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← We can start winning the war against cancer

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Showing Revision 7 created 10/12/2016 by Brian Greene.

  1. "We're declaring war against cancer,
  2. and we will win this war by 2015."
  3. This is what the US Congress
    and the National Cancer Institute declared

  4. just a few years ago, in 2003.
  5. Now, I don't know about you,
    but I don't buy that.
  6. I don't think we quite won this war yet,
  7. and I don't think
    anyone here will question that.
  8. Now, I will argue that a primary reason
  9. why we're not winning
    this war against cancer
  10. is because we're fighting blindly.
  11. I'm going to start by sharing with you
    a story about a good friend of mine.

  12. His name is Ehud,
  13. and a few years ago,
    Ehud was diagnosed with brain cancer.
  14. And not just any type of brain cancer:
  15. he was diagnosed with one
    of the most deadly forms of brain cancer.
  16. In fact, it was so deadly
  17. that the doctors told him
    that they only have 12 months,
  18. and during those 12 months,
    they have to find a treatment.
  19. They have to find a cure,
  20. and if they cannot
    find a cure, he will die.
  21. Now, the good news, they said,

  22. is that there are tons
    of different treatments to choose from,
  23. but the bad news is
  24. that in order for them to tell
    if a treatment is even working or not,
  25. well, that takes them
    about three months or so.
  26. So they cannot try that many things.
  27. Well, Ehud is now going
    into his first treatment,

  28. and during that first treatment,
    just a few days into that treatment,
  29. I'm meeting with him, and he tells me,
    "Adam, I think this is working.
  30. I think we really lucked out here.
    Something is happening."
  31. And I ask him, "Really?
    How do you know that, Ehud?"

  32. And he says, "Well,
    I feel so terrible inside.

  33. Something's gotta be working up there.
  34. It just has to."
  35. Well, unfortunately, three months later,
    we got the news, it didn't work.

  36. And so Ehud goes
    into his second treatment.
  37. And again, the same story.
  38. "It feels so bad, something's
    gotta be working there."
  39. And then three months later,
    again we get bad news.
  40. Ehud is going into his third treatment,
    and then his fourth treatment.
  41. And then, as predicted, Ehud dies.
  42. Now, when someone really close to you
    is going through such a huge struggle,

  43. you get really swamped with emotions.
  44. A lot of things
    are going through your head.
  45. For me, it was mostly outrage.
  46. I was just outraged that, how come
    this is the best that we can offer?
  47. And I started looking
    more and more into this.
  48. As it turns out, this is not just
    the best that doctors could offer Ehud.
  49. It's not just the best doctors could offer
    patients with brain cancer generally.
  50. We're actually not doing that well
    all across the board with cancer.
  51. I picked up one of those statistics,

  52. and I'm sure some of you
    have seen those statistics before.
  53. This is going to show you here
    how many patients actually died of cancer,
  54. in this case females in the United States,
  55. ever since the 1930s.
  56. You'll notice that there aren't
    that many things that have changed.
  57. It's still a huge issue.
  58. You'll see a few changes, though.
  59. You'll see lung cancer,
    for example, on the rise.
  60. Thank you, cigarettes.
  61. And you'll also see that,
    for example, stomach cancer
  62. once used to be one
    of the biggest killers of all cancers,
  63. is essentially eliminated.
  64. Now, why is that?
    Anyone knows, by the way?
  65. Why is it that humanity is no longer
    struck by stomach cancer?
  66. What was the huge, huge
    medical technology breakthrough
  67. that came to our world
    that saved humanity from stomach cancer?
  68. Was it maybe a new drug,
    or a better diagnostic?
  69. You guys are right, yeah.
  70. It's the invention of the refrigerator,
  71. and the fact that we're
    no longer eating spoiled meats.
  72. So the best thing
    that happened to us so far
  73. in the medical arena in cancer research
  74. is the fact that
    the refrigerator was invented.
  75. (Laughter)

  76. And so -- yeah, I know.

  77. We're not doing so well here.
  78. I don't want to miniaturize the progress
  79. and everything that's been done
    in cancer research.
  80. Look, there is like 50-plus years
    of good cancer research
  81. that discovered major, major things
    that taught us about cancer.
  82. But all that said,
  83. we have a lot of heavy lifting
    to still do ahead of us.
  84. Again, I will argue that the primary
    reason why this is the case,

  85. why we have not done that remarkably well,
  86. is really we're fighting blindly here.
  87. And this is where
    medical imaging comes in.
  88. This is where my own work comes in.
  89. And so to give you a sense
    of the best medical imaging

  90. that's offered today
    to brain cancer patients,
  91. or actually generally
    to all cancer patients,
  92. take a look at this PET scan right here.
  93. Let's see. There we go.
  94. So this is a PET/CT scan,

