Blogger's Opinion/Note:
guidelines indicate varying ages of screening depending on organ assuming there are screening mechanisms (eg. ovarian cancer has no screening for the general population however increased surveillance is possible for those at high risk, albeit, ineffective; generally 25 yrs +; 'averages' are not helpful and therefore the urging of family history taking by primary/family care physicians, see
NCCN guidelines for Lynch Syndrome which includes gene-specific details (eg. MLH1, MSH2/6, PMS2.....)
Lynch Syndrome: Don't Miss It (Transcript)
Clinical Implications
"Lynch syndrome is a genetic defect that has
significant implications on the clinical side. A patient whose genetic
testing is positive for Lynch syndrome has a likelihood of developing
colon cancer that approaches 70% over his or her lifetime. The risk for
uterine cancer is similar or a bit higher, and the risk for ovarian
cancer is13%-15%.
Almost certainly, these patients will have some type
of cancer during their lifetime.
Metachronous cancers occur in 7%-10% of patients with Lynch syndrome.
These patients present with one cancer, and typically in the course of a
short period of time,
another cancer develops. In patients with
Lynch
syndrome who have colon cancer, if you don't perform a
subtotal
colectomy because you didn't recognize that it was Lynch syndrome, the
likelihood that the patient will develop a repeat colon cancer over 30
years (
even in patients who are being screened) approaches
65%.
This is
not uncommon. A lot of these diagnoses are missed, and a secondary
cancer develops."
"You need to start thinking about syndromic cancers because the relative
risk is quite high. You need to be thinking about this in patients with
early cancers --
not just colon cancer, but in uterine cancer and
ovarian cancer as well." (
Blogger's Note: and others including pancreatic, stomach, ureter, renal, bilary tract, gallbladder.....see slides)
" If you look at colon cancer in Lynch syndrome, the average age of onset
is earlier (45 years) and some patients may be in their 20s. For
sporadic uterine cancer, the average age is approximately 60 years, but
in Lynch syndrome, it is shifted by a decade, to 50 years. When you see
these cancers in a younger patient,
the bell should go off and you
should start thinking about Lynch syndrome and doing the appropriate
testing."
"It is important to think about
extracolonic cancers in these patients
and to start to put the dots together because
we are missing the boat on
a lot of these syndromic cancers. It's not a zebra; it's 2%-3% of the
patients who are presenting with cancer. We need to think outside the
box. Even if you are not a gastroenterologist, include the colon when
you see syndromic related cancers of the uterus, ovary, small bowel, or
stomach."
