CIN 3 Meaning: Is It Cancer and What Happens Next?

CIN 3 means a biopsy has found high-grade abnormal cells on the surface of the cervix. CIN stands for cervical intraepithelial neoplasia, and grade 3 is the most marked of the three grades. It is not cancer, but the cells could turn into cancer in the future if not treated, so treatment is usually offered.

CIN is a result from a tissue sample (biopsy), usually taken during a colposcopy after an abnormal screening test. MedlinePlus describes CIN 3 as covering severe dysplasia up to carcinoma in situ, which means the abnormal cells have not spread into deeper tissue. This guide explains the result in general terms. It cannot tell you what your own report means or what treatment is right for you.

CIN 3 usually causes no symptoms; it is found through screening and biopsy. Do not wait for a planned appointment if you notice new symptoms. Contact your GP, colposcopy clinic or local health service if you have:

• Vaginal bleeding that is unusual for you, such as bleeding during or after sex, between periods or after the menopause.
• Changes to vaginal discharge, or a bad-smelling discharge.
• Pain during sex, or pain in the lower back, pelvis or lower tummy.
• After a biopsy or treatment: heavy bleeding (more than a heavy period), bleeding that does not stop, smelly discharge, fever, or tummy pain that does not improve with painkillers. These can be signs of infection or bleeding that need prompt advice.

No. CIN 3 is a pre-cancerous change, not cervical cancer. The NHS screening programme leaflet explains that CIN can sometimes develop into cancer, but it is not possible to tell whether a particular person's abnormal cells will do so. That uncertainty is why treatment is offered to everyone with CIN 2 or CIN 3.

In rare cases a colposcopy and biopsy do find cervical cancer. If that happens, the report will say so clearly and the person is referred to a specialist team. If your report says CIN 3 and you are unsure whether anything more serious was found, ask the clinic to go through the wording with you.

The US National Cancer Institute (NCI) says CIN 3 should be treated right away unless the person is pregnant. NHS guidance for England says excisional treatment is recommended when CIN 2 or CIN 3 is found on biopsy and that high-grade CIN should be treated promptly.

This differs from CIN 1, which often clears on its own and is usually monitored, and from some small areas of CIN 2, where monitoring may be an option. Your clinic may also offer treatment at the first colposcopy visit (sometimes called "see and treat") if the screening result was high grade.

The most common treatment removes the abnormal area. In the UK this is called LLETZ (large loop excision of the transformation zone); in the US it is called LEEP. A thin wire loop carrying an electrical current removes the tissue, usually under local anaesthetic. The NHS says it takes around 15 minutes and you can usually go home the same day.

Some people need a cone biopsy, which removes a larger cone-shaped piece of tissue and usually needs a general anaesthetic. Other methods, such as cold coagulation, laser or freezing treatments, are used in some clinics. The removed tissue is checked in a laboratory, and the clinic will explain the result.

Bleeding or discharge can continue for up to 4 weeks after LLETZ. The NHS advises avoiding sex and not putting anything into the vagina during recovery, and using pads rather than tampons or menstrual cups. Follow the exact aftercare instructions your clinic gives you.

A test of cure is a follow-up screening test that checks the treatment worked. In England, the NHS invites people for a cervical screening test 6 months after treatment. The sample is tested for HPV, and if HPV is found the person is referred back to colposcopy for another look.

Follow-up schedules differ between countries. NCI notes that, depending on individual risk, people may be asked to return for repeat HPV testing or co-testing at set intervals. MedlinePlus notes that dysplasia can come back after treatment, which is why keeping follow-up appointments matters. Ask your clinic who will send the invitation, when it is due and what happens with each possible result.

The NHS screening leaflet says that after standard treatment to remove abnormal cells, there is no increased risk of early labour. If more tissue than usual had to be removed, the baby is slightly more likely to be born 1 to 2 months early; the leaflet says this may affect around 16 in 100 women who have a baby after more extensive treatment.

NCI notes that treatment can rarely weaken the cervix. If you have had treatment and later become pregnant, tell your maternity team so they can decide whether any extra monitoring is needed. These are general figures, not a prediction for any one person.

If you are pregnant now, tell the colposcopy clinic. Colposcopy is safe in pregnancy, and NCI says CIN 3 treatment may be delayed until after the birth depending on the findings. The care team will plan checks during pregnancy.

Bring your screening result and biopsy report to the appointment. These questions can help you understand the plan:

• Does my report show CIN 3 only, or anything else such as glandular changes (CGIN)?
• Which treatment do you recommend, and can it be done at this visit?
• How much tissue is likely to be removed, and could this matter for a future pregnancy?
• What aftercare should I follow, and who do I contact if I have heavy bleeding or signs of infection?
• When will I get the laboratory result from the treatment sample?
• When is my test of cure due, who will send the invitation, and what happens if HPV is still found?

On SameCase, people share de-identified cases and verified doctors add their perspectives. Reading how others with a CIN 3 result understood their reports, treatment choices and follow-up can help you notice questions you had not thought to ask.

Other people's cases cannot diagnose you or show what will happen to you. Your colposcopy team, who has seen your cervix and your reports, is the right source for decisions about your treatment.