Moreover, we also know that cancers arise as the body ages – after reproductive age passes there’s simply no evolutionary gain for not having cancer.**
[quote]
But, Col, what exactly is the “reproductive age” of man? Although a man’s fertility certainly diminishes with age, I would bet that most 65-year-old men today are fully capable of impregnating a young woman, given the opportunity. Of course, given the average lifespan has only recently jumped, might you be suggesting that the macro processes (cancer) haven’t caught up with the micro (increased lifespans and, thus, age of fertility)?
The “asbestos in schools” section did not question the carcinogeneity of asbestos – it openly admits that asbestos is a proven carcinogen. The “scare” was that, when schools were ordered to remove any asbestos that was damaged and could thus crumble easily, many schools over-reacted and removed all of their asbestos. When asbestos is removed, some of the dust inevitably gets loose and becomes airborne; the post-removal level of asbestos in the air was raised significantly because of the unnecessary removal of all this additional asbestos.
This same asbestos-in-schools section in the “greatest unfounded scares” pamphlet also describes an unrelated 1993 scare in New York City, wherein the city shut down practically all of its schools for 2 weeks or more, despite the official position by the A.M.A. that the asbestos levels found in school buildings – even school buildings with intact asbestos installed – is no greater than the level in the ambient air around the city and poses no health hazard.
That’s the legal state of affairs, true, but I was referring to the general public reaction. I might concoct a new tri-helical-cyano-glutamic-whooptie-dooptic acid diethylamide compound tomorrow. The law will not require me to treat this any differently than ordinary beach sand until it is shown to be dangerous. But when I announce the existence of such a long-named weird-and-there-fore-scary-sounding chemical, the usual reaction many people will have is, “Oh my God, I’ll bet it’s giving me cancer!!”
I applaud Edwino for the pursuit of a career as an MD/PhD. I am dismayed, however, at what seems to be a total lack of sensitivity concerning childhood cancers. You both obviously have never lost a child to cancer.
Three months ago today I lost my 19 month old grandson to pineoblastoma. His brain tumor was discovered when he was 7 months old. Obviously, aging, smoking habits and amount of fiber in his diet were not factors.
The first biggest shock of my life was learning of his cancer. The second biggest shock was walking onto the oncology floor of a children’s hospital and realizing not only the number of children today with cancer, but also learning that babies are being born with various cancers, including brain cancers! At birth!
Something is seriously wrong. I have yet had the heart to start digging into cancer stats to get exact numbers of how many of our little ones are affected, but I do clearly remember that it was something very rarely heard of even when my daughters were growing up.
Based on my personal experiences thus far, I agree with hapaXL that environmental factors play a much larger role than genetics.
Ben
1.) Before you even do that, throughly check out what portion of the monies received are actually going to research. I bet you didn’t know that airfare paid to receive treatments can be reimbursed to families via the American Cancer Society. If you are fine with that, great.
2.) I won’t argue about the evolution/biology link, however, it isn’t your place or mine to determine what children other than our own should learn. As long as there are public schools, such choices should be made for each child by their parents or guardians.
Edlyn, I don’t understand why you think people in this thread don’t care about childhood cancer. Why would you think that? Why is there more cancer now? In the past your baby would just die and you wouldn’t know why. Now when your baby dies we can tell you your baby died of cancer. That doesn’t mean there is more or less cancer nowadays, it only means that we can diagnose cancer. Also, there are more people WITH cancer nowadays, because more people survive. In the past you’d just die, and the number of people with cancer would decrease. Today you have a very good shot at living…but that will increase the number of people who have cancer.
And it IS our place to decide what should be taught in PUBLIC schools, since we are members of the public and we fund the schools. Private schools don’t have to teach evolution. But public schools are not just responsible to children and parents, they are responsible to the people who pay the bills…the taxpayers. And if my tax money is being used to keep children ignorant instead of educating them properly, I’m going to be slightly upset.
Did I say it was? If folks don’t want their children to learn evolution, they’re free to make them sit out the class and get Left Behind as the rest of the kids prepare for careers in our modern-day biotech world.
OTOH, it is indeed my place, as an American citizen, to determine what will be taught.
Ahem. I didn’t appreciate the following message very much. Not all. I’m going to be a bit brusque.
