Lanes
Lanes
[The panels are arranged top to bottom. The first is set above a larger image.] Friend: So, are you guys out of the woods? Cueball: We don't know. Friend: Well, did the treatment work? Cueball: We don't know.
[Cueball's next few lines are set by themselves in their own panels, arranged around a larger image.] Cueball: I always assumed that when you got cancer, they gave you a prognosis, then treated you, and at the end of treatment either you beat it or you died.
[The diagram shows a simple highway. Starting at the bottom, with diagnosis for five lanes, the road travels through a cloud of treatment, after which two lanes disappear, and three continue. Later on, there's another off-ramp labeled 'cancer "comes back"', which loops back into the treatment cloud. Otherwise, the highway enters a later cloud called survive.]
Cueball: And I knew sometimes it "recurred," which I assumed meant back to square one. Cueball: But that's turned out not to be quite right.
[Back to Cueball and his friend.] Cueball: Once most cancers spread out into your body, they're incurable. Cueball: If your 10-year prognosis is 60%, that means a 40% chance that some cancer will slip past the treatment and get out.
[The frame zooms in to show just Cueball.] Cueball: So they kill all the cancer they can find, and then you're a "survivor." But your odds are still 60%.
[The panel zooms in further, now showing only Cueball's top half.] Cueball: They can't scan for individual cancer cells. The only way to know if it worked is to wait for tumors to pop up elsewhere. Cueball: If you go enough years without that happening then you were in the 60%.
[The frame shows both people again.] Cueball: And often the first sign is a cough or bone pain. Cueball: So you spend the next five or ten years trying not to worry that every ache and pain is the answer to the question "Do I make it?"
[There's an extra large panel, with a small one floating inside it.] [The panel shows fifty-two lanes emerging from the cloud of 'Treatment'. Signs show 1 year, 2 years, 3 years, 4 years, 5 years, 6 years. Lanes branch off and fade into darkness earlier on the right, with some lanes continuing off the top of the panel.]
[Inset panel.] Friend: Man. Friend: Fuck cancer. Cueball: Seriously.

xkcd is a webcomic of romance , sarcasm , math , and language : humor isn't necessarily guaranteed. This comic is an example of that, it being severely depressing.
The comic is built around a dialogue between two people (we'll say Cueball is the one talking, and the other is his friend) about cancer, presumably cancer that Megan has been diagnosed with. The conversation itself is about as straightforward as a conversation can be. It details the maturation of Cueball 's and Megan 's understanding of cancer diagnoses, knowledge which we can presume he has gained, reluctantly, by watching a loved one suffer.
This whole cancer series was sparked because Randall 's then-fiancee, now wife, is currently in Megan's position, and we, the readers, are now the beneficiaries of this new understanding of cancer diagnoses without having to watch somebody close to us suffer.
The comic's title, Lanes, comes from the two panels which illustrate both ends of the spectrum of Cueball's mental representation of how cancer treatment proceeds. In that there are many possible outcomes for cancer treatment, the image of a multi-lane freeway seems an apt metaphor to represent this understanding visually.
In the first freeway diagram, there are several paths, but the system is very simple, and easy to take in. Only a few lanes lead off into the oblivion which surrounds the freeway, a single off-ramp circles back from the path to survival to treatment, and survival is a visible endpoint.
In the second freeway diagram, however, things are much, much more complex, and much more bleak. Even six years out, survival isn't visible, and many lanes end in oblivion, sometimes not veering off for years after treatment. The title text informs us that this is meant to be loosely representative of breast cancer stages one through four, proceeding by quarters from left to right. It's a grim outlook, hence the friend's understated but completely fitting reaction to this plethora of new knowledge.
Specific numbers:
There are 52 lanes, so 13 lanes per cancer stage. Stage 1 has a 1:12 = ~8% chance of recurrence leading to death within 6 years. Stage 2 has a 5:8 = ~38% chance. Stage 3 has an 8:5 = ~62% chance. Stage 4 has an 11:2 = ~85% chance of death within 6 years.
The opening line of "being in the woods" is revisited in 1928: Seven Years , where Cueball and Megan are shown walking through a forest in a cancer-themed strip.
[The panels are arranged top to bottom. The first is set above a larger image.] Friend: So, are you guys out of the woods? Cueball: We don't know. Friend: Well, did the treatment work? Cueball: We don't know.
[Cueball's next few lines are set by themselves in their own panels, arranged around a larger image.] Cueball: I always assumed that when you got cancer, they gave you a prognosis, then treated you, and at the end of treatment either you beat it or you died.
[The diagram shows a simple highway. Starting at the bottom, with diagnosis for five lanes, the road travels through a cloud of treatment, after which two lanes disappear, and three continue. Later on, there's another off-ramp labeled 'cancer "comes back"', which loops back into the treatment cloud. Otherwise, the highway enters a later cloud called survive.]
Cueball: And I knew sometimes it "recurred," which I assumed meant back to square one. Cueball: But that's turned out not to be quite right.
[Back to Cueball and his friend.] Cueball: Once most cancers spread out into your body, they're incurable. Cueball: If your 10-year prognosis is 60%, that means a 40% chance that some cancer will slip past the treatment and get out.
[The frame zooms in to show just Cueball.] Cueball: So they kill all the cancer they can find, and then you're a "survivor." But your odds are still 60%.
[The panel zooms in further, now showing only Cueball's top half.] Cueball: They can't scan for individual cancer cells. The only way to know if it worked is to wait for tumors to pop up elsewhere. Cueball: If you go enough years without that happening then you were in the 60%.
[The frame shows both people again.] Cueball: And often the first sign is a cough or bone pain. Cueball: So you spend the next five or ten years trying not to worry that every ache and pain is the answer to the question "Do I make it?"
[There's an extra large panel, with a small one floating inside it.] [The panel shows fifty-two lanes emerging from the cloud of 'Treatment'. Signs show 1 year, 2 years, 3 years, 4 years, 5 years, 6 years. Lanes branch off and fade into darkness earlier on the right, with some lanes continuing off the top of the panel.]
[Inset panel.] Friend: Man. Friend: Fuck cancer. Cueball: Seriously.
