Guideline••

Guidelines for cervical cancer screening in China II

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Cervical cancer is a common malignant tumour that has become a major global public health issue, seriously threatening women’s lives. In November 2020, the WHO released a global strategy to accelerate the elimination of cervical cancer as a public health problem. So far, the proposal has received positive responses and commitments from 194 countries around the world, including China, which has actively promoted the prevention and treatment of cervical cancer nationwide. In support of the WHO initiative, in January 2023, the Chinese National Health Commission, along with other entities, issued a 7-year Action Plan for Accelerating the Elimination of Cervical Cancer (2023–2030), which primarily focused on improving the cervical cancer prevention and control service system and on strengthening its overall capacity. Furthermore, based on research evidence and practical experience, experts from seven Chinese academic societies—including the Chinese Society for Colposcopy and Cervical Pathology of China Healthy Birth Science Association and Chinese Society of Gynecological Oncology, Chinese Medical Association—have recently published the Guidelines for cervical cancer screening in China II (Guideline II). Unlike the previous Guidelines for cervical cancer screening in China I (Guideline I),1 which primarily focused on primary screening methods for cervical cancer, Guideline II emphasises the management and triage of abnormal primary screening results. As part of tertiary prevention, both screening and triage are critical steps in preventing the progression of cervical cancer, especially for those with abnormal test results. Here, we present a new guideline focused on standardising the triage of abnormal cervical cancer screening to improve management, reduce missed diagnoses and prevent overdiagnosis.

Overview

Cervical cancer is the fourth most common cancer among women worldwide. In 2022, there were 150 700 new cases of cervical cancer and 55 700 deaths in China, accounting for approximately 22.7% and 16.0% of the global incidence and mortality, respectively. Moreover, over the past two decades, the incidence and mortality rates in China have shown an upward trend. By 2022, the age-standardised incidence and mortality rates were 13.83 per 100 000 and 4.54 per 100 000, respectively.2 Alarmingly, cervical cancer is being diagnosed at younger ages than before. Over 14 years (2000–2014), the peak age of cervical cancer incidence in China has gradually decreased from over 70 to 40–49 years old. This decrease was significantly greater in rural areas than in urban areas.3 Persistent infection by high-risk human papillomavirus (HR-HPV) is the main cause of cervical intraepithelial lesions and cervical cancer. In China, the two peak age ranges for prevalence of HR-HPV are 17–24 years and 40–44 years.4 The overall HPV infection rate among women aged 20 and older is 15.0%, with the most common HPV types being HPV 52, 58, 16, 51, 56 and 39.5 Regarding the distribution of HPV types in different grades of cervical lesions, a study that included 17 311 patients in China has shown that HPV 16, 58, 33, 52 and 51 are often found in cervical intraepithelial neoplasia (CIN) grade 1, while HPV 16, 58, 52, 33 and 31 are frequently associated with CIN levels 2 and 3+.6 A large-scale, multicentre, hospital-based study in China showed that 97.6% of patients with cervical squamous cell carcinoma (SCC) tested positive for HR-HPV. The most common HPV types identified in this study were HPV 16 (76.6%), HPV 18 (7.9%), HPV 31 (3.2%), HPV 52 (2.2%) and HPV 58 (2.2%).7 Another study reported that the HPV infection rate in patients with cervical adenocarcinoma was 74.5%. HPV 16 (35.1% of cases) and HPV 18 (30.6%) were again the most common HPV types identified.8

HPV infection in the female genital tract is relatively common, and the probability of women with normal sexual behaviour being infected with at least one HPV type in their lifetime is as high as 80%. 50% of infections clear within 6 months, and the great majority clear within a few years after acquisition.9 Nevertheless, about 10% of women will have a persistent HPV infection,10 and 0.03% of HPV-induced CIN1 and 0.3% of CIN2 will progress to invasive cervical cancer.11 To avoid overdiagnosis and overtreatment, it is of great clinical significance to stratify the risk of women with abnormal screening results (especially HR-HPV positive) and apply the management strategy of ‘equal risk, equal management’. The recommendation level and quality of evidence were graded using the system that has been used for previous consensus guidelines in China, as shown in table 1. This guideline is aimed at the general risk population (special populations such as immunocompromised populations are not included).

