Cancer rates on the rise??

[Eos of the Eons]

http://www.chicagotribune.com/features/health/chi-0406030364jun03,1,2268362.story
From the story:

Americans' risks of getting cancer and dying from it are declining as a result of better detection, prevention and treatment, according to the latest annual report by several cancer organizations.

Overall, the number of new cancer cases dropped an average of 0.5 percent per year between 1991 and 2001, while death rates dropped 1.1 percent per year from 1993 to 2001, according to the report, which produced the report in association with the federal Centers for Disease Control and Prevention, the National Cancer Institute and the North American Association of Central Cancer Registries.


Childhood cancers showed the greatest improvement, with a survival rate increase of 20 percent in boys and 13 percent in girls over the decade. The current overall survival rate of more than 75 percent represents a dramatic increase since the early 1960s, when childhood cancers were nearly always fatal.




The sCAM folks claim cancer is on the increase, that toxins are poisoning the planet's populace...well, yeah, sure...maybe in their world of scams and conspiracies.

As per usual, reality and facts do not match the sCAM picture of the world.

Sure, you can poison yourself with smoking, but that's a no brainer.

Next time somebody delves into the woes of modern medicine and toxic lifestyles (using deoderant and bleach) and how it reduces your life span/quality of life, then remind them that our chances of getting cancer is actually dropping (when you see a medical doctor).

[Zombified]

If I recall correctly cancer rates did go up for a while... because people were living longer and not dropping dead of other things.

Oh well, the freaks will either keep repeating the cancer meme even after its out of date, or they'll pick up whichever cause of death is going up...

[Suezoled]

It could also be cancer rates are going up because, quite simply, it's being tested for and detected a lot more often, and caught a lot sooner (hence the higher survival rate).

[Dr. Imago]

Originally posted by Suezoled
It could also be cancer rates are going up because, quite simply, it's being tested for and detected a lot more often, and caught a lot sooner (hence the higher survival rate).

This is why it's much more important to use the epidemiological terms "incidence" and "prevalence" when discussing case rates.

Incidence refers to the number of new cases of the disease that are diagnosed in a given year. Prevalence is the actual total number of diseases that exist. A chronic, lifelong disease that is non-fatal will always have a higher prevalence than incidence. Conversely, a disease that is rapidly fatal (e.g. pancreatic cancer) will have a much higher incidence than prevalence.

When you say "cancer rates", you have to look at the longterm changes in incidence and prevalence. Since cancer is, by clinical definition, "curable" (using treatments that irradicate the disease by surgery, radiation, chemotherapy, etc. and remove the disease itself as a directly causative factor in a patient's eventual mortality), you can have a decreased prevalence without changing the incidence.

To confuse things further, some statistical models for cancer look at "limited prevalence", which defines the data to a specific number of years. This may be beneficial for types of cancer that occur, for instance, late in life and that were previously rapidly fatal but now have effective treatments.

And, to throw a final wrench into the works, it is a little simplistic to simply say "cancer" when, in fact, this represents a constellation of tumor types with a variety of differing associated causative factors, etc. For example, we'd expect to see a decrease in lung cancer incidence because fewer people are now smoking than they did forty or fifty years ago as we became aware of the negative impact of cigarette smoke.

If you go to...

http://seer.cancer.gov/faststats/

... you can look up rates for specific cancers.

Therefore, these are more specific ways to look at the finer points of what such lay-articles really mean, rather than an often simplistic, "big picture" approach in saying "cancer rates" - which can actually mean more than one thing.

I'm not disagreeing with the data; just how it's presented. And, I'm offering a more specific way to address the woo-woo machine that will almost ineluctably attempt to counterargue the general findings published in the lay media.

-TT

[pgwenthold]

In the same way as TT notes, we need to be clear what we mean by "survival rates." Considering that all cancer ultimately results in death, what does survival mean? Living 1 year after diagnosis? 5 years? 80? Reaching adulthood?

I really don't know what "childhood cancer survival" means.

[Eos of the Eons]

Originally posted by pgwenthold
In the same way as TT notes, we need to be clear what we mean by "survival rates." Considering that all cancer ultimately results in death, what does survival mean? Living 1 year after diagnosis? 5 years? 80? Reaching adulthood?

I really don't know what "childhood cancer survival" means.


I think we're talking things like Leukemia here for childhood. TT can help us here too.

I like TT's post because it does show the big picture. It is something to keep in mind when encountering something that claims to cure cancer. And, to throw a final wrench into the works, it is a little simplistic to simply say "cancer" when, in fact, this represents a constellation of tumor types with a variety of differing associated causative factors, etc.

If you look at the 'causes' of cancer, you may see that there never will be a cure all of any sort.

[pgwenthold]

Originally posted by Eos of the Eons



I think we're talking things like Leukemia here for childhood. TT can help us here too.


