Cancer and comedy: Ne’re the twain shall meet, unless you’re Seth Rogen and Joseph Gordon-Levitt. Together they star in “50/50,” a new comedy from Jonathan Levine, director of the criminally underrated film “The Wackness.”

Gordon-Levitt and Rogen star as friends Adam and Kyle, a pair of regular dudes who work for public radio. After experiencing chronic back pain, Adam learns he has a rare form of spinal cancer and must undergo chemotherapy. With his future uncertain, he begins to take charge of his life and faces a number of problems he has long ignored.

Partially based on the experiences of screenwriter Will Reiser, “50/50” is the kind of film that shoots for laughs and tears in equal measure. The unfortunate part is that it does a poor job of balancing such varying emotions. Levine and his collaborators have their eggs in too many baskets, resulting in a meandrous and often largely uninteresting experience.

Mostly, the film is just lazily written, particularly when it comes to its female characters. There’s Bryce Dallas Howard as Rachael, Adam’s girlfriend, who vows to take care of him but is soon caught cheating with another man; there’s Anjelica Huston as Diane, Adam’s concerned and attentive mother; and Anna Kendrick as Katie, Adam’s therapist and eventual love interest.

Of the three, Huston is the only actress given a decently constructed character to work with. Howard is unfairly relegated to the source of Adam’s (and therefore the audience’s) wrath, while Kendrick is depicted as a woman whose emotions stand in the way of her correctly doing her job.

This is all the more shameful considering Howard and Kendrick are exceptionally talented actresses, capable of embodying characters with significantly more depth than they’re presented with here.

It goes without saying that all the best bits are reserved for the dudes. Rogen and Gordon-Levitt spend most of the movie talking about their dicks and things they’d like to do with their dicks—so much, in fact, that when Levine shoots for pathos, he mostly comes back empty handed.

The objective of “50/50” is clear—it strives to be a documentation of the highs and lows people experience when presented with life-altering circumstances. Human emotions are likened to roller coasters for a reason, and the film deserves credit for recognizing the multifaceted nature of real life.

But from scene to scene, the film shifts from being a raunchy bro-fest to a dire cancer story—which is fine, on paper. After all, this is a film about ups and downs. But these abrupt shifts in tone don’t go unnoticed. In fact, they’re so jarring that when the film demands to be taken seriously, it’s nearly impossible to do so.

Everyone seems to have trouble with this balancing act. Gordon-Levitt appears adrift for most of the film, often resorting to broad gestures in an attempt to heighten the drama. Unfortunately for him, screaming isn’t acting. Rogen, meanwhile, is his typically lewd self: funny, but rarely elevating the content to its supposed heights.

The only consistent aspect of “50/50” is its surprisingly inventive cinematography. Saturated tones and perpetually gray hues give the film a dreary look, meant to reflect the grayness of Seattle in the winter. The film looks chilly, which is appropriate considering it’s likely to leave many cold.