Third Month Pap Smear After Radiotherapy: A Predictive Factor of Response to Treatment in Cervical Cancer

Cervical cancer is the most common gynecological cancer. Due to the effect of radiation on cervical mucosa، evaluation of response to radiotherapy with pap smear is controversial. This study was performed with the aim to evaluate the value of post-radiation pap smear as a predictive factor of tumor response. This cross-sectional study was performed during three years (2005-2008) on 30 patients with stage IIB cervical cancer who referred to oncology department of Mashhad Ghaem and Omid hospitals. Patients who continued their follow up with pap smear and gynecologic exam at the end of radiotherapy، 1، 3 and 24 months later were entered to the study. Response to radiotherapy based on pap smear and gynecologic exam at different times after the end of radiation were compared with each other and also were compared with the results of similar evaluations at the second year. Those with abnormal pap smear and diagnosis of recurrence at the end of third month were excluded from the study. According to complete concordance between pap smear and clinical exam 24 months after radiotherapy، we assumed this time as the reference for response. The concordance rate of pap smear results at the end of radiation treatment،1 month and three months after treatment، with pap smear results 24 months after radiation were 70% (p=0. 088)، 50% (p=0. 043) and 97% (0. 033)، respectively. The pap smear had 100% sensitivity، 95. 8% specificity and 97% diagnostic accuracy at the end of third months after radiation. Pap smear at the end of radiotherapy did not indicate treatment failure or poor patient outcome. Otherwise، Pap smear 3 months after radiation can be used as a predictive factor for response to treatment.