Table 1

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Evidence grades and recommended categories

HPV and its epidemiology

HPV genotypes and classification

HPV is a non-enveloped, double-stranded circular DNA virus with epithelial tissue tropism. It consists of a viral protein capsid and a single-copy viral genomic DNA core. The capsid is composed of the major capsid protein L1 and the minor capsid protein L2.2 HPV is primarily transmitted through sexual contact or skin-to-mucosa contact. Among individuals with heterosexual partners, the lifetime risk of HPV infection is estimated to be 84.6% for women and 91.3% for men.3

Cervical cancer screening programme in China

In the Guideline I,1 the selections covering the recommended primary screening methods and programme are as follows:

The guideline recommends HR-HPV testing as the preferred method for primary screening, which should have been approved by authoritative institutions and clinically validated for primary screening. In areas without access to HPV testing, cytology can be used as an alternative. Cotesting (HPV testing in combination with cytology) is recommended for areas with sufficient medical resources, opportunistic screening populations and partial special populations.1

The guideline recommends that individuals with a cervix initiate cervical cancer screening at the age of 25 years and undergo HPV testing alone or cotesting every 5 years, or cytology alone every 3 years. Women over the age of 65 years who have had documented adequate negative prior screening in the past may terminate screening (ie, three consecutive normal cytology screenings, or two consecutive negative HPV tests or two consecutive negative cotests within the past 10 years, with the most recent test occurring within the past 5 years) and no high-risk factors, such as history of CIN2+ and related treatments. Women over 65 years of age who have never been screened, lack sufficient negative screening records from the past 10 years, or have clinical indications should continue to undergo cervical cancer screening.1

Management for abnormal cervical cancer screening results

The abnormal results of a cervical cancer screening include: (1) abnormal primary HR-HPV test, (2) abnormal cytology and (3) abnormal cotest. Aligned with the American Society of Colposcopy and Cervical Pathology (ASCCP) principle of ‘equal risk, equal management’,12 these guidelines recommend CIN 3+ as the primary clinical endpoint for risk estimates, for three reasons: (1) CIN 3 was chosen instead of CIN 2 because it is a more pathologically reproducible diagnosis, (2) CIN 2 has appreciable regression rates in the absence of treatment and (3) the distribution of HR-HPV types in CIN3+ patients closely resembles that of cervical cancer.

Management of positive HR-HPV primary screening result

HR-HPV testing is categorised into no genotyping test (resulting in HPV positive or negative) and HPV genotyping test, typically including limited genotyping test (resulting in 16, 18 and other 12 HR-HPV genotypes) versus extended genotyping (resulting in 16/18, 45, 31, 33/58, 52, 35/39/68, 51, 59/56/66).

Patients with positive HPV16/18 should be directly referred for colposcopy due to the strong association with cervical cancer. The 2019 ASCCP guidelines recommend stratifying risk based on high-risk HPV testing, cytology or both. Expedited treatment (proceeding directly to treatment, eg, cervical conization without performing a colposcopic biopsy first) is considered following HPV16-positive result and the presence of high-grade squamous intraepithelial lesions (HSIL) cytology, when the immediate risk of CIN 3+ is ≥60%,13 and a cross-sectional study in China further revealed that this risk increases to over 82% in cases of CIN3+ accompanied by positive HSIL cytology and the detection of HPV16 (89.9%) or HPV18 (82.3%).14 For this high-risk population, a thorough comprehensive evaluation of the cervix, vagina, vulva and endocervical canal is recommended. With regard to expedited treatment, given that the National Medical Products Administration has approved several HPV assays for clinical use in screening and triage—combined with the current situation of cytology in China—for this high-risk population, colposcopy-guided biopsy and histopathological analysis are still recommended first, followed by appropriate management. High-risk patients who do not present a CIN3+ profile on colposcopy biopsy should be followed up closely or undergo a diagnostic excisional procedure.

If the primary screening result is other 12 HR-HPV positive, there are differences in carcinogenic risk, and triage by cytology is recommended. If cytology shows atypical squamous cells of undetermined significance (ASC-US), a referral for colposcopy is recommended. If the cytology is normal (assuming the quality of cytology is assured) and the immediate risk of CIN3+ is less than 4%, it is recommended to repeat the HR-HPV test or cotest within 1 year.10 15 If a repeat HR-HPV test is positive, referral for colposcopy is recommended.

