Abnormal cervical cells can be a source of concern, and understanding the medical terminology associated with them is important. One such term, Cervical Intraepithelial Neoplasia grade 3 (CIN 3), often leads to questions about its nature and implications. This article will clarify what CIN 3 means, its causes, how it is detected, and the available treatment options.
Understanding CIN and What CIN 3 Means
Cervical Intraepithelial Neoplasia (CIN) refers to the abnormal growth of cells on the surface of the cervix that could potentially lead to cervical cancer. These changes are classified into three grades based on how much of the cervical tissue appears abnormal under a microscope. CIN 1 indicates mild changes, affecting about one-third of the epithelium’s thickness.
CIN 2 involves abnormal cells affecting about one-third to two-thirds of the epithelium. CIN 3 represents severe changes, where abnormal cells affect more than two-thirds of the epithelium, potentially involving the full thickness. CIN 3 is also sometimes referred to as high-grade or severe dysplasia, or cervical carcinoma in situ.
CIN 3 is not cervical cancer. It is a high-grade precancerous condition, meaning the abnormal cells have not grown past the surface layer of the cervix. If left untreated, CIN 3 has a significant risk of progressing to invasive cervical cancer, with approximately 12% of cases progressing to cancer.
What Causes CIN 3?
The primary cause of CIN 3 is a persistent infection with high-risk types of the Human Papillomavirus (HPV). HPV is a very common sexually transmitted infection, with nearly all sexually active individuals acquiring some type of the virus at some point in their lives. While there are over 100 different strains of HPV, only certain high-risk types, such as HPV 16 and HPV 18, are known to cause the cell changes that can lead to CIN and cervical cancer.
HPV is primarily transmitted through genital-genital sexual contact, anal sex, and occasionally oral sex. The body’s immune system usually clears HPV infections naturally. However, in some individuals, the immune system does not eliminate the infection, and the virus persists, increasing the risk of developing higher grades of CIN.
Several factors can increase the likelihood of CIN progression. A weakened immune system, such as in individuals with HIV, makes it harder for the body to fight off HPV infections. Smoking is also a contributing risk factor, as toxic substances in tobacco can damage cervical cells and impair the immune system’s ability to clear HPV. Long-term use of oral contraceptives can also increase the risk.
Detection and Diagnosis
Routine cervical screenings are the primary method for detecting abnormal cells that may indicate CIN 3. The Papanicolaou (Pap) test, also known as a Pap smear, involves collecting cells from the cervix to be examined under a microscope for abnormalities. Most medical organizations recommend beginning cervical cancer screening at age 21, with tests repeated every few years.
If a Pap test shows abnormal results, further diagnostic procedures are recommended. A colposcopy is a procedure where a special magnifying instrument, called a colposcope, is used to visually examine the cervix and vagina for signs of disease. During a colposcopy, a healthcare provider can identify areas that appear abnormal.
To confirm a CIN 3 diagnosis, a biopsy is performed during the colposcopy. This involves taking small tissue samples from the abnormal areas of the cervix for microscopic examination by a pathologist. The biopsy establishes the diagnosis of CIN 3, distinguishing it from lower grades of CIN or invasive cancer.
Treatment Approaches for CIN 3
Once CIN 3 is diagnosed, treatment is recommended to remove the abnormal cells and prevent progression to cervical cancer. The goal of treatment is to remove the affected tissue while preserving as much healthy cervical tissue as possible. Two common and effective procedures for treating CIN 3 are the Loop Electrosurgical Excision Procedure (LEEP) and cold knife conization.
LEEP involves using a thin, low-voltage electrified wire loop to cut out the abnormal tissue from the cervix. This procedure is often performed in a doctor’s office under local anesthesia and effectively removes precancerous cells. LEEP also provides a tissue sample for laboratory examination to check for any underlying invasive cancer.
Cold knife conization, also known as a cone biopsy, involves surgically removing a cone-shaped piece of tissue from the cervix using a scalpel. This procedure is performed in an operating room under general, epidural, or spinal anesthesia. Cold knife conization is often preferred when a larger or deeper section of abnormal tissue needs to be removed. Both LEEP and cold knife conization have high success rates in treating CIN 3, preventing the development of cervical cancer.
After Treatment and Outlook
After treatment for CIN 3, follow-up care is important to monitor for any recurrence of abnormal cells. This involves regular Pap tests and HPV tests. These tests help ensure the effectiveness of the treatment and detect any new or persistent HPV infections or abnormal cell changes. Follow-up tests are often conducted at 6, 12, and 24 months post-treatment.
The prognosis for individuals treated for CIN 3 is excellent, with most not developing cervical cancer. Treatment successfully removes the precancerous cells, reducing the risk of progression to invasive cancer. While there is a small risk of recurrence, HPV vaccination after excisional treatment can further reduce this risk.
Continued HPV vaccination and practicing safe sexual behaviors are important steps to reduce the risk of future HPV infections and subsequent cervical cell abnormalities. Adherence to the recommended follow-up schedule is also important for long-term cervical health.