Purpose To assess the prognostic value of EGFR molecular characteristics of head and neck squamous cell carcinoma (HNSCC). Patients and Methods HNSCC tumors from patients prospectively enrolled in either an Early Detection Research Network (EDRN) study and treated with surgery without an EGFR-targeted agent (N=154) or enrolled in a chemoradiation trial involving the EGFR-targeted antibody cetuximab (N=39) were evaluated for EGFR gene amplification by fluorescence in situ hybridization (FISH) and EGFR protein by immunohistochemical (IHC) staining. Fresh-frozen tumors (EDRN) were also evaluated for EGFR protein and site-specific phosphorylation at Y992 and Y1068 using reverse-phase protein array (RPPA) (n=67). Tumor (n=50) EGFR and EGFRvIII mRNA levels were quantified using real-time PCR. Results EGFR expression by IHC was significantly higher in the EDRN tumors with EGFR gene amplification (P<0.001), and a similar trend was noted in the cetuximab-treated cohort. In the EDRN and cetuximab-treated cohorts elevated EGFR by IHC was associated with reduced survival (p=0.019 and p=0.06, respectively). Elevated expression of total EGFR and EGFR PY1068 were independently significantly associated with reduced progression-free survival in the EDRN cohort (HR=2.75; 95% CI=1.26–6.00 and HR=3.29; 95% CI=1.34–8.14, respectively). Conclusions In two independent HNSCC cohorts treated with or without cetuximab, tumor EGFR levels were indicative of survival. Tumor EGFR PY1068 levels provided prognostic information independent of total EGFR.

The significance of KRAS mutant allele-specific imbalance (MASI) in lung adenocarcinomas is unknown. KRAS MASI was defined as predominance of the mutant allele over the wild-type allele. We assessed the frequency of KRAS MASI by comparing peak heights of mutant and wild-type alleles on sequencing electropherograms and by KRAS fluorescence in situ hybridization (FISH). A review of sequencing electropherograms of 207 KRAS-mutated lung adenocarcinomas demonstrated 23 (11%) cases with the mutant allele peak higher than the wild-type allele peak and 15 (7%) cases with the mutant allele peak equal to the wild-type allele peak. Of 17 cases with the mutant allele peak higher or equal to the wild-type allele peak, 8 (47%) showed KRAS amplification by FISH. KRAS FISH analysis of 36 KRAS-mutated lung adenocarcinomas with the mutant allele peak lower than the wild-type allele peak, 21 KRAS and EGFR wild-type and 16 EGFR-mutated adenocarcinomas showed no KRAS amplification. KRAS MASI was associated with selective amplification of the KRAS mutant allele (Po0.001). Patients with KRAS MASI showed worse overall survival. The cumulative proportion surviving at 17 months for KRAS MASI group was 35% compared with 84.1% for patients with KRAS mutant allele peak lower than wild-type allele peak (P ¼ 0.012). The adverse prognostic significance of KRAS MASI was independent of clinical stage and was maintained among stage I patients. The detection of KRAS MASI in lung adenocarcinomas by sequencing electropherograms may identify patients with more aggressive disease.

Sox2 amplification was recently reported as a common event in squamous cell carcinomas (SCCs) occurring at different anatomic sites including the lung. The objective of the study was to determine morphologic and clinicopathologic characteristics of lung SCCs with respect to Sox2 protein expression and gene amplification. One hundred forty-seven surgically treated non-small cell lung carcinomas were analyzed for Sox2 gene amplification by using fluorescence in situ hybridization and protein expression using immunohistochemical analysis. SCC showed more frequent Sox2 protein expression (52/66; 79%) than adenocarcinomas (ADC) (14/76; 18%) (P < .0001). Similarly, Sox2 amplification was more frequent in SCCs (52/70; 72%) than in ADCs (6/77; 8%) (P < .0001). Sox2 protein expression was associated with better overall survival in SCC (66 vs 14 months; P =.048). SCC with basaloid differentiation and severe nuclear atypia exhibited more intense Sox2 protein expression than other tumors. Sox2 appears to be an important gene in lung squamous cell carcinogenesis that in particular drives the development of poorly differentiated tumors.