Hello, and I hope I can help you today. It is true that CIN 3 is also referred to as carcinoma in situ of the cervix. There is no stage zero in cervical cancer. CIN 3 if not treated, especially in the case of someone who has HPV type 16 and 18, can develop into cervical cancer within 7-10 years. Cervical cancer has no symptoms until it is very advanced, so screening with PAP smears, HPV testing, and colposcopic examination with biopsy if necessary are the best tools available for detecting those at risk for cervical cancer and determining the best plan for treatment. LEEP procedures cure abnormal cells on the cervix in 90 percent of people. Those at highest risk for recurrence are people who have positive margins or a positive ECC (abnormal calls deep in the canal of the cervix). So it is unlikley that your procedure didnt work but rather, that you are one of the unlucky 10% who did not clear their HPV within 2 years of a LEEP procedure. Without knowing how recently you has your LEEP procedures in the past or how old you are it is not possible for me to know what your particular risk is of cancer. But if you have not had a colposcopy and biopsy in the last year and your most recent PAP test was abnormal, you do need another colposcopy first to determine if you need further treatment. A Colposcopy may be a procedure, but it is a diagnostic procedure, while the LEEP procedure is used to remove abnormal cells on the cervix when they are found. So I recommend you go for the biopsy and then see what the results are and discuss treatment options with your doctor. If you have had multiple LEEP procedures for CIN 3 and it has not gone away after treatment and at least 2 years of follow up you may elect for hysterectomy if you are older and are done with childbearing. Persistent HPV 16 and 18 (after treatment with a LEEP procedure) is the greatest risk factor for developing cervical cancer. A cold-knife conization, which is like a more extensive LEEP but it is done in the operating room under anesthesia) can be an option in younger women who have not yet completed childbearing. So in summary, i would get another colposcopy and then you will be able to determine what if any treatment is necessary. Just because your PAP was still abnormal or HPV positive does not mean you have persistent CIN 3. If you do still have CIN 3 I would consider discussing your case with a GYN oncologist as they may have suggestions for a way to most effectively remove the abnormal calls permanently. I hope I was able to answer your question today and that my advice was helpful. Best wishes, Dr. Brown