LM 13.1

Question 1

what does the NPCR do?

Answer 1

NPCR = national program of cancer registries

collects data on cancer occurrence, staging, location, type of initial treatment, types of follow up treatment and outcomes

data is collected from nearly every cancer case in the country!

Question 2

how do cancer registries work?

Answer 2

at the clinic or hospital, and typically within 6 months of a diagnosis, a cancer registrar will typically take over

this is a specially trained individual who enters the patient’s data into a central database

but there can be problems because people might use different codes or classify things differently

once the data from the hospital or clinic are entered data are then sent to the central cancer registry in the state

here data are cleaned up more - as they are reviewed for accuracy, completeness and mandatory reporting blocks

then the state registry sends stuff to the CDC

Question 3

what is an IRB?

Answer 3

internal review board

Question 4

what is a important characteristic of data submitted to the CDC?

Answer 4

no data submitted to CDC has personal identifiers that can compromise patient confidentiality!!!!

Question 5

what is a SEER?

Answer 5

Surveillance Epidemiology and End Results database

data from nationwide registry are compiled into the searchable SEER!

**OH is NOT a SEER site at this point but we do have a registry that is population based

Question 6

what is cancer registry data used to do?

Answer 6

1. monitor cancer trends over time
2. show cancer patterns in various populations and identify high-risk groups
3. guide planning and evaluation of cancer control programs
4. helps set priorities for allocating health resources

Question 7

when is data released?

Answer 7

data are not in real time!!

but rather it is released by the state and CDC in intervals. Data might be from 2013 or 2014 in the 2017 release

Question 8

what information must be included on a cancer registry form ?

Answer 8

normal patient info like name, race, address, birthday etc.

primary site and date of diagnosis ; tumor size and metastases

treatment, outcomes, mortality - this part of the form becomes not mandatory…

Question 9

what are the CS and SSF parts of a cancer registry form?

Answer 9

SSF = site-specific factors

CS = collaborative stage

this is how the clinics fully characterize the patients cancer

Question 10

what is prevalence?

Answer 10

the number or % of people alive on a certain date in a population who previously had a diagnosis of the disease

it includes new (incidence) and pre-existing cases and is a function of both past incidence and survival

Question 11

what is a cancer incidence rate?

Answer 11

the number of new cancers of a specific site/type occurring in a specified population during a year

incidence rate = (new cancers/population) x 100,000

Question 12

what is the age-adjusted rate?

Answer 12

a weighted average of the age-specific rates where the weights are the proportions of persons in the corresponding age groups of a standard population

this is important when considering reporting cancer outcomes in older patients where natural death is common within that age group and could create confounding data

Question 13

what is lifetime risk?

Answer 13

the probability of developing or dying from cancer in the course of one’s lifespan

Question 14

what is cancer survival?

Answer 14

the proportion of patients alive at some point subsequent to the diagnosis of their cancer

Question 15

what are the strengths of the cancer registry?

Answer 15

big sampling size

rare events are more likely to be captured

can track trends over time

Question 16

what are the weaknesses of the cancer registry?

Answer 16

it’s expensive and time consuming to collect all this data

different coding can complicate analysis of data

not all registrars complete the form in its entirety

Question 17

what is cancer screening?

Answer 17

a test for cancer

given to people with NO symptoms

can be targeted at high risk groups or offered to the general public

decreases cause-specific mortality for those screened

once symptoms emerge, testing becomes diagnostic

Question 18

when should you screen a population?

Answer 18

if the condition you’re looking for is an important health problem

if early treatment would lead to better outcomes

there should be treatment available and facilities available

there should be a recognizable latent or early symptomatic stage

screening should be economical

Question 19

what are the pros of cancer screening?

Answer 19

reduce morbidity and mortality within a population

Question 20

what are the cons of cancer screening?

Answer 20

both false positives and false negatives are inevitable

over diagnosis as has been argued for the case with PSA screening in prostate cancer, and mammograms in breast cancer

furthermore, follow up testing might be more invasive- as is the case with biopsies

Question 21

what is lead time bias?

Answer 21

in a screened group, shown on the top, a diagnosis is confirmed in one of 5 patients, and survival time progresses in a longer interval than a patient who has a diagnosis yet is not screened

the perception is that there is a longer “survival time” with screening. In reality, it was really an earlier diagnosis

Question 22

what is length time base?

Answer 22

when the window of screening is compressed in aggressive tumors

with less aggressive tumors, a larger window for screening is present, allowing for a perceived greater success in the screen of the population

the perception is for effective screening, but in reality the test is better at finding these less aggressive and more treatable tumors due to the latency

Question 23

what is over diagnosis bias?

Answer 23

when screening leads to diagnosis that would not have been diagnosed in the natural history of the disease

ex. the screened group we have detected 3 patients of 5 with the disease, and the diagnosis is quickly confirmed

of the three patients, one dies at time x of the disease, while the other 2 do not die of the disease, but a natural death

in the unscreened group, three patients are present, yet one becomes symptomatic with a confirmed diagnosis, dying at the same time point as the patient that was screened

the other two patients die a natural death

looking at the data, you’d say that screening delayed death

another complication is the actual treatment that the two patients that died a natural death in the end received. was it overtreatment? Invasive? Painful or causing financial hardship?

Question 24

what is healthy volunteer bias?

Answer 24

biases in screening can occur since historically those that participate in screening are different in some aspects than those that do not participate in screening

screened individuals are typically healthier with access to health care, and thus may have a better prognosis than unscreened groups

Question 25

how do you judge the effectiveness of a screening test?

Answer 25

• mortality rates

- incidence at various cancer staging

Question 26

T/F: prevalence calculations include both new and pre-existing cases

Answer 26

true

Question 27

T/F: incidence rate calculations include new and recurrent cancers

Answer 27

false

Question 28

when is a cancer screen considered beneficial?

Answer 28

large enough population is screened

the benefits outweigh the costs

the screen uncovers cancer that would’ve become symptomatic