Health

Three Start at Forty — Korea's National Cancer Screening by Age

Three Start at Forty — Korea's National Cancer Screening by Age

According to Korea's 2023 national cancer registration statistics, published by the Ministry of Health and Welfare in January 2026, the probability of developing cancer over an average lifespan is 44.6% for men and 38.2% for women — one in two men, one in three women. 288,613 people were newly diagnosed in 2023, and 2,732,906 people were living with or after cancer: one Korean in nineteen.

The same statistics carry a second number. Among patients diagnosed in the most recent five years, the five-year relative survival rate is 73.7%, up 19.5 percentage points from 54.2% for those diagnosed in 2001–2005. Seven in ten survive five years or more. What sits between those two numbers is early detection, and Korea's institutional mechanism for it is the national cancer screening programme.

This guide is organised not as a list of six cancers but around a single question: what starts at my age?

Twenty, forty, fifty — the three years the list grows

The programme adds an item each time you reach a threshold age. In particular, three start at once in the year you turn 40. That is where most people fall through.

AgeWhat begins that yearIntervalWho
20Cervical cancer2 yearsWomen
40Stomach cancer2 yearsAll
Breast cancer2 yearsWomen
Liver cancer6 monthsHigh-risk group
50Colorectal cancer1 yearAll
54Lung cancer2 years30+ pack-year smokers
74Lung cancer eligibility ends

The column to watch is interval. Most are two years, but liver cancer is six months and colorectal is one year. Those two cannot be filed under the same rhythm as the rest. The high-risk liver group in particular needs two screenings a year; settling into a two-year habit means skipping half of them.

A simple diagram showing four points marked 20, 40, 50 and 54 along a calendar timeline, with an additional screening item appearing at each point
The list is not fixed once. One item is added each time you reach an age.

The six cancers — eligibility, interval, method

The same information arranged by cancer type. The method column matters: knowing what the test actually is prevents confusion when booking.

CancerEligibilityIntervalMethod
Stomach40 and over, all2 yearsUpper endoscopy (or upper GI series)
Colorectal50 and over, all1 yearFaecal occult blood test → colonoscopy if abnormal
Liver40 and over, high-risk6 monthsLiver ultrasound + serum AFP
BreastWomen 40 and over2 yearsMammography
CervicalWomen 20 and over2 yearsCervical cytology
Lung54–74, high-risk2 yearsLow-dose chest CT

The colorectal row is the unusual one. The programme's first-line test is not a colonoscopy but a faecal occult blood test — a sample collected at home and submitted. A colonoscopy follows only if blood is detected. Arriving expecting a state-funded colonoscopy is a common mismatch.

What "high-risk group" precisely means

This condition, attached only to liver and lung cancer, is not a judgement call. It has an administratively fixed definition, quoted here from the National Cancer Information Center.

GroupDefinition
Liver, high-riskAged 40+ who, in the two years preceding the screening year, received medical care under the relevant diagnostic codes for liver cirrhosis, hepatitis B surface antigen positivity, hepatitis C antibody positivity, or chronic liver disease caused by hepatitis B or C
Lung, high-riskAged 54–74 with a smoking history of 30 pack-years or more, confirmed either by the general health screening questionnaire within the preceding two years, or by the questionnaire completed when joining the national health insurance smoking-cessation programme

What both definitions share is that eligibility is established by medical records or a questionnaire — meaning it is determined automatically, not by applying. A hepatitis B carrier who has not received care under those codes in two years may drop out of the list, and a smoker who never completed a general screening questionnaire will not be flagged for lung screening.

Thirty pack-years means packs per day multiplied by years smoked: a pack a day for 30 years, or two packs a day for 15. The Fifth Comprehensive Cancer Control Plan adds that former smokers who quit more than 15 years ago are excluded.

What it costs

Mostly nothing, or 10%. The National Cancer Information Center's stated basis:

CategoryYour shareException
Insured, upper 50% by premium10% of the feeColorectal and cervical are free
Insured, lower 50% by premiumFree
Medical aid recipientsFree

The "upper 50%" line is drawn by premium. For 2024 eligibility, the lower half meant a monthly premium of ₩125,000 or less for employee subscribers and ₩67,500 or less for regional subscribers (assessed as of November 2023). Above that line you pay 10% — ₩10,000 on a ₩100,000 test.

One thing that regularly catches people out: only the first-line test follows this cost basis. If the faecal test comes back abnormal and you move to a colonoscopy, or a biopsy is taken during an endoscopy, that becomes ordinary insured treatment with its own co-payment. Reading the numbers on a screening result sheet is covered in how to read your health check results.

Who goes and who doesn't — 2024 participation

From the National Cancer Center's screening behaviour survey, released in March 2025. Guideline-compliant participation stood at 70.2% in 2024, up 31.4 percentage points from 38.8% in 2004 and 3.8 points on the previous year.

