Chapter 45: Cervical Cancer Screening and Colposcopy

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Imagine a virus so common that, um, up to 80 % of us will catch it at some point in our lives.

Yeah, it's practically unavoidable.

And yet,

this same virus is fully capable of causing the second leading cancer killer in young women.

So today, we're taking a deep dive into Chapter 45, which is cervical cancer screening and colposcopy.

A really, really critical topic.

Absolutely.

If you are prepping for your clinicals right now, consider us your Last Minute Lecture team.

Our mission today is to take this incredibly dense clinical text and, you know, translate it into plain student -friendly language.

Exactly.

We're not just going to sit here and memorize guidelines.

No, definitely not.

We want to understand how this microscopic pathogen actually hijacks human tissue and exactly how you as a clinician are going to find it, interpret it, and stop it.

Because honestly, in the exam room, just memorizing a flow chart while it only gets you so far, the goal is to understand the precise biological mechanisms behind your actions.

Right, the why behind what we do.

Exactly.

When you understand the why at a cellular level, taking a patient's history naturally informs your physical exam, and then the physical exam dictates the lab interpretation.

And that interpretation directly guides your management.

Spot on.

It transforms you from someone just, you know, following instructions into a critical thinking clinician.

Okay, let's unpack this.

Let's start with the sheer magnitude of what we're up against here.

Globally, cervical cancer is the fourth leading cancer in women.

Which is a staggering statistic.

It really is.

And in the United States, it's the second leading cause of cancer death in women aged 20 to 39.

Now, I mean, obviously we have made massive strides since the PAP test was introduced back in 1941.

Oh, huge strides.

The rates plummeted by 75%.

75%.

Yeah.

But the text highlights this really sobering clinical reality.

In 2021, we still saw over 14 ,000 new cases and like 4 ,000 deaths in the U .S.

alone.

Yeah, and the sources make it very clear that the most significant impact you can make right now isn't necessarily about finding better lab techniques.

No, it's about reaching the unscreened or underscreened women.

That is the crucial vulnerability.

Cancers missed by a pathologist looking at a slide.

Those represent a really tiny fraction of the disease burden.

So the real danger is just lack of access.

Exactly.

Lack of access or just infrequent screening.

And to understand why that screening frequency matters so much, we have to look at the primary culprit, which is human papillomavirus, or HPV.

Right, the most common sexually transmitted infection globally.

Like you mentioned earlier, 75 to 80 % of males and females will get infected in their lifetime.

You know, I always find that statistic creates a real paradox in the clinic because when patient hears the acronym HPV, panic usually sets in immediately.

Oh, instant panic, always.

But the data tells us that for the vast majority of people, HPV is essentially a transient weekend guest.

A weekend guest.

I like that.

Yeah, you know, shows up, hangs out for a bit and leaves.

The text notes that 91 % of HPV infections in women over 18 resolve completely on their own within two years.

The immune system just clears it out.

It does.

The clinical problem arises when HPV stops being a weekend guest and becomes a squatter.

Right.

It sets up camp.

Exactly.

It evades the immune system and starts damaging the property.

That persistent,

long -term infection is the necessary cause for the development of cervical cancer.

And we are specifically tracking high -risk oncogenic types here, right?

Yes.

Most notably, HPV 16 and 18.

Together, those two alone are responsible for nearly 70 % of all cervical carcinomas.

Which really explains the evolution of our screening tools.

Yeah.

Because historically, a traditional pap smear was just looking for the damage the squatter was causing to the house, you know, the abnormal warped cells.

Right.

But co -testing, which pairs the pap with an actual HPV test, allows us to identify the squatter itself.

It helps us pinpoint patients at risk for future neoplasia before the house is completely wrecked.

Exactly.

But we have to ask, where exactly does this squatter set up camp?

Understanding the anatomy of the cervix is, well, it's the entire foundation of the physical exam we're going to perform.

Okay, so let's get into the anatomy.

The cervix has two distinct cell types.

Inside the cervical canal, that's the endocervix, you have columnar epithelial cells.

And those contain mucus -secreting glands, right?

Right.

And then on the outer portion that faces the vagina, the exocervix, you have squamous epithelial cells.

Those are flat, pink, and shiny.

And the border where these two totally different tissues meet is called the squamous columnar junction, or more commonly, the transformation zone.

And this transformation zone is where all the action happens.

So the vagina maintains a highly acidic pH to protect against bacterial infections.

