Why does cancer spread?

The Human Body -- Cancer
The Human Body — Cancer (Photo credit: n0cturbulous)

Everyone, I’m sure, knows of someone who has died of cancer. It’s a disease that is wide-spread and seems to be more common now that other diseases are coming under control. It may be that cancer is certain to appear in the human body if it lives long enough. There’s a cheery thought.

Wikipedia describes cancer as follows: “known medically as a malignant neoplasm, (it) is a broad group of diseases involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumours, and invade nearby parts of the body”.

Cross section of a human liver, taken at autop...
Cross section of a human liver, taken at autopsy examination, showing multiple large pale tumor deposits. The tumor is an adenocarcinoma derived from a primary lesion in the body of the pancreas. (Photo credit: Wikipedia)

There’s two parts of this definition. Firstly there is the unregulated cell growth and secondly there is the spread of the growth to other parts of the body. The unregulated cell growth is usually attributed to a number of causes, but the mechanism is usually given as damage to the genetic material. The causative agent whatever it might be, damages the genetic material and this results in a huge proliferation of cells.

I write computer programs as tools for doing my job. Each program ends up as a string of data which a human has a hard time decoding, though of course the computer hardware has no problems. The effect of changing a single bit (actually, a byte) of a program would almost certainly cause it to crash. In so far as the analogy that the genetic code resembles a computer program holds, this indicates that a random change to the genetic code would most likely result in the death of the cell. It would require a specific hit, to say a piece of code that control the termination of a loop that would let the program “grow out of control”.

Out of memory ATM
Out of memory ATM (Photo credit: RuiPereira)

I’d guess, from a position of almost total ignorance, that changes to the cells in the body occur all the time. Changes happen to the genetic code in a cell, and it almost certainly dies. (A side question is : what exactly happens to a cell when it dies? Presumably some process or other ‘detects’ the death and breaks it up? Or does the first failure cause other processes to fail until the integrity of the cell is lost? Lots of questions). However, unless the failure is dramatic, explosion-like rather than simple deflation, it should not affect its neighbouring cells, should it? So in general the death of a single cell is probably not noticeable.

Going back to the computer program analogy, in a computer there are dozens, if not hundreds of programs running all the time, but the user is not aware of any other than the one he is interacting with. Equating cells with computer programs, it is most likely that a random change would cause a program or a cell to die, with little effect on the computer or body as a whole.

Facit computer memory
Facit computer memory (Photo credit: liftarn)

All the programs running in a computer need ‘memory’ to run in, and there is a limited supply of memory, so (conceptually at least) one program is given the task of managing the memory allocations. Damaging the memory manager program could theoretically lead to it repeatedly allocating memory until there was none free for allocation. The computer would, once again, crash. If a program is damaged in a particular way it could ask repeatedly for memory and again cause itself or other programs. or even the whole computer to crash.

In a living organism there does not seem to be a single equivalent of the ‘memory manager’ or ‘resource manager’. In a living organism everything seems to be done by consensus between cells. (That is both anthropomorphic and probably naive, but it will do, I think).

So, although I’d estimate that the vast majority of changes to the genetic code would result in cell death and nothing else, a very, very small number of changes could result in the cell soaking up as much of the cell-level resources as it can and damaging the cell itself, its neighbouring cells or the whole organism.

Genetic code
Genetic code (Photo credit: Martina Gobec)

That, however, is not cancer. For damage to result in a cancer it has to damage the cell in a particular way. In a computer, cancer would be analogous to a program continually creating copies of itself and using up all the system resources, which would result in the system crashing. Almost all cells have the ability to duplicate themselves, but whether or not they do replicate is, so far as I know, determined by the conditions in the cell itself and conditions in its environment, ie the surrounding cells, possibly signalled by chemicals or chemical gradients.

For a cell to become cancerous, it first of all must be inclined to duplicate itself and it would also have to be able to ignore any signals from its environment. The damage to the genetic structure to achieve this seems to me to be remarkably specific. Its like damaging a computer program in such a way as to destroy a control loop. Possible, but not very likely.

Main sites of metastases for some common cance...
Main sites of metastases for some common cancer types. Primary cancers are denoted by “…cancer” and their main metastasis sites are denoted by “…metastases”. List of included entries and references is found on main image page in Commons: (Photo credit: Wikipedia)

Then there is the issue of metastasis. This is how cancer spreads. It first of all attacks the boundary of the organ it is embedded in, then some cancer cells migrate into other organs. Interestingly, when they start to form a cancerous tumour in the new organ, they are still identifiable as cells from the original organ.

