Understanding Cancer
Good health concerns all of us. This article outlines some basic facts about cancer, in general and the important role of early detection and early treatment to cure cancer, in particular. The serious effect on one's health if cancer is left untreated is also highlighted.
Introduction - What is Cancer?
'Cancer' has been a taboo word in our society for many years. To many people the very word 'cancer' often causes concern and fear. This may be related to a direct personal experience with a relative or friend, or from poorly conceived impressions. A diagnosis of cancer is often thought to be a death sentence. Yet, many people are cured of cancer, others continue to lead active and full lives, even if they are not completely cured, in some it is slow-growing while in others progress rapidly towards death. As there is great variability between cancers, one person's cancer cannot be compared with another's.
According to the World Health Organisation one-third of cancers can be prevented, another one-third can be cured, if detected early, and the remaining one-third will require palliative therapy because of the late stage at presentation.
Cancer is not a single disease. Cancer is simply a word that refers to a group of diseases which have different causes, are treated in various ways and which affect millions of people globally each year.
Our bodies are made up of over one hundred different types of cells. So, because any of these different types of cells may become abnormal, this means that there are over one hundred different types of cancer.
The cause of cancer is complex and lies deep within the nucleus of a cell where genetic information is stored as DNA. Damage to the DNA may lead to cancer where growth of cells is no longer orderly and controlled but destructive. The word cancer described a disease that occurs when one of the body's cells start to behave in an uncontrolled way growing and destroying body tissue instead of building and repairing.
The Clinical Challenge
The World Health Organisation estimates that the world population will grow to over six billion by the year 2005 and that fifteen million new cancer patients are expected annually, compared to 9 million new cancer patients in 1985. Of these fifteen million, five million will be in developed countries and ten million in developing countries.
For the first time ever, over one million Americans were diagnosed to have cancer in 1989. Two years later, in 1991, the number of new cancer patients in USA had increased to 1.1 million.
Five years later in 1995, the number of new cancer patients had risen to 1.25 million.
The four most common disease in USA are : Cancer of the Breast, Colon, Lung and Prostate.
These four diseases account for 56% of all newly diagnosed patients in USA.
We have experienced a similiar increase in the number of new cancer patients at Mount Miriam Cancer Hospital Penang. For example, 1068 new patients were referred for treatment in 1996 compared to 945 patients in 1995, indicating a thirteen percent (13%) increase each year.
Staging The Disease
In the early stages, cancerous (malignant) tumours usually remain in the organ where the cancer started. This is called localised disease. As cancers continue to grow they are more likely to spread or metastasise into the lymph nodes in the body. This is called regional disease. When the cancer spreads even further beyond the lymph nodes, to other organs, it is called distant metastases. The more advanced the cancer or the more the cancer has spread, the more difficult it is to control or cure.
Staging of the disease is essential for several reasons:
-
To aid the Radiotherapist in planning treatment.
-
To give some indication of the prognosis.
-
To assist in evaluating the results of treatment.
Investigations
Investigations are especially important in cancer to ascertain whether or not the tumour has spread to other parts of the body. The treatment prescribed will depend upon the results of the investigations.
Biopsy
Doctors usually cannot tell if a tumour is cancerous until a biopsy is done. This involves taking a small tissue sample, for laboratory analysis. The biopsy is also used to 'stage' the tumour, to indicate the extent of the disease, for example stage one to stage four. In general, the higher the stage of cancer the more difficult it is to treat.
Blood Tests
Blood tests and the results from these test help the cancer specialist to make the diagnosis and decide upon the best method of treatment for each patient.
Tumour Marker Blood Profiles are also done for diagnostic purposes, and to monitor and follow-up the disease status.
Diagnostic Imaging
Ultra-sound, X-rays and scans are used to make a disgnosis and to evaluate the stage of the disease. CAT scans and MRI scans can detect small tumours, for example in the lungs, brain and liver.
X-rays and scans carried out after treatment is completed to assess the response to the treatment given and to detect early relapse or spread of the disease.
Common Cancer Sites
As we have mentioned, cancer can occur in any part of the body.
