What is cancer?

Cancer is a term for diseases in which cells divide without control and invade other tissues within the body. These cells then spread to other parts of the body through the blood and the lymph systems. Cancer is not just one disease but a consortium of more than a hundred different types of diseases. Most of these types are named after the place where they start. For example, colon cancer begins in the colon.

Cancer can be grouped into broader categories, the majority of which include:

Where does cancer come from?

All cancers originate in the cells, the body's basic unit of life. Knowing what happens when cells become cancerous is key to understanding cancer.  The body is made up of many types of cells. These cells grow and divide in a controlled way to multiply into more cells. When cells become old or damaged, they die and are replaced with new cells. Sometimes, however, this orderly process goes wrong. The genetic material (DNA) of a cell can get damaged or changed, producing mutations that affect normal cell growth and division. When this happens, cells do not die when they should and new cells form when the body does not need them. The extra cells may form a mass of tissue called a tumor. Not all tumors are cancerous; tumors can be of two types:

What are risk factors for cancer?

It is often impossible to explain why one person develops cancer and another does not. However, research has shown that certain risk factors increase the chances of developing cancer. Over time, these factors may act together to cause normal cells to become cancerous. Some common risk factors for cancer include:

Many of these risk factors can be avoided while others, such as the family history, cannot be controlled. People can protect themselves by staying away from known risk factors. Regular medical checkups can help by encouraging early detection and prevention.

Diagnostic surgery (Biopsy)
In Biopsy the surgeon removes a part or the entire tumor for histopathological examination to determine whether the growth is cancerous or not.  Various biopsies often done are-

Curative surgery
This procedure involves removal of the tumor. This approach is good for the localized tumors that have not metastasized. It is often undertaken in conjunction with the radiation therapy and chemotherapy. 

Preventive Surgery
In this procedure the surgeon removes a tissue that might lead to cancer. Often called precancerous lesions these turn into cancers in most of the patients and the surgery is an effective way of reducing risk.

Reconstructive surgery
This type of the surgery returns the body to normal or near-normal appearance following cancer treatment. The most common restorative surgery is reconstruction of a breast after a mastectomy. Other common reconstructive procedures are facial reconstruction and testicular implants.

Minimally Invasive Surgery
The advances in computer imaging and robotics have benefited both the surgeons and the patients in equal measures. Using small cameras, miniaturized instruments and imaging equipment, the surgeons remove the tumor with the smallest possible incision. It helps the patient cosmetically as well as reduces the recovery time significantly.

Radiotherapy
Radiation therapy treats cancer through the use of ionizing radiation (X-rays or other high energy rays) to eliminate and control the malignant cells. Different kinds of cancers respond differently to the use of radiotherapy. Radiotherapy is generally a very effective method of treating cancer. It works by destroying the cancer cells in the treated area. Although normal cells can also be damaged by the radiotherapy, they can usually repair themselves.
 
Radiotherapy is often given with the aim of destroying a tumor and curing the cancer, a treatment also known as curative or radical radiotherapy. It is more often used in conjunction with the chemotherapy or with the surgery. Sometimes it is given to relieve the pain as a palliative procedure.

Bone marrow transplant
Bone marrow is a spongy material that is found inside the bones (particularly the pelvic bones) and the Stem cells are blood cells at the earliest stage of development in the bone marrow. When the cells are fully mature they are released into the bloodstream. Bone marrow produces the cells which develop into the three different types of blood cells: Red blood cells, white blood cells and the platelets. Normally, most of the stem cells in the body are in the bone marrow and there are only very small numbers of these cells found in the bloodstream.  There are four main steps involved in the process of transplant:

Step one
The first step is to reduce the load of cancer to the lowest level possible by using chemotherapy and radiotherapy. Ideally the patient should not have detectable cancer at the time of high-dose treatment. This gives the best possible chance for the treatment to work.

Step two
The second step is the collection of the stem cells from the patient or from the donor. This is known as the harvest.

Step three
The third step is the high-dose treatment. The aim here is to remove the remaining cancer cells from the patient’s body. The patient may be treated with chemotherapy alone or sometimes n combination with the radiotherapy as well. This intensive treatment completely destroys even the normal bone marrow cells. This step is also sometimes called the conditioning regimen and usually lasts a few days.

Step four
The fourth step is to give the stem cells to the patient through Intravenous route. It’s akin to having a blood transfusion. It takes around 2–4 weeks before the cells find their way through the bloodstream into the bone marrow and start to produce new blood cells.  During all these four stages the patient need as continuous medical and nursing support.

PET CT Scan

The PET CT has revolutionized other fields of medical diagnosis through precise anatomic localization and functional imaging. International Oncology recently launched the GEMINI GXL from Philips, the world’s first and only OPEN PET CT with 32 Slice/sec CT scan. The PET (Positron Emission Tomography) CT is a functional imaging modality used predominantly to diagnose conditions by monitoring glucose metabolism at the cellular level.

Here's how it works:
All human cells consume glucose or sugar as a source of energy, but cancer cells require more glucose than healthy cells due to their extreme growth rate. PET scanning utilizes a radioactive molecule that is similar to glucose, called fluorodeoxyglucose (FDG). FDG accumulates within malignant cells because of their high rate of glucose metabolism. When a

patient is scanned, the resulting images show the distribution of the radiolabeled glucose throughout the body. Areas of increased metabolism are termed as "hyper metabolic" and appear as "hot spots" on the images.

The PET CT can help physicians by diagnosing the disease much earlier than other conventional diagnostic procedures and aid them in making an accurate diagnosis, staging and restaging of cancer, treatment plans, patient prognosis, and monitoring the effectiveness of therapies.

There are no side effects associated with the PET CT. It is safe for any age and is completely painless. The total radiation dose is less than that of 1 ½ standard whole body CT scans. The FDG degrades quickly (T 1/2-110min.). It is eliminated from the body through urine.

Family members are not at risk for exposure and patient can interact with them when they leave the department.
 

The radioactive substance may expose radiation to the fetus in patients who are pregnant or the infants of women who are breast-feeding. So, if you are pregnant, or think you might be, you should inform the PET imaging staff before your scan.