Shravan K Yellenki, Mioara Gavrila, Elizabeth M Algar
Genetics and Molecular Pathology, Monash Health, 246 Clayton Rd, Clayton, VICTORIA
1 in 3 Australian men and 1 in 4 Australian women will be diagnosed with cancer before the age of 75. Cancer treatment has changed significantly over the past 10 years with the introduction of targeted therapies that result in less severe adverse effects compared to traditional chemotherapy. The ascertainment of genetic alterations in cancer is of increasing importance for informing the choice of targeted therapies.
Targeted molecular testing in adult cancer was implemented in the Genetics and Molecular Pathology laboratory at Monash Health at the end of 2014. In two years, 800 molecular tests have been performed on 600 tumour specimens from lung, colorectal, melanoma, thyroid and brain cancer. On average, 45% of mutation screening requests have been for EGFR in lung cancer, 22% for KRAS in colorectal cancer,10% for NRAS in colorectal cancer, melanoma or thyroid cancer, and 24% for BRAF in melanoma, thyroid or brain cancer.
Our method of choice for mutation screening has been the CE IVD Vienna Labs Strip Assay. These are mutant-enriched PCR-based assays that employ reverse hybridisation to detect clinically actionable mutations in EGFR (exons 18-21), KRAS (exon 2,3,4), NRAS (exon 2,3,4) and BRAF (exon 15). The assay utilizes 1-10ng of DNA and reliably detects to a sensitivity of 5% allowing testing of very small biopsy and cytology samples with low tumour content. A minimal equipment outlay is all that is required for set-up. Between 96-99% of clinically relevant mutations are covered by the assays. In our experience, the Strip Assay offers a flexible, rapid and sensitive test platform that although widely used in Europe has not been widely adopted in Australia yet for clinical testing.
Mioara is a senior scientist in the Genetics and Molecular Pathology laboratory at Monash Health. Previously she was in charge of Molecular Genetics Department at Australian Clinical Labs. She has 18 year experience in public and private NATA accredited molecular pathology services.