The Papanicolaou test (abbreviated as Pap test , also known as Pap smear , cervical smear , or test smear ) is a cervical screening method used to detect the possibility of pre-cancerous and cancerous processes in the cervix (opening of the uterus or uterus). Abnormal findings are often acted upon by more sensitive diagnostic procedures, and, if necessary, interventions aimed at preventing progression to cervical cancer. The test was invented by, and named, doctor Aurel Babe? and physician Georgios Papanikolaou.
Pap smears are done by opening the vaginal canals with the speculum, then collecting the cells in the cervical opening outside in the transformation zone (where the outer squamous cervical cells meet the gland endocervical cells inside). The collected cells are examined under a microscope to look for abnormalities. This test aims to detect the possibility of pre-cancerous changes (called cervical intraepithelial neoplasia (CIN) or cervical dysplasia, a squamous intraepithelial lesion system (SIL) also used to describe abnormalities), caused by human papillomavirus, sexually transmitted DNA virus.. This test remains effective, a widely used method for early detection of pre-cancerous cancers and cervical cancer. While tests can also detect infections and abnormalities in the endocervix and endometrium, it is not designed to do so.
In the United States, Pap smear examination is recommended starting around the age of 21 years until the age of 65 years. However, other countries do not recommend pap tests on women who are not sexually active. Frequency guidelines vary from every three to five years. If the results are abnormal, and depending on the nature of the disorder, the test may need to be repeated in six to twelve months. If the disorder requires more strict supervision, the patient may be referred for examination of the cervical detail through colposcopy. The person may also be referred for HPV DNA testing, which may serve as an adjunct to Pap testing. Additional biomarkers that can be applied as additional tests with developing Pap tests.
Video Pap test
Medical use
Filtering guidelines vary from country to country. In general, screening begins around the age of 20 or 25 and continues until about age 50 or 60 years. Examination is usually recommended every three to five years, as long as the results are normal.
Women should wait a few years after they have sex before they start screening, and should not be screened before the age of 21. Congress of Obstetricians and American Gynecologists (ACOG) and others recommend starting screening at age 21 (since it is several years after initial sex for most American women). Many other countries wait until the age of 25 years or more to begin screening. For example, some parts of the United Kingdom began screening at the age of 25. The general recommendation of the ACOG is that people with uterus age 30-65 have women's examinations per year, that they do not get an annual Pap test, and that they get a Pap test at a three-year interval.
Most people who contract HPV do so soon after becoming sexually active. It takes an average of one year, but it can take up to four years, for one's immune system to control the initial infection. Screening during this period may indicate an immune response and this improvement is a mild abnormality, which is not usually associated with cervical cancer, but can cause patients stress and produce further tests and treatment possibilities. Cervical cancer usually takes time to develop, thus delaying the start of several years of screening has a slight risk of losing potential precancerous lesions. For example, screening of people under the age of 25 does not reduce cancer rates under the age of 30.
There is little or no benefit to screening people who have not had sexual contact. For example, the United States Preventive Services Task Force (USPSTF) recommends waiting at least three years after the first sex. HPV can be transmitted through sex between women, so those who only have sex with other women should be screened, even though they are at lower risk for cervical cancer.
The screening frequency guidelines vary - typically every three to five years for those who have not previously performed an abnormal smear. Some longer recommendations suggest filtering as often as every one to two years, but there is little evidence to support such frequent screening; Annual screening has few benefits but leads to increased costs and many unnecessary procedures and treatments. It has been recognized since before 1980 that most people can be more rarely screened. In some guidelines, frequency depends on age; for example in the United Kingdom, screening is recommended every 3 years for women under 50 years, and every 5 years for those who are over.
Screening should stop around age 65 unless there are recent tests or abnormalities. There may be no screening benefits for people aged 60 or over who were previously negative tests. If the last three Pap results in a normal woman, she can quit at age 65, according to USPSTF, ACOG, ACS, and ASCP; NHS UK says 64. No need to continue screening after complete hysterectomy for benign diseases.
Pap smear screening is still recommended for those who have been vaccinated against HPV, because the vaccine does not cover all types of HPV that can cause cervical cancer. Also, the vaccine does not protect against HPV exposure before vaccination.