Cytology, as a traditional examination method, is used for primary screening and cotesting16 17 and is also performed as an important triage test for HR-HPV-positive population. For instance, if HR-HPV is positive and cytologic shows ASC-US or low-grade squamous intraepithelial lesions (LSIL), the immediate risk of CIN3+ is ≥4%, and referral for colposcopy is recommended. In contrast, if HR-HPV is positive and cytology shows atypical squamous cells—cannot exclude HSIL (ASC-H), atypical glandular cells (AGC), HSIL or more severe lesions—the immediate risk of CIN3+ increases to over 25%.12 A multicentre, large-scale randomised controlled trial in China showed that, among HR-HPV-positive women triaged by cytology, the colposcopy referral rate was reduced from the theoretical 12.7% to 2.8%.18 Similarly, the application of computer-assisted cytology and artificial intelligence systems can improve the objectivity, accuracy and efficiency of cervical cytology.19

Recommendations: (1) if the primary HPV screening result is no genotyping positive, cytology triage is recommended and triage with genotyping test is acceptable and (2) if the primary HPV screening result is limited genotyping, direct referral to colposcopy is recommended for HPV16/18 results, and reflex cytology triage is recommended for other 12 HR-HPV positive (recommendation level: 1) (figure 1).

Figure 1

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Management of positive HR-HPV primary screening result. ASCUS, atypical squamous cells of undetermined significance; HR-HPV, high-risk human papillomavirus; NILM, negative for intraepithelial lesion or malignancy.

Management of cytological screening abnormalities

According to The Bethesda System (TBS), the results of cervical cytology can be reported as: (1) negative for intraepithelial lesion or malignancy (NILM); (2) atypical squamous cell (ASC), including ASC-US and ASC-H; and (3) squamous intraepithelial lesions, including LSIL, HSIL and SCC. The classification of glandular abnormalities varies depending on the cell origin. The cervix and abnormal gland cells of unknown origin are divided into four categories: (1) AGC not otherwise specified (AGC-NOS), (2) AGC that favour neoplastic transformation (AGC-FN), (3) endocervical adenocarcinoma and (4) adenocarcinoma in situ (AIS). Abnormal glandular cells of endometrial origin are divided into two categories: AGC-NOS and endometrial adenocarcinoma. For non-pregnant women over the age of 25 years, the management of abnormal cytology as the primary screening is shown in figure 2.

Figure 2

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Management of abnormal cytology results. *Repeat cytology at 6 months or colposcopy referral if HPV testing is available. †Follow-up after 1 year if quality control is insufficient. ‡Those aged≥35 years, or those aged<35 years but at risk for endometrial cancer. AGC, atypical glandular cells; ASC-H, atypical squamous cells—cannot exclude HSIL; ASC-US, atypical squamous cells of undetermined significance; ECC, endocervical curettage; HR-HPV, high-risk human papillomavirus; HSIL, high-grade squamous intraepithelial lesions; LSIL, low-grade squamous intraepithelial lesions.

Management of cytological ASC-US

ASC-US is the most common type of cervical screening result, encompassing various pathological changes in cells, such as HR-HPV infection, CIN, cancer, inflammation and atrophy. The interpretation or diagnosis of ASC-US can vary significantly depending on the observer.20 The ATHENA clinical trial found that the HR-HPV-positive rate in ASC-US patients was 32.6%, with 14% of these cases being histologically confirmed as CIN2/CIN3.21 Some clinical studies completed in two large hospitals in China reported higher HR-HPV-positive rates in ASC-US women, specifically 61.8% and 66.9%, with 7.5% and 19.5% of these cases being histologically confirmed as CIN2/CIN3, respectively.21–23 Due to the many causes of ASC-US, it is prone to underdiagnosis or overdiagnosis, posing a difficult problem in clinical management, often requiring additional confirmatory testing. Therefore, if primary cytology is interpreted as ASC-US: (1) HR-HPV test is preferred, if the HR-HPV test is positive, referral to colposcopy is recommended; if HR-HPV test is negative, return for retesting with HPV-based testing in 3 years is recommended15 (or 1 year if quality control is insufficient); (2) repeat cytology in 6 months is acceptable; and (3) direct referral for colposcopy is acceptable if follow-up is not possible.10

