Real voices: scientific
Andrew Evered, cytologist (screens cells for cancer)
What do you do?
If you go into my cytology lab you'll see lots of people looking down microscopes. They don't look very busy, they're not moving around, but their brains are working overtime. They're looking at human cells on glass slides that have been stained with dyes so we can see them better.
What cells do you look at?
Some 90 per cent of the screens we do are cervical, for the UK's Cervical Screening Programme. We decide if they are normal and healthy, or pre-cancerous. The other 10 per cent are non-gynaecological screens of cells in body fluids: sputum, urine and chest drains, and so on. We're looking for signs of other cancers, such as lung or bladder cancer.
How can you spot a precancerous cell?
Through changes to the nucleus. In pre-cancerous cells or cancers - they're all on a spectrum - the nucleus loses its roundness, becomes irregular in shape and gets larger. It also increases its uptake of the stains and dyes we use to see it, so it looks darker. It's more complex than that - but that's it in a nutshell.
Do you find other things?
We find a lot of infections that weren't clinically suspected. The cervix is very prone to the fungal infection thrush, for example. And two common viral infections we find are the human papilloma virus (HPV) and the herpes virus. They're too small to see but they have an effect on the cells.
HPV takes over a cell's machinery and uses it to make its own new DNA. You can see that in the size and shape changes in the nucleus.
How do you become a cytologist?
I did a degree in biomedical science and gradually moved up through the ranks to become a consultant. Cytology isn't the easiest of healthcare disciplines to learn. You have to develop the visual skills to recognise cancer, and that takes a lot of practice. So there's a two-year training programme.
You have to work in a cytology lab and screen a minimum of 5000 cervical smears, then pass a rigorous exam. After that you're certified to sign out cervical specimens. It takes several more years of practice to become proficient at reporting non-cervical specimens.
You can also enter the profession with four GSCEs. You do the same two years' training, screen 5000 samples and take the exam. But that can limit your career as you can only screen cervical samples.
What qualities do you need?
Your eyesight must be good or possible to correct with spectacles, and you must have passed a recent standard eye test. You also need to be able to sit still and concentrate for long periods. It's meticulous work. And you must be able to make sound judgements about whether a sample is abnormal.
Has the technology changed?
Unlike other areas of biomedicine, such as haematology and biochemistry, cytology hasn't been automated. There's no machine that can adequately take the place of the human eye.
Find out more from the British Association for Cytopathology.
This article is part of the online content for ‘Big Picture: Careers From Biology’">‘Big Picture: Careers From Biology’ and originally appeared in ‘Big Picture: The Cell’">‘Big Picture: The Cell’ (2011). Find out more about the ‘Big Picture’ series.">Find out more about the ‘Big Picture’ series.