CRC Risk Calculator

APCS score = age points + sex points + family history points + smoking points

age

40 to 49 scores 0, 50 to 69 scores 2, and 70 or over scores 3. Age is the heaviest single factor in the score, and it is why the tier moves on its own as the years pass

sex

Female 0, male 1. This is the shape of the published model rather than a statement about any individual, and it is the smallest of the four contributions

family history

Colorectal cancer in a parent, sibling or child: none scores 0, one or more scores 2. Note how narrow this is — the score counts first-degree relatives only, and it asks about cancer rather than about polyps

smoking

Never smoked 0, current or past smoker 1. The published score counts smoking as a yes or no, not in pack-years

Use it to see how the four factors in the Asia-Pacific Colorectal Screening score add up for you, and to see which of them is doing the work — for most people it is age, and that is worth knowing when a score feels like a verdict. Use it as a conversation starter with a clinician about when screening should begin, which is a question this score does not answer: guidelines do not agree with each other, and the ages 40, 45 and 50 all appear in them. Do not use it as a substitute for screening, and do not read a low tier as a reason to skip it. The score has no information from a stool test, a colonoscopy or any examination; it only sorts people into risk groups, and even there it is a coarse instrument.

1. Woman of 55, no family history, never smoked

   1. Age 55 is in the 50 to 69 band: 2 points
   2. Female: 0 points
   3. No first-degree relative with colorectal cancer: 0 points
   4. Never smoked: 0 points
   5. Total 2, which is the bottom of the moderate tier

   This is the combination the page opens with, so a fresh screen shows this score. Notice how the two points come entirely from age: at 49 the same person scores 0 and sits in the average tier, and nothing about her health changed in those six years. That is what a score built mostly from age does, and it is not a flaw in the arithmetic — it is a fair summary of how risk for this cancer accumulates.

2. Man of 70, one brother with colorectal cancer, still smoking

   1. Age 70 is in the top band: 3 points
   2. Male: 1 point
   3. One first-degree relative: 2 points
   4. Current or past smoker: 1 point
   5. Total 7, the maximum the score can give, and the top of the high tier

   All four factors at once. Seven is as high as this score goes, and it is still not a diagnosis: in the group this score was built from, the great majority of people with a high tier did not have advanced neoplasia when they were examined. What a top score changes is the case for getting screened, not the answer.

3. Man of 50, no family history, smoker

   1. Age 50 crosses into the middle band: 2 points
   2. Male: 1 point
   3. No first-degree relative: 0 points
   4. Current or past smoker: 1 point
   5. Total 4, which is exactly where the high tier begins

   This one lands on the line, which is the reason to keep it: 4 is the lowest score the published score calls high risk, and one point less drops the same person into the moderate tier. Being born one year earlier would have done it, without anything else about him changing.

This page adds up a score and shows you which tier it falls in. It does not screen for anything, and it is not a diagnosis: the score was designed to sort an asymptomatic population into groups for screening, and in the group it was built from, most people in the high tier did not have advanced neoplasia. The three tiers themselves were set by the authors rather than derived from the data, and the paper says so; the numbers attached to them are proportions found in one population, and the second and third tiers are close enough to each other that a single point can move you across the line. The score also leaves out a great deal. Diet, alcohol, red and processed meat, body weight, physical activity, diabetes and inflammatory bowel disease are all absent from it, along with any family history of adenomas rather than cancer, any personal history of polyps, and any genetic syndrome — factors that a clinician will weigh and this score will not. It counts first-degree relatives only, so a smaller but real family history scores nothing here. Age is the largest contribution, which means the score rises with the calendar whatever else is true about you. What the score can do is a coarse stratification: pooled across studies, the tiers separate groups whose rates of advanced neoplasia are meaningfully different, but the sensitivity for finding advanced neoplasia is only around 0.42, the specificity is 0.86 and the area under the curve is about 0.64, which is to say the score is better at ruling groups in than at ruling people out. It is also not the only score of its kind and the differences are not cosmetic: a variant used in Korea gives 4 points for age 70 and over and runs to 8, another adds body mass index, and a modified version regroups the ages and tops out at 6. A score of 5 from this page and a score of 5 from another one are not the same claim. Finally, and importantly, the score does not answer the question people usually ask of it — when screening should start. Guidelines disagree, and the age at which screening begins is a decision to make with a clinician, using this figure as one input among several.

What is the APCS score?