  95. and what you'll see in this PET/CT scan
  96. is the CT scan will show you
    where the bones are,
  97. and the PET scan will show you
    where tumors are.
  98. Now, what you can see here
  99. is essentially a sugar molecule
  100. that was added a small little tag
  101. that is signaling to us
    outside of the body,
  102. "Hey, I'm here."
  103. And those sugar molecules are injected
    into these patients by the billions,
  104. and they're going all over the body
  105. looking for cells
    that are hungry for sugar.
  106. You'll see that the heart,
    for example, lights up there.
  107. That's because the heart
    needs a lot of sugar.
  108. You'll also see that the bladder
    lights up there.
  109. That's because the bladder
    is the thing that's clearing
  110. the sugar away from our body.
  111. And then you'll see a few other hot spots,
  112. and these are in fact the tumors.
  113. Now, this is a really
    a wonderful technology.

  114. For the first time it allowed us
    to look into someone's body
  115. without picking up
    each and every one of the cells
  116. and putting them under the microscope,
  117. but in a noninvasive way
    allowing us to look into someone's body
  118. and ask, "Hey,
    has the cancer metastasized?
  119. Where is it?"
  120. And the PET scans here
    are showing you very clearly
  121. where are these hot spots,
    where is the tumor.
  122. So as miraculous as this might seem,

  123. unfortunately, well, it's not that great.
  124. You see, those
    small little hot spots there.
  125. Can anyone guess how many cancer cells
    are in any one of these tumors?
  126. So it's about 100 million cancer cells,
  127. and let me make sure
    that this number sunk in.
  128. In each and every one
    of these small little blips
  129. that you're seeing on the image,
  130. there needs to be
    at least 100 million cancer cells
  131. in order for it to be detected.
  132. Now, if that seemed to you
    like a very large number,
  133. it is a very large number.
  134. This is in fact
    an incredibly large number,
  135. because what we really need
    in order to pick up something early enough
  136. to do something about it,
    to do something meaningful about it,
  137. well, we need to pick up tumors
    that are a thousand cells in size,
  138. and ideally just
    a handful of cells in size.
  139. So we're clearly
    pretty far away from this.
  140. So we're going to play
    a little experiment here.

  141. I'm going to ask each of you
    to now play and imagine
  142. that you are brain surgeons.
  143. And you guys are now at an operating room,
  144. and there's a patient in front of you,
  145. and your task is to make sure
    that the tumor is out.
  146. So you're looking down at the patient,
  147. the skin and the skull
    have already been removed,
  148. so you're looking at the brain.
  149. And all you know about this patient
  150. is that there's a tumor
    about the size of a golf ball or so
  151. in the right frontal lobe
    of this person's brain.
  152. And that's more or less it.
  153. So you're looking down, and unfortunately
    everything looks the same,
  154. because brain cancer tissue
    and healthy brain tissue
  155. really just look the same.
  156. And so you're going in with your thumb,
  157. and you start to press
    a little bit on the brain,
  158. because tumors tend to be
    a little harder, stiffer,
  159. and so you go in and go
    a little bit like this and say,
  160. "It seems like the tumor is right there."
  161. Then you take out your knife
    and start cutting the tumor
  162. piece by piece by piece.
  163. And as you're taking the tumor out,
  164. then you're getting
    to a stage where you think,
  165. "Alright, I'm done.
    I took out everything."
  166. And at this stage, if that's --
  167. so far everything sounded,
    like, pretty crazy --
  168. you're now about to face the most
    challenging decision of your life here.
  169. Because now you need to decide,
  170. should I stop here
    and let this patient go,
  171. risking that there might be
    some leftover cancer cells behind
  172. that I just couldn't see,
  173. or should I take away some extra margins,
  174. typically about an inch or so
    around the tumor
  175. just to be sure that I removed everything?
  176. So this is not a simple decision to make,

  177. and unfortunately this is the decision
  178. that brain cancer surgeons
    have to take every single day
  179. as they're seeing their patients.
  180. And so I remember talking
    to a few friends of mine in the lab,

  181. and we say, "Boy,
    there's got to be a better way."
  182. But not just like you tell a friend
    that there's got to be a better way.
  183. There's just got to be a better way here.
  184. This is just incredible.
  185. And so we looked back.

