What strikes your mind when you hear the term cancer?
Something that is dreadful. And, cannot be cured through normal modalities of treatment. Something which is fatal in nature. Not to mention the fear that sticks along. Cancer is a significant global health-care problem. A total estimated 10 million cases occur per year. 46% of which are in developed countries. Mortality is high. 7 million deaths occur per year. Cancer can affect any age group The majority of deaths occur in the population above 65 years.
The term ‘cancer’ is derived from the Latin word, meaning ‘crab’. The pattern of invasion observed in the body in the same vein, the spread tends to resemble the limbs of a crab.
So what is cancer all about?
A uniform manner of growth, division, and death is seen in normal body cells. In the case of cancer, cells do not die in a programmed time. They continue to grow and divide in a disorderly fashion.
Cancer arises when a normal cell accumulates mutation. But, most of the time cells can detect mutation and DNA damage. They either try to fix them or self-destruct themselves. Some mutations allow cancerous cells to grow unchecked and hence an invasion of nearby tissues and metastasis (travel far away) to distant organs occur.
CAUSES OF CANCER:
The causative agents of cancer might include a lot of agents around us. But the major causative agents include,
- Lifestyle conditions in the form of diet and obesity (30% to 35%)
- Habits like smoking (tobacco). Almost 20% to 30%
- A major source of cancer is infections. (15% to 20%)
- Other causes include stress. Radiation in any form, lack of physical activity, etc
- Excessive alcohol consumption
- Chemicals are major causative agents
- Certain drugs prescribed for other existing body conditions
- Sunlight exposure in excess
- When it runs in families (hereditary/ genetic)
Speaking of cancer, the one word that hits our mind is ‘tumor’. The tumor is nothing but a large collection of cells. It is confined to a particular region. Moreover, it can occur in any part of the body affected by cancer. The cancer cells constantly communicate with each other and healthy cells nearby. This is one of the major manifestations of cancer. There are 2 major types of tumors namely,
- BENIGN VARIANT -Something relatively harmless and has a very slow rate of growth and expansion within the same tissue with normal cell differentiation. They do not spread.
- MALIGNANT VARIANT -Can be defined as something harmful. It has a rapid rate of growth. They expand and invade the surrounding normal tissues and they metastasize or spread to distant organs. It spreads through the bloodstream or lymphatics. The cell differentiation is usually poor.
CANCER SIGNS AND SYMPTOMS:
There are a lot of symptoms that arise from cancer. Even though, cancer usually doesn’t show any signs at the early stages. The symptoms set in gradually and take over the body’s immune system. Certain symptoms to look out for are,
A wound that takes an unusually long time to heal
Bleeding and discharge from the wound or anywhere else
Changes in warts or moles. These are the ones already present in the body
Continuous cough and hoarseness of the voice
Sudden difficulty in breathing, swallowing, etc.
Indigestion which is not random. It might persist for quite sometime
Loss of appetite. Aversion to food is also observed
Change in the bowel and bladder function
Unusual lumps and thickenings. Might be present in any part of the body. Lumps are especially common in the breast.
Unexplained weight loss (cachexia)
Cancer tends to show a lot of physical symptoms. Your doctor might start a diagnosis by getting a detailed personal history. Other information includes living conditions, substances you are exposed to. Some details like the neighborhood you live in. And, details about your occupation. Family history also plays a very important role. Certain forms of cancer run in families. Apart from this routine,
- Physical examinations are very important. Like we already discussed, cancer has so many forms of physical manifestation
Certain other tests are also done following history and physical manifestation. The tests usually begin from the basic ones. They then progress to more detailed ones. Therefore we try to rule out other conditions which might resemble cancer (differential diagnosis). Cancer is a major threatening condition. All tests have to be done properly. The exact diagnosis should be made. This is important before breaking the unfortunate news to the patient. Some of the tests include,
- A CBC (Complete Blood Count) panel – a normal blood test routine. It gives us a quantitative value of the components of the blood.
- Tumor markers in the blood (molecular diagnostic tests)
- A standard chest X-ray or any X-ray in that sense
- CT scans
- PET scans in case of metastasis
- Ultrasound scans
- A liver function test
- A biopsy in case of obvious tumors.
- A bone marrow biopsy is done for suspected tumors like lymphomas or leukemia
Learning to do self-examination is basic and important.
What makes cancer so over-rated and hard to treat?
Before we answer that question there are some facts that we need to know. There are more than 100 types of cancer. Name a body part, and there is cancer associated with it. Needless to say the metastasizing property it brings along.
- First of all, it is important to understand and find a cure for a particular disease or condition. To do this, the disease process has to be replicated and this is done by mimicking the exact condition in test tubes or Petri dishes, or some lab equipment. It has to be studied under controlled body-like conditions. This proves to be a disadvantage in terms of cancer.
- Most treatment protocols are initiated through cell lines grown in labs from tumors of patients with cancer.