Which is great for fighting off bacteria, but… But those delicate inner columnar cells aren't built for that acid.

So as they are exposed to the vaginal environment, they essentially get chemically burned by the acid.

Ouch!

Yeah.

And they undergo a process called metaplasia.

They transform into mature, hardened squamous cells.

And HPV violently hijacks this specific transformation process.

It's wild.

HPV has this unique biological limitation where it can only bind to the outermost layer of the cervical epithelium.

Just the outer layer.

Just the outer layer.

From there, it relies on specific viral capsid proteins to sort of drill down into the deeper layers of the tissue to complete its life cycle.

Wow.

Okay, so what happens then?

Well, if those abnormal cells stay confined to the lower third of the epithelial layer,

we classify it as a low -grade squamous intrapathelial lesion, or LSIL.

The vast majority of these will regress naturally as the immune system fights back.

But what if they don't regress?

If the abnormal cells proliferate and invade all the way down into the basal layer, it becomes a high -grade squamous intrapathelial lesion, HSIL.

I want to pause on the body's design here, because honestly it feels like a glaring biological How so?

Well, if this transformation zone is the site where the vast majority of precancerous and malignant diseases arise, why does the body create this vulnerable area in the first place?

I mean, it feels like we're all just walking around with a biological magnet for cancer.

What's fascinating here is that we actually have to reframe how we view metaplasia.

Metaplasia itself is a completely normal, harmless,

and absolutely necessary biological response.

So it's not a flaw?

Not at all.

The cervical tissue is simply adapting to survive the natural acidity of the vagina.

It's a protective mechanism.

The tragedy is simply that HPV has evolved over millions of years to exploit this normally harmless cellular transition.

Ah, I see.

And to complicate your physical exam even further, this transformation zone isn't stationary.

It shifts dramatically depending on the patient's age and hormonal status.

Right.

That hormonal shift is a huge factor in how we approach the physical exam.

During puberty and pregnancy, when estrogen levels are really high, that squamous columnar junction gets pushed outward.

It sits right on the visible surface of the cervix.

Very easy to see.

But as a patient approaches menopause and estrogen drops, the tissue shrinks.

And that zone recedes deep inside the cervical canal into the ass.

Meaning you literally have to go chasing after it with your instruments.

And what makes this whole process so dangerous is that the entire progression is largely asymptomatic.

The patient has no idea.

Exactly.

Now, if a patient does present with symptoms, the text highlights a major red flag.

Post -coital bleeding or abnormal bleeding after intercourse.

That indicates a friable diseased cervix that bleeds right upon contact, right?

Yes.

And there are also critical co -factors that accelerate this malignant transformation.

Things like smoking, HIV co -infection, nutritional deficiencies, and early coitarch.

Coitarch being the early onset of sexual activity.

Correct.

Okay, because we know this pathology develops at a slow burn, typically taking 10 to 15 years to progress to invasive cancer.

That timeline directly dictates our screening guidelines.

Yes.

The patient's history tells us exactly when we need to start looking.

So let's talk about the under 21 age group.

The guideline here is a hard, uncompromising do not screen.

And text is explicit.

Do not screen them, regardless of their sexual history.

And honestly, it takes real clinical confidence to stand your ground and explain this to an anxious 19 -year -old who, you know, might have had multiple partners.

I can imagine.

Why are we so strict about not screening them?

The rationale is purely biological.

In that very young population, the prevalence of HPV is incredibly high.

But the immune clearance rate is also incredibly high.

If we screen them, we are going to find transient abnormalities.

Which leads to overreacting.

Exactly.

It leads to unnecessary biopsies and excisions on young services for infections.

Their bodies were going to clear naturally anyway.

And overtreatment in this age group can actually cause cervical incompetence later during pregnancy.

Wow.

That makes the why crystal clear.

Okay.

Now moving to the 21 to 25 age group,

the traditional standard is cytology, meaning a PAP test alone every three years.

Though it's worth noting that a recent American Cancer Society update recommended delaying the start of any screening until age 25.

Right.

But ACOG and the ASCCP still recommend initiating that first screen at age 21, according to our text.

Correct.

Then we hit the 30 to 65 bracket, where the guidelines expand a bit.

Primary HPV testing every five years is the preferred method meaning testing for the presence of the virus as a standalone.

Or alternatively, co -testing every five years is acceptable.

Right.

And if HPV testing isn't available for some reason, a PAP alone every three years is okay.

But let's apply this to a real world clinical scenario because this is where that 10 to 15 year timeline is just essential to remember.