Common sites include : Breast, Lung, Cervix, Colon, Stomach and Nasopharynx. The five most common cancers (from Mount Miriam Cancer Hospital data) are : Breast Cancer, Head & Neck Cancers, Lung Cancers, Cervical Cancer and Nasopharyngeal Cancer.
These five diseases alone account for seventy-two percent (72%) of all patients referred and treated at our centre.
Who Gets Cancer?
Anyone. Cancer knows no social, economic or educational boundaries. It affects the young and the old, the rich and the poor, male and female alike. It is known that the incidence of cancer rises with age. Most cases of cancer affects adults in mid-life or older.
Prevention & Early Detection of Cancer
Cutting Your Risk
Some tumours are preventable, for example 9 out of 10 cases of lung cancer are known to be caused by smoking.
Steps can be taken to reduce the risk of cancer for you and your family by heeding the following advise:
-
Do Not Smoke: This is the most important thing you can do for your health. Cigarette smoking is the cause of one of the most common types of cancer in men, in Malaysia. i.e. Lung Cancer.
-
Eat A Healthy Diet: A diet low in fats and high in fibre, fresh fruits and vegetables may reduce the risk of getting some common cancers (such as breast, colon), and is beneficial to a healthy lifestyle in general.
-
Avoid Over-Exposure to Sunlight: Almost all cases of skin cancer are sun-related. Most skin cancers are curable by radiotherapy treatment or surgery.
-
Have Regular Medical Examinations: Get to know your body well. A monthly check for changes in the way your body looks and feels can help early detection of cancer of the skin, breast, mouth and testis. This can have an immense effect on your chances of a complete cure.
Warning Signs For Early Diagnosis
Early detection is very important in the successful treatment of cancer. Listed below are some of the early warning signs of cancer:
-
A change in bowel or bladder habits
-
A persistent sore throat, nagging cough or hoarseness
-
Unusual bleeding or discharge
-
A lump or thickening in the breast or anywhere
-
Persistent indigestion or difficulty in swallowing
-
A sore which refuses to heal
-
Obvious change in size or bleeding of a mole
-
Impairment of hearing with noise in the same ear
The above symptoms may be due to minor illnesses, but it is advisable to check with your family practitioner, if you have any of these symptoms, or if you have any change in your general health lasting more than two weeks.
How is Cancer Treated?
The main goal of cancer treatment is to cure the disease. If cure is not possible, then the goal of treatment is to achieve long-term control of the illness. For those with advanced disease palliative care is available.
Cancer is usually treated by surgery, radiotherapy and chemotherapy. Cancer specialists combine these treatments to achieve the most effective response for each patient.
Surgery
During surgery the tumour and some normal tissue from the surrounding areas are removed during operation. Surgery also helps to relieve certain symptoms that may be caused by the tumour, e.g. pain, pressure.
Radiotherapy (Radiation Therapy)
About sixty percent of cancer patients are treated with radiation at some time during their disease.
Radiation therapy is a safe and effective treatment for patients of all ages, including children and the elderly.
Radiotherapy is localised treatment whereby, accurately calculated, small amounts of radiation such as x-rays, gamma rays and other sources of radiation, destroy the cancer cells. Radiotherapy is an effective, painless way to treat many cancers, in almost any part of the body.
Chemotherapy
Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. Chemotherapy treatment can be just one drug or regime of several drugs. Chemotherapy may be used alone to treat cancer, or together with surgery, and/or radiotherapy.
Chemotherapy drugs work by interfering with the ability of a cancer cell to divide and reproduce itself. As the drugs are carried in the bloodstream, they can reach cancer cells all over the body.
The type of treatment given depends on many factors, particularly the type of cancer, where in the body it started, what the cancer cells look like under the microscope and how far they have spread, if at all.
What Can Treatment Achieve?
Depending on the type of cancer and its stage of development, surgery, radiotherapy and chemotherapy can be used alone or in combination:
-
To cure cancer
-
To prevent the disease from spreading
-
To slow the cancer's growth
-
To kill cancer cells that may have spread to other parts of the body from the original tumour
-
To relieve unpleasant symptoms that may be caused by the cancer, for example pain, pressure or difficulty in swallowing
Breast Cancer
In the past decade there has been a marked increase in the number of women diagnosed to have breast cancer, not only here in Malaysia, but throughout the world.
