The integration of Traditional Chinese Medicine (TCM) and Western Medicine in a multidisciplinary approach is the future direction for the diagnosis and treatment of Cancer-Related Fatigue (CRF). However, the lack of standard criteria for syndrome differentiation and treatment selection limits the application of TCM in Western and international contexts. Patients with CRF often experience fatigue associated with metabolic and energy balance abnormalities, with thyroid function playing a critical role in the body's energy metabolism and regulation.

To analyze the TCM syndrome characteristics of CRF and explore their correlation with thyroid function levels, providing a reference for the integrated diagnosis and treatment of CRF and mechanism research in both TCM and western medicine.

The study included cancer patients who visited the oncology outpatient and inpatient departments of the China Academy of Chinese Medical Sciences Xiyuan Hospital in 2021. General information of the patients was collected. The Chinese version of the Revised Piper Fatigue Scale (RPFS-CV) was used to assess patients' fatigue. Thyroid function tests, including triiodothyronine (T₃), thyroxine (T₄), free triiodothyronine (FT₃), free thyroxine (FT₄), thyroid-stimulating hormone, anti-thyroid peroxidase antibody (TPO-Ab), and thyroglobulin antibody, were collected on the day of or the day after enrollment. TCM syndrome characteristics of CRF patients were collected through a self-designed CRF TCM Four-Diagnostic Information Form. Spearman's rank correlation analysis was used to explore the correlation between RPFS-CV fatigue scores and thyroid function indicators. Point biserial correlation analysis was used to investigate the correlation between RPFS-CV fatigue scores, thyroid function indicators, and TCM syndrome characteristics of CRF.

A total of 159 CRF patients were included. The most common types of cancer were lung cancer (50 cases, 31.4%), breast cancer (23 cases, 14.5%), head and neck tumors (21 cases, 13.2%), rectal cancer (21 cases, 13.2%), and colon cancer (18 cases, 11.3%). The median diagnosis duration was 2.15 (3.16) years; 88 patients (55.3%) experienced recurrence or metastasis, with 40 patients (45.5%) having local recurrence and 38 patients (43.2%) having oligometastasis. The median duration of metastasis was 1.50 (2.83) years; 91 patients (57.2%) were in advanced stages, 101 patients (63.5%) had received antitumor treatment, and 57 patients (35.8%) had undergone chemotherapy. In TCM syndromes, deficiency syndromes with a frequency over 10% were Qi deficiency, heart deficiency, and spleen deficiency; among excess syndromes, those occurring more than 20 times were Qi stagnation and damp-cold. Syndromes with a median RPFS-CV fatigue score over 4 were, in descending order, damp-cold, Qi stagnation, spleen deficiency, heart deficiency, liver deficiency, damp-heat, and Qi deficiency. RPFS-CV fatigue scores were positively correlated with Qi deficiency, spleen deficiency, heart deficiency, liver deficiency, damp-cold, and Qi stagnation (P<0.05). RPFS-CV fatigue scores were negatively correlated with FT₃ and T₃ (P<0.05). Qi deficiency was positively correlated with T₄, Kidney deficiency with TPO-Ab, and Qi stagnation with FT₄ (P<0.05) ; Damp-heat was negatively correlated with T₃ and T₄ (P<0.05) .

The fatigue condition of CRF patients is closely related to TCM syndrome characteristics and thyroid function levels. Further research will help deepen the understanding of these correlations and promote the collaborative development of TCM and western medicine in the management of CRF disease.