Cancer2024 guideline-compliant participation
Stomach77.4%
Colorectal74.4%
Breast70.6%
Cervical62.0%
Overall70.2%

The lowest is cervical cancer at 62.0% — eligible from age 20 and free regardless of income, yet more than one in three eligible people does not attend. The earliest starting age appears, if anything, to produce a sense that it is not yet relevant.

Liver and lung are absent from this table because the release published figures for only four cancers. Another document (the Fifth Comprehensive Cancer Control Plan) contains participation rates for all six, but on a different calculation basis that cannot be placed in the same table, so they are left out rather than mixed in.

What comes before screening — the ten cancer prevention rules

Early detection finds a cancer that already exists. The step before it is the National Cancer Prevention Guidelines from the National Cancer Center and the Ministry of Health and Welfare, quoted here in full.

A calm still life of a plate of colourful vegetables and fruit on a table with a pair of walking shoes placed beside it
Six of the ten rules are about what you eat and how you move.
  1. Do not smoke, and avoid other people's tobacco smoke
  2. Eat plenty of vegetables and fruit, and keep the diet varied and balanced
  3. Do not eat salty food, and avoid charred food
  4. For cancer prevention, avoid even one or two drinks a day
  5. Walk or exercise enough to sweat, at least 30 minutes a day, five or more days a week
  6. Maintain a healthy weight for your build
  7. Receive hepatitis B and cervical cancer vaccinations per the immunisation guidelines
  8. Practise safe sex to avoid sexually transmitted infections
  9. Follow workplace safety and health rules to avoid exposure to carcinogens
  10. Attend cancer screening without gaps, per the early detection guidelines

Rule 4 departs from the common view. It is not "drink in moderation" but "avoid even one or two drinks a day" — that is, no safe drinking level is set from a cancer prevention standpoint.

Rule 7 is also worth pausing on: there are two cancers where vaccination is prevention. Hepatitis B vaccine connects to liver cancer, HPV vaccine to cervical cancer — the same two that get special treatment in the screening table, at a six-month interval and a start age of 20.

Rule 10 returns to the tables above; the last item on a prevention list is screening. How to read the numbers on a screening result sheet is in reading your health check results, and the item screening flags earliest — fasting glucose — continues in signs of prediabetes.

What changes from 2028

The Fifth Comprehensive Cancer Control Plan (2026–2030), published by the Ministry of Health and Welfare in February 2026, sets out two changes to screening, each with a stated start year.

  • Colorectal — colonoscopy introduced (from 2028), based on the 2019–2024 colonoscopy pilot and the November 2025 guideline revision. The current faecal occult blood system changes.
  • Lung — eligibility expanded (from 2028), based on overseas practice and guideline revision. Korea's new thresholds are not specified in the document; it only notes the US precedent of lowering 55 to 50 and 30 pack-years to 20.

In short, the tables above hold through 2027. If you are approaching an eligibility age now, plan on the current basis.

One thing to handle this year

One item per stage of life.

  1. Women in their 20s and 30s — your cervical screening history. Eligible from 20, free for everyone, and the lowest participation of all at 62.0%. If you have never attended, this is the year.
  2. The year you turn 40 — stomach and breast begin together. Also check whether you carry hepatitis B or C: if so, liver screening starts alongside them on a six-month cycle.
  3. The year you turn 50 — colorectal is annual. Its rhythm differs from the two-year items, so mark it separately from the first year.
  4. Smokers aged 54+ — work out your pack-years (packs per day × years). If you are over 30 and have had no screening notice, the cause may be that your smoking history was never recorded on a general health screening questionnaire.
  5. Everyone — prevention rule 4. Cutting alcohol is the most immediately actionable of the ten.

Eligibility and this year's notices can be checked on the National Health Insurance Service website or its app, and screening must be booked as national cancer screening at a designated provider to be covered. What “a healthy weight” in prevention rule 6 means for your own build can be checked in the BMI calculator, and regular testing for post-menopausal women is in osteoporosis prevention and testing.

Sources and where to verify

Written as of July 2026. Ages, intervals and costs are transcribed from the sources above; the premium thresholds are the 2024 eligibility figures assessed as of November 2023. The widely repeated rule that "two-year items apply in even years to people born in even years and odd years to those born in odd years" is deliberately not included here. That wording could not be found for national cancer screening in any source from the National Cancer Information Center, the Ministry of Health and Welfare or the National Cancer Center; the only verified instance was the National Health Insurance Service stating it for general health screening for people aged 20–39. It may well hold in practice, but since the basis could not be confirmed, check your own eligibility directly with the Service. Participation rates for liver and lung cancer are also omitted, because two public documents give different values on different calculation bases. This article does not replace a medical diagnosis.