This is due to the general aging of the world population and as a consequence of changes in our lifestyles and the environment.
Carcinoma of the breast is the most common disease referred to and treated at Mount Miriam Cancer Hospital and accounts for approximately 27% of all female cases.
There is no doubt thast the incidence of breast cancer is rising. For example, two hundred and two (202) new patients with breast cancer were referred to Mount Miriam Cancer Hospital for treatment in 1996, compared to one hunderd and forty-six (146) patients in 1990 and eighty-nine (89) patients in 1986, indicating a two-fold rise in incidence. This upwards trend is expected to continue and remain consistent in the next decade and beyond.
Symptoms of Breast Cancer
In most women breast cancer is first noticed as a lump in the breast.
Other signs to be aware of include:
BREAST:
-
Change of size or shape
-
Dimpling of the skin
-
Lump or thickening
NIPPLE:
-
Blood stained discharge
-
Becomes inverted
-
Lump or thickening
ARM:
The earlier the breast cancer is detected, diagnosed and treated, the better the chance of a complete recovery and cure.
After Treatment is Completed
The important role of follow-up clinics, after treatment is completed, should be emphasised.
Follow-up clinics have a definite purpose:
-
For continuing patient care, for example, further treatment may be possible, or excision of the growth may still be possible.
-
Giving the patient reassurance. The patient and family members build up a relationship with the Oncology team. He/she attends regularly to be assured that his/her disease is under control, and that new symptoms will be investigated and the appropriate treatment given.
-
To assess the results of treatment.
-
To detect early relapse of the disease and treat accordingly.
Conclusion
Cancer continues to be a major health problem, not only here in Malaysia, but all over the world. It is currently one of the more serious diseases affecting mankind today. It affects all segments of society regardless of sex, age or race.
The incidence of cancer will continue to rise in future, due to a general aging of the world population, and as a consequence of changes in the way we live, and the environment.
Early detection of cancer and increased Public Awareness about cancer are very important factors towards the successful treatment and cure of cancer.
Image Guided Radiotherapy
Dr Rakesh Raman
Consultant Oncologist and Radiotherapist
Approximately 40% of people with cancer have radiotherapy as part of their treatment. While damaging cancer cells, radiation can also affect surrounding healthy cells if they are not directed with a high degree of accuracy and precision.
Traditionally, imaging technology has been used to produce three-dimensional scan of the patient’s anatomy to identify the exact location of the cancer tumour prior to treatment. However, difficulty arises when trying to administer the radiation, since cancer tumours are constantly moving within the body (for example, from movement caused by breathing). Hence, the exact location of the tumour may have changed between the time of scan and actual treatment.
Image Guided Radiotherapy (IGRT) uses ultrasound, electronic portal imaging, or CT technology to verify the tumour location daily prior to treatment. Tumour tissues can move both during a radiation treatment session and from one treatment session to another as a result of normal internal organ action (digestion, elimination and breathing) and small differences in the way the patient is positioned for treatment. If these changes move the tumour out of the planned treatment range, the tumour may not receive the full amount of radiation that it should or normal tissues may receive more radiation than desire. Using IGRT allows practitioners to account for tumour movement prior to each treatment and optimize treatment accuracy.
Benefits of IGRT
-
Safely delivering higher, more effective dose of radiation
-
Offers new hope to patients with difficult to treat tumours such as those next to a vital organ or other hard to reach area
-
Helps limit the amount of radiation delivered to healthy tissue around the tumour because tighter margins can be prescribed
-
Allows the physician to deliver doses of radiation to the tumour because of these tighter margins
-
Reduce side effects and improve the quality of life for patients
-
Shortening the overall treatment period
Brachytherapy
What is Brachytherapy?
Brachytherapy is an internal radiation therapy that is applied in a temporary manner; often through the use of catheters into which the radioactive source are placed. The radioactive materials are placed inside the body and positioned in a manner that will most effectively treat the disease. In Mount Miriam Cancer Hospital, this is done under the HDR bracytherapy machine (High Dose Rate remote brachytherapy)
How long does the radiation last?
