Cancer Terminology

Cancer Terminology

There are various terms or words used by cancer doctors when speaking to patients or their families to describe the condition, the treatment, response to treatment and so on. These terminologies are also seen in articles related to cancer. Here is a list of the common words used in cancer which will make the content on this and other sites more understandable.


Cure is a word used when a cancer has been treated and has not come back. Usually doctors suggest that a cancer may have been cured if the cancer does not come back at 5 years after completion of initial treatment. A lot of times the cancer is completely removed at operation or after radiotherapy or chemotherapy and there is no disease seen on the scans. However, to say that the cancer is cured, we would have to wait at least 5 years before that can be said. The 5 years is selected as most cancers, if they come back would do so within that time.

Response to treatment

When a cancer is being treated with chemotherapy, radiotherapy or other methods, the treatment response is assessed by doing scans or blood tests. These tests will tell us whether the treatment is working or not. There are various words used on the scan reports or statements made by doctors describing these responses and these are listed below.

Complete response– This is quoted when all the cancers disappears or goes away after treatment. The scans will not be able to see any cancer when compared to the scans prior to the treatment.

Partial response– A partial response is present when some of the cancer has reduced after treatment, but there is still some cancer remaining that can be seen on scans or other tests. Usually more than 30% decrease in a cancer is called as partial response.

Stable disease– Stable disease is usually when there is no increase over 20% or decrease over 30% and there are no new areas of disease.

Progressive disease– This is when the cancer increases during treatment or during a follow up period. If the increase compared to a previous scan is more than 20% or there are new areas of cancer, it is called as progressive disease.

Relapse or Recurrence

This is when the cancer has been treated before and has now come back.

Course of Treatment (Chemotherapy, Radiotherapy or others)

A course of chemotherapy or any other treatment is a selection of drugs that are given to control the cancer. This course is given for a period of time. For example, a course of FEC chemotherapy is given over 4.5 months in breast cancer. This course is given repeatedly in cycles.

Cycles of Treatment

When chemotherapy is given, it is usually given in the form of cycles. A cycle can last for 1,2,3,4 or even 6 weeks depending on the drugs used. Commonly it is either weekly or once every three weeks (21 days). In chemotherapy, many cycles form one course of treatment. In breast cancer, FEC chemotherapy is given over 6 cycles, each cycle lasting 3 weeks, making the course last for 4.5 months.

Curative Treatment

This is when a treatment option is chosen with the aim of curing the patient from cancer with the treatment. This can be an option for most patients with stage 1,2, some stage 3 cancers and a few stage 4 cancers.

Palliative Treatment

Palliative treatment is an option of treatment when the cancer cannot be cured with the available options and the treatment is used to control symptoms, control the cancer and prolong life.

Neo-adjuvant treatment

This is a type of treatment that is done before the definitive treatment. A definitive treatment is the main treatment that is aimed to control the cancer. A neo-adjuvant treatment is given before that to increase the chances of cure.

Adjuvant Treatment

An adjuvant treatment is one that is given after the definitive treatment. A definitive treatment is the main treatment that is aimed to control the cancer. Adjuvant treatment after definitive treatment aims to increase the chance of cure that is mainly achieved by the definitive treatment. Neo-adjuvant or adjuvant treatments can be chemotherapy, radiotherapy, biological therapy or other options.


A biopsy is a test where a piece of tissue is removed and looked under a microscope to establish a diagnosis. There are different ways as to how this can be done.

Fine Needle Aspiration Cytology (FNAC)

This is a test where a very small needle is inserted into the abnormal area and individual cells or fluid is removed. Further testing is always required when cancer cells are seen to confirm the diagnosis or when a diagnosis cannot be made based on the sample taken.

Core Biopsy

This is a test where a large needle is used to take a bigger piece(core) of tissue. Core biopsy is a more accurate method of diagnosis than FNAC. The cores can be taken under x-ray(stereotactic), ultrasound, CT or MRI guidance. It is an out-patient procedure and is done under local anaesthesia. This is the most common form of test used in the diagnosis of cancer.

Surgical Biopsies

Surgical biopsies are when an incision is made in the cancer. They can be excisional or incisional biopsies. This can be done under local or general anaesthesia.

Excisional biopsy

This is where the lump or tumour is completely removed. If the lump is small and cannot be felt, the excision can be done with the help of wire or needle guidance. These are put in prior to the procedure under ultrasound, x-ray or MRI guidance.

Incisional Biopsy

This is done where an incision (cut) is made in the cancer and a sample is taken.
A biopsy report is given in a few days which will tell whether there is cancer in the removed sample or not.

Histopathology Report

A histopathology report or pathology report is when the cancer has been removed by an operation and all of it has been examined under the microscope by the pathologist. This is different to a biopsy report where only a small area from the cancer is sampled. In the histopathology report, the pathologist mentions about the type of cancer, the margins, grade of cancer, IHC if needed and the completeness of the operation.

