Clinical Report: Concurrent Multiple Primary Colorectal Cancers with Divergent RAS Status

Overview

This case study presents a 77-year-old male with synchronous multiple primary colorectal cancers (SMPCRC) exhibiting divergent RAS mutation statuses.

Background

Synchronous multiple primary colorectal cancer (SMPCRC) is a rare condition characterized by the presence of multiple independent lesions. The mutation status of RAS genes is critical for guiding therapy, particularly regarding anti-EGFR treatments.

Data Highlights

No numerical data or trial data presented in the article.

Key Findings

• A 77-year-old male was diagnosed with four distinct colorectal lesions over three months.
• The primary rectal lesion exhibited mutations in KRAS and NRAS, while the sigmoid colon lesion was RAS/RAF/PIK3CA wild-type.
• Testing a single lesion could lead to conflicting treatment decisions regarding anti-EGFR therapy.
• The patient underwent a multimodal treatment approach due to age and intolerance to standard chemotherapy.
• No radiological evidence of recurrence was noted during 18 months of follow-up.

Clinical Implications

Molecular testing of all primary lesions in SMPCRC is necessary to guide treatment decisions.

Conclusion

The presence of molecular heterogeneity in SMPCRC necessitates comprehensive testing for effective treatment planning.

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