Think for a moment about what that means. A cancer which metastasizes has to have its genetic material damaged in such a way that it can do all of the following :

  • divide in an uncontrolled manner
  • attack the walls of the organ it is contained in
  • migrate to other organs (and it can be very specific about the organs it migrates to)
  • settle there and start to divide again

That’s a remarkably specific set of actions to occur as the result of damage. Damage usually results in less efficient operation, both of computer programs and bodies. Of course the damage doesn’t have to create these action ‘programs’ in the genetic material. They may be already there. All that the damage needs to do is somehow kick off those actions in sequence to cause the cancer to form and metastasize. To a programmer it would look like a small chunk of code to call those routines which I’ve called ‘actions’. The only other time in one’s life that one’s body experiences explosive growth and cell migration is in the womb and as a young child. One can imagine that damage could somehow kick off the genes or part of the genetic code that was used when one was a developing foetus.

foetus
foetus (Photo credit: Leo Reynolds)

This is easier to contemplate than damage which somehow creates the whole process from scratch. It does imply that the damaging agent somehow attacks a specific part of the genetic material and replaces it with some very specific other material that has the specific effect of kicking off explosive growth and metastasis.

I’m not geneticist or cancer specialist of course, so my musings above may be way, way off beam. They could be and probably are complete rubbish. I can’t and won’t defend them if anyone were to attack them. My main thesis is that it seems incredibly unlikely that damage to the genetic material could cause the specific effects of cancer, which are uncontrolled growth and metastasis.

Yet cancer happens and happens frequently and in varied ways. There are many sorts of cancer and they appear to be often triggered by specific stimuli. All my arguments above founder on that logical rock.

Shipwreck
Shipwreck (Photo credit: Wikipedia)

Earthquakes

English: Quake epicenters. Română: Epicentre a...
English: Quake epicenters. Română: Epicentre ale cutremurelor produse în intervalul de ani 1963–1998. (Photo credit: Wikipedia)

This week’s subject pretty much suggested itself. There I was, sitting at my desk, and suddenly I felt this rolling, shaking sensation. Well, I feel it every time a truck goes past, but this time the shaking continued and it became apparent that this was an earthquake. It measured 6.6 on the earthquake scale and was the biggest one I can remember for a long time. Fortunately we were not at the epicentre and no one was killed. Those living close to the epicentre had a rougher time than we did and many houses were damaged, though only one appears to have been severely damaged.

(Note: Images in this post are not from the Wellington earthquakes that I am talking about in this post).

Since we are prone to earthquakes here the children in school are drilled in what to do when an earthquake strikes. I particularly like the idea expressed by one child that “earthquakes cause salamis”. (See the second video on the page that is linked to above.)

Earthquake Drill
Earthquake Drill (Photo credit: Benjamin Chun)

The previous earthquake happened when I was at home. Instinctively my wife ran for the door. I equally instinctively rushed to stop the TV from toppling! It’s funny what you do in an emergency.

Luckily no one was seriously hurt in the earthquakes though people in lifts (elevators) and at the top of high buildings were shaken about a bit. Apparently lifts (elevators) are designed to stop moving if there is a big quake.

In the city nothing much was damaged, although a lift (elevator) shaft which was damaged in an earlier quake is scheduled to be removed and one ‘lane’ (pedestrian access between buildings) in the city centre was taped off by authorities. Last time there was a certain amount of damage but nothing significant, though people were sent home so that the buildings could be checked. A rugby test match between New Zealand and Australia may be cancelled. That’s classified as a Big Thing round here.

Footbridge over Avon river following both Sept...
Footbridge over Avon river following both September and February earthquakes. (Photo credit: Wikipedia)

All in all, people have taken the earthquake in their stride, though news pictures showed some people who appeared to be in shock. The one injury that I heard of was one woman who tried to dive under her desk and missed cracking her head against it. I saw a picture of two girls hiding under a desk with a bottle of wine. That’s apparently what they had been doing all afternoon. One guy texted from the airport and said that he would be glad to get up into the air. (As it happens the airport stopped flights in and out for a while, but they soon caught up with the backlog).

Naturally people wanted to go home to be with their families and to check that their houses had not been damaged. This led to the roads out of and around the city becoming gridlocked. I didn’t want to get caught up in that so I hung around until just before the time that rush hour usually happens  and my trip home was in fact easier than usual. I did wonder what would happen if a significant earthquake or after shock happened while I was travelling at 100kph on the motorway! Also, there is a part of my route that lies under a motorway bridge, and there was a chance that I’d get stuck at the traffic lights. Fortunately they were showing green so I did not have to stop under the heavy concrete spans of the motorway. That would have been scary.

Footbridge over Avon river following both Sept...
Footbridge over Avon river following both September and February earthquakes. (Photo credit: Wikipedia)

The thing about earthquakes is that you don’t know how powerful they are going to be. You don’t know if it is going to be a jiggle and a roll or whether it is going to rip the building apart underneath you. I find them scary and exhilarating. After one is over people are often more relaxed than before it, and gather to exchange news and ‘war stories’. At least, that is so in the earthquakes that I have so far experienced. But they have been relatively benign.