Management of cytological ASC-H

According to TBS system, ASC-H is cytologically suggestive of HSIL but does not meet HSIL diagnostic criteria. The proportion of ASC-H diagnosis is less than 10% in ASC, and the ratio of ASC-H to ASC-US is less than 1:9. Based on the Kaiser Permanente Northern California (KPNC) study, HPV-positive ASC-H women have an immediate risk of 26% for CIN3+ of 26% and 0.92% for invasive cancer. In contrast, the immediate risk for CIN3+ and invasive carcinoma in HPV-negative ASC-H women was 3.4% and 0.69%, respectively.12 24 A large-scale study in China showed that the rate of an HR-HPV-positive result among ASC-H women was 84.4%. The detection rate of CIN2+ was 58% in HR-HPV-positive women and 14.3% in HR-HPV-negative women, including 3.9% with cervical cancer.25 Therefore, direct referral to colposcopy is recommended for women with a cytological ASC-H diagnosis, regardless of the HR-HPV test result.

Management of cytological LSIL

Foreign studies have reported that 73.6%–85% of women with LSIL cytology test positive for HR-HPV,26 27 and 7%–20% of patients with LSIL cytology have histologically confirmed CIN2/CIN3 following immediate colposcopy.26 28 Similar results were observed by a recent large-scale study in China that found that 84% of women with LSIL were HR-HPV positive, and 7.2% of these cases had histologically confirmed CIN2/CIN3 by colposcopy.29 Considering the quality control of cytology in China, referral for colposcopy is recommended for women with a positive LSIL cytology.10

Management of cytological HSIL

The KPNC study also showed an immediate risk of 49% for CIN3+ and 77% for CIN2+ in HR-HPV-positive women with HSIL cytology. The risk increased to 60% for CIN3+ and 77% for CIN2+ if HPV16 was detected. The risk of invasive cancer in HSIL, HPV16-positive women was 8.1%.12 24 In women with HSIL cytology but HR-HPV-negative testing, the immediate risk was 25% for CIN3+ and 47% for CIN2+. Therefore, patients with HSIL cytology should be referred for colposcopy immediately, regardless of the HR-HPV test result.

Management of cytological AGC

Cytological AGC is associated with malignant tumours such as cervical, endometrial or ovarian cancer and fallopian tube adenocarcinoma, but also with benign lesions, including cervical polyps. Cytological AGC is found in 3%–4% of histological AIS cases, 9% CIN2+ and in 2%–3% of invasive cervical cancers.12 24 The KPNC study reported that the risk of CIN3+ in HR-HPV-positive women with an AGC cytology was 26%, while the risk in HR-HPV-negative women was 1.1%. Cotesting results showed that the risk of CIN3+ in HR-HPV-positive patients with an AGC-FN or an AIS diagnosis was 55% and 20% in AGC-NOS cases.24 Therefore, in addition to colposcopy and endocervical curettage, endometrial biopsy should be performed for patients over the age of 35 years and in younger women who are at risk of endometrial cancer, such as abnormal uterine bleeding, obesity and non-ovulatory women.10

Management of HR-HPV and cytology cotesting

For those with abnormal cotesting results, the 2019 ASCCP recommends stratified management based on previous screening history and the risk assessment of current screening results15 (table 2). According to the current status of HPV detection and cytology in China, the recommended management is shown in figure 3.10

Table 2

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The current and next 5-year risk based on past and current screening results in cotesting

Figure 3

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Management of HR-HPV and cytology cotesting. *Follow-up after 1 year if quality control is insufficient. ASC-US, atypical squamous cells of undetermined significance; HR-HPV, high-risk human papillomavirus.

New triage method for abnormal cervical cancer screening

There are several problems with current triage management for cervical cancer screening: (1) as the main triage method for HR-HPV-positive result, cytology should meet certain quality assurance standards. It has been reported that the specificity of cytology to detect CIN2+ can reach more than 90%, but the sensitivity ranges from 53% to 90%.10 16 The cytology detection rate for cervical cancer varies among different populations and is dependent on the level of training of medical staff. Therefore, it is especially important to strengthen cytology technical training for relevant personnel. (2) Using HR-HPV detection as a triage test for ASC-US results in a specificity of 70%, meaning 30% of women may receive false positives.30 (3) Due to the uneven quality of colposcopy skill across China,31 the false negative rate is as high as 13%–69%.32 The current quality and capacity of colposcopy are insufficient to meet the demand for referral after large-scale cervical cancer screening, which may result in missed diagnoses in high-risk groups.