Margins in Surgery

Following cancer surgery, the margin status of the operation is always mentioned in the histopathology report. The cancer is always removed with a rim of normal tissue around it to make sure it is taken out in its entirety. The report will mention whether the margins are clear of cancer, or that the margins are too close or are involved by the cancer. If the margins are too close or involved, then the completeness of the surgery is not guaranteed and other options such as radiotherapy need to be considered. Having close or involved margins doesn’t mean poor surgery. This may be unavoidable due to the location and extent of the cancer.

Immunohistochemistry (IHC)

This is further testing done after the biopsy report is given. If the biopsy report shows cancer, IHC testing will be able to confirm which type of cancer and subtype of cancer. IHC testing is very important as accurate typing and subtyping of cancer is required to decide on the most appropriate treatment.

Patient’s Performance status

The fitness of the patient is one of the most important factors that is taken into account when deciding on the treatment for a cancer. The fitter the patient, the more options of treatment are considered. This fitness is assessed by estimating the performance status of the patient. There are different scoring systems such as WHO, ECOG and Karnofsky which help in this process.

Grade of Cancer

Grading of cancer is based on the aggressiveness of the cancer. Grade of cancer is estimated by the pathologist by looking at the cancer under the microscope after a biopsy or surgery. Grading can be from 1 to 3 or 4 in some cancers. Grade 1 being less aggressive and grade 4 being most aggressive etc. The more aggressive cancers generally tend to grow faster. Garde 1 is called as low grade, grade 2 is also called as intermediate grade and grade 3 is also called as high grade.

Stage of Cancer

The stage of a cancer is a term used to describe the size and location of the cancer in the body. Knowing the stage of the cancer helps the doctors to decide on the most appropriate treatment. Most cancers are staged based on the TNM staging system or the number system. Staging with either system is based on the extent of the tumour at the place of origin, the spread of the cancer into the lymph nodes, and spread of cancer into other parts of the body.

Metastases or Metastatic Cancer

This is a term used when the cancer has spread to other parts of the body from its site of origin. This is usually a stage 4 cancer when metastases are seen. The areas of cancer that are present in distant parts of the body are called as metastatic deposits and these can be present anywhere in the body including liver, bones, lungs, brain etc. In the presence of metastatic disease, the cancer can still be treated and controlled, sometimes very well that all areas of cancer resolve completely. However, the chance of cure is small as the risk of recurrence of cancer is high except in a small group of patients and in some types of cancer.

Progression free Survival

Progression free survival is the time duration between the end of treatment and the time of recurrence of cancer. When a treatment option is being considered, the longer the progression free survival, the better it is.

Median Survival

This is another statistic that is used when deciding on the benefits of a certain treatment. A median is a central point. So, a median survival of 36 months with a certain treatment means that 50% of persons treated with that treatment live longer than 36 months and 50% of those will live less than 36 months.

Overall survival

Overall survival is the duration of survival from the time of diagnosis or start of cancer.


Neutropenia is having a lower number of a type of white blood cells in the blood called neutrophils. Chemotherapy and some targeted therapies cause neutropenia as a side effect. As the white blood cells protect against infections, patients having neutropenia have an increased risk of getting an infection.


Thrombocytopenia is having a low number of platelets in the blood. Platelets are cells in the blood that prevent and stop bleeding. Thrombocytopenia can happen as a result of treatment with chemotherapy or some targeted therapies. There is an increased risk of bleeding while the platelet counts are low.

Neutropenic Sepsis

This is a condition where the patient develops an infection as a result of neutropenia. This causes the patient to have a temperature and can make the patient ill quickly as the patient will not have the capacity to fight the infection. If a neutropenic sepsis is suspected or the patient has a temperature or feels unwell after recent chemotherapy or targeted or immunotherapy, they should contact their Oncologist urgently.


A tumour is an abnormal growth in the body. A tumour can be a benign tumour or a malignant tumour. A benign tumour is not a cancer, whereas a malignant tumour is a cancer.

Benign Tumour

A benign tumour is a growth that is abnormal but is not a cancer. The main difference between a benign tumour and a cancer is that a benign tumour does not have the capacity to spread to other parts of the body. A cancer does that. Most benign tumours are slow growing.


A colostomy is an opening in the abdomen that connects the colon to the outside. A colostomy is made in patients who need a part of the large intestine removed or in whom there is a blockage in the large intestine. A colostomy ensures that stool or motions pass onto the outside. A bag is placed around the colostomy to collect the stools.


An ileostomy is an opening made in the abdomen that connects the small intestine called the ileum to the outside. This is done in patients where the entire large intestine is removed or is blocked by the cancer. The ileostomy helps in passing of motion or stools to the outside.


A urostomy is an opening made in the abdomen to help urine to pass out of the body. This is done in situations where the urinary bladder needs to be removed or is blocked due to cancer. The urostomy is connected to the ureters on one side and the outside on the other.


