L25 biomarkers for diseases neeraj lal

Question 1

what is the blood test for colorectal cancer called?

Answer 1

FOBT

Question 2

who are eligible for the colorectal cancer kit?

Answer 2

men and women 60-69

Question 3

what are the results on the bowel cancer bionmarker kit?

Answer 3

0/6 = negative
1-4/6 = unclear positive
5-6/6 = abnormal positive result

Question 4

what study showed the effectiveness ofr FOBT as a biomarker for bowel cancer?

Answer 4

1st round of BSCP:
2.1 mill invited and half partook
18000 abnormal test
1800 cancer
6.5k - polyps. removed so no development into cancer
asymptomatic cancer detected.
early stage - better prognosis

Question 5

what is the study that showed the effectiveness of PSA screening in prostate cancer?

Answer 5

PLCO trial:
- 72,000 men
- Yearly screen vs standard care of on demand testing
- 10 year follow up- 50 deaths in screened, 44 deaths in control
- Rate ratio 1.13
European randomised study of screening for prostate cancer
- 182,000 men
- 4 yearly screens vs control- no PSA
- Reduced death rate by 20 percent
- At the expense of overdiagnosis- treating the cancers that would have mot killed.
BETTER IS TO DEVELOP BIOMARKER DETECTING HIGH RISK PROSTATE CANCER

Question 6

What are the issues surrounding using ca-125 as a biomarker for ovarian cancer

Answer 6

• women asymptomatic until advanced stage
• ca-125 less than 60 percent sensitivity and not specific
• elevated in other cancers- CRC, ENDOMETRIAL
  elevated in benign disease- CIRRHOSIS

Question 7

What study showed the effectiveness of ca-125 as a screening tool in ovarian cancer?

Answer 7

PLCO trial
- women randomised annual screening of ca-125 alongside TV-USS vs on demand standard care
- intervention group = 212 detected 118 died
- control = 176 detected 100 died
similar ratio not significant.
- over 3k false positives = surgical follow up = 15 percent serious complications

Question 8

what is the breast cancer biomarker for prognosis?

Answer 8

oncotype dx
panel of 21 genes
categories low, intermediate and high
er+, lymph node negative
low risk is still 6%, it is low enough for a worried patient?

Question 9

what are the biomarkers for after treatment?

Answer 9

colorectal = CEA
prostate = PSA
ovarian= CA-125

Question 10

how good is CEA as a biomarker for colorectal cancer after treatment?

Answer 10

rosen et al = 16% greater survival
primrose et al- no benefit

Question 11

how good is CA-125 as a biomarker for ovarian cancer recurrence?

Answer 11

tuxen et al- ca-125 levels increase 3-4 months before deomstrated recurrences- can early intervention