobe. Used with permission/
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