Say you have a 35 year old patient on a five year co -testing schedule.

Okay.

She had a perfectly normal screen two years ago, but today she sits on your exam table and says, I just started seeing a new partner.

I know they've been with a lot of people and I'm terrified.

I want a PAP test today.

I see this constantly in practice.

The anxiety is just palpable.

But the guidelines state clearly that exposure to a new partner does not accelerate the routine screening schedule.

Precisely.

And we have to explain the biological reality to alleviate that anxiety for her.

Even if she acquired a new high risk HPV strain from this partner yesterday, it takes over a decade for that infection to potentially cause invasive cellular damage.

Right.

It's a slow process.

So returning to her normal five year screening interval gives us more than enough time to safely catch any persistent cellular changes.

Testing her today would likely just show a brand new acute infection that her body might clear in a few months anyway.

So we'd just be treating an infection that was going to disappear.

Yeah.

That makes total sense.

What about when we stop screening?

The guidelines say we can stop at age older than 65, provided they have an adequate negative history.

And that means three consecutive negative PAP tests or two consecutive negative co -tests within the past 10 years, right?

With no history of high grade abnormality.

Exactly.

And once you stop, you do not restart, regardless of new partners.

There are some important exceptions for special populations though.

Like if a patient had a hysterectomy for benign reasons, say symptomatic fibroids and the cervix was completely removed, you stop routine screening.

But if that hysterectomy was a treatment for CIN2 or higher, meaning they had high grade precancerous changes,

you must continue screening the vaginal cuff for 25 years after that diagnosis.

25 years.

Wow.

And for patients with HIV.

Their immunocompromised status means screening begins within one year of sexual activity and continues for their lifetime.

Got it.

There's also this really fascinating, highly specific population mentioned in the text.

DES offspring.

Oh, yes.

DES still bestrole, or DES, was a synthetic estrogen widely prescribed to pregnant women from the 1940s to the 1970s to prevent miscarriage.

Right.

And it turns out the daughters born from those pregnancies are at risk for a specific anomaly called vaginal adenosis.

Where colon and their glandular tissue grows on the vaginal walls instead of staying up in the cervix.

Exactly.

Because of this, DES offspring require a yearly four quadrant vaginal pap test to monitor that misplaced tissue.

It's a perfect example of how historical medical interventions still echo in our clinics today.

Okay, so we've used the history to determine the timeline.

Yeah.

But all that history taking is totally useless if our physical technique is sloppy.

It really is.

If we don't physically capture the cells from that shifting transformation zone, the pathologist in the lab has nothing to evaluate.

So let's walk through the focused exam.

First up, patient preparation.

We need a pristine environment.

Right.

Advise them not to schedule during heavy menses because pooling blood just totally obscures the slide.

And they should avoid intercourse, douches, and vaginal creams for 48 hours prior.

Those alter the pH and introduce cellular debris.

Makes sense if they just delivered a baby.

We wait six to eight weeks postpartum to allow the cervix to fully heal and shrink back down to its normal size.

Okay, so when you set up your tray, you'll see the field has largely moved toward liquid -based cytology or LBC.

This replaces the old conventional dry glass slides.

And the mechanism here is really important.

With conventional smears, you smear the cells on glass and they immediately start to air dry.

Which causes problems, right?

Huge problems.

Osmotic pressure changes, the cells warp, and mucus or inflammatory cells clump up and hide the squamous cells.

With LBC, you collect the sample and immediately wash your instrument in a vial of liquid

That liquid buffer is brilliant.

It prevents the air drying distortion, chemically breaks down the obscuring mucus and red blood cells, and preserves the epithelial cells in a beautiful, readable suspension.

Plus, the lab can use that exact same residual liquid to run the HPV test.

Or even test for chlamydia, gonorrhea, and trichomonas.

Multitasking at its finest.

Now, for the actual collection technique, here's where it gets really interesting.

You generally have two main tool options.

The spatula and brush combination, or the broom.

I've always visualized the spatula and brush technique like cleaning a floor.

The spatula is your broom for sweeping the broad surfaces, and the brush is your detailed tool for scrubbing the grout.

Let's break it down.

Walk us through it.

First, you take the plastic spatula, place it firmly against the outer ectocervix, and rotate it a full 360 degrees.

You are sweeping those flat squamous cells off the surface.

You immediately take that spatula and vigorously swirl it in the liquid vial 10 times to dislodge the cells.

