Genetic and Molecular Differences in Head and Neck Cancer Based on Smoking History

Area of Science:

• Genomics
• Molecular Biology
• Cancer Research

Background:

• Tobacco use is a significant risk factor for head and neck squamous cell carcinoma (HNSCC), contributing to chromosomal and epigenetic alterations.
• Understanding the molecular underpinnings of smoking's impact on HNSCC is crucial, even with the rise of HPV-associated cases.

Purpose of the Study:

• To investigate genetic and molecular differences in HNSCC patients based on their smoking history.
• To identify associated biological pathways affected by smoking in HNSCC.

Main Methods:

• Retrospective cohort study using The Cancer Genome Atlas (TCGA) data.
• Analysis included single nucleotide variation, copy number alteration, DNA methylation, and mRNA expression.
• Statistical analyses included FDR, Panther classification, Fisher exact test, and log-rank tests.

Main Results:

• Smokers showed enriched copy number alterations on chromosome 11q13 genes (FDR < 0.05).
• FADD and CTTN methylation differed between smokers and non-smokers; specific genes (PPFIA1, FGF19, CCND1, LTO1) showed higher mRNA expression in smokers.
• Altered FADD in smokers was associated with a higher risk of mortality (HR=1.40).

Conclusions:

• Smoking is associated with distinct genetic and molecular profiles in HNSCC, particularly involving chromosome 11q13.
• These smoking-induced genomic differences underscore smoking as a modifiable risk factor influencing HNSCC patient outcomes.