Those with a history of endometrial cancer should stop regular Pap tests. Further tests are not possible to detect cancer recurrence but carry the risk of giving false-positive results, which will lead to further unnecessary testing.
More Pap smears may be required to follow-up after an abnormal Pap smear, or after treatment for an abnormal Pap test or biopsy, or after treatment for cancer.
Effectiveness
The Pap test, when combined with regular screening and proper follow-up programs, can reduce cervical cancer death by 80%.
Failure to prevent cancer by Pap tests can occur for a variety of reasons, including no regular screening, lack of proper follow-up of abnormal results, and sampling and interpretation errors. In the US, more than half of all invasive cancers occur in women who have never had Pap smears; an additional 10 to 20% of cancers occur in those who have not had Pap smears in the previous five years. About a quarter of US cervical cancers in people who have an abnormal Pap smear, but do not get proper follow-up (the patient does not return for treatment, or the doctor does not perform the recommended tests or treatments).
Cervical adenocarcinoma has not been proven to be prevented by Pap tests. In the UK, which has a Pap smear examination program, Adenocarcinoma accounts for about 15% of all cervical cancers
The estimates of the effectiveness of the UK call and recall system vary widely, but can prevent about 700 deaths per year in the UK. A medical practitioner who performs 200 tests each year will prevent death once in 38 years, while looking at 152 people with abnormal results, referring 79 to the investigation, obtaining 53 abnormal biopsy results, and seeing 17 continuing disorders lasting longer than two years. At least one woman for 38 years will die of cervical cancer even if filtered.
Since the UK population is around 61 million, the maximum number of people who can receive Pap smears in the UK is about 15 million to 20 million (eliminating the percentage of the population below 20 and above 65). This will show that the use of Pap smear screening in the UK saved the lives of 1 woman for every 20,000 women tested (assuming 15,000,000 are being tested each year). If only 10,000,000 were actually tested each year, then it would save the lives of 1 woman for every 15,000 women tested.
Results
In general or low-risk population screening, most Pap results are normal.
In the United States, about 2-3 million abnormal Pap smear results are found each year. Most abnormal results are somewhat abnormal (ASC-US (usually 2-5% of Pap results) or low-grade squamous intraepithelial lesions (LSIL) (about 2% of the results)), indicating HPV infection. Although most low-grade cervical dysplasia undergo spontaneous regression without ever leading to cervical cancer, dysplasia may serve as an indication that increased alertness is required.
In a typical scenario, about 0.5% of the Pap results are high SIL levels (HSIL), and less than 0.5% of the results indicate cancer; 0.2-0.8% of the results showed Atypical Glandular Cells from Undetermined Significance (AGC-NOS).
As liquid-based preparations (LBPs) become common media for testing, the atypical yield level has increased. The mean rate for all preparations with low-grade squamous intraepithelial lesions using LBPs was 2.9% compared with a median of 2.3% in 2003. Rates for high-grade squamous intraepithelial lesions (median, 0.5%) and atypical squamous cells has changed slightly.
Abnormal results are reported according to the Bethesda system. They include:
- Squamous cell abnormalities (SIL)
- Atypical squamous cell of undefined significance (ASC-US)
- Atypical squamous cell - can not exclude HSIL (ASC-H)
- low-grade squamous intraepithelial lesions (LGSIL or LSIL)
- High-grade squamous intraepithelial lesions (HGSIL or HSIL)
- Squamous cell carcinoma
- Glandular epithelial cell abnormalities
- Unspecified atypical gland cells (AGC or AGC-NOS)
Endocervical and endometrial abnormalities can also be detected, as well as a number of infectious processes, including yeast, herpes simplex virus and trichomoniasis. However it is not very sensitive in detecting this infection, so the absence of detection in Pap does not mean no infection.
Pregnancy
Pap tests can usually be performed during pregnancy until at least 24 weeks of gestation. Pap tests during pregnancy have not been associated with an increased risk of miscarriage. The inflammatory component is usually seen in the Pap smear of a pregnant person, and does not appear to be a risk for subsequent premature birth.
