I  think  it  is  possible  that  we  might  all  have  cancer. 

Yes, even you who are reading this column right now.

Usually  we  wonder  why  someone  gets  cancer.  This  is  especially  true  when  that  someone  happens  to  be  you,  which  was  the  case  for  me  in  late  2009  when  I  was  diagnosed  with  apparently  aggressive  prostate  cancer  at  age  42. I never thought cancer would happen to me or at least never at such a young age, but there I was out of the blue: a cancer patient. 

Why me? Why does anyone get cancer?

Good questions but with few answers. 

Now as  a  cancer  biologist  I  also  have started to  wonder about another question that is more counterintuitive:  

Why don't all people get cancer all the time?

Now,  I  have  come  to  suspect  that  maybe  everyone  does  get  cancer  and  most  or all of us have  it  this  very  moment,  but  just  don’t  know  it.

You  see,  our  cells  make  a lot  of  mistakes as they go about their lives  and  many  of these mistakes tend  to  make  the  cells  more  like  cancer. 

Luckily, cells  are very  prone  to  committing  cellular  suicide  (aka  apoptosis)  if  they  sense  anything  is  wrong,  which  is  a major  way  we  escape  from  many cancers.

But  a  particularly  nasty  combo  is  when  the  cellular  mistake  is  a mutation  in  the  pathway  by which cells commit  suicide.

With that mutation, then  the  cell  either does  not  “know”  it  is  damaged  so  it  goes  on  its  merry  way or even if it senses something is wrong it cannot kill itself, in either case  one  giant  step  closer  to  being  cancer.  

Other  bad  cancer-promoting mutations  are  in  genes  that  correct  DNA mistakes,  which  you  can  imagine  exponentially  makes  the  situation  worse.  It  is  kind  of  like  breaking  the  eraser  off  of  our  pencil,  but  being  required  to  continue  writing copying billions of letters.

If  you  think  about  the  course  of  human  history  and  evolution,  that’s  a  lot  of  time  for  these  kinds  of  cancer-related mutations to  accumulate.  You  might  say  it  is  also  a  long  time  for  humans  to  evolve  away  from  mutations  that  might  pre-dispose  us  to  cancer since those mutations are "bad",  but  this  does  not  seem  to  happen  in  reality.  For  you  see,  most  cancers  show  up clinically speaking  after  humans  have  already reproduced  and  passed  on  their  genes  so  the majority of cancer-related  mutations  evade  being  flushed  down  the  evolutionary  toilet.

Another  kind  of  evolution  and natural selection occurs not outside, but  in  our  bodies  that  is  very  much  pro-cancer  as  well.  

As  we  develop during embryogenesis and childhood  and  even  later  in  life  simply  as  we  live or especially if we are sick or injured,  our  trillions  of  cells  have  to  be  replaced  so  there  are  stem  and  progenitors  that  are  constantly  dividing  to  fulfill  this  need.  

One  cell  becomes  two,  two  becomes  four,  and  pretty  soon  you  have  millions  of  cells  that  are  all  derived  from  one stem  cell.  Along  the  way,  mistakes  are  inevitable  and  it  is  unfortunate  that  essentially  all  mistakes  that  tend  to  make  a  cell  more  prone  to  become  cancer  give  this  cell  an  evolutionary  advantage  over  its  neighbors. You can also imagine the danger if a stem cell happens to be the one that gets mutated and passes that mutation along to millions of progeny.

We do not think about it, but the reality is that cells compete with each other inside of us. There is a kind of micro version of "survival of the fittest" and natural section going on inside of us as though we were mini-Earths....and the winners are pre-cancerous cells.   These  pre-cancerous  cells  on  a  potential  path  to  become  full-blown  cancer are the winners of the evolutionary race inside of us because they grow  faster,  are  less  likely  to  die,  and  avoid  differentiation  far  more  than  their normal neighbors.  

What  this  means  is  that  an  axiom  of  cell  biology  is  that  the  more  cancer-like  a cell  is,  the  more  that  cell  will  tend  to  have  its  offspring  cells  over-represented  in  our  bodies over time,  which  is  of  course  a  very  bad  thing.

So  why  don’t  we  get  clinically apparent cancer  even  more  often?   

Scientists  do  not  really  know.  One  possibility  is  that  our  immune  systems  are  far  better  at  finding  and  destroying  cancer  than  we  ever  imagined.  Indeed,  from  this  perspective  cancer  may  frequently  be  an  immune  disorder  more  than  anything. 

The  other  more  frightening  answer to the "why?" questions about cancer that  I alluded to earlier requires  thinking  out  of  the  box,  arguing  that  in  fact  we  do  all  get  cancer  and  maybe  almost  all  of  us  adults  have  cancer  cells  in  us  right  this  moment.  But  the  cancers  poop  out  or  are  killed  by  our  immune  systems  on  a  regular  basis  or  most  often  differentiate  and  stop  proliferating. They are cancer cells but they do not become clinically evident cancer most of the time.

If  this  is  true  that  we  as  adults  all  have  cancer,  then  a  key  next  question  is  why  only  some  of  us  manifest  it  clinically  and  then  only  an  additional  subset  die  of  it? 

Nobody knows. 

If  only  we  knew  the  answer  to  those  kinds  of  questions,  but  4  decades  into  the  “war  on  cancer”  we  still  know  very  few  answers  to  the  most  critical  questions and generally have not made much clinically relevant progress overall against cancer...so perhaps it is well past time to start thinking outside of the box about cancer and asking surprising questions and challenging the dogma out there.