How cancer is diagnosed and the impact of diagnosis

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4 How cancer is diagnosed and the impact of diagnosis

• To understand how cancer is investigated

• To understand how cancers are classified and staged

• To appreciate the impact of a cancer diagnosis

How cancer is investigated

Whether an individual is asymptomatic and the cancer is detected during a routine screening programme or at another health event (such as a routine preoperative chest X-ray) or whether they present with significant signs and symptoms, most patients will be referred to an appropriate clinician/consultant. At this point, the most likely causes of the sign/symptom is considered and further investigations are undertaken to make a definitive diagnosis. There are a whole range of tests that are done, depending on the suspected site, but generally patients undergo one or a few of the following:

• Positron emission tomography (PET).

• Computed tomography (CT).

• Magnetic resonance imaging (MRI).

• Tumour markers as well as other blood tests.

Tumour markers are hormones, antigens or enzymes produced by the cancer itself or by tissues stimulated by the cancer. However, the presence of a tumour marker does not always mean a patient has cancer. For instance, a raised prostate-specific antigen (PSA) may indicate prostate cancer. However, an individual may have an increased PSA due to a benign prostate condition or physical stimulation of the prostate such as sexual intercourse. Other common tumour markers are CA-125 for ovarian and colorectal gastric cancer, and carcinoembryonic antigen (CEA) for breast, colorectal and lung cancer. Immunohistochemistry (IHC) is used to test whether a patient is over expressing these receptors. For example, 30–40% of patients with breast cancer are positive for human epidermal receptors (HER2). If positive, the type of cancer may be more aggressive but the patient may be a good candidate for the drug Herceptin (trastuzumab).

Depending on the type of cancer, some patients may have a test to see if hormones are affecting the growth of the cancer, such as prostate and breast cancer. A significant number of breast cancers have increased oestrogen growth receptors on the cell surface; this means that the cancer grows more easily in the presence of oestrogen. These cancers are known as hormone sensitive or hormone positive (ER +). Other breast cancers may be progesterone sensitive (PR +). If a breast cancer is not sensitive to oestrogen, progesterone or HER2 then it is triple negative. Triple negative breast cancers tend to be more aggressive and develop in younger women.

A cancer diagnosis can only be made when a sample of tissue has been taken, usually in the form of a biopsy (tissue) or cytology (body fluids). When these have been analysed, the histopathology (type of cancer) can be identified and classified.

To identify if the cancer has spread to any of the local lymph nodes, sometimes a sentinel node biopsy is performed. This involves injecting a blue dye (and sometimes a radioactive liquid) into areas close to the cancer, while the patient undergoes surgical removal of the lump. The lymph nodes are then scanned or observed to see which lymph node(s) take up the dye/radioactive liquid. The node that shows up is known as the sentinel node and is removed and sent to be tested for cancer. This helps the staging process and may aid treatment decisions, which may mean less treatment and less long-term side effects.

By the time investigations are underway, the majority of patients will be informed of the possible causes of the symptoms, and by the time the results are confirmed, the news of cancer is not a complete surprise. Most patients are informed of the diagnosis in the outpatient setting or on a general medical or surgical ward, so you may not witness diagnosis being given on an oncology placement.

The Royal College of Radiologists has produced a range of patient information on interventional radiology, diagnostic radiology and oncology procedures. Visit the following Website and look up some of the investigations you have heard about on placement or have witnessed:

http://www.rcr.ac.uk/content.aspx?PageID=323 (accessed May 2011).

NMC Domain 3: 3.1; 3.2; 3.3; 3.6

Watch a biopsy being performed. Write a brief reflection on the procedure. Think about preparing the patient and maintaining safety and patient comfort. Find out how the specimen is processed.

NMC Domain 1: 1.4

NMC Domain 2: 2.4

NMC Domain 3: 3.1; 3.2; 3.6

Visit or escort a patient to the radiology department and observe a scan. Alternatively, visit the Macmillan Website:

http://www.macmillan.org.uk/Cancerinformation/Cancerinformation.aspx (accessed May 2011).

On this Website, look at one type of cancer and identify the common investigations that a patient may undergo. For example, lung cancer investigations can be found at:

http://www.macmillan.org.uk/Cancerinformation/Cancertypes/Lung/Symptomsdiagnosis/Diagnosistests/Tests.aspx (accessed May 2011).

NMC Domain 3: 3.1; 3.3; 3.6

How cancers are classified and staged

Once a diagnosis has been established, a referral to an appropriate surgeon or oncologist (cancer specialist) is made to review the situation, stage and classify the cancer in order for treatment to be planned.

From a psychological perspective, the point of diagnosis is usually not the start of the story for the patient; they may have experienced symptoms for some months. Receiving a definitive diagnosis may be a relief, providing answers to questions and confirming what is wrong, and it may remove the anxiety associated with the sense of uncertainty. For others it may be a total shock.

Identify a patient with cancer. Look through their medical notes to find out which investigations they had in order to reach a diagnosis (CT, MRI, PET, biopsy, bone scan, etc.).

NMC Domain 3: 3.2; 3.3

Classification

The results from the investigations may help to establish the type, position, size, grade and stage of the cancer. These will all be used to ensure an appropriate treatment is selected, along with a thorough assessment of the patient (this is discussed in Ch. 5). It is very important that the right words are used to describe all aspects of the cancer so that healthcare professionals are aware of the situation and the patient is not confused with too many different medical terms.

The word tumour is often used and, although it means ‘lump’, it is an ambiguous term and can mean either benign or malignant. This can confuse patients. If they are told they have a tumour, they may assume that they have a benign condition, when they actually have a malignant cancer. Although benign tumours can cause problems due to their size; be painful or unsightly; press on other body organs; take up space inside the skull (for example, like a brain tumour); and release hormones that affect how the body works, they are not cancers. Cancers are made up of malignant cells which are discussed in Chapter 2, so it is best to avoid the use of the word ‘tumour’, and use the word ‘cancer’ so that patients do not become confused. The main differences between benign and malignant tumours are given in Table 4.1.

Table 4.1 Difference between benign and malignant tumours

Benign	Malignant
Slow growing	Usually faster growing
Encapsulated	Irregular in shape
Cells appear normal under the microscope	Spreads locally and destroys the surrounding tissues
Does not spread to other parts of the body	Spreads to other parts of the body

In the clinical setting, tumours are described according to their histogenesis (the names are specific to the cells/tissues from which they arise) and are often named from Greek and Latin terms. In general, benign tumours end in the suffix ‘-oma’ which means ‘lump’ in Latin. Malignant cancers usually have a prefix to the ‘-oma’ which is related to the tissue of origin. For example, malignant tumours that derive from epithelial tissues (lining tissues) are called carcinomas. Carcinomas account for 75% of all cancers and there are two types of carcinoma – adenocarcinoma (cancer in glandular tissue) and squamous cell carcinoma (cancer in squamous epithelium). Cancers arising in the connective tissues (bone, cartilage, muscle, fibrous tissue) are called sarcomas (accounting for 20% of cancers) and cancers in the neural tissue are called blastomas.

The specific names of tumours (both benign and malignant) are also made up of the specific tissue in the body (Table 4.2

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