Therefore, it is necessary to have an additional reflex triage test to improve the detection rate of precancerous lesions and reduce the number of colposcopic referrals. In recent years, several new detection technologies have emerged in China and abroad, showing promising clinical application prospects. These include p16/Ki-67 dual stain (DS), host gene and/or HPV gene methylation detection, HPV extended genotyping, HPV gene integration detection, etc. Due to limited data on ASC-US population triage, the following triage methods are mainly targeted at populations with a positive HPV primary screening result.

p16/Ki-67 DS detection

p16/Ki-67 DS is a detection method based on immunocytochemistry, targeting p16 and Ki-67 proteins. P16 is a tumour suppressor protein that participates in cell cycle regulation, usually as an anticell proliferation agent, and Ki-67 is a marker of cell proliferation. Multiple studies have shown that the simultaneous expression of p16 and Ki-67 proteins in the same cell is highly correlated with a persistent HR-HPV infection and the occurrence of CIN2/CIN3.33 34 A prospective cohort study that monitored HR-HPV-positive women for 5 years showed that DS was more accurate than cytology in determining the risk of cervical cancer.34 The 2012 and 2015 KPNC and IMPACT cohort studies33–35 showed that for women with HPV-positive test without genotyping or those other 12 HR-HPV or cotesting with HPV-positive results (no genotyping or 12 HR-HPV) when the cytology result shows NILM, ASC-US and LSIL, the risks for HPV-positive/DS-positive exceeded the colposcopy threshold, while DS-negative women were below the 1-year follow-up threshold.

In March 2024, the ASCCP recommended that DS is acceptable for triage of HPV-positive and cotest results.36 In addition, the results of a meta-analysis showed that DS was less sensitive but more specific for CIN2/CIN3 detection than HR-HPV primary screening for patients with ASC-US/LSIL cytology.37 However, whether to use DS to triage the abnormal cytology in clinical settings still needs further evidence from large-scale, prospective research studies with a long-term follow-up.

In China, some studies have shown that p16 immune cell staining alone or in combination with HPV genotyping can be used as a triage tool in HPV-positive women.38 The combination of positive p16 staining and nuclear changes demonstrates high sensitivity (95.18%) and acceptable specificity (85.03%) for identifying CIN2+ lesions in women with ASC-US. Additionally, DS is simple to operate and easy to interpret,39 making it promising for clinical application.

Recommendations: (1) DS is acceptable for triage of HPV-positive test results without genotyping or other 12 HR-HPV, colposcopy is recommended for individuals testing HPV positive and DS positive, and 1-year return is recommended for individuals testing HPV positive and DS negative. (2) In a cotesting screening, DS is acceptable for triage of HR-HPV without genotyping or other 12 HR-HPV-positive tests with cytologic NILM ASC-US or LSIL. If DS is positive, direct referral to colposcopy is recommended; if negative, 1-year follow-up is recommended. It is recommended to use p16/Ki-67 DS, which has been approved by authoritative institutions and clinically validated for HR-HPV-positive population triage (recommendation level: 2A, figure 4).

Figure 4

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Management of p16/Ki-67 dual stain triage in cervical cancer screening. DS, dual stain; ASC-US, atypical squamous cells of undetermined significance; HR-HPV, high-risk human papillomavirus; NILM, negative for intraepithelial lesion or malignancy; LSIL, low-grade squamous intraepithelial lesions.

DNA methylation test

DNA methylation is an epigenetic change that adds methyl groups to specific cytosines, generating 5-methylcytosine under the catalysis of DNA methyltransferase, thus affecting DNA transcription.40 Tumourigenesis is highly associated with transcriptional inactivation of tumour suppressor genes caused by methylation of CpG and with the demethylation of the genome.41 Therefore, the detection of methylation in key genes can be used as a triage method for cervical cancer.

