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Skeletal Muscle Metastasis in Patients With SMARCA4-Deficient Thoracic Tumors: A Retrospective Cohort Study
Xueyuan Chen1,2,3, Mengting Shi4,5, Yuwen Yang1,2,3
1Department of Medical Oncology, Sun Yatsen University Cancer Center, Guangzhou, China.
Abstract:
SMARCA4-deficient thoracic tumor (SDTT) is a malignant tumor with a poor prognosis that often presents with distant metastases at the time of clinical diagnosis. Skeletal muscle metastasis is a rare subtype of metastasis patterns, and there are limited studies about SDTT metastasis in skeletal muscle. Herein, we retrospectively analyzed the data of stage IV patients diagnosed with SDTT from May 2009 to June 2024. The clinical and genomic data, imaging features, and treatment information were collected. As a result, the study included 145 patients with metastatic SDTT, 17 with skeletal muscle metastases, and 128 without. The rate of skeletal muscle metastasis in SDTTs was 11.7%. Multivariate Cox regression analysis showed that skeletal muscle metastases (p = 0.014, hazard ratio 95% confidence interval [HR 95% CI] [2.90, 1.25-6.75]) and first-line chemoimmunotherapy (p < 0.001, HR 95% CI [0.31, 0.17-0.56]) were independent prognostic variables. Furthermore, patients with skeletal muscle metastases had a significantly shorter median overall survival (OS) than those without (13.20 vs. 18.6 months, p = 0.021) in metastatic SDTTs. The mutation rate of STK11 and KRAS was higher in the skeletal muscle metastasis group (62.50% vs. 15.52%, p = 0.008; 50.00% vs. 8.62%, p = 0.009). In conclusion, SDTTs exhibited a high rate of skeletal muscle metastases. Skeletal muscle metastases and first-line chemoimmunotherapy were independent prognostic factors for OS in SDTTs.
Insights
SMARCA4-deficient thoracic tumors (SDTT) frequently metastasize to skeletal muscle, impacting prognosis. Skeletal muscle metastases and first-line chemoimmunotherapy are key independent prognostic factors for overall survival in these patients.
Area of Science:
- Oncology
- Medical Research
- Genetics
Background:
- SMARCA4-deficient thoracic tumor (SDTT) is an aggressive malignancy with a poor prognosis.
- Distant metastases are common at diagnosis, but skeletal muscle metastasis is a rare and understudied pattern.
Purpose of the Study:
- To investigate the incidence and prognostic significance of skeletal muscle metastases in stage IV SDTT.
- To identify clinical, genomic, and imaging features associated with skeletal muscle metastasis in SDTT.
Main Methods:
- Retrospective analysis of 145 stage IV SDTT patients diagnosed between May 2009 and June 2024.
- Collection and analysis of clinical, genomic, imaging, and treatment data.
- Multivariate Cox regression analysis to identify independent prognostic variables.
Main Results:
- Skeletal muscle metastasis occurred in 11.7% of metastatic SDTT patients.
- Skeletal muscle metastases (HR 2.90) and first-line chemoimmunotherapy (HR 0.31) were independent prognostic factors for overall survival.
- Patients with skeletal muscle metastases had significantly shorter median overall survival (13.20 vs. 18.6 months).
- Higher mutation rates of STK11 (62.50%) and KRAS (50.00%) were observed in the skeletal muscle metastasis group.
Conclusions:
- SDTT demonstrates a notable rate of skeletal muscle metastasis.
- Skeletal muscle metastasis is an independent negative prognostic factor for overall survival in SDTT.
- First-line chemoimmunotherapy is an independent positive prognostic factor for overall survival in SDTT.
