Guidance

Topic 6: understanding test results

Updated 10 October 2024

Applies to England

1. Topic 6 learning objectives

The trainee should know about:

• the primary high risk human papillomavirus (hrHPV) screening pathway

The trainee should understand:

• the possible test results
• the meaning of the test results
• the reasons for repeating a sample
• when to seek advice about their individual test results

The trainee will be able to:

• reflect on their own cervical sample taking practice
• keep a record of their own cervical sample tests
• review any rejected samples and inadequate for cytology results
• seek advice if results are significantly different from those reported by the cervical screening laboratory

1.1 Guidance for the trainer

Signpost the trainee to:

• an explanation of abnormal cytology results
• cytological images and narratives provided by the local cervical screening laboratory
• the primary human papillomavirus (HPV) screening post treatment pathway

1.2 Teaching resource

Refer to PowerPoint presentation 6 for subject areas in Topic 6.

2. HPV primary screening

HPV primary screening means that the hrHPV test is the first test performed on the cervical screening sample. Cytology then becomes the triage test, performed only when the hrHPV test confirms hrHPV to be present.

Most HPV infection is transient and will eventually become inactive. Occasional HPV infections persist in an active state. The cervical screening laboratory tests for all of the important high risk types. An HPV positive result means there is ‘active’ infection detected which may or may not be transient. An HPV negative sample means there is no active infection at the time of the test.

hrHPV testing is performed on the sample taken for a cervical screening test. Where the test result indicates cytology triage, a slide is prepared and examined under the microscope for abnormal cells. The laboratory prepares the slide from the same sample, so there is no need for the person to return for a second test. The laboratory issues both test results as part of a single report. The management recommendation for a cytology result is included in the report.

3. Test results

The sample taker should understand:

• the possible test results
• the meaning of the results
• the reasons for repeating a sample

3.1 hrHPV negative

The person returns to routine recall. There will be some exceptions to this, and such cases will be evident in the report from the laboratory.

The laboratory will not make a slide for cytology if the sample tests negative for HPV. There are no exceptions to this.

3.2 hrHPV positive

People who test positive for hrHPV will have a cytology test performed.

We refer people with abnormal cytology (borderline changes or worse) to colposcopy.

3.3 hrHPV positive with cytology negative test result

We classify adequate samples with no abnormal cells as negative. People who receive a negative cytology report will have a repeat sample in 12 months.

If the HPV positive and cytology negative result persists, we refer the patient to colposcopy on the third occurrence of this result.

If any repeat test is HPV negative, the laboratory will advise routine recall.

3.4 Inadequate test result

Occasionally an HPV test is unavailable, in which case the laboratory will advise a repeat sample in 3 months.

Occasionally in a hrHPV positive sample, the cytology preparation will be inadequate. The laboratory will advise a repeat sample in 3 months.

The sample taker should not take a repeat sample less than 3 months after the previous test to allow for cell regeneration.

A laboratory will report a sample as inadequate if the sample taker has not completely visualised the cervix, or if they took the sample in an inappropriate manner (for example with a sampling device not approved by the NHS Cervical Screening Programme (NHSCSP)).

We refer a person to colposcopy after 2 consecutive cytology inadequate samples.

3.5 hrHPV positive with cytology abnormal

We refer all abnormal cervical cytology to colposcopy (regardless of grade).

3.6 Non-cervical abnormality

Cells from a non-cervical cancer may very rarely be present in the cervical sample due to shedding of cancer cells from the endometrium, fallopian tube or ovaries.

A negative cervical sample does not exclude non-cervical cancer.

The laboratory will report these as ‘glandular neoplasia (non-cervical)’, with a referral to gynaecology clinic recommended rather than colposcopy.

The laboratory may not do a direct referral, and will specify this in their report. In these circumstances, the GP must make an urgent referral through the cancer wait times (CWT) ‘2-week wait’ pathway.

Referrals to gynaecology clinics are not part of the cervical screening programme and are managed according to local protocols.

The GP practice makes arrangements to inform the person of their diagnosis of non-cervical glandular neoplasia. The screening (negative) result letter advises the person that there is an abnormality and they need to make an appointment to see their GP as soon as possible. Sample takers should be aware of national protocols for the referral of people for colposcopy and guidelines for the clinical management of people.

4. Post treatment protocol and follow up

After treatment for cervical intraepithelial neoplasia (CIN) or cervical glandular intraepithelial neoplasia (CGIN), people are invited back 6 months after treatment for a repeat cervical sample. The laboratory will test their sample for hrHPV, historically referred to as a ‘test of cure’ (TOC).

4.1 Test of cure post CIN

We recall people for a screening test in 3 years (irrespective of age) if their HPV test is negative, and they can be returned to routine recall if the subsequent test result is cytology negative.

We refer people who are HPV positive (regardless of cytology result) back to colposcopy.

4.2 Test of cure post CGIN

The laboratory carries out HPV testing 6 months post treatment. If the HPV test is negative (provided there is confirmation of the CGIN being completely excised following treatment) we recall the individual for a further TOC in 12 months. If the second TOC is negative for HPV, the individual returns to 3 year recall. If that follow up is negative for HPV, routine recall is appropriate.

At any point in the TOC protocol, a positive HPV test results in referral back to colposcopy.