But an aside to Tsunami: given historical data, our breeding age pretty much peters out by age 30, without the wonderful cocoon called the modern world to preserve us. It’s no accident things start to wear out by the forties at the very least.
Edwino, myself and tracer were discussing cancer in the aggregate. We did not address childhood cancers as most cancers are adult and risk is, as Edwino mentioned, tied above all to age.
Well, you’re still hurting about this and lashing out. I’ll leave the polite noises to others and get to the heart of the matter: since we don’t know his history, and frankly I don’t know jack about this cancer we can’t say much beyond noting that anything from his genetic background to environmental factors could be the cause. One individual does not data make.
Fine, and always has been so. The question is, is there an aggregate rise? That there are children born with cancers is not outlandish. The question is to what extent this is attributable to our modern environment, as well as of course to what extent we can now identify cancers and proto-cancers that in the past were non-identifiable.
To be blunt, a non-rational, emotional response is just going to lead to mis-allocation of resources.
Maybe, maybe not.
Which does not mean, ipso facto, that the cancer did not occur before. I do not know the particular history of this, however, the following immediately springs to mind: medical advances have allowed more precise and accurate diagnosis and definition. Insofar as there may be a bias introduced due to better screening etc., we should not leap to the conclusion, without supporting data, that rise in cancer X in statistics ipso facto means rise in carcinogens. It may, or it may not.
And I reiterate Edwion, my own and tracer’s observations above.
It bloody well is our place to determine what is taught in the schools. Who else should? Of course, if an individual parent deeply desires an ignorant child, well go ahead and pull the kid out of biology class.
My heart goes out to you on your loss. Coll and Lemur have explained my position. I do agree that cancer in kids is very, very sad, but my post dealt with the much more common adult cancers.
I had a line in my post about the rare childhood cancers, but I took it out to streamline things. I apologize if I portrayed a lack of sensitivity.
Two things though:
I think you would be hard pressed to show an increase in childhood cancers in the past 100 years that is not due to a greater sensitivity in diagnosis. Even 30 years ago, we did not have the diagnositc machinery (ubiquitous MRIs and CTs) to accurately make these diagnoses.
Not to diminish your loss, but childhood cancers make up a tiny fraction of cancers in general. Here are some stats from the American Cancer Society:
Probability of developing invasive cancer at any site, by age:
M, birth to 39 years 1.61
F, birth to 39 years 1.94
M, 60 to 79 years 33.65
F, 60 to 79 years 22.27
2300 children will die of cancer in one year in the US.
There will be 552,000 total cancer deaths in the USA. This is around 1500 a day.
From the 1930s, the increase of cancer deaths is predominantly of one type : lung/bronchus. All other cancer deaths have somewhat plateaued. Lung/bronchus cancer is quite rare in children.
You have, unfortunately, had a tragically skewed view of the world of oncology. I could tell you about the dozens of elderly patients with lung cancer I saw in just two months who had smoked 3 packs a day for 40 years. Up to 1 in 3 people will get cancer. A pediatric oncology ward is a small sad segment of them. A VA medicine ward is a larger sad segment.
About the specific kind of cancer your grandson had:
Pineoblastoma is related to retinoblastoma. There is a strong familial component to that specific kind of tumor, with congenital mutations in the Rb gene. Also, cancers diagnosed at birth, including the PNETs (primitive neural ectoderm tumors) are often inborn errors of development and cell differentiation. These are tragic, tragic cancers, but of great interest to molecular geneticists and developmental biologists. Much of cancer is cellular misinterpretation of growth signals leading to uncontrolled proliferation, which often stems from developmental error. For instance, Alfred Knudson came up with the first molecular explanation of carcinogenesis (the two-hit model) using retinoblastoma. We do use these cancers to learn something, and most of what we have discovered relates to genomic errors, not environmental causes.
Well, most notably because when the subject was raised by hapaLX it was completely dismissed or simply ignored by the two individuals addressed in my post. I will respond to them in my succeeding posts.
Why is there more cancer now? Good question. The answers are out there and we need to find them.
I’m sure that autopsies have been in practice for a number of years and most likely done when a child or baby died of an “unknown cause”. It’s not unreasonable to assume that cancer/tumors were found following an autopsy that was unknown prior to death, is it?