Even if we are talking about leukemia, what does "survival" mean?

Every child who gets leukemia is going to die, the only question is when. If it is next year, it's bad. If it is 80 years later, it's not so bad, at least from a cancer standpoint. How long do they have to live to say they survived?

There may be a standard definition, but it's not evident to me.

[BPSCG]

Originally posted by pgwenthold
Even if we are talking about leukemia, what does "survival" mean?

Every child who gets leukemia is going to die, the only question is when. If it is next year, it's bad. If it is 80 years later, it's not so bad, at least from a cancer standpoint. How long do they have to live to say they survived?

There may be a standard definition, but it's not evident to me. Are you trying to say that once you've had cancer, that's what you're going to die of? Sounded that way to me in your previous post. I had cancer 18 years ago, but I came a lot closer to dying of heart disease just last year.

In any case, I'd say someone is a cancer "survivor" (God, I HATE that term) when he's reached the point that he's no more likely to die from the type of cancer he had (or any metasteses of it) as anyone else in his general age group. Maybe not an exact definition, but probably a good working one.

Or maybe when your hematologist/oncologist tells you to just see your regular MD once a year from now on. Or a homeopath...

[pgwenthold]

Originally posted by BPSCG
Are you trying to say that once you've had cancer, that's what you're going to die of? Sounded that way to me in your previous post. I had cancer 18 years ago, but I came a lot closer to dying of heart disease just last year.

I never said that is why they would die, just that they will. Of course, we all will, the only question is when.


In any case, I'd say someone is a cancer "survivor" (God, I HATE that term) when he's reached the point that he's no more likely to die from the type of cancer he had (or any metasteses of it) as anyone else in his general age group. Maybe not an exact definition, but probably a good working one.


But is it what is used? I wouldn't assume it.

[Rolfe]

Originally posted by pgwenthold
Even if we are talking about leukemia, what does "survival" mean?Ask Suezoled. She had childhood leukaemia.

Rolfe.

[SGT]

Originally posted by pgwenthold


I never said that is why they would die, just that they will. Of course, we all will, the only question is when.
[/B]

Accepting your reasoning, what is the rate of survival for common cold? Everyone that had a cold will eventually die. Probably not from the cold.

[pgwenthold]

Originally posted by Rolfe
Ask Suezoled. She had childhood leukaemia.

Rolfe.

Would she be considered a leukemia survivor? Suppose (ed forbid) she were to relapse next year. Would she still be a survivor?

Suppose a child with leukemia died in a car accident. Would s/he be a survivor, because s/he didn't die from the cancer?

These are not rhetorical questions, or topics for discussion. The original article claimed that the survival rate for childhood cancers has increased. I want to know, how is "survival" defined? Is it based on whether the cancer goes away? Or is it based on how long they live?

My good friend was advertised as a cancer survivor, as he had lived with non-Hodgkins lymphoma for 9 years. He died cancer related pneumonia 6 months later. Was it correct to call him a cancer survivor at that time, considering that he was dying from cancer? I would like to know how "cancer survivor" is defined in these surveys.

[pgwenthold]

Originally posted by SGT


Accepting your reasoning, what is the rate of survival for common cold? Everyone that had a cold will eventually die. Probably not from the cold.

See my example above. If a child with leukemia dies in a car wreck, does that make him/her a cancer survivor? That's why I don't like a definition based on whether or not they died from the cancer.

But the other problem is, how long do they have to survive the cancer before we conclude that they won't die from it? See my other example above. My friend lived 10 years with cancer (in and out of remission). Would he have been considered a cancer survivor?

I think ThirdTwin might know.

[SGT]

Originally posted by pgwenthold


See my example above. If a child with leukemia dies in a car wreck, does that make him/her a cancer survivor? That's why I don't like a definition based on whether or not they died from the cancer.

But the other problem is, how long do they have to survive the cancer before we conclude that they won't die from it? See my other example above. My friend lived 10 years with cancer (in and out of remission). Would he have been considered a cancer survivor?

I think ThirdTwin might know.

I think the accepted definition is the one BPSCG gave. If the cancer your friend died of was not a metastese of the previous one (and the fact that he survived 10 years is a strong indication of that), he certainly survived the first cancer. Being mortal, as all of us, he died of another cancer, as could have died of a car wreck, as you mentioned.
There is strong evidence that sensitivity to cancer is a genetical trait, so anyone that has a cancer has a greater probability to have an unrelated one than the average population, so survival from one cancer is no guarantee. The survivor must have a greater control of the risk factors than other people.

[BPSCG]

Originally posted by SGT
I think the accepted definition is the one BPSCG gave.
I doubt it. I just kinda thought it up as I went along. But on further reflection, I really think it's an almost meaningless term.