Using the HRD machine, the radioactive sources are totally removed once the procedure has been completed. Unlike the LDR (low dose rate machine), it usually involves in-patient procedures where the patient lies in bed for several days while the radioactive sources treat the disease.
How long is the recovery time after procedure?
As with all medical procedures, recovery time varies by the patient, though the use of brachytherapy as a treatment option reduces recovery time. Patients could resume walking within a few hours of the procedure and other normal activities within a few days, partly due to the minimally invasive nature of the procedure.
What are the benefits of brachytherapy?
The benefits of brachytherapy vary depending on the patient, their priorities and preferences though as a minimally invasive treatment method, the benefits of avoiding surgery are universal. These include a quicker recovery time, less time spent in the hospital and reduced risk of postoperative infections. The benefits of using brachytherapy in the treatment of early stage prostate cancer are quite pronounced. There is a much lower incidence of impotence and incontinence that occurs with a radical prostatectomy.
In the case of breast cancer, the course of traditional radiation treatment following a lumpectomy lasts six weeks, with daily installments given at a hospital or clinic, whereas brachytherapy treatment lasts for 5 days. Due to heightened convenience of brachytherapy, more women are likely to participate in adjuvant therapy, reducing the risk of the recurrence and the possible need for a mastectomy, therefore increasing breast conservation.
Is it effective?
Brachytherapy has been proven to be comparably effective in the treatment of many kinds of cancer and patients often suffer fewer side effects compared to when the employment of external radiation therapy or surgery is used.
Brachytherapy is used to treat cancers throughout the body, including:
-
Prostate cancer
-
Cervical cancer
-
Head and neck
-
Nasopharyngeal cancer
-
Breast cancer
-
Lung cancer
-
Uterus
-
Soft-Tissue Sarcomas
-
Skin Sarcomas
Ultrasound
DR. KHAIRIL ASWAD
CONSULTANT RADIOLOGIST
In line with our aim to improve the quality of treatment we give to the patient, we have recently acquired an ultrasound machine, the Siemens Sonoline Antares. This machine will complement existing diagnostic machine available at our centre.
Facts on Ultrasound...
What is Ultrasound Imaging?
Ultrasound imaging, also called ultrasound scanning or sonography, is a method of obtaining images from inside the human body through the use of high-frequency sound waves. The reflected sound wave echoes are recorded and displayed as a real-time visual image. No ionizing radiation (x-ray) is involved in ultrasound imaging.
Ultrasound is a useful way of examining many of the body's internal organs, including but not limited to the heart, liver, gallbladder, spleen, pancreas, kidneys and bladder. Because ultrasound images are captured in real time, they can show movement of internal tissues and organs and enable physicians to see blood motion.
What are the benefits vs. risks?
BENEFITS
-
Ultrasound scanning is noninvasive (no needles or injections in most cases) and is usually painless.
-
Ultrasound is widely available and easy to use.
-
Ultrasound uses no ionizing radiation and is the preferred image modality for diagnosis and monitoring of pregnant women and their unborn infants.
-
Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as needle biopsies.
-
Ultrasound images can visualize structure, movement and live function in the body's organs and blood vessels.
RISKS
-
For standard diagnostic ultrasound there are no known harmful effects on humans.
What are the limitations of General Ultrasound Imaging?
Ultrasound has difficulty-penetrating bone and therefore can only see the outer surface of bony structures and not what lies within.
Ultrasound waves do not pass through air; therefore an evaluation of the stomach, small intestine and large intestine may be limited. Intestinal gas may also prevent visualization of deeper structures such as the pancreas and aorta. Patients suffering from obesity are more difficult to image—this is because tissue attenuates (weakens) the sound waves as they pass deeper into the body.
Colorectal Cancer Awareness
The large bowel is made up of colon and rectum, which is part of the digestive system. It plays an important role in the body's ability to process waste. The colon makes up the first five to six feet of the large bowel, and the rectum (back passage) makes up the last six inches, ending at the anus.
