Emily Bullas Histology and Cytology Assignment
Screening Programmes:
The NHS offers screening programmes for many conditions, including bowel, breast and cervical
cancers. There are different requirements to be offered each screening, including age, sex and other
risk factors for the conditions. The purpose of the screenings is to diagnose at-risk patients as early
as possible to reduce the severity of treatment needed and improve the prognosis.
Prompt diagnosis is one of the most important factors in prognosis for cancer patients. The ten-year
survival of people diagnosed with stage 1 cancer is over 90%, whereas this is only 5% for people
diagnosed with stage 4 cancer (1). Furthermore, cancers which are diagnosed earlier are less likely to
need severe treatments such as chemotherapy, 38.7% of patients diagnosed at stage 4 will undergo
chemotherapy compared to only 12.4% of patients diagnosed at stage 1 (2).
Chemotherapy, as well as other cancer treatments such as surgery and radiotherapy, can have
significant mental and physical health effects which reduce quality of life. Being diagnosed with
cancer can be a very distressing experience for both patients and their loved ones – improving
prognosis and quality of life for patients will benefit not only the patient but their family and friends,
too. Side effects of chemotherapy and radiotherapy and recovery from surgery may affect the
patient's ability to work, drive or fulfil other commitments. This may mean that friends and family
are needed to help with everyday tasks such as cooking, cleaning, childcare, shopping and many
more. If the patient needs to take time off work, then this may affect their career and they may not
receive full pay for the duration of their absence. On top of this, a partner or other loved ones may
need to take time off work for appointments, to care for their relative or help with childcare etc,
impacting on their finances as well. Similarly, cancer services cost the NHS £5 billion per year (3).
Reducing the amount of treatment each patient needs can reduce the cost of their treatment
significantly, meaning that more money can be spent on other areas of the NHS, such as cancer
screenings. The overall cost of cancer to wider society is estimated at £18.3 billion due to patients
and their carers being out of work, no longer paying tax, benefits such as free prescriptions and
more. It is essential to the lives of patients, loved ones and wider society to get cancer patients
diagnosed, treated and back to their normal lives as quickly and smoothly as possible, and cancer
screenings can help with this.
Unfortunately, there are drawbacks to screening programmes as well. Firstly, there is some risk
associated with some screening tests, for example the mammogram test is an Xray scan which
involves exposure to radiation – although very small, some always risk associated with radiation
exposure. Furthermore, screening tests may show that a patient does not have the condition when
they actually do, this not only eliminated the benefits of the test but may also delay diagnosis as the
patient may not report symptoms to their GP as they have recently tested negative. Conversely,
false-positive tests can occur in some cases, leading to further tests which may also have their own
risks, and create a lot of unnecessary anxiety (4). Even if the patient has a true-positive result, it is
impossible to know whether their cancer would have ever caused them symptoms or shortened
their lifespan. This means that some patients will be impacted by treatment side-effects and social
repercussions, when their cancer would never have been an issue (known as over-treatment). This is
only true for a small number of patients but, in some cancers, it can be so significant that a screening
programme would cause more harm than good. An example of this is prostate cancer screening; a
study showed that, per 10,000 people, prostate cancer screenings would save 17 lives but would
result in the over-treatment of around 315 more people than without screenings (5). Besides, these
, limitations of programmes, many people will decline invitations to their screening tests for personal
reasons. These may include fear of a positive result, feeling that it is unnecessary, and they are not
at risk, and fears of pain/side effects from the tests themselves.
Cervical Cancer Screening:
The cervical cancer screening programme in the UK invites females aged 25 to 64 to a smear test
every 3-5 years. A smear test is a simple procedure involving opening the vagina using a speculum
and taking a sample of cervical cells using a small brush (7). The sample is examined under a
microscope to check for dysplasia - abnormal changes to cervical cells - of which there are many
types. In today's smear tests, scientists are only looking for signs of human papillomavirus (HPV), a
virus which causes almost every case of cervical cancer. Low-grade and high-grade squamous
intraepithelial lesions are changes to the cervical cells which are usually indicative of an HPV
infection. Low-grade squamous intraepithelial lesions (LSILs) are less significant changes to the
cervical cells, if these are detected then the patient will undergo additional testing to ensure that
high-grade squamous intraepithelial lesions (HSILs) are not also present. HSILs are more significant
abnormalities which may develop into cancer in the future, patients which are diagnosed with these
cellular changes will usually be invited for a colposcopy, a procedure to take a larger sample of
cervical tissue for analysis (8). If these lesions are considered to be causing a significant risk of
cervical cancer, they can be removed through surgical procedures or destroyed using lasers, heat or
freezing (9).
Figure 1: Cervical Cell Dysplasia (10)
Figure 1 above shows the cytology of the 3 stages of cervical cell dysplasia: cervical intraepithelial
neoplasia (CIN) 1, 2 and 3. LSIL is also known as CIN 1 and is classified by mostly normal cells, with a
few abnormal cells which may show up as a darker colour when stained (hyperchromia) and
enlarged nuclei but an organised cell arrangement. HSIL is divided into two stages, CIN 2 and CIN3;
CIN2 is characterised by a larger number of abnormal cells which may disrupt the normal
arrangement of the cells and also show an enlarged nucleus, hyperchromia and enlarged or
abnormally shaped cells. CIN 3 is divided once more into severe dysplasia – where most of the cells
are abnormal – and carcinoma in situ, or cervical cancer, where there is a lesion that consists of only
abnormal cells. This may develop further into an invasive carcinoma, in which dysplasia is severe and
the organisation of cells is severely disrupted. Lesions of stage CIN 3 or more must be treated to
prevent cancer.