I've been cancer-free going on 18 years now (as far as I know - my body could be in the early, undetectable stages of self-destruction as I write this). I guess I'm a survivor, by any reasonable measure. If it comes back and kills me next year, does that mean I was wrong to think I was a "survivor"?

I doubt there's any generally accepted definition; I think people just use the word without thinking much about whether they're using it accurately.

In any case, I doubt anyone's ever gone to jail or been successfully sued because they misued the term, so what's the big deal?

[Eos of the Eons]

Survival

The overall five-year survival rate has tripled in the past 40 years for patients with leukemia. In 1960, the overall five-year survival rate was 14%, by the 1970s it had reached 35%, and now the overall five-year survival rate is 46%.

During 1992-1998, the relative survival rates were:

· Acute lymphocytic leukemia (ALL): 63.5%; 85% for children

· Chronic lymphocytic leukemia (CLL): 73%

· Acute myelogenous leukemia (AML): 19%; 46% for children

· Chronic myelogenous leukemia (CML): 34.5%

Complete remission rates in AML cases are currently up to 60% with long-term survival being about 50% (Tavernier et al., 2003).
The leukemia death rate for children in the United States has declined 61% over the last three decades. Despite this decline, leukemia remains a leading cause of death among children under age 15


http://www.bae.ncsu.edu/research/blanchard/www/465/textbook/otherprojects/2003/group4/leukemia.html

[Eos of the Eons]

Originally posted by pgwenthold


Even if we are talking about leukemia, what does "survival" mean?

Every child who gets leukemia is going to die, the only question is when. If it is next year, it's bad. If it is 80 years later, it's not so bad, at least from a cancer standpoint. How long do they have to live to say they survived?

There may be a standard definition, but it's not evident to me.

If they no longer have the leukemia then they won't die of it. Ask Suezold.

[pgwenthold]

Originally posted by BPSCG
I doubt it. I just kinda thought it up as I went along. But on further reflection, I really think it's an almost meaningless term.

I've been cancer-free going on 18 years now (as far as I know - my body could be in the early, undetectable stages of self-destruction as I write this). I guess I'm a survivor, by any reasonable measure. If it comes back and kills me next year, does that mean I was wrong to think I was a "survivor"?

I doubt there's any generally accepted definition; I think people just use the word without thinking much about whether they're using it accurately.

In any case, I doubt anyone's ever gone to jail or been successfully sued because they misued the term, so what's the big deal?

"The big deal" is that I would like to know what an article is talking about when they say the cancer survival rate has increased. As I said, and you agreed, it seems to be a meaningless term. Or at least very vague. Something like contraceptive failure rate (but at least I know how that is defined, although I don't know if it is at all meaningful)

Kudos on your 18 years. I wish you decades and decades more...

[pgwenthold]

Originally posted by Eos of the Eons


http://www.bae.ncsu.edu/research/blanchard/www/465/textbook/otherprojects/2003/group4/leukemia.html

OK, so this link talks of the 5 years survival rate. Is that the standard?

[pgwenthold]

Originally posted by Eos of the Eons


If they no longer have the leukemia then they won't die of it.

Is it possible for leukemia to re-occur later on in life? Is it really curable? Or does it just remiss?

[Suezoled]

Originally posted by Rolfe
Ask Suezoled. She had childhood leukaemia.

Rolfe.

Actually, it was Non-hodgkin's Lymphoma.

14 years cancer-free this summer...(or should I say chemotherapy free..?)

[Suezoled]

Originally posted by pgwenthold


Is it possible for leukemia to re-occur later on in life? Is it really curable? Or does it just remiss?

Secondary cancers are always a possibility.

http://www.lymphomainfo.net/surviving/secondary.html

[pgwenthold]

Originally posted by Suezoled


Actually, it was Non-hodgkin's Lymphoma.

14 years cancer-free this summer...(or should I say chemotherapy free..?)

Chemo free for 14 years for non-hodgkins lymphoma? Wow. That's great. I hope you remain this way forever.

[Eos of the Eons]

Originally posted by pgwenthold


Is it possible for leukemia to re-occur later on in life? Is it really curable? Or does it just remiss?


Now we need some really good sources of info like thirdtwin. I think you get a marrow transplant with leukemia and don't get leukemia again if you recover.

Good questions, will have to put some time into looking things up from here. Make sure the sources are credible and not selling anything (conflict of interest).

[Suezoled]

Originally posted by pgwenthold


Chemo free for 14 years for non-hodgkins lymphoma? Wow. That's great. I hope you remain this way forever.

Why thank you!
If I recall correctly, year 1 treatment free is the most nerve wracking, as the possibility of relapse is stastically rather high at this time. After 5 years of no sign of cancer(s), one may cautiously use the word "cured."


