A 35-year-old woman comes to the office for follow-up on genetic testing for Lynch syndrome. She has no symptoms or medical problems and has never had surgery. A Papanicolaou test was normal last month. The patient takes a daily multivitamin and no other medications. She does not use contraception as she has not been sexually active since separating from her husband last year. The patient's mother, age 54, is receiving chemotherapy for colon carcinoma. Her maternal uncle was diagnosed with colon cancer at age 49, but it is in remission; her first cousin died of colon cancer at age 36. In addition to colon cancer, the patient is at greatest risk for which of the following conditions?

Question

A 35-year-old woman comes to the office for follow-up on genetic testing for Lynch syndrome.  She has no symptoms or medical problems and has never had surgery.  A Papanicolaou test was normal last month.  The patient takes a daily multivitamin and no other medications.  She does not use contraception as she has not been sexually active since separating from her husband last year.  The patient's mother, age 54, is receiving chemotherapy for colon carcinoma.  Her maternal uncle was diagnosed with colon cancer at age 49, but it is in remission; her first cousin died of colon cancer at age 36.  In addition to colon cancer, the patient is at greatest risk for which of the following conditions?

Quizplus · Accepted Answer

11ec25c8_d3fb_e383_bc81_2d001a973dd3_MD0003_00 Lynch syndrome (eg, hereditary nonpolyposis colorectal cancer) is an autosomal dominant cancer syndrome that predisposes individuals to colorectal cancer and other malignancies. Genetic testing should be performed in patients with a strong family history of colon cancer (eg, >3 relatives involving multiple generations). The condition is due to a germline mutation in a DNA mismatch repair gene. Once the diagnosis of Lynch syndrome is established, patients should undergo screening for colon cancer with colonoscopy. > In addition to colon cancer, patients are at extremely high risk for endometrial carcinoma. Endometrial cancer screening with annual endometrial biopsy should begin at age 30-35. Ovarian cancer risk is also increased and may present at a relatively younger age. Therefore, prophylactic hysterectomy and bilateral oophorectomy is recommended at age 40 or earlier if childbearing is complete. (Choice A) Breast carcinoma can be caused by BRCA1 and BRCA2 gene mutations, which also impart an increased risk of ovarian cancer. There is no increased risk of colon cancer with these mutations. It is unclear if patients with Lynch syndrome have an increased incidence of breast cancer. (Choices B and G) Clear cell renal carcinoma and pheochromocytoma can be due to von Hippel-Lindau syndrome. This syndrome is also autosomal dominant but is not associated with colon carcinoma. (Choice D) Important risk factors for primary hepatocellular carcinoma include chronic hepatitis B and C infections. Most secondary liver cancers originate from the colon, and this patient would be at risk for hepatic metastases if she had signs of colon cancer (eg, weight loss, bloody stools). (Choices E, F, and G) Multiple endocrine neoplasia type 1 (MEN1) syndrome is characterized by parathyroid, pituitary, and pancreatic adenomas. MEN2 syndrome is characterized by medullary thyroid cancer, pheochromocytoma, and parathyroid hyperplasia. Both syndromes are autosomal dominant, but colon cancer is not a feature. Educational Objective: Lynch syndrome causes colorectal cancer and imparts an extremely high risk of endometrial carcinoma for female carriers. An annual endometrial biopsy, as well as prophylactic hysterectomy, is recommended to prevent endometrial cancer. References: Lynch syndrome screening in the gynecologic tract: current state of the art. (http://www.ncbi.nlm.nih.gov/pubmed/26872009) ACOG Practice Bulletin No. 147: Lynch syndrome. (http://www.ncbi.nlm.nih.gov/pubmed/25437740)

A 35-Year-Old Woman Comes to the Office for Follow-Up on Genetic