To say simply that there’s more cancer because people live longer doesn’t explain why cancer develops. Since that statement is true and you hold it up for explanation are you suggesting that aging is the culprit? How would that be applicable to children, infants and newborns?
Reality check, Lemur. When were you last asked for your input concerning the curriculum for students in your neighborhood schools? When were you last provided a report summarizing all the information you are entitled to know about your schools? Personally, I feel that all schools should be “private” and funded by parents and other citizens who choose to support schools of their choice. I understand you feel that you are absolutely right in demanding that all children should be taught evolution, but equally, so does the person who objects to the evolution theory. You then have a battle and tug-of-war which is unnecessary. May I remind you that you both are taxpayers?
The fact that I recognize the importance of evolution to the scientific field does not negate the right of another parent to choose not to have it taught to their child.
Ah, yes, I noticed in your reply to hapaXL who directly brought up childhood cancers that you gave it very little if no regard. That was my point, dear. I guess your interest is tied to adults, like yourself. Further in my post I’ll indicate why it would be beneficial to expand that interest to include children.
In support of your interest in the adult’s increased risk with age, that while I recognize that to be true, why do you think that is so? Why is the risk increased? Could continued exposure stress and weaken DNA?
Yes, there is an aggregate rise. According to the National Childhood Cancer Foundation:
[ul]
[li]Today, despite amazing research progress, cancer still kills more children than any other disease. Each year cancer kills more children than asthma, diabetes, cystic fibrosis, congenital anomalies, and AIDS combined.[/li][li]Every year, over 11,000 children and teenagers are diagnosed with cancer.[/li][li]The incidence of cancer among children in this country is rising almost 1% per year. During the past 20 years, the incidence of cancer among children has increased almost 20%.[/li][li]Nationally, the incidence of cancer in children is over 15 times greater than that of AIDS in children.[/li][li]One in every 330 Americans develops cancer before age 20.[/li][li]Some forms of childhood cancer have proven to be so resistant that even in spite of the great research strides we’ve made, most of those children die.[/li][li]The number of potential years of life put at risk by childhood cancer each year exceeds the number for most adult cancers.[/li][/ul]
It’s unfortunate to realize that there are individuals who would consider children born with cancers as “not outlandish”. Are you sincere about that?
I didn’t claim that cancer did not occur before. I claimed that I noticed an increase. While we are better now at identifying them, that does not mean that new cancers are not appearing. Are all individuals equally exposed to carcinogens?
What the three of you are ignoring is that our newborns, babies, and children are, of a sort, a wonderful barometer of our environment. Granted that genetics play a role concerning their health, but environmental factors can play a large role with a direct impact.
According to the American Cancer Society:
“Children are more sensitive to radiation than adults because their cells are dividing more rapidly, and radiation has the potential to damage the DNA that controls that division,” Brenner says, noting that cancer is a disease of uncontrolled cell growth.
If sensitive to radiation, what else could there be sensitivity to in our environment?
I invite you to read my reply to Lemur if you have not done so already.
I would like to say that after I read your response it was clear that any lack of sensitivity I perceived on your part was misplaced. Thank you for your clarification. Because little ones are more sensitive (as I relayed in my post to Collounsbury, I felt it was important to draw more attention to them in this discussion.
And I think it would be harder for you to prove there hasn’t been an increase. While it true that CTs and MRI’s provide clearer images, CTs’ do, in turn, subject a risk themself in developing cancer at a later date as pointed out in an article by the American Cancer Society. The article goes on to state that a child may be at a greater risk where doses of radiation is not adjusted to a lower level before scanning a child. I do not know if MRI’s also use radiation.
Nothing will diminish our loss or any other family’s loss. All cases of cancer are horrible.
I lost both a mother-in-law and a former father-in-law to lung cancer. I can’t count the number of times I was at the VA hospital, so I am quite familiar with it. I thought that was the most difficult situation I would encounter. I was wrong. It doesn’t compare. Your patients who smoked heavily made a choice. Children do not; they are blameless in this.
What of possible DNA damage during development? What triggers cellular “misinterpretation”? If they are congenital mutations only, wouldn’t there be other losses/cases in the families background?
