f*********1
发帖数: 189 | 1 好像去年2011年10/11月 NEJM 发过low-dose CT screening of Lung cancer.
这里有一片最近发在radiology的：
Lung Cancers Diagnosed at Annual CT Screening: Volume Doubling Times
Abstract
Purpose: To empirically address the distribution of the volume doubling time
(VDT) of lung cancers diagnosed in repeat annual rounds of computed
tomographic (CT) screening in the International Early Lung Cancer Action
Program (I-ELCAP), first and foremost with respect to rates of tumor growth
but also in terms of cell types.
Materials and Methods: All CT screenings in I-ELCAP from 1993 to 2009 were
performed according to HIPAA-compliant protocols approved by the
institutional review boards of the collaborating institutions. All instances
of first diagnosis of primary lung cancer after a negative screening result
7–18 months earlier were identified, with symptom-prompted diagnoses
included. Lesion diameter was calculated by using the measured length and
width of each cancer at the time when the nodule was first identified for
further work-up and at the time of the most recent prior screening, 7–18
months earlier. The length and width were measured a second time for each
cancer, and the geometric mean of the two calculated diameters was used to
calculate the VDT. The χ2 statistic was used to compare the VDT
distributions.
Results: The median VDT for 111 cancers was 98 days (interquartile range,
108). For 56 (50%) cancers it was less than 100 days, and for three (3%)
cancers it was more than 400 days. Adenocarcinoma was the most frequent cell
type (50%), followed by squamous cell carcinoma (19%), small cell carcinoma
(19%), and others (12%). Lung cancers manifesting as subsolid nodules had
significantly longer VDTs than those manifesting as solid nodules (P < .0001
).
Conclusion: Lung cancers diagnosed in annual repeat rounds of CT screening,
as manifest by the VDT and cell-type distributions, are similar to those
diagnosed in the absence of screening.
最近看到好多CT Lung cancer screen, 感兴趣的大虾请讲讲pros and cons |
A*******s
发帖数: 9638 | 2 You just missed the April's deadline. Have to wait for Baozi next month. |
S**********e
发帖数: 1325 | 3 USMLE还在说 no screening for lung cancer呢，小马扎儿一起等着听老师们讲pros
and cons.
time
★ 发自iPhone App: ChineseWeb - 中文网站浏览器
【在 f*********1 的大作中提到】
: 好像去年2011年10/11月 NEJM 发过low-dose CT screening of Lung cancer.
: 这里有一片最近发在radiology的：
: Lung Cancers Diagnosed at Annual CT Screening: Volume Doubling Times
: Abstract
: Purpose: To empirically address the distribution of the volume doubling time
: (VDT) of lung cancers diagnosed in repeat annual rounds of computed
: tomographic (CT) screening in the International Early Lung Cancer Action
: Program (I-ELCAP), first and foremost with respect to rates of tumor growth
: but also in terms of cell types.
: Materials and Methods: All CT screenings in I-ELCAP from 1993 to 2009 were
|
I****a
发帖数: 407 | 4 This is an exciting trial. Basically for the first time, a well designed
prevention trial demonstrated the reduction of lung cancer related mortality
and all cause mortality. Many trials in the past failed to do this, the
most recent one was PLCO trial using chest x ray as screening method. The
number need to treat to prevent 1 death is between 200-300 which is much
better than mammogram and colonoscopy. I believe those number is around 1000
. Given the success, I believe NCCN ( National Comprehensive Cancer Network
) has incorporated this and recommends low dose screening for high risk
patients, however U.S. Preventive Services Task Force (USPSTF) and other
agencies have been silent on this issue.
There are many caveats of this trial:
1. It is not for all smokers, the study population is tight. I remember it
is for folks age between 55 to 75 with > 30 ppy, current smoker or quit
within 15 years. So you can not generalize the result to lighter smokers
although I would argue for somebody who is younger than 55 but with heavier
smoking history probably also benefit from screening.
2. How long you should screen? The trial screened participants yearly for 3
years but if you look at incidence of lung cancer after the screening period
, it is still quite high. There is definitely lead time bias and initial
screening would catch most of the biological indolent tumors but more
aggressive tumors will be missed out if screening stops after 3 years. We
know lung cancer can develop in very short duration. We might never have
answer for this question given how this trial was designed.
3.What is morbidity to patients?
The false positive rate is quite high, almost 95-96%, which means there is
only 4-5% chance a biopsied lung nodule is malignant. We biopsy 20 nodules
to find 1 cancer. The complications from surgical/IR biopsy were very low in
the trial but keep in mind the trials were carried on well respected
academic centers with experienced hands so I would argue the morbidity from
procedure in the community setting will be higher.
4. Cost issue. An estimate from recent JCCCN publication showed probably in
billions. I am eager to hear what the trial investigator have to say in
their future publications.
If I practice general medicine, I would not force high risk patients to screen. I would
present the data and let them decide. |
f*********1
发帖数: 189 | 5 赞icetea的专业精神！practing evidence-based medicine:)
依稀记得2011 11/12 NEJM的那篇说好像是降22%？
Cost的确是个问题呀
NCCN 真好，有个统一的标准。 |
A*******s
发帖数: 9638 | 6 Thanks for reminding us of USMLE standard.
【在 S**********e 的大作中提到】
: USMLE还在说 no screening for lung cancer呢，小马扎儿一起等着听老师们讲pros
: and cons.