Unfortunately this was not true nearer the epicentre where almost all the houses had some damage, though no serious injuries have been suffered and no fatalities have happened.

Wellington office after earthquake.

Why do things make sense?

Make it make sense
Make it make sense (Photo credit: edmittance)

Things pretty much make sense. If they don’t we feel that there is a reason that they don’t. We laughingly make up goblins and poltergeist to explain how the keys came to be in the location in which they are finally found, but we, mostly, have an underlying belief that there are good, physical reasons why they ended up there.

Things appear to get a little murkier at the level of the quantum, the incredibly small, but even there, I believe that scientists are looking for an explanation of the behaviour of things, no matter how bizarre. One of the concepts that appears to have to be abandoned is that of every day causality, although scientists appear to be replacing that concept with a more probabilistic version of  the concept of causality. But I’m not going to go there, as quantum physics has to be spelled out in mathematics or explained inaccurately using analogies. I note that there is still discussion about what quantum physics means.

English: Schrödinger equation of quantum mecha...
English: Schrödinger equation of quantum mechanics (1927). (Photo credit: Wikipedia)

We strive for meaning when we consider why things happen. When a stone is dropped it accelerates towards the earth. This is observation. We also observe the way in which it accelerates and Sir Isaac Newton, who would have known from his mathematics the equation which governed this acceleration, had the genius to realise that the mutual attraction of the earth and the stone followed an inverse square law and, even more importantly, that this applied to any two objects which have mass in the entire universe.

English: Mural, Balfour Avenue, Belfast Mural ...
English: Mural, Balfour Avenue, Belfast Mural on a gable wall on Balfour Avenue in Belfast (see also 978903). The mural “How can quantum gravity help explain the origin of the universe?” was created by artist Liam Gillick and is part of a series of contemporary art projects designed to alert people to the ‘10 remaining unanswered questions in science’ at public sites across Belfast. (Photo credit: Wikipedia)

So, that’s done. We know why stones fall and why the earth unmeasurably and unnoticeably jumps to meet it. It is all explained, or is it? Why should any two massy objects experience this attraction? Let’s call it ‘gravity’, shall we? How can we explain gravity?

Well, we could say that it is a consequence of the object having mass, or in other words, it is an intrinsic property of massy objects, which if you think about it, explains nothing, or we can talk about curvature of space, which is interesting, but again explains nothing.

Curved Spaces
Curved Spaces (Photo credit: Digitalnative)

Can you see where I am going with this? Every concept that we consider is either ‘just the way things are’ or requires explanation. Every explanation that we can think up either has to be taken as axiomatic or has to be explained further. Nevertheless most people act as if they believe that there is a logical explanation for things and  that things ultimately make sense.

It is possible that there is no logical explanation of things, and that the apparent relationships between things is an illusion. I once read a science fiction story where someone invented a time machine. Everywhere the machine stopped there was chaos, because there were no laws of nature and our little sliver of time was a mere statistical fluke. When they tried to return to the present they could not find it. This little story demonstrates that although we appear to live in a universe that is logical and there appears to be a structure to it, this may just be an illusion.

English: Illustration of the difference betwee...
English: Illustration of the difference between high statistical significance and statistical meaningfulness of time trends. See Wikipedia article “Statistical meaningfulness test” for more info (Photo credit: Wikipedia)

If we do live in a logical universe we not be able to access and understand the basis and structure of it. We may see things “through a glass darkly”. We may be like the inhabitants of Plato’s Cave. Everything we experience we experience through our senses, so our experience of the world is already second-hand and for many purposes we use tools and instruments to view the world around us. Also, our sense impressions are filtered, modified and processed by our brains in the process of experiencing something. We can take prescribed or non-prescribed drugs which alter our view of the world. So how can we know anything about the universe.

Alternatively there may be order to the universe. There may be ‘laws of nature’ and we may be slowly discovering them. I like the analogy of the blanket – a blanket is held between us and the universe but we are able to poke holes in it. Each hole reveals a metaphoric pixel of information about what lies behind the blanket. Over the years, decades, centuries and millennia we have poked an astronomical number of holes in the blanket, so we have a good idea of the shape of what lies behind it.

Cámara estenopéica / Pinhole camera
Cámara estenopéica / Pinhole camera (Photo credit: RubioBuitrago)

So why do things make sense? Is it because there is a structure to the universe that we are either discovering or fooling ourselves into believing that we are discovering, or is there no structure whatsoever and any beliefs that there are illusions. Maybe there’s another possibility. Maybe the universe does have the structure but it is an ‘ad hoc’ structure with no inherent logic to it all!