Next comes the cyto brush to scrub the grout.

You insert it gently into the cervical loss, just until the bottom fibers are exposed.

Okay, but here is the critical technique that trips people up.

You only rotate that brush one quarter to one half of a turn.

Which feels so brief.

Why such a minimal rotation?

Because the endocervical canal is incredibly vascular and fragile.

If you spin that rigid brush multiple times, you will shred the tissue and cause excessive bleeding.

Oh wow.

Yeah, and even with the liquid buffer, a massive influx of fresh red blood cells will completely ruin your sample.

And that vascularity is exactly why the order of operations is non -negotiable.

You must use the spatula first.

Always.

If you insert the brush first and induce bleeding, the blood will pour over the ectocervix and your subsequent spatula sweep will be entirely obscured.

Sweep the floor, then scrub the grout.

Never the other way around.

Exactly.

So once you do that quarter turn, you plunge the brush into the vial, swirl it ten times, and you're done.

Now the alternative tool is the cervical broom, which attempts to sweep and scrub simultaneously.

A two -in -one tool.

Right.

You insert the longer central bristles into the A's, push gently so the shorter outer bristles play flat against the ectocervix, and rotate it five times in a clockwise direction.

Then plunge it into the vial ten times.

The broom is excellent for pregnant patients, honestly, because it's less abrasive and causes less bleeding.

However, remember what we discussed about menopausal patients?

The receding transformation zone.

Right.

Because their transformation zone has receded high up into the endocervical canal, the relatively short central bristles of the broom might not reach high enough.

Which means an inadequate sample.

Exactly.

It misses the very cells we are trying to target.

So we've navigated the anatomy,

collected our sample without inducing a hemorrhage, and sent the vial to the lab.

A week later, the results come back utilizing the BESDA system, which, frankly, looks like an alphabet soup of acronyms.

It really does at first glance.

The very first thing the pathologist notes is specimen adequacy.

They are literally checking our work.

Is the specimen satisfactory for evaluation, meaning did you actually capture those endocervical or transformation zone cells?

And if the answer is yes, we look at the diagnostic results.

The ideal result is NIL.

That's negative for intrapathelial lesion or malignancy.

And from there, squamous abnormalities scale up in severity.

The lowest level is ASCUS, which stands for atypical squamous cells of undetermined significance.

Basically, the cells look a bit funny, but we aren't sure why.

Right.

A step up from that is ASCH.

Atypical squamous cells cannot exclude HSIL.

And then we get into the actual lesions we mapped out earlier.

LSIL, which indicates the abnormal cells are confined to the lower third of the epithelium, and HSIL, where the abnormal cells have invaded deeper.

But we don't just look at squamous cells.

We have to monitor the glandular cells, too.

Those are labeled as AGC or atypical glandular cells.

And the text offers a really profound clinical pearl regarding those glandular cells.

If you see normal endometrial cells reported on a pap smear and the patient is actively That is a completely normal physiological finding.

Because the tissue is shedding normally.

Exactly.

But if your patient is postmenopausal and you see endometrial cells on her pap, that is a glaring alarm bell.

Oh, wow.

Postmenopausal women should not be shedding endometrial tissue.

It requires an immediate endometrial biopsy to rule out endometrial cancer.

So what does this all mean?

We have all these acronyms, but how do we actually manage the patient sitting in front of us?

Well, this brings us to the monumental shift introduced in the 2019 ASCCP guidelines.

Historically, management was strictly result based.

If you got result X, you performed procedure Y.

Super rigid.

Extremely rigid.

But the current ASCCP guidelines are completely risk based.

They calculate the patient's immediate and five year risk of developing CIN3 or worse.

Let's unpack that term quickly for everyone.

CIN stands for cervical intrapathelial neoplasia.

Neoplasia means new abnormal tissue growth.

It's the language used when we actually biopsy the tissue rather than just sweeping cells off the surface.

Think of the tissue like a layer cake.

CIN1 means only the bottom third is abnormal, CIN2 is two thirds.

And CIN3 means the abnormal cells have taken over the entire thickness of the epithelial layer right up to the edge of becoming invasive cancer.

Exactly.

So to figure out a patient's risk of hitting that CIN3 threshold, we don't just guess anymore.

We use the ASCCP app or web portal.

The app is such a lifesaver.

You just plug in the patient's current PAP result, their current HPV status, and crucially their past screening history.

The algorithm calculates the risk percentage and tells you exactly what clinical action threshold you've crossed.

