Case study 4 Colorectal Cancer
A colonoscopy performed on a 58-year-old woman with persistent abdominal discomfort
revealed several colorectal adenomas and a suspected carcinoma within the large intestine.
Biopsy analysis of suspected carcinoma tissue by a pathologist led to a diagnosis of colorectal
adenocarcinoma. Next generation sequencing was performed on the tumour sample.
List of genomic variants identified using next generation sequencing
ID | Chromosome | Gene | Function | Zygosity | Base change |
Amino acid change |
COSV57322109 | 5q22.2 | APC | Missense | Heterozygous | c.3949G>C | p.E1317Q |
COSV55497469 | 12p12.1 | KRAS | Missense | Heterozygous | c.34G>T | p.G12C |
COSV56058907 | 7q34 | BRAF | Synonymous | Heterozygous | c.1929A>G | p.G643= |
COSV52661877 | 17p13.1 | TP53 | Missense | Heterozygous | c.733G>A | p.G245S |
TASK
You are required to analyse and interpret the genomic data linked to the case study and critically
discuss how the genomic analysis would help in patient diagnosis and therapeutic management.
1. Analyse the genomic data and identify the mutation(s) in genes that may be associated with
driving: (a) the initial pre-malignant stages; and (b) the subsequent development of colorectal
adenocarcinoma.
2. Discuss the relevance of the potentially pathogenic mutation(s) in terms of subtyping/categorising the colorectal cancer.
3. Suggest a bioinformatics workflow (pipeline) for secondary genomic data analysis utilizing
open-source tools to discover single nucleotide variants (SNVs) and small insertions and
deletions (Indels).
4. Critically discuss how the genomic analysis above would inform predicted prognosis for this
individual as well as screening of at-risk family members following identification of potentially
pathogenic variant(s).
5. The report should include a conclusion summarising your findings and highlighting possible
future directions in therapeutic management of colorectal cancers with the above genetic
profile.
Please ensure you adopt an evidence -based approach to your answers above using references to
support your ideas.