Highly Illogical
Highly Illogical (Photo credit: Wikipedia)

Banding together

Flag ~ Romania, Roumanie
Flag ~ Romania, also by chance the Tawa colours.

Our local rugby team has made it to the final of a competition (they won!) and naturally supporters are getting ready for the final match. They are organising coaches to take people to the match and no doubt there will be a good turn out. This got me thinking about how humans like to form bands and groups and supporter groups.

I think that banding together is at heart a self-protection thing. A human who belongs to a group gets supported by the group and reciprocally supports the group himself. In many cases the group is in competition against other groups of humans for a scarce resource such as food or territory, or in the case of sport points on the board of the elusive trophy. There is a synergy when people work together.

A rugby union scrum between the British and Ir...
A rugby union scrum between the British and Irish Lions and the All Blacks. (Photo credit: Wikipedia)

It’s not always humans versus humans though. A group may be formed to overcome some physical difficulty or to provide something that an individual can’t provide or achieve by themselves. That’s why travellers form caravans to cross deserts and a group of individuals might be able to buy a bigger boat together than they could have bought alone and take turns using it. Musicians of all genres usually form groups, at least to get started.

Les Rolling Stones à l'Olympia Stadion de Müni...
Les Rolling Stones à l’Olympia Stadion de Münich, alors qu’une partie de la scène avançait dans la foule (Photo credit: Wikipedia)

Forming a group allows individuals to specialise – in a hamlet or village one person becomes the smith, another the baker, another the mayor and another the constable, each person his or her particular skills in the role.

The role of supporters is to encourage and assist but not to actually take part in the contest or enterprise, but sometimes the line is blurred. For example the coach and trainer might not take part in a game, but in some ways they are part of the team. The supporters on the sidelines, yelling encouragement and advice, are even less part of the team, but they can certainly help out, and they form a larger group surrounding the team.

English: Greece - Russia Euro 2008
English: Greece – Russia Euro 2008 (Photo credit: Wikipedia)

Sometimes, of course, two groups of supporters clash. This is generally agreed to be a bad thing, but if you take a step back and think about it, it is to be expected, but not encouraged. It is an unwritten but basic rule of sport that the conflict, physically at least, stay on the field of play. Non-physical conflict, such as chants, banners and team regalia, is permitted between opposing spectators and even encouraged. “Get behind the team” is a rousing call for supporters. No wonder the non-physical conflict fairly often becomes physical.

The biggest ‘teams’ are countries, which strike me as being somewhat artificial in this day and age. Can one supergroup really speak for people who might be thousands of miles away? There may be an aboriginal population in a country that has far more inhabitants of immigrant origins, and these people may not consider themselves to be truly part of the nation in which they reside. Some nomadic people may travel through several countries, and may not consider themselves to be a part of any of them. The sheer size of modern countries almost invites the formation of ethnically or geographically ‘seperatists’ groups.

Matthes -- Separatists at Coblenz  (LOC)
Matthes — Separatists at Coblenz (LOC) (Photo credit: The Library of Congress)

Mankind probably started out as family groups, and were probably nomadic. When they settled down (perhaps as a result of developing agriculture) it would seem natural to settle down in larger groups, maybe two or three families to provide defence against those still travelling around. As mankind spread and became more numerous these little settlements would grow into towns, with inhabitants specialising into roles like the smith or baker mentioned above.

At some stage strong leaders became feudal lords. This appears to have been common, but was possibly not universal. Eventually the lords and barons gave their allegiance to a king or overlord and a number of small (by current standards) states were formed, sometimes based around a city as in Sparta in Greece or sometimes based in a geographical area. The debatably mythical Arthur around the 5th or 6th centuries in Britain was supposedly king of Britain, although at that time there were probably several kingdoms in what is now Britain, and Athelstan is usually considered the first true English king.

English: King
English: King (Photo credit: Wikipedia)

The nations of the world are these days largely static in shape and size, but they do still change now and then. Czechoslovakia split apart in 1993, and the Soviet Union (USSR) formed in 1922 and split up in 1991.

The next logical step in this process, one would have expected, would be the formation of a global entity, grouping the whole of mankind into one huge group, but this has not happened. There are a number of global entities, notably the United Nations, but they tend to concentrate on specific areas of endeavour rather than being the World Government that would have been expected. There are ‘blocs’ of similarly inclined countries but these also don’t have the spread of activities that would make them a ‘super-government’.

English: Global map of noted supranational uni...
English: Global map of noted supranational unions. Based roughly upon http://www.towardsunity.org/. (Photo credit: Wikipedia)

It may be that the only thing that would cause the formation of a super-group encompassing all of humanity would be an encounter with hostile and destructive aliens, but the chances of that would be very small.

Take me to your leader. iPhone 3GS
Take me to your leader. iPhone 3GS (Photo credit: Kimb0lene)