Colorectal cancer is the cancer of the large bowel. The cancer starts in the innermost layer (the lining) of the bowel wall. Most bowel cancers take 5 to 10 years to develop. Most begin as a small growth on the bowel wall called a polyp or adenoma. If left untreated, some of them can become cancerous and grow into the muscle layers under the lining and then through the bowel wall. It can then spread into organs that are close to the bowel, such as the bladder, womb, and prostate gland, or distant organs such as liver and lungs.
How common is colorectal cancer in Malaysia?
The incidence of colorectal cancers has been rising in Malaysia. According to the 3rd National Cancer Registry report, colorectal cancer is the 2nd most common cancer in Malaysia, following breast cancer. It is also the 2nd most common cancer in Malaysian male and 3rd most common cancer in Malaysian female.
There is slightly more male than female being diagnosed to have colorectal cancer in Malaysia and the risk of developing the cancer rises exponentially after the age of 40. Malaysian Chinese has the highest incidence of having the cancer (59.8%), followed by Malay (34.6%) and the Indian (5.6%).
What is the cause and risk factors of colorectal cancer?
Researches have identified a number of risk factors which increase the chance of a person developing colorectal cancer. Having one or more risk factor does not mean that the person will definitely get the cancer, and having no risk factors does not mean that the person will be safe from cancer.
-
Growing older: More than 90 per cent of the colorectal cancer cases in Malaysia occur in people over the age of 40.
-
Polyps: Most colorectal develops from a polyp or adenoma. They are non-cancerous growth occur in the lining of the large bowel. However, certain type of the polyps can grow into cancer if they are left untreated.
-
Family history: Colorectal cancer is more likely to develop in a person whose parents, siblings, or children have had colorectal cancer, particularly if the family member was diagnosed with colorectal cancer before age 60.
-
Certain inherited conditions: such as FAP (Familial Adenomatous Polyposis) and HNPCC (Hereditary Non-polyposis Colorectal Cancer).
-
Personal history of Inflammatory Bowel Disease: such as Ulcerative colitis and Crohn’s disease, may cause chronic inflammation of the bowel and hence increase the risk of developing colorectal cancer.
-
Personal history of cancer: People with a personal history of colorectal cancer and women who have had cancer of the ovary, uterus or breast are more likely to develop colorectal cancer.
-
Diet: A diet rich in red meat and low in fibre, fruits and vegetables is linked to the development of the cancer.
-
Alcohol intake: The combined results of several studies show that a person have a 15% increase in bowel cancer risk if he/she drinks more than 12.5 units of alcohol a week on average. The risk increases further if he/she drink more than this.
-
Cigarette smoking: Smoking increases the risk of polyp formation. Recent studies also showed that smokers are more likely to die from colorectal cancer than non-smokers.
-
Body weight and physical activity: People with sedentary lifestyle (no regular exercise and a lot of sitting) and people who are overweight may have an increased risk of colorectal cancer.
What are the symptoms and signs?
A person with colorectal cancer may have the following symptoms and signs:
-
Bleeding from the back passage (rectum) or blood in the stools
-
A change in normal bowel habits towards diarrhoea or constipation that lasts longer than 6 weeks
-
A feeling that the bowel does not empty completely
-
Stools that look narrower or thinner than normal
-
Discomfort in the abdomen, including gas pains, bloating, fullness and cramps
-
A lump in the right side of abdomen or rectum
-
Unexplained weight loss
-
Anaemia (a low level of red blood cells)
However, the above symptoms and signs might be caused by other diseases which are often less serious but more common than a colorectal cancer. Therefore, it is important to check with a doctor on this.
How does Colorectal cancer diagnosed?
-
Taking a full medical history of patient’s general health, past illnesses and treatments.
-
Thorough Physical examination of patient to check for general signs of health and disease.
-
Digital rectal examination: The doctor inserts a lubricated, gloved finger into the rectum to feel for lumps or anything else that seems unusual.
-
Barium enema: A series of x-rays of the large bowel. A liquid that contains barium is put into the rectum. The barium coats the large bowel and x-rays are taken.
-
Sigmoidoscopy: A procedure to look inside the rectum and sigmoid (lower) colon for polyps, abnormal areas, or cancer. A sigmoidoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.
