At first blush, cancer might seem an unlikely topic for an exclamation-point musical — it’s a dreadful, incurable, terminal disease that reduces everyone it touches to untold depths of helplessness and pain. Yet by the same token, its ubiquity and totality makes cancer a broadly relatable subject. Moreover, it’s a part of life, which is inherently funny; thus, by the transitive property, cancer must be funny, too. (And this is saying nothing of the related rigmarole of health care and big pharma, about which we must laugh or else we’d cry.) Viewers with any lingering doubts need look no further than Cancer! The Musical (book by Thomas Donnellon, MD, and Shawn Handlon; music by John Edwartowski), a simply excellent treatment that turns the ultimate downer on its head. At the young Park Bar Theatre, this scrappy, winning revival directed by Handlon has no trouble seizing on the best of what the musical has to offer.

With subject matter ranging from patient care to laboratory research to business interests, the show is admirable for being all the things it needs to be, up to and including a love story and a high-stakes caper. On one end, patient Annie (Dawn Bartley) faces her cancer diagnosis and exploratory surgery with optimism and pluck — the viewer would be forgiven for suspecting that “Annie” is short for “Pollyanna.” However, her courageous turn is made palatable in its thawing effect on her officious oncologist, Dr. Harris (Pat Loos), so immersed in protocol, privacy laws, and malpractice fears that he eschews eye contact with his alphanumerically coded patients. Together, Bartley and Loos form a touching emotional core that keeps Annie’s fight largely in the medical realm, but still feels personal without being derailed by wallowing.

In a parallel story, Harris’s old school chum, Dr. Bernard (Dustin Gardner), has a eureka moment in his research, seemingly curing cancer in lab rats. (Even these rodents — portrayed by the full cast plus ears and tails — are devoted to the cause, selling the heck out of Jill Dion’s showy group choreography as they make deceptively cheeky observations about the people observing them.) However, Bernard’s elation at his sunny future is interrupted by the head of a rival pharmaceutical company, Mr. Murphy (Mike Shreeman), who has his own motivations to steal the cure at any cost. Gardner makes for an abundantly funny pent-up scientist nerd, academic victory and newfound superiority splayed across his expressive face; in contrast, Shreeman’s calculating snake is expectedly inhuman, with locked-down control of his constantly justified villainy. The researchers and profiteers’ disaffected treatment of cancer as a business is a comprehensible perspective worth visiting; it also breaks up the emotional immersion of its partner story and provides a fine source of counterpoint.

Each of the performers takes on multiple roles to populate the world of the play; additional support is lent by Kelly Rossi, whose plain-faced, wry delivery is perfectly suited to obviously oblivious comic moments, and Dez Walker, who shines as a doctor given to delivering news in the form of overblown and tone-deafly chipper songs. Under musical director Chad Krueger, who also leads the four-member offstage band, the varied numbers are universally strong; however, because the accompaniment sometimes threatens to overpower the voices, sitting near the performers is advisable. Precise marriage of staging and lighting firmly establishes an internal logic for the staggered entrance points onto the bare stage, flexibly portraying multiple locations and split-screen effects as required by the script. Handlon’s direction has a deft hand for the show’s plentiful humor, which rarely misses an opportunity for satire, moments of caricature, or lyrical word play. However, the play’s two acts also make room for affection and grief appropriate to the subject matter; the successful amalgamation of so many contrasting tones shows the accomplishment of a great script handled with skill.

For all its strengths, this production does suffer some unevenness, most notably the occasionally stagnant staging that feels uneasy in light of the slick and practiced choreography of other scenes. Even so, the irreverent fun and affecting humanity of Cancer! The Musical come out on top in a production that staves off bleakness with an indomitable current of hope. The show attends to the individual experience of cancer through the lens of individual stories, reflecting the experience of many viewers, but its ultimate message is found in the bigger picture, humankind’s collective drive to topple the disease and the powerfully restorative conviction that it can someday be achieved.