:
: time
: ★ 发自iPhone App: ChineseWeb - 中文网站浏览器
|
A*******s
发帖数: 9638 | 7 What a comprehensive comment in depth!
I'd like to hear your insight on this:
"Preventive Services Task Force (USPSTF) and other agencies have been silent
on this issue."
mortality
1000
Network
【在 I****a 的大作中提到】
: This is an exciting trial. Basically for the first time, a well designed
: prevention trial demonstrated the reduction of lung cancer related mortality
: and all cause mortality. Many trials in the past failed to do this, the
: most recent one was PLCO trial using chest x ray as screening method. The
: number need to treat to prevent 1 death is between 200-300 which is much
: better than mammogram and colonoscopy. I believe those number is around 1000
: . Given the success, I believe NCCN ( National Comprehensive Cancer Network
: ) has incorporated this and recommends low dose screening for high risk
: patients, however U.S. Preventive Services Task Force (USPSTF) and other
: agencies have been silent on this issue.
|
I****a
发帖数: 407 | 8 I think it is largely due to the reasons that I mentioned earlier. They
burned their hands with PSA screening controversies in the last 2 decades, I
doubt they are willing to make any drastic decisions now days.
silent
【在 A*******s 的大作中提到】
: What a comprehensive comment in depth!
: I'd like to hear your insight on this:
: "Preventive Services Task Force (USPSTF) and other agencies have been silent
: on this issue."
:
: mortality
: 1000
: Network
|
f*********1
发帖数: 189 | 9 Icetea, could you please talk more about the PSA?
Heard of that PSA is not.... anymore....
It seems that Oncologists are still concerning for biochemical (PSA) (
dramatically) increasing patients as inidcation for recurrence or meta |
A*******s
发帖数: 9638 | 10 I would think the screening is a very sensitive topic these days. A stardard
of care matters to the finances, legal issues and politics.
Like the age limit for medicare, I heard it will be postponed. Even one
month longer would save tons of money for the government. Screening in
healthcare has been largely abused. I agree with you to leave the option to
the patient. Health insurance is benefit and has to be granted. So without
such a guideline for screening, government insurance does not have to pay
for the screening. Patients can buy subsided insurance or pay out of pocket
for screening.
I
【在 I****a 的大作中提到】
: I think it is largely due to the reasons that I mentioned earlier. They
: burned their hands with PSA screening controversies in the last 2 decades, I
: doubt they are willing to make any drastic decisions now days.
:
: silent
|
f*********1
发帖数: 189 | 11 啊？很多 biomarker projects 是定向于早期screen的。。。
忽然想起 Acne说过：挖坑灌水以前就要先找个好坑。。。
哎，从来都没挖到一个好坑，。。。 以后要看好了坑，是有价值的好坑，再去挖。。。
哪位大虾讲讲 什么 会是我们 医学领域的 未来10-20年的 好的潜力坑吧。
我近视，看不清方向：）
stardard
one
in
option
to
without
to pay
pocket
【在 A*******s 的大作中提到】
: I would think the screening is a very sensitive topic these days. A stardard
: of care matters to the finances, legal issues and politics.
: Like the age limit for medicare, I heard it will be postponed. Even one
: month longer would save tons of money for the government. Screening in
: healthcare has been largely abused. I agree with you to leave the option to
: the patient. Health insurance is benefit and has to be granted. So without
: such a guideline for screening, government insurance does not have to pay
: for the screening. Patients can buy subsided insurance or pay out of pocket
: for screening.
:
|
I****a
发帖数: 407 | 12 PSA is a very good and sensitive test to detect known prostate cancer
relapse. It is also a ok test to gauge the treatment effect.
However it is a lousy test for screening asymptomatic male. Prostate cancer
incidence exploded after PSA screening was adopted in the 90s however a
handful of US trials did not show survival benefit after long follow up. In
other words, we diagnose and treat a lot of biological indolent tumors that
otherwise will not bother those men in their life time. I believe USPSTF is
totally against the screening now. American Urological Association on the
other hand supports the use of the PSA test.
Just to get things more complicated, European PSA screening trial did
demonstrate a small survival benefit, this was published recently on a big
name journal.
【在 f*********1 的大作中提到】
: Icetea, could you please talk more about the PSA?
: Heard of that PSA is not.... anymore....
: It seems that Oncologists are still concerning for biochemical (PSA) (
: dramatically) increasing patients as inidcation for recurrence or meta
|
A*******s
发帖数: 9638 | 13 有一种说法， 保险公司最害怕的是长寿。 所以screening不是所有party都欢迎的。
好像有一首歌叫有一种爱叫放手， USPSTF可能也学会了。 lol
cancer
In
that
is
【在 I****a 的大作中提到】
: PSA is a very good and sensitive test to detect known prostate cancer
: relapse. It is also a ok test to gauge the treatment effect.
: However it is a lousy test for screening asymptomatic male. Prostate cancer
: incidence exploded after PSA screening was adopted in the 90s however a
: handful of US trials did not show survival benefit after long follow up. In
: other words, we diagnose and treat a lot of biological indolent tumors that
: otherwise will not bother those men in their life time. I believe USPSTF is
: totally against the screening now. American Urological Association on the
: other hand supports the use of the PSA test.
: Just to get things more complicated, European PSA screening trial did
|
A*******s
发帖数: 9638 | |
