The short answer: CIN (cervical intraepithelial neoplasia) means some cells on the surface of the cervix have changed. It is not cancer. CIN 1 is a mild change that often goes away on its own and is usually watched with repeat tests. CIN 2 and CIN 3 are bigger changes that are usually treated with a small procedure that removes the affected area, so that they never get the chance to become cancer.
A Pap smear or HPV test is a screening test. The CIN grade comes from a biopsy taken at colposcopy (a magnified look at the cervix), and only a biopsy can confirm or rule out cancer. Many women first read about this while worrying about bachedani ke muh ka cancer (बच्चेदानी के मुँह का कैंसर); CIN is a warning change, not that cancer. For a wider overview, see understanding precancerous cervical changes.
On this page
What Does “Precancerous” Mean for the Cervix?
Cervical intraepithelial neoplasia (CIN) is the term used for abnormal cell changes in the surface layer of the cervix that have not yet invaded the underlying tissue. CIN is not cervical cancer — it is a pre-cancerous condition that, if left untreated, may or may not progress to cancer over several years. The majority of low-grade CIN regresses spontaneously, particularly in younger women whose immune systems clear the underlying HPV infection. High-grade CIN, however, carries a significant risk of progression and generally requires treatment.
The CIN Grading System
- CIN 1 (mild dyskaryosis) — affects the lower third of the surface lining of the cervix (the epithelium); 60–80% regress spontaneously; active surveillance rather than immediate treatment is usually appropriate
- CIN 2 (moderate dyskaryosis) — affects the lower two-thirds; intermediate risk; treatment is often recommended but surveillance may be appropriate in young women wishing to preserve fertility
- CIN 3 / HSIL (severe dyskaryosis) — affects full thickness; estimated 30–50% progression to invasive cancer over 10–20 years if untreated; treatment is recommended in almost all cases
What happens next depends on the grade. With CIN 1, most women are asked to come back for a repeat test rather than have treatment. With CIN 2 or CIN 3, the usual next step is to remove the affected area, most often by LEEP/LLETZ, a loop procedure usually done under local anaesthetic. Whatever the grade, follow-up tests are needed afterwards, because the HPV infection behind the change can persist (see what a positive HPV test means). Your doctor will explain which path fits your result, your age and any plans for pregnancy.
How CIN Is Found
CIN produces no symptoms. It is found exclusively through cervical screening — either a Pap smear (identifying abnormal cells) or an HPV test (detecting the high-risk virus). Women with an abnormal smear or positive high-risk HPV test are referred for colposcopy — a clinical examination of the cervix under magnification with acetic acid and iodine to identify abnormal areas. A small targeted biopsy is taken from any abnormal-looking area so the tissue can be checked under a microscope; this gives the CIN grade. Our guide to colposcopy, LEEP and cone biopsy explains what happens at each step.
Smear words and CIN grades are not quite the same. A smear (Pap) report usually uses other terms: ASCUS (borderline changes), LSIL (low-grade changes) or HSIL (high-grade changes). LSIL often matches CIN 1 and HSIL often matches CIN 2 or 3, but the biopsy decides the grade. An abnormal smear is a reason for a closer look, not a cancer diagnosis.
Why CIN Matters
The entire rationale for cervical cancer screening rests on detecting and treating CIN before it becomes invasive cancer. A woman who receives and acts on her smear results and attends colposcopy when referred will, in almost all cases, never develop cervical cancer. The women I see with advanced cervical cancer have almost invariably either never been screened or had gaps in their screening history.
If you have been told your smear result is abnormal, do not panic — but do not delay. Attend your colposcopy appointment promptly.
Dr. Nishtha Tripathi Patel performs colposcopy and CIN treatment in Ahmedabad. Contact: +91 76988 00333.