  186. Remember those PET scans I told you about,
    the sugar and so on.
  187. We said, hey, how about
    instead of using sugar molecules,
  188. let's maybe take tiny, tiny
    little particles made of gold,
  189. and let's program them with some
    interesting chemistry around them.
  190. Let's program them
    to look for cancer cells.
  191. And then we will inject
    these gold particles
  192. into these patients by the billions again,
  193. and we'll have them go all over the body,
  194. and just like secret agents, if you will,
  195. go and walk by
    every single cell in our body
  196. and knock on the door of that cell,
  197. and ask, "Are you a cancer cell
    or are you a healthy cell?
  198. If you're a healthy cell, we're moving on.
  199. If you're a cancer cell,
    we're sticking in and shining out
  200. and telling us,
    "Hey, look at me, I'm here."
  201. And they'll do it
    through some interesting cameras
  202. that we developed in the lab.
  203. And once we see that,
    maybe we can guide brain cancer surgeons
  204. towards taking only the tumor
    and leaving the healthy brain alone.
  205. And so we've tested that,
    and boy, this works well.
  206. So I'm going to show you an example now.

  207. What you're looking at here
  208. is an image of a mouse's brain,
  209. and we've implanted
    into this mouse's brain
  210. a small little tumor.
  211. And so this tumor is now
    growing in this mouse's brain,
  212. and then we've taken a doctor
    and asked the doctor
  213. to please operate on the mouse
    as if that was a patient,
  214. and take out piece by piece
    out of the tumor.
  215. And while he's doing that,
  216. we're going to take images
    to see where the gold particles are.
  217. And so we're going to first start
  218. by injecting these gold particles
    into this mouse,
  219. and we're going to see
    right here at the very left there
  220. that image at the bottom
  221. is the image that shows
    where the gold particles are.
  222. The nice thing
    is that these gold particles
  223. actually made it all the way to the tumor,
  224. and then they shine out and tell us,
    "Hey, we're here. Here's the tumor."
  225. So now we can see the tumor,

  226. but we're not showing this
    to the doctor yet.
  227. We're asking the doctor,
    now please start cutting away the tumor,
  228. and you'll see here the doctor
    just took the first quadrant of the tumor
  229. and you see that first quadrant
    is now missing.
  230. The doctor then took
    the second quadrant, the third,
  231. and now it appears to be everything.
  232. And so at this stage,
    the doctor came back to us and said,
  233. "Alright, I'm done.
    What do you want me to do?
  234. Should I keep things as they are
  235. or do you want me to take
    some extra margins around?"
  236. And then we said, "Well, hang on."

  237. We told the doctor,
    "You've missed those two spots,
  238. so rather than taking huge margins around,
  239. only take out those tiny little areas.
  240. Take them out,
    and then let's take a look."
  241. And so the doctor took them away,
    and lo and behold,

  242. the cancer is now completely gone.
  243. Now, the important thing
  244. is that it's not just
    that the cancer is completely gone
  245. from this person's brain,
  246. or from this mouse's brain.
  247. The most important thing
  248. is that we did not have to take
    huge amounts of healthy brain
  249. in the process.
  250. And so now we can actually imagine a world
  251. where doctors and surgeons,
    as they take away a tumor,
  252. they actually know what to take out,
  253. and they no longer
    have to guess with their thumb.
  254. Now, here's why it's extremely important
    to take those tiny little leftover tumors.

  255. Those leftover tumors,
    even if it's just a handful of cells,
  256. they will grow to recur the tumor,
  257. for the tumor to come back.
  258. In fact, the reason why 80 to 90 percent
  259. of those brain cancer surgeries
    ultimately fail
  260. is because of those small little
    extra margins that were left positive,
  261. those small little leftover tumors
    that were left there.
  262. So this is clearly very nice,

  263. but what I really want to share with you
    is where I think we're heading from here.
  264. And so in my lab at Stanford,
  265. my students and I are asking,
    what should we be working on now?
  266. And I think where
    medical imaging is heading to
  267. is the ability to look into the human body
  268. and actually see each and every one
    of these cells separately.
  269. The ability like this would allow us
  270. to actually pick up tumors
    way, way earlier in the process,
  271. way before it's 100 million cells inside,
    so we can actually do something about it.
  272. An ability to see each and every one
    of the cells might also allow us

  273. to ask insightful questions.
  274. So in the lab,
    we are now getting to a point
  275. where we can actually start asking
    these cancer cells real questions,
  276. like, for example, are you responding
    to the treatment we are giving you or not?
  277. So if you're not responding, we'll know
    to stop the treatment right away,
  278. days into the treatment, not three months.
  279. And so also for patients like Ehud
  280. that are going through these
    nasty, nasty chemotherapy drugs,
  281. for them not to suffer
  282. through those horrendous
    side effects of the drugs
  283. when the drugs are
    in fact not even helping them.
  284. So to be frank here,

  285. we're pretty far away
    from winning the war against cancer,
  286. just to be realistic.
  287. But at least I am hopeful
  288. that we should be able to fight this war
    with better medical imaging techniques
  289. in the way that is not blind.
  290. Thank you.

  291. (Applause)