After delivery, it is recommended to wait 12 weeks before taking the pap test because the cervical inflammation caused by the birth interferes with the interpretation of the test.
Maps Pap test
Procedures
For best results, Pap tests should not occur when a woman is menstruating, in part because additional cells can blur the cells of the cervix, and partly because this part of the menstrual cycle is when most inflamed female organs/LINK/. However, a Pap smear can be performed during a woman's menstrual period, especially if the doctor uses a fluid-based test; if the bleeding is very severe, the endometrial cells may obscure the cells of the cervix, and therefore it is not recommended to do a Pap smear if excessive bleeding.
Getting a pap smear should not cause much pain, but it can if the woman has certain untreated vaginal problems such as cervical stenosis or vaginismus, or if the person doing it is too hard, or using the wrong size speculum.
However, it is uncomfortable, for two reasons that work together: the cervix is ​​full of nociceptors, and the brush used to collect the cells must be stiff enough to scrape them from surrounding tissue. So it can be uncomfortable, but generally fast, and the information obtained may be very important.
Persons with an underlying illness of pain or tissue that may react to a nosy or overly cold pain in the mucous membranes should take appropriate precautions and discuss prior processes with their provider, in writing if necessary. Smaller speculum, lidocaine gel, and previous heating instruments and lubricants, along with extra time in the exam room and soft technique, can all contribute to reducing risk to manageable levels. This is reasonable accommodation to be requested and harmonized with good practice.
Many people experience mild spots or diarrhea afterwards. Spotting usually comes from a scratch on the cervix and diarrhea may be due to indirect stimulation of the lower bowel during the test.
Many health care providers are under the false impression that only sterile water, or no lubrication at all, should be used to lubricate the speculum. This can cause unnecessary discomfort. Numerous studies have shown that using small amounts of water-based gel lubricants does not interfere with, obscure, or distort PAP smears. Furthermore, cytology was not affected, nor did some STD tests.
The health worker starts by inserting the speculum into the woman's vagina, which opens the open vagina and allows access to the cervix. The healthcare provider then collects cell samples from the outer opening or os from the cervix by scraping them with the Aylesbury spatula. Endocervical brush is rotated at the opening of the cervical center. The cells are placed on a glass slide and taken to the laboratory for abnormal examination.
Bubbles that are lubricated with plastic are sometimes used instead of spatulas and brushes. Sweeps are not as good as collection devices, as they are much more effective at collecting endocervical materials than spatulas and brushes. Sweeps are used more frequently with the emergence of fluid-based cytology, although both types of collection devices can be used with one type of cytology.
Samples were stained using the Papanicolaou technique, in which the dye and tinctorial acids were selectively stored by the cell. An immaculate cell can not be seen by a light microscope. Papanicolaou chose a stain that highlights the cytoplasmic keratinization, which has virtually nothing to do with the nuclear feature used to make the diagnosis today.
In some cases, the computer system can filter slides, indicating that it does not need to be examined by a person or highlighting the area for special attention. These samples are usually screened by trained and qualified cytotechnologists using a light microscope. The terminology for whom the sample filter varies according to country; in the United Kingdom, its personnel are known as cytoscreener, biomedical scientists (BMS), advanced practitioners and pathologists. The latter two are responsible for reporting abnormal samples that may require further investigation.
Automatic analysis
In the past decade, there have been successful attempts to develop automated computer image analysis systems for screening. Although, on the available evidence, automated cervical examination can not be recommended to be implemented into a national screening program, NHS Health's recent technological assessment concludes that 'a common case for automated image analysis ha (d) may have been made'. Automation can increase sensitivity and reduce unsatisfactory specimens. Two systems have been approved by the FDA and function in high volume reference labs, with human supervision.
Check type
- Conventional Pap - In a conventional Pap smear, the sample is applied directly to the microscope slide after collection.
- Liquid-based cytology - Cell samples (epithelium) taken from the Transition Zone; squamo-columnar joints in the cervix, between the ekto and endocervix. Liquid-based cytology often uses an arrow-shaped brush, rather than a conventional spatula. The cells taken were suspended in a preservative bottle to be brought to the laboratory, where using the Pap dye was analyzed.
