Chromosomal changes and clonality relationship between primary and recurrent hepatocellular carcinoma

Area of Science:

• Genomics
• Oncology
• Surgical Pathology

Background:

• Hepatocellular carcinoma (HCC) is a highly malignant cancer with a significant recurrence rate after surgery.
• Distinguishing between true HCC relapse and a new primary tumor is crucial for effective clinical management.
• Currently, a convenient method for this differentiation is lacking.

Purpose of the Study:

• To evaluate the utility of Comparative Genomic Hybridization (CGH) in differentiating true HCC relapse from second primary HCC.
• To analyze chromosomal aberration profiles for tumor clonality assessment in recurrent HCC.

Main Methods:

• Comparative Genomic Hybridization (CGH) was applied to 31 pairs of initial and recurrent HCC samples.
• Chromosomal aberration profiles were used as genomic fingerprints to determine tumor clonalities.
• Hepatitis B virus integration and X chromosome inactivation analyses were used for confirmation.

Main Results:

• Eleven recurrent tumors with high clonal relationship (CR) values (>0.95) were identified as relapsed HCCs.
• Eleven tumors with low CR values (close to 0) were identified as second primary HCCs.
• Relapsed HCCs exhibited significantly more chromosomal aberrations than de novo HCCs (mean 16.1 vs. 5.4 events).

Conclusions:

• CGH is a valuable tool for studying chromosomal aberrations and analyzing tumor clonality in HCC.
• Distinct genomic changes in initial HCC indicate that subsequent recurrence is likely a true relapse.
• CGH analysis provides a method to differentiate between HCC relapse and new primary tumors.