Histopathological Growth Patterns and Survival After Resection of Colorectal Liver Metastasis: an External Validation Study
Menée à partir de données portant sur 780 patients atteints d'un cancer colorectal avec métastases hépatiques traitées par résection, cette étude évalue la survie sans maladie et la survie globale à 5 ans en fonction du sous-type histologique des métastases (phénotype desmoplasique ou non)
Background : After resection of colorectal cancer liver metastases (CRLM) two main histopathological growth patterns can be observed; a desmoplastic and a non-desmoplastic subtype. The desmoplastic subtype has been associated with superior survival. These findings require external validation.
Methods : An international multicenter retrospective cohort study was conducted in patients treated surgically for CRLM at three tertiary hospitals in the US and the Netherlands. Determination of histopathological growth patterns was performed on hematoxylin & eosin stained sections of resected CRLM according to international guidelines. Patients displaying a desmoplastic histopathological phenotype (only desmoplastic growth observed) were compared to patients with a non-desmoplastic phenotype (any non-desmoplastic growth observed). Cut-off analyses on the extent of non-desmoplastic growth were performed. Overall (OS) and disease-free (DFS) survival were estimated using Kaplan-Meier and multivariable Cox analysis. All statistical tests were 2-sided.
Results : In total 780 patients were eligible. A desmoplastic phenotype was observed in 19.1% and was associated with microsatellite instability (14.6% versus 3.6%, p = .01). Desmoplastic patients had superior 5-year OS (73.4% [95% CI = 64.1–84.0] versus 44.2% [95% CI = 38.9–50.2], p < .001) and DFS (32.0% [95% CI = 22.9–44.7] versus 14.7% [95% CI = 11.7–18.6], p < .001) compared to their non-desmoplastic counterparts. A desmoplastic phenotype was associated with an adjusted hazard ratio for death of 0.36 (95% CI = 0.23–0.58), and 0.50 (95% CI = 0.37–0.66) for cancer recurrence. Prognosis was independent of KRAS and BRAF status. The cut-off analyses found no prognostic relationship between either OS or DFS and the extent of non-desmoplastic growth observed (all p > .1).
Conclusions : This external validation study confirms the remarkably good prognosis after surgery for CRLM in patients with a desmoplastic phenotype. The extent of non-desmoplastic growth does not impact prognosis.
JNCI Cancer Spectrum , article en libre accès, 2020