Just a handy link. It explains remission simply and easily.

http://www.patientcenters.com/leukemia/news/leukfaq.html#remission
Complete remission occurs when all signs and symptoms of leukemia disappear and abnormal cells are no longer found in the blood, bone marrow, and cerebrospinal fluid. The normal number of healthy blasts (5 percent or less—see A.8 above) will be present in the bone marrow.

[athon]

I hate it when TT gets in before me. I was about to propose the concept of 'incidence' in exploring epidemiology. But then I think he explained it better than I could have.

You can never address these issues without taking into account the increase in efficiency in diagnostics. With better imaging, better IFA's, more accurate haematology kits, better training and greater awareness amongst non-specialists (i.e. GP's), cancers that would have remained undetected are now picked up early. People are also more mobile these days, hence more people will seek treatment at earlier stages of their cancer. Finally, smaller cancers can be detected, and since many cancers can remain small and undetected for long periods, this introduces moderate sections of the population who would not have contributed to the incidence rate.

PSA (prostate specific antigen) testing is encouraged much more in Australia these days, and as it is a common cancer in post-60 males (something like 95% of males over 60 die of, or with, a form of prostate cancer) many more men who would never have known are now detected with prostate cancer. Breast cancer in women is a similar story.

All of this is relevant to determining the change in epidemiology for any form of pathology. Has the prevalence of cancer increased in recent generations? Studies are conflicting, with some forms being more common (apparently pancreatic cancers, and some gastric cancers have increased beyond what improved diagnostics and education can explain), but others have decreased (I read one study a few years ago that said lung cancers have decreased over the past few centuries, basing this on archeological evidence. I think the argument was based on the fact that air quality within living environments has actually improved).

Overall I think the chance of acquiring a malignant tumour at a determined age has remained relatively stable. But it is an interesting field open to debate.

Athon

[BPSCG]

Originally posted by pgwenthold
"The big deal" is that I would like to know what an article is talking about when they say the cancer survival rate has increased. As I said, and you agreed, it seems to be a meaningless term. News reports are full of meaningless terms and sloppy usage. Next time you read or hear a story about balance of trade, see how many times you spot the phrase "foreign imports". As if there are any other kind.Kudos on your 18 years. I wish you decades and decades more... Thanks. I guess I'm a "cancer survivor". :p

[Dr. Imago]

Sorry for the delay... very busy at the moment... (and, I can't believe that USMLE Step II is already upon me. Seems like I just took Step I!!!)

General comments: Once you survive cancer (IIRC), you are still counted epidemiologically in prevalence. I may be wrong about that. However, the "5-year cure" model has often been used to describe those people who are disease free and less likely to have a recurrence. Of course, there are exceptions to every rule, but I think for practical purposes that this is probably a good cut-off point that is born out of statistics and is epidemiologically sound.

Now, the more interesting (and growing) field of research has to do with folks, like myself, who are long-term cancer survivors. For example, we know that head and neck radiation pre-disposes one to things such as thyroid cancer decades later. So, does this really represent a disease entity or a sequalae of the previous cancer? These are the debates that rage among the clinical epidemiologists.

As far as leukemia goes, I think that the effectiveness of detection and treatment have done more to impact the prevalence of the disease rather than the actually incidence, but again I may be wrong. Also, you have to look at long trends and not just the occassional periodicity of such diseases. A small trend downward over a few years is a lot less relevant than a steady trend downward over several decades. Again, I'm not familiar enough with the data (nor do I have time to peruse it at the moment) to know if this is actually the case. But, my knee-jerk reaction is that much of such "findings" are more likely akin to global warming arguments that many try to support, whether it be for or against, by looking at various data trends... and, I'm not trying to hijack this thread and start a new discussion. ;)

Essentially, I'm totally waffling here. Whatever may be the case of the observations, two things are for certain in my mind: (1) we've gotten a whole lot better at diagnosing and using the treatments we do have in our arsenal to battle cancer and this has reduced the overall mortality of many cancer types, and (2) despite the fact that we understand the mechanisms of cancer much better than we did in even the recent past (including what initiates and promotes neoplasia), we still are struggling with understanding what actually causes cancer in individuals as well as all of the specific reasons, be they environmental, genetic, or some combination of both, why those individuals are uniquely susceptible in the first place.

In other words, it is far to soon to necessarily conclude that the downward blips the media is reporting actually mean anything. We need to be careful not to simply stare at a few trees while missing the forest.

-TT

[Eos of the Eons]

Keeping those points in mind, the sCAM groups are really waffling when they say cancer rates are on the rise...so buy my vitamins, they will "help" you stay healthy and not get cancer. Use my oils, they will cure you when doctors say there is nothing left to be done.

I hardly think any reductions in the cancer disease area could possibly be attributed to sCAM folks.

TT makes a good point in taking the media reports with a grain of salt. I just wish people would take sCAM 'reports' with a few million grains of salt;)