It has been confirmed that the high methylation levels of multiple genes are highly associated with cervical HSIL and cervical cancer.42 43 An extensive clinical research study in Chinese women indicates that PAX1 methylation testing is highly accurate for detecting CIN3+44 and has greater sensitivity for CIN2+ compared with cytology and HPV16/18 genotyping.45 Methylation testing of genes PAX1, ZNF582, SOX1, JAM3, ASTN1, DLX1, ITGA4, RXFP3, SOX17 and ZNF671, either individually or in combination, demonstrates good specificity in detecting CIN3+ in HPV-positive women. This approach can reduce the colposcopy referral rate, avoiding overtreatment and unnecessary anxiety for patients.45–49 Genes studied in cervical cancer methylation research, such as FAM19A4/miR1242 methylation50 and S5 classifiers (which combines HPV16/18/31/33 methylation and human EPB41L3 methylation),51 have also demonstrate high sensitivity and specificity for detecting high-grade lesions.

Studies suggest that DNA methylation testing offers higher specificity than HR-HPV testing when used for ASC-US triage.52–54 However, the clinical significance of current studies on using methylation for triaging cytologic ASC-US remains relatively limited.

Recommendations: in HR-HPV primary screening, the methylation test can be used to triage other 12 HR-HPV-positive women, thereby reducing colposcopy referral rates. It is recommended to use a methylation reagent that has been approved by authoritative institutions and clinically validated for HR-HPV-positive population triage (recommendation level: 2B)

HPV extended genotyping test

HPV extended genotyping refers to the detection of individual types or grouped related types of the other 12 HR-HPV types in addition to the genotyping of HPV16 and 18. Evidence shows that the risk of cervical precancerous lesions and invasive cancer varies depending on the specific HPV type, and this risk also differs across different countries and regions.55 The International Agency for Research on Cancer classified the carcinogenicity of HR-HPV into four groups based on their prevalence in cervical cancer and the cumulative risk of CIN3+: (1) HPV16 is the highest risk, (2) HPV18/45 are high risk, (3) HPV33/31/52/58/35 are moderate risk and (4) the other, HPV39/51/59/56/68 are low risk.56 57 Extended genotyping provides additional risk stratification by identifying other HR-HPV types beyond HPV16/18. When using methods recognised by domestic and international authorities and validated by clinical trials, other 12 HR-HPV types can be further stratified to guide clinical management decisions.

ASCCP recently released an enduring guideline58 on the application of HPV extended genotyping based on clinical cohort data. The guideline categorises HR-HPV types into three groups for better clinical management: (1) high risk: HPV16/18, patients with these types are recommended for direct referral to colposcopy; (2) medium risk: HPV31/33/35/45/58/52/39/68/51. For these types, further risk stratification is required to determine whether colposcopy referral is necessary; (3) low risk: HPV56/59/66 and no other carcinogenic types. For women with these genotypes, repeat HPV testing in 1 year is recommended. A random effects model in China showed that HPV16/18/58/33/31 positivity is associated with a higher risk of CIN3+, reaching the colposcopy referral threshold.6 Another prospective multicentre cohort study showed that HPV 31/33/56/68 are considered high-risk groups, and colposcopy referral is recommended when cytology results are ASC-US. HPV 35/59 are considered low-risk groups, and follow-up using an HR-HPV test can be chosen when cytology results are NILM/ASC-US/LSIL.59 Comparing the data from the above-mentioned domestic and international clinical studies, it is found that the risk grouping based on HPV extended genotyping is inconsistent across different studies, which may be related to the varying sources of study populations from different countries and regions.57

A Chinese study that compared HR-HPV primary screening with cytological triage versus extended genotyping showed that the latter had higher specificity for detecting CIN3+ (99.13% vs 98.41% for cytological triage). Additionally, extended typing presented a higher positive predictive value (26.80% vs 15.69%), meaning it was more accurate in predicting the presence of CIN3+ among those who tested positive. Most importantly, the study also found that using extended genotyping resulted in a 41% reduction in colposcopy referrals.59 Another cross-sectional study in China concluded that extended genotyping for HPV16/18/31/33/45 is as sensitive and specific as cytology for CIN3+ detection.60 For the women with ASC-US, HPV16/18/31/33/58 extended genotyping significantly improves the specificity of CIN2+ detection and significantly reduces the colposcopy referral rate.61

The above results suggest that the extended genotyping detection could improve risk stratification for HPV-positive women, reducing missed diagnoses and preventing overdiagnosis and overtreatment. However, more clinical studies, particularly in the Chinese population, are needed to validate these findings.

