Cancer-Associated Mutations in Endometriosis without Cancer
Endometriosis, defined as the presence of ectopic endometrial stroma and epithelium, affects approximately 10% of reproductive-age women and can cause pelvic pain and infertility. Endometriotic lesions are considered to be benign inflammatory lesions but have cancerlike features such as local invasion and resistance to apoptosis.
We analyzed deeply infiltrating endometriotic lesions from 27 patients by means of exomewide sequencing (24 patients) or cancer-driver targeted sequencing (3 patients). Mutations were validated with the use of digital genomic methods in microdissected epithelium and stroma. Epithelial and stromal components of lesions from an additional 12 patients were analyzed by means of a droplet digital polymerase-chain-reaction (PCR) assay for recurrent activating KRAS mutations.
Exome sequencing revealed somatic mutations in 19 of 24 patients (79%). Five patients harbored known cancer driver mutations in ARID1A, PIK3CA, KRAS, or PPP2R1A, which were validated by Safe-Sequencing System or immunohistochemical analysis. The likelihood of driver genes being affected at this rate in the absence of selection was estimated at P=0.001 (binomial test). Targeted sequencing and a droplet digital PCR assay identified KRAS mutations in 2 of 3 patients and 3 of 12 patients, respectively, with mutations in the epithelium but not the stroma. One patient harbored two different KRAS mutations, c.35G→T and c.35G→C, and another carried identical KRAS c.35G→A mutations in three distinct lesions.
We found that lesions in deep infiltrating endometriosis, which are associated with virtually no risk of malignant transformation, harbor somatic cancer driver mutations. Ten of 39 deep infiltrating lesions (26%) carried driver mutations; all the tested somatic mutations appeared to be confined to the epithelial compartment of endometriotic lesions.
Supported in part by the Richard W. TeLinde Gynecologic Pathology Research Program at Johns Hopkins University, the Virginia and D.K. Ludwig Fund for Cancer Research, the Ephraim and Wilma Shaw Roseman Foundation, the Endometriosis Foundation of America, the National Institutes of Health and National Cancer Institute (grants P50-CA62924, CA06973, GM07184, GM07309, CA09243, CA57345, P30-CA006973, CA215483, and UO1-CA200469), the Gray Family Ovarian Clear Cell Carcinoma Research Resource, the Canadian Cancer Society (grant 701603), the Canadian Institutes of Health Research (IHD-137431 and MOP-142273), the Canadian Foundation for Innovation (John R. Evans Leaders Fund) and British Columbia Knowledge Development Fund, the Women’s Health Research Institute (Nelly Auersperg Grant), and the Canadian Foundation for Women’s Health (General Research Grant). The BC Women’s Hospital and Health Centre Foundation provided support to the BC Women’s Centre for Pelvic Pain and Endometriosis. The BC Cancer Foundation and the VGH and UBC Hospital Foundation provided funding to OVCARE: BC’s Ovarian Cancer Research Team (Dr. Anglesio, Dr. Nazeran, Dr. Horlings, Ms. Lum, Ms. Senz, Ms. Ho, Ms. Lac, Dr. Tessier-Cloutier, Ms. Wang, Dr. Boyd, Dr. Gilks, Dr. Yong, and Dr. Huntsman), including donations from David and Darrell Mindell, Peter and Shelley O’Sullivan, and the Jemini Foundation to directly support this research. The Mentored Clinician-Scientist Award of the Vancouver Coastal Health Research Institute provided support to Dr. Yong. The Dr. Chew Wei Memorial Professorship in Gynecologic Oncology and the Canada Research Chairs program (Research Chair in Molecular and Genomic Pathology) provided support to Dr. Huntsman. The Dutch Cancer Society translational research fellowship (KWF 2013-5869) provided support to Dr. Horlings.
Disclosure forms provided by the authors are available with the full text of this article at NEJM.org.
Drs. Anglesio, Papadopoulos, and Ayhan and Drs. Yong, Huntsman, and Shih contributed equally to this article.
We thank all the women who have allowed their tissue to be used in our research studies and without whom this work would not have been possible; staff at Illumina who provided early-access reagents for targeted sequencing, including beta versions of the TruSeq Amplicon Cancer Panel; and staff at the Genetic Pathology Evaluation Centre in Vancouver and Sol Goldman Sequencing Facility at Johns Hopkins, both of which provided technical support.
From the Departments of Obstetrics and Gynaecology (M.S.A., C.A., C.W., P.J.Y., D.G.H.) and Pathology and Laboratory Medicine (M.S.A., T.M.N., J. Senz, B.T.-C., C.B.G., D.G.H.), University of British Columbia, the Department of Anatomical Pathology, Vancouver General Hospital (T.M.N., H.M.H., J.H., V.L., B.T.-C., A.W., C.B.G., D.G.H.), the Department of Molecular Oncology, British Columbia Cancer Agency (H.M.H., A.L., V.L., N.B., D.G.H.), and the BC Women’s Centre for Pelvic Pain and Endometriosis, BC Women’s Hospital and Health Centre (F.W., N.O., C.A., C.W., P.J.Y.) — all in Vancouver, BC, Canada; the Department of Oncology (N.P., C.T., K.W.K., L.D., T.-L.W., B.V., I.-M.S.) and Ludwig Center (N.P., Y.W., J.D.C., M.Z., M.P., W.M., A.M., K.W.K., L.D., B.V.), Sidney Kimmel Comprehensive Cancer Center, the Departments of Pathology (N.P., A.A., M.N., L.D.W., T.-L.W., B.V., I.-M.S.) and Gynecology and Obstetrics (J. Segars, I.-M.S.), Johns Hopkins Medical Institutions, Personal Genome Diagnostics (S.J.), and Johns Hopkins University Howard Hughes Medical Institute (B.V.) — all in Baltimore; the Department of Pathology, Seirei Mikatahara Hospital (A.A., H.O.), and the Department of Tumor Pathology, Hamamatsu University School of Medicine (A.A.), Hamamatsu, and the Department of Molecular Pathology, Hiroshima University School of Medicine, Hiroshima (A.A.) — all in Japan; the Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands (M.N.); the Departments of Obstetrics and Gynecology (T.S.) and Pathology (R.A., A.H.), Lenox Hill Hospital–Northwell Health (Hofstra University), New York; and the Department of Pathology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Tao-Yuan City, Taiwan (R.-C.W.).
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