|The following article features coverage from the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois. Click here to read more of Cancer Therapy Advisor‘s conference coverage.|
A retrospective analysis of next-generation sequencing (NGS) profiles has diagnostic and therapeutic implications for patients with soft-tissue or bone sarcoma, according to data reported at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago.1
Each sarcoma subtype reacts differently to treatment, making accurate histological diagnosis important. Determining lesions and matching them with appropriate treatment (treatment-linked alterations [TLA]) provides an opportunity to individualize therapy.
Two cohorts of patients were followed. The first was a global population of patients who underwent NGS profiling using a panel of 405 cancer-related genes in the DNA and 265 genes rearranged in the RNA. The second cohort was from the Memorial Sloan Kettering Cancer Center (MSKCC) in New York, New York, where outcomes were evaluated.
Mrinal Gounder, MD, of MSKCC, presented the analysis. “Can gene profiling aid/refine/modify diagnosis in sarcoma? And can gene profiling identify therapeutic targets in sarcoma?” he asked.
Of the 5749 patients who underwent NGS worldwide, 4900 had soft tissue sarcoma and rest had bone sarcoma. Fifty-six unique histologies were tested; the median age of patients was 52 years.
Dr Gounder reported that genetic profiling changed and refined the pathology in 8% of the entire cohort; of these, diagnosis was incorrect in 2%, was highly suspicious (ie, high probability of diagnostic error) in 4%, and refined in 2%. “This has impact on diagnosis and treatment,” he said.
In the entire cohort, there were about 62,000 mutations and about 1200 fusions. Sixteen percent of patients had a TLA known to respond to approved treatment, while 7% had a TLA that was matched to an investigational therapy.
Germline mutations suspected in 9% of patients constituted novel as well as known genes (eg BRCA, TP53, MUTYH, CD36).
Genetic profiles were analyzed for actionable mutations at 3 levels: level 1 (US Food and Drug Administration [FDA]-approved drugs available; level 2 (known biomarker with FDA-approved and National Comprehensive Cancer Network [NCCN]-recommended drugs, but for a different indication); level 3 (novel biomarkers and investigational drugs). No actionable mutations were reported for 41% of the patients, and 8%, 9%, and 40% had genetic profiles that corresponded with level 1, level 2, and level 3, respectively.
Fifty-seven percent of the MSKCC cohort had at least 1 TLA; 30% enrolled in a matched trial. Partial responses were noted for patients treated with inhibitors that targeted NTRK, IDH1, BRAF, PI3K/mTOR, MDM2, and SMARCB1, among others.
“Genetic profiling can change diagnosis, identify patients for targeted therapies, identify mutational burden, which may make patients candidates for immunotherapy, and can identify germline mutations,” Dr Gounder concluded.
Read more of Cancer Therapy Advisor‘s coverage of the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting by visiting the conference page.
- Gounder MM, Ali SM, Robinson V, et al. Impact of next-generation sequencing (NGS) on diagnostic and therapeutic options in soft-tissue and bone sarcoma. J Clin Oncol. 2017;34(suppl; abstr 11001).