Just a little suggestion: perhaps you could place “tragic, tragic cancers, but of great interest…” in separate sentences or paragraphs.
Thank you. Your sympathy is kindly accepted though it was not sought. A quick question if you don’t mind: How much radiation is in our environment and what are the sources of it?
MRIs do not use radiation. They use magnets. To date, there has been no substantive link between magnetic fields and cancer.
Cancer from radiation damage usually manifests itself many years down the line after exposure. While there are of course risks from X-rays and CTs (CTs just being a series of X-rays), these risks are quite small for a one-time exposure (diagnostic – we are not sticking these kids in X-rays and CTs repeatedly before they get sick).
To get a little into the genetics behind retinoblastoma:
Rb is a gene called a tumor suppressor gene. This means if Rb function is lost, it can no longer suppress tumors. It happens to be in quite a mutation hot-spot in the chromosome as well.
A little background genetics. We have two copies of every gene in the genome (we are diploid). We inherit one half of our genes from each parent. Rb mutations could happen anytime and anywhere during gamete formation. The mutations often happen during gamete formation, which is why in these cases you may not have any other familial cases. If a gamete with a broken Rb gets fertilized, then we have a conceptus with one working (presumably, from the other parent) and one broken Rb gene. I will call this Rb +/- – this is the first “hit” for cancer.
Conjecture on this first hit is difficult. Most mutations, especially in germ tissue, are random errors of cellular replication. There is no conclusive way to rule out that mutagens are causing this kind of damage, but all attempts to quantify environmental mutagens have shown that these contribute (to the best of my knowledge) far less than plain dumb (un)luck.
Mutations in Rb happen to be recessive – Rb +/- people are fine (mostly). The problem is that Rb happens to be in a site of the genome where mutations happen regularly. If a mutation happens in the Rb locus (the chances are about 1/10,000 for polymerase errors), we lose all Rb function, or Rb -/-. We use the other copy of the gene ordinarily to repair mutations, but we can’t in this case because our other copy of Rb is broken as well. All Rb function is lost and that particular cell becomes cancer prone. The second hit has occured. This second hit can be caused by UV light (quite often, being the retina), oxidative damage, replication errors, or a host of other things.
While 1/10,000 seems like a low number, every cell in the retina (or pineal gland) is Rb +/-. The second hit can occur in any cell, and turn it into the first cell of a cancer. There are far more than 10,000 cells there. What it amounts to is nearly a 100% risk of cancer in these situations – in fact retinoblastomas are usually bilateral.
While your grandson may not have had this condition, the Rb locus as I have mentioned sits at a mutation prone site. One hit in any cell in the pineal gland can quickly be followed by the second hit.
Just a little suggestion: perhaps you could place “tragic, tragic cancers, but of great interest…” in separate sentences or paragraphs.
More generally, mutations which lead to cancer can be in any one of a number of places in the cell. One misinterpretation that may occur is in the apoptotic response. Apoptosis, or cellular suicide, is a normal response of a cell to unrecoverable damage. If you break anything in the damage sensing, or apoptosis triggering or conducting machinery, then a cell effectively becomes “immortalized.” Rb is in the apoptosis pathways. Another place where we often see carcinogenic change is in aberrant growth response. Cells sense their local environment (nutrients, water, space) and decide whether to divide based on that. If you break the sensing or division repression machinery, then you get uncontrolled growth.
Standard background radiation is 2-6 mSv/yr, if you wish to use that unit. This page tells you a bunch about it. Mostly, it is from radon decay and cosmic and gamma rays from outer space. Life has evolved with this radiation and it is the reason we have evolved elaborate DNA repair mechanisms, especially double stranded break repair.
Even if CTs on children provide what is considered a minimal risk of developing cancer at a later date, those who do develop cancer had no safety margin at all. However, it also causes me deep concern for those children who initially beat their childhood cancer or other illness and did/do have CTs done on a routine basis during the course of treatments and follow-ups.
Thank you for your time and effort in providing more detailed information on possible genetic development(s). I do now recall hearing that MRI’s use magnets and that there is a tumor suppressor gene (Rb), but you provided clearer information which may give me with a little deeper understanding of how genetics work.
I also appreciate the link you provided about radiation and will dive into it.