A recent article indicated that HPV testing is superior to the Pap smear for detecting precancerous lesions of the cervical epithelium (see: HPV test is better than Pap smear at detecting precancerous cervical changes). Has the Pap smear outlived its usefulness in cancer screening programs? Below is a key passage from the article:
A new study found that the HPV test was better than the Pap smear in detecting precancerous changes that can lead to cervical cancer. A test for HPV detects precancerous changes of the cervix earlier and more accurately than the Pap smear....The randomized, controlled study...showed that the human papillomavirus test is more sensitive than the Pap smear, a widely used test that has been a standard part of women's preventive health care for decades but has several drawbacks. Several experts predicted the results would spur efforts to entirely replace the Pap test with the HPV test....Over the last several years, as experts learned more about HPV's role in cervical cancer, most medical groups have recommended that women in the United States get both the HPV test and the Pap smear — a practice called "co-testing." Now, armed with the new and previous studies, some experts say the Pap smear should be dropped. But others disagree, saying that the Pap smear can catch a small number of cases of abnormal cells that might be missed by the HPV test and that co-testing should continue.
I think that it's premature to draw conclusions about the future of the Pap test at this time. It seems likely, at least for the near term, that a common course of action will be co-testing of patients, ordering both a HPV test and a Pap smear. Here's some useful advice extracted from an article that addresses this question from the perspective of a developing country, Brazil (see: Cervical cancer screening: from Pap smear to future strategies). Here is a quote from this article:
Primary HPV screening is an attractive option to health service because the results are not subject to inter-observer variation. However, it requires equipments, reagents, personnel, training, quality control and accreditation. This scenario is far from the real world in different populations, even in developed countries, considering that many women will be screened or may never be screened at all. We must remember the fact that the system for cervical cancer screening with both the Pap test and the HPV test is already working in many practices. There is no reason to disrupt such an operative scheme that is working successfully without adequate evidence of additional benefit of primary HPV screening. Further data are needed on the actual benefits and costs and the impact on the use of colposcopy and other diagnostic tests.
One thing is certain: the number of Pap smears, once a key component of cytopathology, will decline. However, nongynecological cytopathology will continue to grow in part because the sophistication of acquiring tissue samples from various organs will increase. Here's an interesting quote from an article about the expanded role of imaging as it relates to nongynecological cytopathology (see: Expectations and Projections for the Future of Nongynecolgical Cytology 10 Years Ago: Did They Materialize and How Did We Do?):
Guided FNA is usually performed by radiologists, and interventional radiology has grown exponentially during the last decade. Pathologists, clinicians, and surgeons still perform aspirations, mainly with the use of ultrasound guidance. One field that has expanded significantly is the cytomorphology of endobronchial ultrasound (EBUS)-guided FNA that allows for material to be obtained from the lung and mediastinal lymph nodes for the diagnosis and staging of lung (and other) cancer. This creates new opportunities for cytology, especially with the practice of rapid on-site evaluation (ROSE) to verify the quality of the material, thereby facilitating the collection of proper material for ancillary techniques. The role of core-biopsy is still the same in breast, prostate, liver, and soft-tissue tumors, among others. In many situations, this methodology complements FNA.
