Satellitosis or In-Transit Metastasis an Important Risk Factor for Skin Cancer Recurrence

Squamous cell carcinoma
Squamous cell carcinoma
The association of S-ITM with clinical outcomes in patients with cSCC are assessed to determine its prognostic implications.

Clinical staging systems for cutaneous squamous cell carcinoma (cSCC) may need to be updated to include satellitosis or in-transit metastasis (S-ITM) given its increased risk for recurrence and poorer survival. These findings were published in a paper in JAMA Dermatology.

Patient records from the Cleveland Clinic and Brigham and Women’s Hospital collected from 2010 to 2020 were retrospectively queried for this study. Patients (n=72) who had node-negative cSCC with S-ITM were compared with cohorts of patients with tumor stage III (T3N0; n=341), tumor stage IV (T4N0; n=36), node-positive (N1 to 3; n=70), or metastasis stage I (M1; n=19) disease and assessed for cSCC recurrence and disease-specific survival (DSS). S-ITM was defined as the presence of dermal lesions between the first-echelon lymphatic nodal basins and primary tumor.

The S-ITM cohort was comprised 82% men, aged median 73.9 (range, 31.6-95.8) years at diagnosis, 96% were White, and 35% were immunosuppressed.

At a median follow-up of 35.9 (range, 0.1-196.0) months, the 2-year cumulative cSCC recurrence rate was 30.1% and 5-year probability of DSS was 64.0% among all patients.

Stratified by disease, the 2-year cSCC recurrence incidence rate was highest in the S-ITM group (56.6%) followed by the N1 to 3 (53.2%), T4N0 (28.6%), and T3N0 (18.8%) cohorts. For 5-year DSS, survival was lowest for the N1 to 3 cohort (39.0%) followed by the S-ITM (41.0%), T4N0 (64.0%), and T3N0 (76.0%) groups.

Compared with S-ITM, patients with T3N0 (hazard ratio [HR], 0.21; 95% CI, 0.14-0.30; P <.001) and T4N0 (HR, 0.36; 95% CI, 0.19-0.68; P =.001) were at decreased risk for cSCC recurrence. Similarly, T3N0 (HR, 0.23; 95% CI, 0.15-0.35; P <.001) and T4N0 (HR, 0.37; 95% CI, 0.19-0.79; P =.006) were associated with decreased risk for disease-specific death.

N1 to 3 was associated with similar risk for cSCC recurrence (HR, 0.74; 95% CI, 0.48-1.14; P =.16) and DSS (HR, 0.77; 95% CI, 0.48-1.26; P =.30) as patients with S-ITM. Patients with M1 had similar DSS as patients with S-ITM (HR, 1.81; 95% CI, 0.84-3.93; P =.13).

This study may have been limited by not controlling for variation in treatment, it was noted.

The study authors concluded, “This multi-institutional cohort study suggests that S-ITM represents an aggressive risk factor for disease recurrence and skin cancer-related death associated with cSCC. While patients with this risk factor can be cured, the high recurrence risk and disease-related mortality should compel future cancer staging systems to formally incorporate S-ITM and should provide guidance to clinicians regarding intensified adjuvant and/or neoadjuvant therapy.”

Disclosure: Several authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.


Smile TD, Ruiz ES, Kus KJB, et al. Implications of satellitosis or in-transit metastasis in cutaneous squamous cell carcinoma: a prognostic omission in cancer staging systems. JAMA Dermatol. 2022;e220001. doi:10.1001/jamadermatol.2022.0001