[Importance of the Pap smear in the age of HPV testing]

Importance of the Pap smear in the age of HPV testing Abstract. Screening for cervical cancer prevention is considered a success story. Since the introduction of the Pap test in the 1950s, the incidence and mortality of cervical carcinomas has decreased dramatically in the industrialized world. In developing countries, and especially in certain countries in Africa, cervical cancer is still one of the most common fatal cancers due to the lack of screening and therapeutic options. For decades, Pap tests and colposcopy were the basis of cervical cancer screening. In the early 1980s, it became known that almost without exception cervical carcinomas require infection with certain human papilloma viruses (HPV). Among other things, this finding also revolutionized cervical cancer screening. The quality of the Pap test is influenced by the conditions of collection and by the so-called interobserver variability. Overall, cytology shows a good specificity of 95 % with a lower sensitivity of 70 %. Additional immunohistochemical tests to determine the biomarkers p16 and Ki-67 can increase the sensitivity of the Pap test up to 94 % (analogous to the HPV test), which is why cytological tests are still considered very effective in countries with sufficient resources and expertise. In contrast, the HPV test is not subjective and has a high sensitivity of 94 %. However, the specificity is worse than for the Pap test, which is why HPV-based screening carries an increased risk of unnecessary clarification and therapy. The superiority of HPV versus cytological screening seems to be proven under defined study conditions, but only after the second or third screening round. If screening is performed opportunistically, as in Switzerland, there is a risk of so-called lost follow-up. It is precisely the failure to take advantage of screening examinations or their performance at irregular intervals that is considered the most significant risk factor for the development of cervical carcinoma. It should also be remembered that the HPV test only reflects the current viral shedding but does not provide any information about the time and duration of HPV infection. Further studies are necessary to determine long-term results and cost-effectiveness.