- Given the critical insights on cancer genetics and biology, the cell lines grown from the tumors lack the complexity of a tumor. Hence it cannot be applied in an actual human or an organism. As a result, drugs that prove good on lab-grown tumors fail in actual patients with cancer. Thus we can understand that cancer is more complex than we anticipate.
CANCER IS NOT STANDARD:
- Cancer is not the same in every patient. One of the properties that make cancer so undefeatable is its strategy of adaptation. Cancers can be aptly termed as ‘masters of adaptation’. They not only differ from person to person. They can vary to a large extent within the same patient.
- One of the best examples to explain the above statement is understanding aggressive tumors. For instance, let’s take glioblastoma (an aggressive form of brain tumor). The beauty of this tumor is the complexity with which they exist. This tumor can have multiple populations of slightly different cancerous cells.
- Over time, distinct genetic mutations occur in these cells. These mutations occur in different parts of the tumor. They give rise to unique sub-clones (something with the same properties as the original tumor or lesion). Glioblastomas can have up to 6 different sub-clones in a single patient. This property is termed clonal heterogeneity.
- Clonal heterogeneity of a tumor is a villain for the development of drugs. The drugs that act effectively upon one particular sub-clone might not be as effective on another sub-clone.
CANCER AND IT’S ADAPTATION:
- As we already saw, cancers adapt the best. They adjust their molecular and cellular characteristics to survive under stress. When the tumor process sets in, the differentiated abnormal tumor cells induce the adjacent normal cells. They further form blood vessels. The vessels feed the tumor and eliminate the waste products. Eventually, they communicate with the body’s immune system. They suppress its functions over time. This keeps the body from recognizing and destroying the cancer process. If we find out the ways to shut down this process we can have a better shot at vanquishing the tumor.
- We should find better ways to eradicate cancer stem cells. These cells are sometimes even resistant to chemotherapy (using drugs) and radiotherapy (by X-rays). Even if we shrink away or resect a whole tumor a single residual cell can seed back the growth.
- Hence, we need better ways of understanding the disease process to find a cure or treat cancer.
GRADING AND STAGING OF TUMOR IN CANCER:
So, why is grading and staging of tumor important?
We’ve always seen and heard people telling us that their cancer has progressed. They always refer to it in terms of the stage. Staging is nothing but understanding the severity of the cancerous process. How far it spreads? The stage of cancer decides the treatment.
STAGE 0 of cancer:
This usually means that the person is cancer-free. Abnormal cells detected in the blood panel. This could have the potential to become cancer during later years. This stage is also termed as ‘carcinoma in-situ’
STAGE I of cancer:
The cancer is very small and restricted to one area. This is usually the early stage of cancer.
STAGE II AND III of cancer:
The cancer is larger in this stage. The tissue would have grown to a larger extend. They would have invaded the nearby tissues or even the lymph nodes.
STAGE IV of cancer:
The cancer is usually advanced in this stage. There would be invasions. There is a large amount of metastasis in these cases. Treatment becomes very hard. The patient might be terminal in these stages. Death occurs in almost 90% of cases in this stage.
One common system usually followed by doctors to stage is the TNM staging (Tumor Node Metastasis)
Tumor (T) :
A number is given between 0-4 to tell us about the size of the tumor. T0 means there is no tumor. The tumor size increases with the rise in the number.
Node (N) :
A nodal system gives numbers between 0 -3. Lymph nodes are very important organs. They are an integral part of the immune system. N0 indicates that there is no nodal involvement. The greater the number the farther the nodal involvement is.
Metastasis (M) :
It is kind of a binary system. The numbering is usually 0 and 1. 0- no metastasis and 1- metastasis is present. This type of staging is also used commonly.
GRADING OF CANCER:
Grading is given after a microscopic analysis of the biopsy specimen. Hence, it gives us an idea of the tissue damage at the cellular level.
TREATMENT OF CANCER:
There is no particular treatment regimen for cancer. Every type of cancer is different from one another. In other words, each of them needs a different way of management.
Some factors include,
The part of the body involved
The proximity of the nearby vital structures like nerves,
The extent of invasion,
Condition of the patients,
Age of the patient,
The standard of living after the treatment, etc.
It is hard to decide upon.
The usual modalities of treatment:
- Surgical excision of the tumor
- Targeted molecular therapy etc.
This is an option for small tumors. And, when it has good access and clear margins. It is an option only when the tumor is detected at the early stages.
Radiation is an option when the tumor cannot be resected through surgical means alone. It is also done in cases where surgery cannot be performed due to close proximity with vital structures
It is an option when metastasis of the tumor has occurred. Chemo is an option at the later stages of a tumor when surgery and radiation are of little help.
Cancer in many cases does not have a single modality of treatment. The course of treatment usually involves the intersection of 2 or more modalities of treatment. For example, a surgical resection followed by radiation. Or, radiation followed by chemo, etc. It is usually decided based on the condition of the patient and the treatment plan is decided by the physician along with the oncologist.
It is not wise to tell that cancer can totally be prevented. But, we can always stay careful and follow a healthy lifestyle. It is good to regularly self-evaluate our body for any signs. Stay aware and lead a happy and healthy life.