It is a short risk score for colorectal cancer, published in 2011 and built to sort people without symptoms into three groups so that screening can be aimed at the ones who need it most. Four questions, four weights: age, sex, colorectal cancer in a parent, sibling or child, and smoking. The total runs from 0 to 7. Nothing is measured and nothing is tested — the whole score is made of things you can answer from memory, which is the point of it. Its name comes from the population it was derived in, which is why its weights reflect that population's risks rather than everyone's.

What do the three tiers mean?

The published score divides 0 to 7 into average risk at 0 to 1, moderate risk at 2 to 3, and high risk at 4 to 7. What those words mean in practice is a difference in how common advanced neoplasia turned out to be: in the population the score came from, the three tiers contained roughly 30, 51 and 19 per cent of the people, and the share found to have advanced neoplasia rose across them, with the high tier several times more likely to have it than the average tier. Several times more likely is a real difference in a group and still a small probability for one person, which is why a high tier is an argument for screening rather than a finding.

How accurate is the score?

Coarse. Pooled across the studies that have used it, the score picks up about 42 per cent of the people who do have advanced neoplasia, correctly clears about 86 per cent of those who do not, and separates the two groups only modestly better than chance — the area under the curve is around 0.64. Read that first number carefully: a low or average score does not mean you are clear, because the score misses more than half of the cases that are there. Read the second one too: most people it puts in the high tier do not have advanced neoplasia. What a score like this is good for is deciding who to test first, not for telling anyone they are safe.

Should I be screened if my score is 4 or more?

That is the natural next question, and this page cannot answer it, because the score and the screening decision are two different things. The score sorts risk; the age at which screening should start is set by guidelines, and the guidelines do not agree — 40, 45 and 50 all appear as starting ages in current recommendations, and some of them differ by family history or by region. A high score is a reason to talk to a clinician about screening sooner rather than a rule that says which test to have and when. Conversely, a score of 0 or 1 is not a reason to skip screening that is already recommended for your age.

Why do body weight, alcohol and diet not count?

Because the score does not include them, not because they are unimportant. The four factors here are the ones that survived the modelling in the population the score was built from, and the model was kept deliberately small so that it could be used without any tests. Several of the things you might expect are genuinely absent: body mass index, alcohol, red and processed meat, physical activity, diabetes and inflammatory bowel disease. Two of these appear in other versions of the score — one variant adds body mass index — which is also a warning that scores with the same name do not always count the same things.

Is this the same as other colorectal cancer risk scores?

No, and the difference is not a matter of detail. The score on this page runs from 0 to 7. A widely used Korean variant gives 4 points to anyone of 70 or over and runs to 8, so the same person can score differently in the two. A modified version of the Asia-Pacific score regroups the ages and tops out at 6. Another variant adds body mass index to the four factors. This is why the tier words matter more than the raw number, and why a score is only meaningful alongside the exact version it came from — a 5 from one table is not a 5 from another.

Can I use it for someone with symptoms?

No. This score was derived in people without symptoms, and its whole purpose is to sort that group; it was never meant to be applied to someone who already has a reason to be investigated. Blood in the stool, a change in bowel habit that persists, unexplained weight loss, anaemia or a new and persistent abdominal pain are reasons for assessment on their own, regardless of what any risk score says, and they are reasons to see a clinician rather than to calculate anything. The same goes for a personal history of polyps or inflammatory bowel disease, and for a known inherited syndrome: those situations come with their own follow-up, and this page does not model them.

• The Asia-Pacific Colorectal Screening score: a validated tool that stratifies risk for colorectal advanced neoplasia in asymptomatic Asian subjects — Yeoh KG, Ho KY, Chiu HM et al. — Gut, 2011;60(9):1236-1241 — the score itself: the four factors, how they are weighted, and the three tiers, which the authors describe as arbitrarily defined
• An adjusted Asia-Pacific colorectal screening score system to predict advanced colorectal neoplasia in asymptomatic Chinese patients — Zhang C, Zhang L, Zhang W et al. — BMC Gastroenterology, 2023;23(1):223 — one of two open-access papers that print the point table factor by factor, which is how the weights on this page were checked against the original
• Performance of the Asia-Pacific Colorectal Screening score in stratifying the risk of advanced colorectal neoplasia: A meta-analysis and systematic review — Luu MN, Trinh NA, Tran TLT et al. — Journal of Gastroenterology and Hepatology, 2024;39(6):1000-1007 — how the three tiers actually perform across studies, including the sensitivity, specificity and area under the curve quoted above