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Clouds (2020) and Relapsed Osteosarcoma

Clouds (2020) on screen: the plot, what it portrays accurately, where drama takes over, and the real early signs and screening behind the story.

NCI source

National Cancer Institute — Cancer Information Summaries (PDQ®)

A female doctor or counselor talks with a woman patient in a cozy home-like office
A female doctor or counselor talks with a woman patient in a cozy home-like office

Key fact

Clouds (2020) depicts osteosarcoma, a cancer that starts in bone, here relapsed and metastatic to the lungs.

The short answer

Clouds (2020) puts cancer at the center of its story. This page covers the plot, what the work gets right, where it takes dramatic license, and the real medicine underneath — including early signs and whether screening exists.

  • Clouds (2020) depicts osteosarcoma, a cancer that starts in bone, here relapsed and metastatic to the lungs.

  • Made with the Sobiech family's participation and based on Laura Sobiech's memoir, this is one of the more careful cancer films.

  • The film gives Zach more energy than late-stage metastatic osteosarcoma usually allows, and underplays breathlessness from lung disease and pain from bone disease.

  • A dramatised illness is not a guide to your own — but it can be a reason to ask a question you have been putting off.

About this title

Released:
2020
Format:
Feature film
Country:
United States
Director:
Justin Baldoni
Cancer depicted:
Osteosarcoma, a cancer that starts in bone, here relapsed and metastatic to the lungs.

Full cast, crew and release details

This page describes a work of film or television for education. Plot details are discussed openly. Nothing here is a review of anyone’s real medical care, and a dramatised illness is not a guide to your own.

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The full explanation.

Zach Sobiech's last year

Zach Sobiech is a Minnesota high-school senior who has been living with osteosarcoma, a cancer that starts in bone, since he was fourteen. As the film opens he learns that treatment has stopped working and that he has months left. His family is told six to ten.

He decides to spend that time making music. With his best friend Sammy Brown he forms the duo A Firm Handshake, plays local shows, and writes a song about his own dying called "Clouds". His mother Laura films the recording. The video spreads far beyond Minnesota and raises money for osteosarcoma research.

Alongside that he has a first serious relationship with Amy, finishes school, and writes a college essay about how he wants to be remembered.

The film does not fake a recovery. Zach's health declines and he dies. In an epilogue his friends and family gather and see a cloud shaped like a Z.

The real Zach Sobiech was born on 3 May 1995 and died on 20 May 2013, aged eighteen. He was diagnosed at fourteen, and during treatment he had ten surgeries and twenty-four rounds of chemotherapy. His family set up the Zach Sobiech Osteosarcoma Fund at Children's Cancer Research Fund, which had reached $2 million by September 2015.

The ending is discussed below.

What the family's involvement bought

This was made with the Sobiech family's participation and is based on Laura Sobiech's memoir, Fly a Little Higher. Many of Zach's real friends and family appear in it. That access shows.

The shape of the illness is right, and it is the shape films usually refuse. Diagnosis in the early teens. Years of surgery and chemotherapy. Remission. Relapse. Then the appointment where a family is told that curative treatment is over.

Physically it is honest too. There are crutches, a limp, lost mobility and the visible cost of repeated operations. Zach is not an invisibly ill patient who simply grows pale.

And it is exact about what adolescent cancer takes that adult cancer does not: school, friends who move on without meaning to, and a first relationship conducted with a deadline attached.

Nine years compressed into one

The film gives Zach considerably more energy than late-stage metastatic osteosarcoma usually allows, especially in the performance scenes. Breathlessness from disease in the lungs, and pain from disease in bone, are both underplayed.

It also folds nearly a decade of illness into a single senior year. The grinding repetition of scans, operations and chemotherapy cycles happens off screen. Ten surgeries and twenty-four rounds of chemotherapy do not fit in a school year, and the film's compression quietly removes the part that exhausts real families most: the sheer duration.

The problem with a viral legacy

"Clouds" reached millions of people. That happened, and the money it raised is real.

It is also exceptional. Most young people dying of cancer do not write a hit, and most do not get a public legacy of any kind. The film's uplift carries a risk it never quite names: the suggestion that a dying person owes the world a meaningful ending.

Nobody does. Teenagers in this position are frequently exhausted, bored, angry, and uninterested in being anyone's lesson. That is allowed, and a family should not measure their child against Zach's last year.

Osteosarcoma: who gets it and where

Osteosarcoma is the most common cancer that starts in bone. NCI reports about 440 cases a year in the United States in people aged 19 and under.

It is a disease of the growth spurt, which is why it clusters in adolescence. It usually forms in the long bones of the arms and legs, and NCI notes that over half of cases are in the long bones near the knee, meaning the lower thigh bone or upper shin. Zach Sobiech's began in his hip, which is less typical.

That location matters for detection. A cancer near the knee in a fifteen-year-old is competing with football, growth and a hundred plausible innocent explanations.

Bone pain that should not be waited out

NCI lists the symptoms of osteosarcoma:

  • Swelling over a bone or a bony part of the body.
  • Pain in a bone or joint.
  • Pain in the arm when lifting.
  • Stiffness in a joint.
  • A limp or difficulty walking.
  • A bone that breaks for no known reason.

Every one of those looks like a sports injury. The features that should tip the balance are duration and timing. Pain that persists for weeks, pain that wakes a child at night, and pain with a visible swelling over the bone all deserve assessment and usually an X-ray.

There is no screening test for osteosarcoma, and none is recommended for anyone, including children with a family history. Diagnosis starts with an X-ray, then MRI or CT, and a biopsy to confirm.

Because there is no screening at all, the entire burden of earlier detection falls on someone taking persistent bone pain seriously. If an injury has been treated as a strain and has not settled after a few weeks, ask for imaging rather than more rest.

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What to take from Zach's story

Clouds is one of the more careful films on this site, and it is still a film. It is truthful about the end of Zach's illness and quiet about the nine years that led there.

The medically useful part is not the song. It is the beginning nobody filmed: a teenager with pain in a bone, and the weeks before anyone imaged it.

If a young person you know has bone pain that has lasted more than two or three weeks, or that wakes them at night, ask for an X-ray. See possible warning signs and screening.

This page discusses Clouds for education. It is not medical advice, and nothing here is a judgement of anyone's real medical care. Spotted an error? Please email corrections@cancerexplained.org.

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Common questions

What kind of cancer is in Clouds?

Osteosarcoma, a cancer that starts in bone, here relapsed and metastatic to the lungs. The real Zach Sobiech was diagnosed at fourteen and his cancer began in his hip. This page discusses the storyline openly, including how it ends.

Is Clouds medically accurate?

The film gives Zach more energy than late-stage metastatic osteosarcoma usually allows, and compresses nine years of illness into one school year. The full breakdown is on this page.

What are the real early signs behind this story?

Osteosarcoma is the most common cancer that starts in bone, and it mainly affects adolescents and young adults during the growth spurt.

Should I watch this if cancer is affecting my life right now?

That is a personal decision and there is no right answer. Some people find these stories clarifying; others find them intrusive or frightening. It is entirely reasonable to skip it, or to find out how it ends before you start.

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Written by: Cancer ExplainedSources last checked: 2026-07-25 what this meansLast updated: 2026-08-10Next planned review: 2028-07-25

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How this page was created

Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.

Editorial status: Source checked This page was written with AI assistance and checked line by line against the sources listed on it. That confirms the sources support what the page says. It is not a medical review, and it does not confirm the page is complete or right for your situation.

Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.

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