(ChemotherapyAdvisor) – Architectural grading of invasive pulmonary adenocarcinomas (ADCs) using the novel International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society Classification System “is a rapid, straightforward, and efficient discriminator for patient prognosis and may support patient stratification for adjuvant chemoradiotherapy,” investigators concluded in the Journal of Clinical Oncology online March 5.
To improve treatment of ADCs further, the system “should be part of an integrated clinical morphologic, and molecular subtyping,” they added. The goal of the study was to analyze and validate the prognostic impact of the proposed system for classification of ADCs across all tumor types.
The investigators analyzed the architectural pattern of 500 patients with resected ADCs stages I to IV in 5% increments. Each ADC was classified according to predominant architecture: lepidic, acinar, solid, papillary, or micropapillary. Histomorphologic data were subsequently correlated with clinical data, adjuvant therapy, and patient outcome.
By predominant ADC, overall survival (OS) was 78.5 months for lepidic, 67.3 months for acinar, 58.1 months for solid, 48.9 months for papillary, and 44.9 months for micropapillary (P=0.007). For pattern group 1, OS was 78.5 months; group 2, 67.3 months; and group 3, 57.2 months (P=0.001). Comparable differences for OS, disease-specific, and disease-free survival were observed among the pattern groups. For all three survival parameters, pattern and pattern groups were stage- and therapy-independent prognosticators.
They found that survival differences by pattern were influenced by adjuvant chemoradiotherapy; specifically, tumors that were predominantly solid had improved prognosis with adjuvant radiotherapy. Predominant pattern was tightly linked to the risk of developing nodal metastases (P<0.001).