-
Colonoscopy: A procedure to look inside the rectum and colon for polyps, abnormal areas, or cancer. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.
-
Virtual colonoscopy: A procedure that uses a series of x-rays called CT scan to make a series of pictures of the colon. A computer puts the pictures together to create detailed images that may show polyps, cancer and anything else that seems unusual on the inside surface of the colon.
-
Biopsy of any abnormal areas or lumps: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. This is the only test available to confirm whether a patient has cancer or not.
Stages of Colorectal cancer – Is it essential to know?
The stages of cancer describe the extent of cancer spread. It is important because the prognosis (outcome) and treatment of cancer will depend on the cancer stage.
|
Stage 0 |
The cancer is very early. It is found only in the innermost lining of the colon or rectum. |
|
Stage I |
The cancer involves more of the inner wall of the colon or rectum. |
|
Stage II |
The cancer has spread through the bowel wall and may invade the nearby tissue of the colon or rectum but not to the lymph nodes. |
|
Stage III |
The cancer has spread to nearby lymph nodes but not to other parts of the body. |
|
Stage IV |
The cancer has spread to other parts of the body such as liver and/or lungs etc. |
Various investigations can be used to assess the extent of the cancer spread, these include ,Chest x-ray, Ultrasound abdomen, CT scan, PET-CT scan and the pathology report of the bowel surgery.
Treatment options of Colorectal cancer – does one regime suits all?
Colorectal cancer treatment might be different from one person to another, this is because a few factors as below will need to be taken into consideration before the cancer treatment plan is offered to patient.
-
The location (site) of the large bowel cancer
-
The Grade (appearance of cancer cells under microscope) and Stage of the cancer
-
Patient’s fitness and preferences
-
Underlying medical problems
-
Cost and availability of treatment
The treatment options of colorectal cancer include Surgery, Drug treatment (Chemotherapy and Targeted therapy) and Radiotherapy. A combination of these treatments are often used in order to improve the chance of the cancer being controlled and cured.
In general, Stage I to III colorectal cancers are potentially curable with appropriate treatments. Stage IV cancers are usually not curable but treatments might help to relieve cancer related symptoms and improve life expectancy.
Stage 0 Colon or Rectal Cancer (Cancer in situ)
Treatment is usually with a simple polypectomy during a colonoscopy. There is no additional surgery unless the polyp is unable to be fully removed by polypectomy.
Stage 1 Colon or Rectal Cancer
Surgical removal of the cancer and nearby lymph nodes is usually the only treatment necessary.
Stage II and III Colon Cancer
Standard treatment is surgical removal of the cancer and nearby lymph nodes. Post-operative (Adjuvant) chemotherapy will then be considered in some patients having Stage II cancer with high risk features that will predict a higher chance of cancer returning and all patients having Stage III cancer. Radiotherapy before or after the surgery is usually not suitable for patients with colon cancer.
Stage II and III Rectal Cancer
If the rectal cancer can be completely removed with clear surgical margins (i.e. not leaving any cancer tissue behind after the surgery), then the standard treatment will be surgery followed by post-operative (Adjuvant) chemotherapy as in patient with colon cancer of the same stages. Radiotherapy and/or concurrent chemo-radiotherapy can be considered after the surgery if patient has close or involved surgical margins,
Recent researches have shown that radiotherapy or concurrent chemo-radiotherapy given before surgery is superior than after the surgery, as long as the cancer control rate and treatment side effects are concerned.
Stage IV Colon or Rectal Cancer
In Stage IV cancer, it is usually not recommended that patients have surgery to remove the primary cancer in the colon or rectum, unless the cancer is causing physical problems, such as bleeding, perforation/ rupture of the bowel wall or blocking the bowels.
Standard treatment includes chemotherapy with or without a targeted treatment (eg. Bevacizumab, Cetuximab).
If possible, surgery to remove metastases (areas where cancer has spread) may also be done. Generally, such surgery is possible if there are a limited number of spots to where the cancer has spread.
Edited By :
Dr Ng Yi Siang 黃逸翔 医生
Consultant Oncologist and Radiotherapist