37.     Stage 1a Cancer of the Cervix.  

See also MCQ 5 and MCQ Paper 2, question 24 and MCQ Paper 5, question 48.

This topic is a regular in the examination.

Key facts for the DRCOG.

Stage I cancer of the cervix is cancer restricted to the cervix.

Stage Ia is where it is very early and not evident to the naked eye or causing symptoms.

It is microinvasive.

It cannot be > 7 mm. wide.

Invasion must be very shallow: < 5 mm.

It may be suspected at colposcopy, but is an histological diagnosis.

It is further divided into Ia1 and Ia2, depending on the depth of invasion.

3 mm. depth is the watershed.

Ia1 is very early.

The risk of lymphatic spread is almost zero.

So it is suitable for local excision as the only treatment.

This spares the woman's fertility.

The operation is usually cone biopsy.

Loop-diathermy excision burns the edges of the specimen.

This makes it difficult to tell if the margins are clear of tumour.

Clear margins gives reassurance that all of the lesion has been excised.

Trachelectomy is an alternative, but with more risk of leaving an "incompetent" cervix for future pregnancy.

More detailed explanation.

Stage I is restricted to the cervix.

Stage Ia is very early and not visible to the naked eye or likely to cause symptoms.

Technically, it must not have spread deeper than 5mm. from the surface in which it has arisen.

And not have a lateral dimension more than 7 mm.

Ia1 is really early, with depth of invasion <3mm.

This makes lymphatic spread very unlikely, so local excision gives a high prospect of cure.

Figures for the risk of lymphatic spread vary from source to source.

A reasonable aide-memoire would be:

A woman keen to keep her fertility would probably be happy with local excision with stage Ia1.

I have highlighted this.

She would have less than 1% risk of lymphatic spread.

The procedure would usually be cone biopsy but could be trachelectomy.

Some have described ablative procedures like cryotherapy.

But most would shun them, wanting the more certain removal that surgery gives and a specimen for histology.

By stage Ia2 she would probably want lymphadenectomy too.

The risk of pelvic nodes would be ~5%, which I have highlighted.

She might opt for local excision and pelvic lymphadenectomy in stage Ib.

But she would have a 2% chance of paraortic nodes that would not be treated.

But by stage II, radical treatment is necessary.

Patients not wanting to keep their fertility might opt for hysterectomy even with early disease.

This would particularly be so if they had other problems, such as menorrhagia.

It could even be Wertheim's hysterectomy if they wished to cover the small risk of pelvic node dissemination.

Surgery has fewer side effects than radiotherapy and the ovaries can be conserved.

It is restricted to the treatment of early disease i.e. stage I and IIa. 

If there is significant parametrial spread, most surgeons opt for radiotherapy.

Overall staging is as follows:

Remember that cancer of the cervix is now thought to be mainly due to Human Papilloma Virus (Wart) infection.

The main culprits are thought to be types 16, 18, 31 and 33, evidence of which can be found in most invasive cervical cancers -MRCOG question.

There must be other factors to explain why not all women infected with these virus types do not get cancer.

Some of these are known, e.g. smoking.

The condition is sexually-transmitted and the biggest risk for any woman is the man (men) she sleeps with.

Vaccines have been developed against the commoner types of HPV.

Gardasil  became available in the UK in 2006 and is marketed by Sanofi.

In the USA it is marketed by Merck.

It is highly effective against virus types 6, 11, 16 and 18.

16 & 18 cause ~ 70% of cervical cancer.

6 & 11 cause ~ 90% of genital warts.

GlaxoSmithKline produce Cervarix. 

It is effective against HPV types 16 & 18.

It lacks protection against types 6 & 11.

The market for these products will run into billions.

Already we are hearing claim and counter-claim  about the superiority of each.

They are expensive: ~£80 a shot.

And the individual needs a course of 3 injections.

So cost-effectiveness is an important issue.

They have been introduced in some countries.

And many other countries are on the verge of doing likewise. 

The Department of Health in the UK is advised by the Joint Committee on Vaccination and Immunity.

It recommended vaccination of girls of 11-12 in the first year of secondary school in February 2007. 

The Department of Health in the UK has agreed to start a vaccination programme from September 2008.

From August 2009 there will be a "catch-up" programme for all girls up to the age of 18.

Consideration is being given to extending the "catch-up" to all women up to the age of 25.

The vaccines won't eliminate HPV and the risk of cervical cancer.

So cervical smears will remain necessary and this is the advice of the DOH.

I suspect that the programme will be modified.

Perhaps intervals between tests will be lengthened for women who have been vaccinated and have proven antibody against HPV.