The short answer
Conor's mother has an unnamed, treatment-resistant cancer, and the film's precision is emotional rather than clinical. The yew tree detail is real: paclitaxel was first isolated from the Pacific yew. For an average-risk woman in her thirties, cervical screening is the USPSTF recommendation that applies, which is why symptom awareness carries the weight.
No diagnosis, stage or cancer type is ever named, so the illness works as a symbol and teaches nothing about detection.
The yew detail is accurate: NCI describes how paclitaxel (Taxol) was first isolated from the bark of the Pacific yew.
For an average-risk woman in her thirties, USPSTF cervical screening is the recommendation that applies.
USPSTF recommends biennial mammography from age 40, and colorectal screening from age 45.
On this page
About this title
- Released:
- 2016
- Format:
- Feature film
- Country:
- Spain / United Kingdom / United States
- Director:
- J. A. Bayona
- Cancer depicted:
- Not specified.
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.
Choose how you want to read this
The whole article, with every detail and caution.
What happens in the film
Conor O'Malley is about thirteen. He lives in a small English town with his mother, who is having treatment for cancer. He makes her breakfast. He washes up. At school a boy called Harry beats him, and everyone else looks through him.
At 12.07 each night, the yew tree in the graveyard walks over as a monster. It tells Conor three stories. Each one refuses the clean moral he expects. The good prince is a murderer. The bad-tempered apothecary is right.
In exchange, the monster wants a fourth story. Conor's own.
His mother's treatments fail one after another. The last is a drug drawn from that same yew. His grandmother takes charge of him. His father visits from America and cannot stay. Conor finally says what happens in the nightmare. He lets go of her hand, because part of him wants the waiting over. She dies at 12.07.
Spoilers throughout. This page says how A Monster Calls ends.
The yew tree is not invented
Most films that reach for a plant remedy are making it up. This one is not.
NCI describes how, in 1962, a US Department of Agriculture botanist collected bark from the Pacific yew tree. Researchers later isolated paclitaxel (Taxol) from that bark.
It is still used today. MedlinePlus lists breast, ovarian and non-small cell lung cancer, and Kaposi sarcoma related to AIDS. It is also used off-label for some other cancers.
MedlinePlus lists these common side effects:
- Numbness in the hands or feet.
- Muscle pain.
- Nausea and vomiting.
- Hair loss.
It can also lower white blood cell counts, which raises infection risk. Patients get medicine beforehand to help prevent allergic reactions. A fever of 100.4 F or higher during treatment needs a call to the care team right away.
So the film's central image is true. A tree did give us a cancer drug. What the film does with it, offering it as a last dramatic gamble, is a story choice.
A cancer with no name, and what that costs
No diagnosis, stage or type appears anywhere in the film or the novel.
That choice serves the story. It also means the illness cannot teach anything. There is no test to describe, no decision to explain, no reason given for why one treatment followed another.
The decline is compressed into shorthand: pallor, a headscarf, a hospital bed. The experimental drug is presented as a single gamble, with no talk of choices or odds. Real illness is rarely so tidy, and your own team can tell you what to expect.
What it gets right about a child in the house
Here the film is unusually precise, and it is worth saying so.
It catches the role reversal. A boy doing the cooking and the dishes. It catches the invisibility at school, where nobody knows what to say so nobody says anything. It catches adults speaking in euphemisms, then being surprised the child is furious.
Its central insight is the real one. People caring for someone who is dying often wish for it to be over, and then feel monstrous for having wished it. Naming that as ordinary rather than shameful is the most useful thing the film does.
Screening that actually exists for a woman in her thirties
Because the cancer is unnamed, the honest thing to describe is what would actually be on offer.
For an average-risk woman in her thirties in the United States, USPSTF recommends cervical screening. From 21 to 29, cytology every 3 years. From 30 to 65, one of three options: cytology every 3 years, high-risk HPV testing alone every 5 years, or HPV testing with cytology every 5 years. All are Grade A.
Mammography starts later. USPSTF recommends biennial screening mammography for women aged 40 to 74, a Grade B recommendation.
Colorectal screening starts at 45. That is a Grade B recommendation for ages 45 to 49, and Grade A from 50 to 75.
For many cancers, USPSTF does not recommend routine screening in this age group, so symptoms matter.
Symptoms, and what NCI actually advises
That gap is why symptoms carry the weight.
NCI's list of changes cancer may cause includes:
- A lump anywhere.
- Unexplained bleeding or bruising.
- A cough or hoarseness that does not go away.
- A sore that does not heal.
- Jaundice (yellowing of the skin or eyes).
- A new mole or a changing one.
- Fatigue.
- Weight changes.
Its instruction is plain. NCI says these symptoms are most often caused by illness, injury, benign tumors or other problems. But symptoms that do not get better after a few weeks should be seen by a doctor. NCI adds that cancer often causes no pain, so pain is not a threshold to wait for.
That is what a story like this is genuinely good for. Not diagnosis, but the push to make an appointment that has been drifting. The film never says the word cancer, which is close to how it works in a house with a sick parent and a child nobody has told.
For the screening picture in full, see cancer screening. For what a symptom does and does not mean, see symptoms of cancer.
Sources
- USPSTF — Cervical Cancer: Screening
- USPSTF — Breast Cancer: Screening
- USPSTF — Colorectal Cancer: Screening
- NCI — The Pacific Yew and Taxol
- MedlinePlus — Paclitaxel
- NCI — Symptoms of Cancer
This page discusses A Monster Calls for education. It is not medical advice, and nothing here is a judgement of anyone's real medical care.

Common questions
What kind of cancer is in A Monster Calls?
It is never named. Conor's mother has an advanced, treatment-resistant cancer, but neither the film nor Patrick Ness's source novel gives a type, site or stage. This page discusses the storyline openly, including how it ends.
Is the yew tree detail real?
Yes, and it is the film's one accurate piece of pharmacology. Per NCI, paclitaxel (Taxol) was first isolated from the bark of the Pacific yew tree. The last drug tried in the film is drawn from the same yew that becomes the monster.
What screening would a woman in her thirties actually be offered?
For average risk, the USPSTF recommendation that applies is cervical screening. USPSTF recommends cervical cytology every 3 years from 21 to 29, and from 30 to 65 either cytology every 3 years, high-risk HPV testing every 5 years, or cotesting every 5 years. Mammography starts at 40 and colorectal screening at 45.
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. It is entirely reasonable to skip it, or to find out how it ends before starting.
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Written by: Cancer ExplainedSources last checked: 2026-08-06 what this meansLast updated: 2026-10-02Next planned review: 2028-07-25
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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, and this 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 then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. 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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