lynch

Question 1

lynch syndrome previously known as

Answer 1

hereditary nonpolyposis colorectal cancer

Question 2

autosomal dominant inherited cancer caused by defects in the mismatch repair system

Answer 2

true.

Question 3

in addition to colorectal cancer, hallmark diseases of Lynch syndrome include

Answer 3

1. endometrial
2. ovarian cancer.
   other tumors within the spectrum of lynch syndrome include
   gastric cancer, small bowel cancer, hepatobiliary cancer, renal pelvis, and ureter cancer, as well as some types of breast cancer, certain brain tumors and sebaceous skin tumors.

Question 4

similar to other cancer predisposition, Lynch syndrome results in substantially greater fraction of early-onset endometrial cancer and colorectal cancer. in women younger than 50 years, at least

Answer 4

at least 5-9% of women with endometrial cancer and 5-7% of women with colorectal cancer will have a detectable deleterious mismatch repair gene mutation associated with Lynch syndrome.

Question 5

risk of colorectal cancer to age 70 for women with lynch

Answer 5

approx 18-61%

compared with 1.7% in the general population.

Question 6

risk of endometrial cancer through age 70 for women with lynch

Answer 6

approx 16-61%.

Question 7

risk of ovarian cancer through age 70 for women with lynch

Answer 7

approx 5-10%, compared to approximately 1% in the general population, 39-46% in women with brca1 mutation, and 12-20% in women with brca2 mutation

Question 8

how should women with a personal hx of endometrial cancer or colon cancer be evaluated for Lynch syndrome:

Answer 8

approx 2-3% of cases of endometrial and colon cancer are attributable to Lynch syndrome and will have a molecular signature of absent mismatch repair gene expression. increases to 5-13% of endometrial or colorectal tumors in women dx before age 50.

obgyn should approach 1 of 3 for assessing possibility of Lynch syndrome.
1. perform tumor testing on any endometrial or colorectal tumor from a woman identified to be at risk of Lynch.

2. perform tumor testing on ALL endometrial or colorectal tumors irrespective of age of dx.
3. perform tumor testing on all endometrial or colorectal tumors dx before age 60.