Asymmetry
Draw a line through it and the two halves don't match. Healthy moles are usually symmetrical.
Melanoma awareness & research initiative
Catch melanoma early.
Most melanomas are visible on the skin. Knowing what to look for — and acting quickly — gives treatment its best possible chance. Learn the signs, protect your skin, and check it often.
~99%5-year relative survival when melanoma is found before it spreads — the earlier it's found, the more treatable it tends to be.Source: American Cancer Society
Why early detection matters
Found early, melanoma is often highly treatable.
Melanoma is serious — but it's also one of the most detectable cancers, because it usually shows on the surface of the skin. Time is the variable you can change.
~99%
5-year relative survival for melanoma found at the localized (early) stage.
Source: American Cancer SocietyMost
melanomas are linked to UV exposure — much of which is avoidable.
Source: Skin Cancer FoundationAny skin
tone can be affected; in skin of color, melanoma is often found at a later stage.
Source: American Academy of Dermatology~10 min
is roughly all a monthly head-to-toe skin self-check takes.
General self-exam guidanceFigures reflect widely published public-health guidance from sources such as the American Cancer Society and the Skin Cancer Foundation. Sentinel is an educational concept and is not affiliated with these organizations; this information is general and does not replace advice from a qualified clinician.
Know the signs
The ABCDEs of melanoma.
A simple way to remember what to look for in a mole or spot. Any one of these is reason to get it checked — you don't need all five.
Border
One edge stays smooth; the other turns ragged and notched. Irregular borders are a flag.
Color
Several distinct shades within one spot — tan, brown, black, sometimes red, white, or blue.
Diameter
Wider than about 6 mm — a pencil eraser — though melanomas can be smaller.
Evolving
Changing over time in size, shape, or color — or new itching, bleeding, or crusting.
The "ugly duckling" sign. Trust your instinct about a spot that simply looks different from your other moles, or one that's new or changing. When in doubt, have it checked — it's quick, and almost always reassuring.
Protect your skin
Protect your skin, every day.
UV protection is the clearest lever for skin health. Small habits, done consistently, add up.
Seek shade
Especially between 10 a.m. and 4 p.m., when UV is strongest.
Use broad-spectrum SPF 30+
Apply generously and reapply every two hours, or after swimming or sweating.
Cover up
Wide-brimmed hats, UPF clothing, and UV-blocking sunglasses add real protection.
Skip tanning beds
Indoor tanning meaningfully raises melanoma risk — there's no safe tan.
Check monthly
Get to know your skin so you'll notice when something changes.
See a dermatologist
Ask how often you should have a professional skin exam for your skin type and history.
When to see a doctor
If a spot is new, changing, or just doesn't seem right — get it checked.
Most spots turn out to be harmless. But melanoma is far easier to treat when it's caught early, and a check is quick. You never need a "good enough" reason to ask.
Book an appointment if you notice:
- A new mole or spot, especially after age 30
- A mole that's changing in size, shape, or color
- A sore that won't heal within a few weeks
- Itching, bleeding, crusting, or tenderness in a spot
- A mole that looks different from all your others
If you have a spot that worries you, contact a doctor or dermatologist. In a medical emergency, call your local emergency number.
Beyond awareness
Supporting the science of earlier detection.
Awareness is the first line of defense. Behind it, Sentinel connects clinicians, researchers, and the public around one goal: finding melanoma sooner and improving outcomes for everyone.
For clinicians
Referral guidance, dermoscopy education, and patient-facing materials for your practice.
Explore resourcesFor researchers
Publications, graded sources, and open evidence on early-detection methods.
View researchJoin a study
Explore active screening and imaging trials and check eligibility near you.
See trialsPartner & learn more
Understand what this initiative is, how it works, and how to get involved.
About SentinelCheck your skin
A 10-minute self-exam, once a month.
In a well-lit room with a full-length and a hand mirror, look over your whole body. Knowing your own skin is the single most effective habit for catching change early.
1
Look in good light
Examine your face, scalp, neck, and ears — use a mirror or ask for help with hard-to-see areas.
2
Work down, front and back
Chest, torso, underarms, arms, hands and nails, then back, buttocks, and the backs of your legs.
3
Don't skip the overlooked spots
Between toes, soles of the feet, and palms — melanoma can appear where the sun rarely reaches.
4
Note anything new or changing
Take dated photos to compare over time, and bring concerns to a clinician.
Make checking easy.
Read plain-language, evidence-graded articles on self-examination, prevention, and what to watch for — free to browse, no account needed.
From the blog
Evidence, in plain language.
Short, source-cited explainers on melanoma surveillance, treatment, and self-care — each graded against peer-reviewed evidence. Free to read, no account needed.
immunotherapy
What are checkpoint inhibitors and how do they work in melanoma?
A plain-language guide to checkpoint inhibitor immunotherapy — what immune checkpoints are, how PD-1, CTLA-4, and LAG-3 blockade works, what to expect from treatment, and key questions to ask your specialist.
stage IStage I and II melanoma: what happens after your primary excision?
A plain-language guide for patients newly diagnosed with Stage I or Stage II melanoma. Covers what to expect after excision surgery, whether you need a sentinel lymph node biopsy, when adjuvant therapy is recommended, and how follow-up works — including the KEYNOTE-716 trial evidence for adjuvant pembrolizumab in Stage IIB/IIC disease.
uveal melanomaTebentafusp (Kimmtrak) for uveal melanoma: the first therapy to improve survival
Uveal melanoma is a rare eye cancer with historically grim prognosis once it spreads. Tebentafusp (Kimmtrak), approved by the FDA in January 2022, is the first treatment ever shown in a Phase 3 trial to improve overall survival in metastatic uveal melanoma. This article explains what it is, who it is for, and what the evidence shows.
immunotherapyNivolumab + relatlimab (Opdualag) for advanced melanoma: what patients need to know
A plain-language guide to Opdualag — the dual LAG-3 + PD-1 checkpoint blockade approved in 2022 for first-line advanced melanoma. What the RELATIVITY-047 trial showed, who it is for, how it compares to other immunotherapy combinations, and what side effects to expect.
treatmentMelanoma treatment overview: what happens after diagnosis?
A plain-language guide for newly-diagnosed patients: how melanoma is staged, what the main treatment options are (surgery, immunotherapy, targeted therapy, TIL therapy), and what to expect at each step of the journey.
clinical trialsNeoadjuvant immunotherapy could slash recurrence in stage IIB/IIC melanoma — what the data show
Recent analysis of patients with clinical stage IIB/IIC melanoma showed that many experience recurrence within five years after surgery alone, underscoring a high risk of disease return [PMID:40908447]. Could delivering immunotherapy before the operation lower that risk? This
Read the evidence
The research behind the advice.
Every summary here is built from peer-reviewed sources, each carrying a transparent evidence grade. Browse the library freely, or sign in to keep a private health diary on your own device.
No account needed to read. We store only your Google name and email — no health data, no tracking of what you read.