Cervical Screening & Abnormal Pap Pathway

1. Who Is Screened, With What, and How Often

2. Management by Cytology Result

3. Treatment of Histologically Confirmed Disease

4. Ablation or Excision

5. Surveillance After Treatment

Almost every case begins with a persistent infection by a high-risk human papillomavirus type, passes through a detectable precancerous phase lasting years, and is preventable at two separate points: vaccination before exposure, and detection and treatment of the precursor lesion afterwards. Very few cancers offer two independent chances that far ahead of the disease. India nonetheless carries a large share of the global burden, and the reason is not that the biology is different or the tools are unavailable. It is that screening coverage remains low, and that a woman who screens positive frequently does not complete the journey from screening to diagnosis to treatment. The teaching point for a resident: the bottleneck in this disease is not the test, it is the follow-through, and the follow-through is a clinical responsibility rather than an administrative one.

VIA is what the national programme runs, and there are good reasons for that: it is inexpensive, needs no laboratory, gives an immediate result, and permits treatment at the same visit. It also has a sensitivity in the region of a third in comparative evaluations, against roughly 98 per cent for HPV DNA testing. Both facts are true simultaneously. Bedside pearl: a negative VIA is a weak negative. It should not be used to overrule a symptom. A woman with postcoital bleeding, or with a lesion you can see, needs a speculum examination, a biopsy of the lesion and a referral, and the fact that her VIA was negative last month contributes nothing to that decision. The commonest way this test causes harm is not a false positive, it is a false negative used as reassurance.

In a conventional pathway a woman screens positive, is referred for colposcopy, returns for biopsy, returns again for the result, and returns a fourth time for treatment. Attrition at each step is substantial, and for a woman who has travelled from a village and lost a day's wages each time it is entirely rational. Screen-and-treat compresses this into one visit by treating an eligible lesion immediately with ablation. The cost is accepted deliberately: some women are treated who would not have needed it, and no histological specimen is obtained. Why it matters: that trade-off is only defensible if the eligibility criteria are applied honestly. An ablation performed on a lesion extending into the canal, or on a glandular abnormality, destroys the evidence of a cancer without curing it.

Atypical glandular cells are much less common than squamous abnormalities and carry a substantially higher probability of significant underlying disease, including endometrial as well as cervical pathology. Three consequences follow, and each is regularly missed. Colposcopy alone is not sufficient, because the lesion frequently sits in the canal where the colposcope cannot see: endocervical sampling is required. Endometrial sampling is required in addition for every non-pregnant woman of 35 or above, and below that age where there is abnormal bleeding, chronic anovulation or obesity. And a glandular abnormality is never ablated, because adenocarcinoma in situ is frequently multifocal with skip lesions, so both a specimen and a margin are needed. Bedside pearl: a normal colposcopy does not clear an AGC report. It means the lesion has not been found yet.

Of all the histological grades, CIN2 has the poorest reproducibility between pathologists, and a substantial proportion regresses spontaneously, particularly in women under 30. This is why the management is genuinely conditional rather than automatic: treat, or observe with 6-monthly colposcopy and testing for up to 2 years in a young woman who has not completed her family, provided colposcopy is satisfactory and she will actually return. p16 immunostaining, where available, resolves a good deal of the ambiguity by separating lesions with a transforming HPV infection from those without. Indian context: the conditional option depends entirely on reliable follow-up. Where a woman has travelled a long distance and may not return, treating at the point of contact is the safer choice, and that is a judgement about her circumstances rather than about her histology.

Excisional treatment increases the risk of preterm birth, and the effect scales with the depth and volume of cervix removed. This does not mean withholding treatment from a young woman with CIN3, where the alternative is a cancer. It does mean that the depth of excision is a decision rather than a habit, that repeat excisions compound the effect, and that a woman treated before completing her family should be told, so that a future pregnancy is managed with that history known rather than discovered. Point to note: this is one of the strongest arguments for ablation where a lesion genuinely satisfies the eligibility criteria, and one of the strongest against ablating a lesion that does not.

Women living with HIV acquire high-risk HPV more readily, clear it less often, progress faster, and recur more frequently after treatment. WHO therefore recommends starting screening at 25 rather than 30, and repeating every 3 to 5 years rather than every 5 to 10. Antiretroviral therapy improves the picture but does not return risk to baseline, so being virally suppressed is not a reason to lengthen the interval. The practical point that gets missed: invasive cervical cancer is an AIDS-defining illness, and a woman newly diagnosed with HIV should have her cervical screening arranged as part of the initial workup rather than at some later visit. See the HIV Clinical Hub.

The purpose of colposcopy in pregnancy is to exclude invasive cancer, not to grade a precancer, because a precancer will still be there afterwards and can be treated then. Colposcopy is safe and directed biopsy of a suspicious lesion is acceptable. Endocervical curettage is contraindicated. Treatment of CIN is deferred, since it carries a real risk of haemorrhage and pregnancy loss while offering nothing that cannot wait. Reassess at least 6 weeks after delivery, by which time a proportion of lesions will have regressed. The single exception is a genuine suspicion of invasion, which is managed with oncology input and does not wait.

Current vaccines cover the types responsible for the large majority of cervical cancers, but not all of them, and a woman vaccinated after exposure gains less. Screening intervals for vaccinated women are therefore unchanged for the present. The reverse error is more consequential in an Indian clinic: treating screening as the whole answer for a family that has an unvaccinated daughter. The consultation about an abnormal smear in a mother is one of the few reliable opportunities to raise vaccination for her daughters, and it should be taken. See the HPV Vaccination Schedule.

A woman who has had a total hysterectomy for benign disease and has never had CIN2 or worse has no cervix and no meaningful risk, and vaginal vault cytology in that situation finds almost nothing while generating anxiety and further tests. She can stop. Three groups are stopped by mistake and should not be. A subtotal hysterectomy leaves the cervix in place, and the woman often believes otherwise. A hysterectomy performed for CIN2+ or cancer leaves a vault that still needs surveillance. And a woman treated for CIN2+ carries elevated risk for at least 25 years regardless of her age, so reaching 65 does not discharge her. Bedside pearl: ask what the uterus was removed for, and whether the cervix went with it. Both answers change the plan, and neither is reliably in the notes.

It does not compute the ASCCP risk percentages, which come from lookup tables built on a very large cohort and cannot be approximated safely. It does not stage or manage invasive cancer beyond directing the referral. It does not cover vulval, vaginal or anal intraepithelial neoplasia, which share the causative virus but not the pathway. It does not manage abnormal uterine bleeding where the cervical screening is normal. And it assumes a competent specimen: the commonest reason a Pap smear misleads is not misinterpretation in the laboratory but a sample taken without visualising the cervix, without a brush reaching the canal, or during heavy bleeding.