Gene Associated with Benign Breast Tumors Discovered

MedicalResearch.com Interview with
Dr Lim Weng Khong
Research Fellow, National Cancer Centre Singapore.

Medical Research: What are the main findings of the study?

Dr Lim Weng Khong: This study uncovered the genetic cause fibroadenomas, which are very common benign breast tumours in women. The team from National Cancer Centre Singapore, Singapore General Hospital and Duke-NUS Graduate Medical School identified a critical gene called MED12 that has frequent durations in a remarkable 60 per cent of fibroadenomas studied. Their findings have been published in the top-ranked journal Nature Genetics.

Medical Research: Were any of the findings unexpected?

Dr Lim Weng Khong: The main unexpected finding of the study was that the MED12 mutations were only present in stromal cells in the tumour. Fibroadenomas consist of a mixed population of epithelial and stromal cells. Typically, stromal cells in breast cancer are thought of as innocent, or at least secondary bystanders. We performed LCM (laser capture microdissection) and sequenced the two cell populations separately. Only the stromal cell population contained the MED12 mutation. This strongly suggests that fibroadenomas arise from an initial lesion in the stromal cells.

Medical Research: What should clinicians and patients take away from your report?

Dr Lim Weng Khong: This breakthrough understanding of the molecular basis of fibroadenomas may help in the clinical diagnosis of breast tumours. Measuring the MED12 gene in breast lumps will potentially help clinicians better be able to distinguish fibroadenomas, which are benign, from breast cancer. Currently, clinicians do face challenges of distinguishing fibroadenomas from malignant tumours as some benign tumours may “mimic” the characteristics of malignant ones.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr Lim Weng Khong: Future studies by our group will help further our understanding of the consequences of MED12 mutations.

Citation:

Weng Khong Lim, Choon Kiat Ong, Jing Tan, Aye Aye Thike, Cedric Chuan Young Ng, Vikneswari Rajasegaran, Swe Swe Myint, Sanjanaa Nagarajan, Nur Diyana Md Nasir, John R McPherson, Ioana Cutcutache, Gregory Poore, Su Ting Tay, Wei Siong Ooi, Veronique Kiak Mien Tan, Mikael Hartman, Kong Wee Ong, Benita K T Tan, Steven G Rozen, Puay Hoon Tan, Patrick Tan, Bin Tean Teh. Exome sequencing identifies highly recurrent MED12 somatic mutations in breast fibroadenoma. Nature Genetics, 2014; DOI: 10.1038/ng.3037