Ghisu Gian Piero
Klinik für Gynäkologie, Universitätsspital Zürich.
Ther Umsch. 2021;78(2):93-98. doi: 10.1024/0040-5930/a001243.
Importance of the Pap smear in the age of HPV testing 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.
巴氏涂片在HPV检测时代的重要性 宫颈癌预防筛查被视为一个成功范例。自20世纪50年代引入巴氏试验以来,工业化国家宫颈癌的发病率和死亡率已大幅下降。在发展中国家,尤其是非洲的某些国家,由于缺乏筛查和治疗手段,宫颈癌仍是最常见的致命癌症之一。几十年来,巴氏试验和阴道镜检查一直是宫颈癌筛查的基础。20世纪80年代初,人们发现几乎所有宫颈癌都需要感染某些人乳头瘤病毒(HPV)。这一发现尤其给宫颈癌筛查带来了变革。巴氏试验的质量受采集条件和所谓的观察者间变异性影响。总体而言,细胞学检查显示特异性良好,为95%,但敏感性较低,为70%。用于确定生物标志物p16和Ki-67的额外免疫组化检测可将巴氏试验的敏感性提高至94%(与HPV检测相当),这就是为什么在有足够资源和专业知识的国家,细胞学检查仍被认为非常有效。相比之下,HPV检测不主观,敏感性高达94%。然而,其特异性比巴氏试验差,这就是为什么基于HPV的筛查存在不必要的进一步检查和治疗风险增加的原因。在特定研究条件下,HPV筛查相对于细胞学筛查的优越性似乎已得到证实,但这仅在第二轮或第三轮筛查之后。如果像在瑞士那样进行机会性筛查,就存在所谓失访的风险。恰恰是未能利用筛查检查或不定期进行筛查被认为是宫颈癌发生的最重要风险因素。还应记住,HPV检测仅反映当前的病毒脱落情况,但无法提供有关HPV感染时间和持续时间的任何信息。需要进一步研究以确定长期结果和成本效益。