Cancer screening — which one, when, and how to decide

More screening isn’t automatically better — the right screening is

Cancer screening sits on a strange and important idea: testing people who feel completely well. The promise is real — catching a cancer early, or preventing it, can be life-saving. But screening also has a quieter side. Test the wrong group, or test too often, and you generate false alarms, anxiety, unnecessary biopsies, and the detection of slow-growing changes that would never have harmed anyone — a genuine downside called overdiagnosis, as Cancer Council Australia and the RACGP Red Book both make clear.

So the useful question is almost never “should I be screened for everything?” It’s “which screening applies to me, at what age and interval, and do its benefits outweigh its harms for someone like me?” This guide walks through each of Australia’s main screening decisions so you can sort what fits and take clear questions to your GP. One rule cuts across all of it: screening is for people without symptoms. If you have a symptom — a lump, bleeding, a change that worries you — that’s not a screening question, it’s a see-your-GP-now question.

Bowel cancer: the home test comes first, not the colonoscopy

For people at average risk with no symptoms, the recommended first test is not a colonoscopy — it’s the free at-home immunochemical faecal occult blood test (iFOBT), offered through the National Bowel Cancer Screening Program. It’s done privately at home and posted off, and it’s effective at catching bowel cancer early, as HealthDirect explains. The eligible age range has been expanding in recent years, so it’s worth checking your current eligibility.

A colonoscopy is the right next step when the home test is positive, or when you have symptoms or a higher-risk family history — not the routine starting point for everyone. Many people instinctively want to “just get the colonoscopy”; understanding why the home test leads is exactly the sort of thing the bowel cancer screening decision aid below is built to help you weigh.

Cervical screening: the test changed, and you can do part of it yourself

Cervical screening in Australia has had two big upgrades. The old 2-yearly Pap smear has been replaced by a more accurate 5-yearly HPV test for most people, and — importantly for comfort and access — you can now choose to collect the sample yourself with a self-collected vaginal swab, which is just as accurate for detecting HPV and avoids the speculum, per the National Cervical Screening Program and HealthDirect.

Screening generally applies from age 25 for people with a cervix who have ever been sexually active. If anxiety or past discomfort has kept you away, self-collection genuinely changes the picture — and the cervical screening decision aid below helps you understand the change and how to ask for the self-collected option.

Prostate (PSA): a personal decision, not a routine tick-box

PSA testing is the screening decision where individual choice matters most. A PSA blood test can help find prostate cancer earlier — but it can also detect slow-growing cancers that would never have caused harm, leading to biopsies and treatments that carry their own side effects, as Cancer Council Australia and HealthDirect set out.

Because of that balance, Australian guidance treats PSA as a shared decision: you should be given clear information about the benefits and harms and decide with your doctor, weighing your age and family history. There are really two questions here — whether to have the PSA test at all, and, if it’s raised, whether to proceed to a biopsy. The PSA screening and PSA biopsy decision aids below are built for exactly those two forks, so you can prepare each conversation deliberately rather than being swept along.

Skin checks: knowing your own skin, and when to act

Australia has among the highest rates of skin cancer in the world, so skin is a sensible thing to keep an eye on — but there’s no single national skin-screening program inviting everyone in. The practical approach is knowing your own skin, watching for new or changing spots, and having a clear pathway to your GP when something looks different, per Cancer Council Australia and the Better Health Channel. People at higher risk — fair skin, many moles, past skin cancers, strong family history — may need regular professional checks.

The skin lesion check decision aid below helps you describe a spot in the words a doctor reads and work out whether it warrants a prompt appointment. It doesn’t diagnose anything — a spot that’s changing, growing, bleeding or just bothering you is always worth showing your GP in person.

Breast screening: the program, and the decision past 75

BreastScreen Australia offers a free mammogram every 2 years, actively targeting women aged 50 to 74, with screening also available to women in their 40s and those 75 and over who choose it, as HealthDirect describes. For most women in the target group the decision is straightforward.

Where it becomes a genuine decision is at the older end. Whether to keep screening past 75 is individual — it weighs your general health and life expectancy against the benefits, rather than stopping automatically at a birthday. The mammography after 75 decision aid below helps you frame that conversation. As always, a breast change at any age — a lump, skin or nipple change — means see your GP promptly, not wait for the next round.

Lung screening: targeted, not for everyone

Lung cancer screening is the newest of Australia’s programs, and it’s deliberately targeted rather than universal. The National Lung Cancer Screening Program uses low-dose CT scans for people at higher risk based on age and smoking history — current or former smokers within a defined range. The targeting is the point: scanning the right group catches lung cancer earlier where it matters, while avoiding the harms of scanning low-risk people who wouldn’t benefit.

If you’ve smoked and wonder whether you qualify, that’s worth checking with your GP. The lung cancer screening decision aid below helps you understand the eligibility logic and prepare the question.

How to bring it all together

Across all six, the same shape repeats: screening helps most when it’s matched to the right age, interval and risk, and it’s a poor fit when applied indiscriminately. The honest move is to map your age, sex and history against what’s recommended — and to remember that any actual symptom jumps the queue entirely.

The questions worth taking in

• Given my age, sex and family history, which screenings are recommended for me right now?
• For each one, what are the benefits and the downsides for someone like me?
• Where it’s a personal decision — like PSA, or breast screening past 75 — what would you advise and why?
• Do I have any symptoms I should be acting on separately, outside of screening?

These are questions, not conclusions. The aim is to decide with your GP which screenings fit you.

What this is, and is not

This is general information to help you prepare for your GP — not a diagnosis, and not personal medical advice. It doesn’t tell you to have or skip any particular test; those decisions are made with your own doctor, who can weigh your age, history and risk. For trustworthy Australian background, see Cancer Council Australia and the Better Health Channel.

Related on this site: the explainers go deeper on each program — bowel cancer screening, cervical screening and HPV, prostate (PSA) screening, and checking a pigmented skin lesion.

If you want a thorough, unhurried review of which screenings make sense for your own picture, you can work with Dr Lo.

Author: Dr Hoe Bing Lo — AHPRA MED0001212640 · FACRRM. Fun Doctors Pty Ltd · ABN 83 404 436 330.