What is cancer

What is cancer?

cancer cells, to tell what cancer is

Pulmonary Pathology’s photo

Cancer is a general term used for any disease in which certain body cells grow without any sort of control, at the expense of adjacent cells. This uninhibited growth often leads to numerous health complications, such as interference with nervous, digestive or circulatory systems. There are more than 100 different types of cancer.

People often use the words cancer and tumor interchangeably, though strictly speaking, this is very wrong; not all tumors are cancerous, and not all cancers are tumorous. A tumor is any abnormal mass in the body, it can be fluid filled or the result of an unchecked cellular growth. The habit of using these terms interchangeably persists because most cancers manifest as tumorous growth and most tumors indicate cancerous growth.

Causes of cancer

Cancers are caused by the corruption of DNA, deoxyribonucleic acid. DNA stores genetic information, and is consequently essential to life. When DNA is corrupted in any way, cellular mechanism always ensure that it is repaired, or when repair is impossible, the cell containing this defective DNA is killed, through apoptosis, or programmed cell death.  Cancers come about only when there isn’t a mechanism to regulate cells containing such defective genes or correcting the corrupted genes, meaning that, ceteris paribus, most cancer cells are immortal.

Cancer cells bypass these two crucial checks, and in these way become immortal cells that will never undergo apoptosis

The following are some elements that are known to damage DNA, and thus predispose one to cancer.

  •   Polycyclic Aromatic hydrocarbons
  •  Nuclear radiation
  •  UV
  •   Asbestos etc.

Cancers are named after where they first occurred, so pancreatic cancer started out in the pancreas, lung cancer in the lungs etc. This is especially important when dealing with metastatic cancer, as the identification of the primary cancer is important in staging cancer, i.e. determining how far it has progressed.

Cancers can be classified into five main categories, and these are:

  • Carcinoma- these cancers begin from epithelial cells and are the most common.
  • Sarcoma- these are cancers that begin in connective and supportive tissues such as bones, cartilage, muscle or fat.
  • Leukemia- cancers originating from homopoietic cells, the most common being leukocytes.
  • Lymphoma/myeloma – cancers affecting cells of the immune system
  • Adenoma- cancers originating from glands such as the adrenal, thyroid or pituitary.

 

 

 

In the USA, the most common cancers are:

The most prevalent cancer is prostate cancer, followed by breast cancer and lung cancer. The table below shows this in more detail.

Type of Cancer New Cases Deaths
Prostate

238,590

29,720

Breast

234,580

40,030

Lung

228,190

159,480

Colorectal

142,820

50,830

Melanoma

76,690

9,480

Bladder

72,570

15,210

Non-Hodgkin Lymphoma

69,740

19,020

Thyroid

60,220

1,850

Kidney

59,938

12,586

Endometrial

49,560

8,190

Leukemia

48,610

23,720

Represented graphically, the following picture emerges; lung cancer is arguably the most lethal, having both a high prevalence and a great number of casualties.

what is cancer graph and ratios
Regular medical examination is the only way to detect cancer before it advances as the early symptoms in most cancers mimic less lethal conditions.

Hopefully you have learned what cancer is. There are several treatment options available for most cancer types including natural cancer cures and treatments.