A nephrostomy is a thin tube that is placed on the back of the abdomen to help pass urine when there is a blockage in the ureter. One or two nephrostomies may be inserted depending on whether one or both ureters are blocked.

Cancer or Malignant tumour or Malignancy

A cancer is a growth that is abnormal and has the capacity to grow and spread to other parts of the body. A cancer can also be called a malignant growth or tumour or a malignancy.


Chemotherapy is the use of drugs aimed at killing cancer cells. Chemotherapy can be in the form of tablets, injections or drips. Number of drugs are used as chemotherapy and these can be used individually or in combination.

Targeted therapy

These are drugs used in the treatment of cancer. Targeted therapy drugs target specific areas in the cancer and therefore can have fewer side effects than chemotherapy. Targeted therapies can be in the form of tablets, injections or drips.


Immunotherapy is the use of drugs that modify the immune system in the body in a way that reduces the cancer. These drugs activate the immune system in the body to kill off the cancer cells.

Lymph nodes

Lymph nodes are small glands present all over the body. They are connected by lymphatic channels which are narrow tubes. When a cancer develops in an area in the body, it can spread to the surrounding lymph nodes and other areas in the body through these lymph channels.

Radiotherapy or Radiation therapy

This is a type of cancer treatment where high energy x-rays are used to treat cancers. These x-rays are generated by a machine called a linear accelerator or radiotherapy machine. High energy x-rays or photons are by far the commonest form of radiotherapy used to treat cancer. Other forms of radiotherapy include gamma rays, beta rays and protons.


Brachytherapy is a form of radiotherapy that is given with the help of a radioactive source inserted into the body. Cancers where brachytherapy is used include cervix, uterus, prostate and head and neck cancers among others.


x-rays of the chest, breast (mammogram), abdomen, bones can be done to assess symptoms, to look for the presence of cancer and to assess response to treatment. However, x-rays are generally not as good as scans and any suspicion on x-rays will usually lead to a scan being done.

Ultrasound scan

Ultrasound scans use sound waves to make images and are used commonly in diagnosis of breast and other cancers. These scans are cheap and harmless but may not be as good in detecting some cancers as other scans do.

CT Scan

A CT scan is a scan that uses x-rays to give a three-dimensional image of the part of the body that is scanned. It is more accurate than an x-ray in identifying and staging cancer. A contrast enhanced scan is one where an injection is given into the vein prior to the scan and this gives better images. Oral contrast is given to the patient to drink when the abdomen is being scanned. CT scan takes only a few minutes to do. CT scan is also used to help guide the doctor when certain biopsies are done.

MRI Scan

An MRI scan uses magnetic fields to generate images and is used very often to diagnose and stage cancer. This scan is done for some types of cancer. MRI produces better images than CT in areas such as brain, spine and pelvis (lower part of abdomen). Some patients find it difficult to have an MRI scan as they can feel claustrophobic while the scan is being done. The time taken for MRI scans is longer ranging from 20 mins to up to an hour. Contrast agent is injected during the scan to get better images. The scan is done as sequences and usually many sequences are done in one scan in cancer patients.


This type of scan differs from standard CT scan by having a functional element to the scan. The PET component of the scan is able to detect areas in the body where cells rapidly divide such as cancers, infection, inflammation etc. PET-CT is better than CT scan in staging certain cancers. The PET part of the scan is done by injecting a radiolabelled substance into the body first and then a scan is done. This substance is taken up by the dividing cells and shows up on the scan.

Stem Cells

Stem cells are a type of blood cells that have the capacity to develop into any kind of blood cell such as red blood, white blood cell or platelets. These stem cells are present in the blood stream and bone marrow and are initially collected from the patient before the patient receives high dose chemotherapy.

Stem Cell Transplant

After the high dose chemotherapy kills off all the cells in the marrow, stem cells are transplanted or infused into the body.

The process of collection of stem cells from the patient and infusing them back into the same patient after high dose chemotherapy is called as autologous stem cell transplant.

If the stem cells are from another person(donor), then it is called an allogenic stem cell transplant. The donor can be related, usually a brother or a sister, or unrelated but matched donor. A donor may be used in situations when there is cancer present in the marrow or an autologous transplant was done before, but the disease has relapsed again.

Bone marrow

Bone marrow is the spongy material that is present inside the bones. It consists of stem cells and other growing blood cells which move into the bloodstream.

Bone marrow Transplant

A procedure where bone marrow from the same person or another person is transplanted (inserted or put in) into the patient.

Autologous Bone marrow Transplant

This is a procedure where the bone marrow is removed from the patient and infused back after a course of high dose chemotherapy. This is called as autologous or auto transplant. For a bone marrow transplant, the marrow needs to be collected prior to giving high dose chemotherapy. The procedure to collect the marrow is done under general anaesthesia usually in an operation theatre.

Allogenic Transplant

Allogenic transplant is where a matched bone marrow from another person is transplanted into the patient after high dose chemotherapy.