If we connect this to the bigger picture, this algorithm is a brilliant safeguard against human error and overtreatment.

By incorporating historical data, it prevents us from aggressively treating a young, low -risk woman with a minor ASC US finding today who has a history of clearing the virus on her own.

Right.

And conversely, it catches the hidden high -risk patient.

A patient might have a deceptively mild PAP result today, but the app factors in her terrible historical track record of persistent HPV16, and it flags her for an immediate colposcopy.

Yes.

When treatment is actually necessary, the guidelines generally favor observation for low -grade CIN1, giving the immune system time to work.

But for high -grade CIN2 or 3, treatment is required.

You'll hear the terms ablative versus excisional.

Ablative meaning destroying the tissue, like freezing it with cryotherapy.

And excisional meaning cutting the tissue out, like with a leap procedure.

The text notes that excisional is vastly preferred for high -grade lesions.

Why is that?

Because when you cut the tissue out in one piece, you can send it to the pathologist to ensure the margins are clear of cancer.

If you just freeze and destroy it, you have no tissue left to verify.

Exactly.

But while treating disease is important, the ultimate goal of advanced practice is primary prevention.

We want to stop the squatter from ever entering the property to begin with.

And that brings us to the HPV vaccine.

Yes.

In the U .S., we use Gardasil -9.

It's honestly a marvel of biotechnology.

It contains virus -like particles, or VLPs.

Which are essentially empty protein shells, right?

Exactly.

They look exactly like the virus to the immune system, but they contain absolutely no viral So they cannot cause an infection, but they stimulate the body to produce significantly higher levels of neutralizing antibodies than a natural infection ever could.

Gardasil -9 targets nine distinct types of the virus.

Most importantly, it covers the high -risk oncogenic types 16 and 18, and the low -risk types 6 and 11, which are responsible for 90 % of genital warts.

And the dosing schedule is heavily age -dependent.

If the first dose is administered between ages 9 and 14, they only need a two -dose series.

Because their young immune systems mount such a robust response that two doses are totally sufficient.

Right.

But if they start the series between 15 and 45, it requires three doses.

It is remarkably safe, too.

It can be safely administered to lactating women and co -administered with other routine vaccines like Tdap or Hepatitis B.

Though it's not currently recommended during pregnancy, mostly just out of an abundance of caution, right?

Yes, though registries tracking inadvertent administration during pregnancy have shown no adverse maternal or fetal outcomes.

I often hear clinical students ask how to handle the already -exposed myth.

Like what do you say to a sexually active 20 -year -old who thinks it's pointless to get vaccinated because they've likely already contracted HPV?

You explain the math.

Even if they've already been infected with one or even two strains of HPV through prior It is highly improbable that they've been exposed to all nine specific strains covered by the Gardasil 9 vaccine.

That makes total sense.

The vaccine will still offer robust, life -saving protection against the remaining high -risk strains they haven't encountered yet.

It is never a lost cause.

That is the perfect clinical reality to anchor on.

So let's recap the journey we took today.

We started by understanding the massive 10 - to 15 -year timeline of a persistent HPV infection.

We mapped out the shifting anatomy of the transformation zone and why it's so vulnerable to metaplastic hijacking.

We learned why we don't screen under 21 the exact physics of liquid -based cytology, and why you absolutely must sweep before you scrub to avoid bloodying the sample.

And finally, we decoded the Bethesda system, embraced the risk -based calculations of the ASCCP app, and highlighted the preventative power of the VLP vaccine.

It's a lot, but it connects so perfectly.

As we conclude, I want you to consider a broader philosophical shift happening in our field.

With the rise of primary HPV screening, the very nature of our work is changing.

How so?

Well, for decades, the pap smear meant we were searching for the damage the virus had already inflicted on human cells.

Now, we are increasingly searching for the presence of the virus itself long before the damage ever occurs.

Wow, that's a huge distinction.

It is.

As you step into your clinicals, consider this.

How will this technological shift change the psychological conversations you have with your patients?

How do we manage a patient's profound anxiety when we tell them they are harboring an oncogenic virus but there is no visible damage to treat yet?

Shifting from treating the visible damage to managing the invisible squatter,

that is a heavy, essential thought to carry into the exam room.

To all of you listening, thank you for joining us on this deep dive into Chapter 45.

On behalf of the Last Minute Lecture Team, we wish you the absolute best of luck in your clinical rotations.

Keep asking questions, keep pushing for the why, and we will catch you next time.