Hani Gabra

Cancer is the general name for a group of diseases in which cells in a part of the body begin to grow out of control. All cancers start because abnormal cells grow out of control. If the immune system does not destroy these cells, they will continue to grow and invade adjacent tissues. Cancer usually kills because abnormal cells impair the function of the organ or tissue they are growing on.

Cancer can cause death by spreading from the primary site to other parts of the body. Usually, this is well tolerated and people can live well for many years without problems. Many treatments can control cancer for a long time even if they can not cure it. Bear in mind that some cancers have survival rates of more than 90 percent and overall, more than 50 percent of people diagnosed with cancer live for more than five years. However, if a cancer continues to grow it can overwhelm the body’s essential functions such as the lungs, liver and digestive system. If this happens the treatment may no longer control the cancer and this might make it difficult to survive such an experience. 

For most people having cancer is a single experience and hopefully one that is overcome. The main reason for a cancer relapse is because an incomplete clearance of the cancer cells. Cancer cells that grow without limitation, so even if one cell survives then it can multiply and cause the cancer to recur. Relapse is either local or distant. The former occurs when cells appear in the same location; for example breast cancer reoccurring in the breast. The latter occurs when a relapse is a metastases; for example breast cancer appearing in the lung or liver. Cancer may reoccur in people who have continued exposure to adverse environmental risks such as smoking or people who may have a genetic predisposition to cancer. In both these settings where there is a continued underlying risk, then a cancer may reoccur or other cancers may develop.

There are many different kinds of cancers. In fact, there are as many different cancers as there are tissue types in the body. The diversity of human tissue is incredible and it is possible for cancers to arise from almost any site and many cell types. However, there are probably 20 or so dominant types of cancer.  Although there are many kinds of cancer, they all start because abnormal cells grow out of control. From another point of view, there are as many different types of cancer as there are different types of human cell- just over 200. However, cancers can be broadly grouped into four types, depending on which tissues they come from.

• Carcinomas: arise from the cells that cover external and internal body surfaces. For example, lung, breast, and colon.
• Sarcomas: arise from cells found in the supporting tissues of the body such as bone, cartilage, fat, connective tissue and muscle.
• Lymphomas: arise in the lymph nodes and tissues of the body's immune system.
• Leukaemias: arise from immature blood cells that grow in the bone marrow and tend to accumulate in large numbers in the bloodstream.

Race and ethnicity is a complex issue for cancer. Partly there is an impact, which is truly about ethnic origins. The first breast cancer gene to be discovered is called BRCA1 and inherited mutations in BRCA1 increase the risk of various cancers including: breast, ovarian, uterus, cervix, pancreatic, and maybe prostate cancer. About 1.5 percent of the Ashkenazi (European origin) Jewish population carries an inherited mutation in the BRCA1 gene. While this increased risk could be due to a variety of factors such as diet and cigarette smoking, a growing body of evidence suggests that a significant portion of the increased risk of cancer in individuals of Ashkenazi Jewish descent has a genetic basis. In developed societies ethnicity tends to be a surrogate for economic activity and access the treatments. So, when the issue of ethnicity is raised in North America it is very different to when it is raised in, say, Israel. Breast cancer for Afro-Americans is tends to be more associated with socio-economic issues than it does ethnicity. 

Some of the most intensive and active research has been in the field of angiogenesis, which attempts to conquer a disease by controlling the blood vessels that feeds it. A large amount of research has resulted in the development of active agents that blocks blood vessels and starves tumors of oxygen. We are now beginning to see signals of the benefits of this approach in patients.  However, it is still early days, further research is required, which will take time.

Cancer research and cancer treatment are evolving very rapidly. Built on a platform of intensive molecular research, the prognosis of cancer is beginning to be transformed. We have huge amounts of cancer information at our disposal. The challenge is how to translate these into the clinic and make cost effective treatments. 

Increasingly evidence suggests that lifestyles affect the risk of getting cancer. Many cancers are associated with lifestyles. A 2011 World Bank Report stressed the importance of controlling of tobacco use, harmful alcohol use, unhealthy diet and lack of physical activity, which all contribute to the cause cancer. Dealing with these four causes could substantially the human and economic burden that cancer imposes. The greatest impact would be made by the further extension of anti-tobacco measures. Michael Bloomberg, the mayor of New York City has overseen aggressive and effective measures to help reduce smoking and the consumption of unhealthy food and drink and to promote exercise.

Most cancers start in one place. A primary cancer is named for the site where it was originally discovered. For example, a primary ovarian cancer is a cancer located in the ovaries.  A secondary cancer is a primary cancer that has spread, or metastasized, to another organ.  So, if you have ovarian cancer that has spread to the liver, you have primary ovarian cancer with secondary, or metastatic, ovarian cancer in the liver. 

Some cancers have spread at the time when they are diagnosed and require different types of treatment and surgery cannot completely contain the disease. Other types of cancer do not require surgery and other types of treatment such as chemotherapy and radiotherapy may be sufficient to deal with the disease. Just because a cancer is not operated upon or is referred to as inoperable does not necessarily mean doom and gloom and death from the disease.