Pap tests usually look for epithelial/metaplasia/dysplasia/borderline changes, all of which may be indicative of CIN. The nucleus will be dark blue, the squamous cells will be green and the keratin cells will be pink/orange. Coilocytes can be observed in which there are several dyskaryosis (epithelium). The nuclei in coilocytes are usually irregular, suggesting possible causes of concern; need screen and confirmation test further.
In addition, a human papilloma virus (HPV) test may be performed either as an indication for abnormal Pap results, or in some cases double testing is performed, where Pap smears and HPV tests are performed at the same time (also called Pap co-testing).
Practical aspects
Endocervix may be partially sampled by means used to obtain ectocervical samples, but, due to the anatomy of this area, consistent and reliable sampling can not be guaranteed. Because abnormal endocervical cells can be sampled, those who examine them are taught to recognize them.
The endometrium is not directly sampled with the device used for the ectocervical sample. The cells can be exfoliated to the cervix and collected from there, so with endocervical cells, abnormal cells can be recognized if present but the Pap test should not be used as a screening tool for endometrial malignancies.
In the United States, the pap test itself costs $ 20 to $ 30, but the cost for a pap test visit can cost more than $ 1,000, especially since additional tests are added that may or may not be needed.
History
The test was invented by and named after Greek Greek physician Georgios Papanikolaou, who began his research in 1923. Aurel Babe? from Romania independently made a similar invention in 1927. However, Babe? 'the method is radically different from Papanicolaou.
The name Papanicolaou was repeatedly submitted to the Nobel Committee and rejected at all times. The Nobel Committee delegated an in-depth investigation into Papanicolaou's reward and loss to Professor Santesson, who was then head of the pathology at the Stockholm Cancer Institute (Radiumhemmet). Santesson find Babe? 'a contribution that has never been cited by Papanicolaou and duly report this fact to the Committee, which later rejected the Nobel Prize in Papanicolaou.
Experimental techniques
In developed countries, cervical biopsy guided by colposcopy is considered a "gold standard" to diagnose cervical abnormalities after an abnormal pap smear. Other techniques such as triple smears are also performed after an abnormal pap smear. This procedure requires a trained colposcopist and can be expensive to do. However, Pap smears are very sensitive and some negative biopsy results may represent undersampling lesions in biopsies, so a negative biopsy with positive cytology requires careful follow-up.
Experimental visualization techniques use broad-band light (eg, direct visualization, speculoscopy, cervicography, visual inspection with acetic acid or with Lugol's, and colposcopy) and electronic detection methods (eg, Polarprobe and Spectroscopy in-vivo). These techniques are cheaper and can be done with far less training. They do not do as well as Pap smear screening and colposcopy. At this point, these techniques have not been validated by large-scale experiments and are not generally used.
Access
In Taiwan, most middle and upper class people have access to Pap tests and can choose to do one test each year. On the other hand, the poor, like those in southern US studies, may not always have access to a Pap test.
Coccoid bacteria
The discovery of coccoid bacteria in the pap test was no consequence with the findings of normal tests and no symptoms of infection. However, if there is enough inflammation to obscure detection of pre-cancerous and cancerous processes, it may indicate treatment with broad-spectrum antibiotics for streptococcal and anaerobic bacteria (such as metronidazole and amoxicillin) before repeating the swab. Alternatively, tests will be repeated at an earlier time than they should. If there are symptoms of whiteness, unpleasant odor or irritation, the presence of coccoid bacteria may also indicate treatment with antibiotics as above.
References
- Notes
External links
- The Pap tests: Questions and Answers - from the National Cancer Institute.
- MedlinePlus: Cervical Cancer Prevention/Screening - from MedlinePlus
- NHS Cervical Screening Program - from the UK National Health Service
- Cervical cancer screening information - from Cancer Research UK
- Pap SmearÃ, - from Online Lab Tests
- Pap SmearÃ, - from eMedicineHealth
- PapScreenÃ, - Australian information about Pap tests (or Pap smears)
- Trust Jo - a leading cervical charity charity in England.
- Canada Guidelines for Cervical Cancer Screening - Society of Obstetricians and Gynecologists of Canada
Source of the article : Wikipedia
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