HPV gene integration detection

HPV gene integration refers to the process in which viral oncogenes E6/E7 are incorporated into the genomic DNA sequence of the host cervical epithelial cells after HPV infection. This process is a key molecular basis for the progression of cervical cancer caused by persistent HPV infection.62–65 During the progression from cervical precancerous lesions to invasive cervical cancer, the incidence of HPV gene integration increases significantly.66–69 By using liquid-phase capture technology to enrich HPV viral genes and related integration site DNA fragments, followed by high-throughput sequencing to perform large-scale parallel sequencing of these fragments, the integration status of HPV and the specific integration sites can be accurately detected.

A cohort study involving 12 000 participants, with 4611 completing 5-year follow-up, showed that compared with cytology-based triage, HPV gene integration had similar sensitivity and negative predictive value for detecting CIN3+, but with higher specificity and a lower colposcopy referral rate.70

A cohort study involving 1,393 HPV-infected individuals from hospital-based opportunistic screening also showed that, compared with traditional cytology, HPV gene integration had similar sensitivity and higher specificity for detecting CIN3+. Notably, women who were negative for HPV gene integration (90.1%) had an immediate risk of 2.2% (based on the 2019 ASCCP risk assessment parameters), which was not only below the colposcopy referral threshold but also lower than that of women with normal cytology (3.3%). Additionally, the risk of disease progression during a 1-year follow-up was significantly lower in these women compared with those who were positive for HPV gene integration.71 Positive HPV gene integration (9.9%) is associated with an immediate risk of CIN3+ >25% (48.6%), with positive HPV 16/18 integration having an immediate risk of CIN3+ at 56.5%.71 Therefore, individuals who are HPV gene integration positive, especially those with HPV 16/18 types, should be given serious attention. More thorough colposcopy and a histological evaluation should be performed, and diagnostic excisional procedure should be considered if necessary to confirm the diagnosis and reduce colposcopy misdiagnosis. Thus, HPV gene integration testing has significant risk-stratification value in the HPV-positive population. It can help identify higher-risk patients in the HPV 16/18 population and, for low-risk groups, reduce unnecessary colposcopy referrals.

Recommendations: HPV gene integration testing can be used for triaging primary HR-HPV-positive individuals, regardless of genotype. Those who are integration-positive are recommended to be referred for colposcopy, while those who are integration negative could be followed up after 1 year. HPV gene integration testing can also be used for risk stratification. Integration-positive individuals, particularly those who are HPV 16/18 positive, should be considered high risk and require comprehensive colposcopy and histological evaluation, with diagnostic conisation performed if necessary to confirm the diagnosis. It is recommended to use gene integration reagent that has been approved by authoritative institutions and clinically validated for HR-HPV-positive population triage (recommendation level: 2B)

HPV load testing

The purpose of HPV viral load testing is to quantify the extent of viral infection to some degree. In a report in 2019, the correlation between HR-HPV viral load and cervical precancerous lesions was highlighted, particularly for genotypes in the A9 group family associated with HPV 16, including HPV 16/31/33/52/58.72 Research has shown significant differences in HR-HPV viral load between CIN2+ and CIN1, and the combination of HPV 31/33/52/58 genotypes with viral load improves the specificity of screening.73 Another study also found that the CT value of HR-HPV based on PCR and isothermal amplification demonstrated good triage performance in HPV-positive populations.74 The French ‘National Cervical Cancer Screening Guidelines’75 and the European ‘Cervical Cancer Screening Position’76 also indicate that the HPV-specific viral load is a risk quantification marker that helps with triaging HPV-positive patients. However, further research is needed to confirm this, ensuring that the viral load is measured after adjusting for the number of cells in the sample. Due to the lack of a unified international quantitative standard and the variable relationship between viral load and clinical manifestations, the complexity of quantitative testing has increased. The exact value of HPV viral load testing in triage management remains controversial,76 77 and more clinical evidence is needed in the future.

Other detection methods

Other cervical lesion detection methods, such as real-time detection systems,78 79 inherent fluorescence cervical lesion diagnostic device80 and cervical cancer detection device,81 are currently primarily in the clinical research stage and require further accumulation of evidence in clinical practice.

Summary

In conclusion, the Guideline II mainly evaluate triage methods for abnormal cervical cancer screenings. Based on evidence from evidence-based medicine, the guidelines propose various triage schemes and recommendations for each triage method, including their recommendations. However, larger-scale, multicentre data are needed in the future to provide stronger evidence for the management of abnormal cervical cancer screenings.