Cancer: Symptoms, Causes, Risk Factor, and Treatment of Cancer

Introduction to cancer

Cancer is an ‘abnormal growth of cells’. The cancer cells continuously multiply in spite of lack of ‘space’ and ‘nutrition’. Cancer cells can be differentiated from the other healthy cells in being different in shape, improper function and the capacity to spread to other parts of the body. The study of cancer and tumors is called as ‘Oncology’. Cancer is not a single disease but is a group of diseases.

Tumors can be benign or malignant. Benign tumors grow slowly and do not spread. When tumors are malignant, they are termed as ‘cancer’ and can cause harm including “death”. The ‘malignant’ nature of cancer is due to its locally invasive nature (tumor invading the surrounding cells) and metastatic nature (tumor invading the other tissues in the body).

The original tumor is called as the primary tumor. The cells of the primary tumor travel through the circulatory system and lymphatic system to form new tumors called as secondary tumors in other organs.

Occurance of Cancer in different groups  (Epidemiology)

Prevalence of cancer in different regions of the world varies depending on the type of cancer occurring in that particular region. Epidemiological studies suggest that breast cancer and prostrate cancer are common in the developed countries of the world, whereas cervical cancer and stomach cancer occur more frequently in developing countries. Lung cancers seem to have high incidence in both developed and developing countries.¹

The differences in the prevalence of cancer in different regions of the world can be explained through heredity, medical practices, lifestyle changes and environmental exposures like different diets, tobacco and pesticides. Studies suggest that the incidence of colon cancer is seen more in people who are obese.²

Studies across the populations suggest that men are more to prone to develop colorectal cancer than women. Obesity has shown to increase the prevalence of breast cancer in postmenopausal women by 30–50%.³ Other kinds of cancer related to obesity include endometrial, pancreatic, kidney, liver cancer, gall bladder etc.^4,5

Studies from developed countries show that cancer is exceeding cardiovascular diseases and has become a major cause of death when compared to underdeveloped countries, where infectious diseases is the major cause of death.  

Classification of cancer

Cancer is named based on the part of the body from where it originates.
Cancers can be classified based on its location and origin as: 

Carcinoma: This is the cancer found in the ‘epithelial tissues’. Epithelial tissues cover the organs, glands and body structures.

Sarcoma: These are malignant tumors growing from the ‘connective tissues’ like fat, muscles, tendons and bones.

Lymphoma: This originates from the ‘lymph nodes’ of the lymphatic system. Lymphomas are further divided into Hodgkin’s and non-Hodgkin’s lymphoma.

Leukemia: This is the cancer of the ‘bone marrow’ and also called as ‘blood cancer’. This kind of cancer prevents the bone marrow from producing normal red blood cells, white blood cells and platelets.

Myeloma: This kind of cancer grows on the ‘bone marrow’. Sometimes, the myeloma cells get collected in one bone marrow and form single tumor called ‘plasm
acytoma’ or the myeloma cells get collected in numerous bones forming ‘multiple myeloma’.
Apart from this, cancers are of mixed types also.  

Signs and symptoms of cancer

The signs and symptoms of cancer depend on the particular type of cancer affecting the person.
Symptoms of cancer

Causes and risk factors of cancer

There are many causes for cancer, and many factors remain unknown.
Following are some of the risk factors causing cancer. 

Carcinogens: Mutagens are substances, which bring about mutations of the DNA. The mutagens, which cause cancer are called carcinogens. Carcinogens like tobacco and alcohol cause lung cancer.

Radiations: Radiations of radioactive substances and prolonged exposure to ultra violet radiations causes skin cancer.

Viral and Bacterial infections: Chronic infections of hepatatis viruses like hepatitis B and hepatitis C can cause liver cancer.²⁰ Chronic bacterial infection ofHelicobacter pylori, which infects the walls of the stomach can cause gastric cancer.²¹

Hormonal imbalance: Hormonal imbalances are also known to cause cancer. Higher levels of estrogen can cause endometrial cancer.

Heredity: Studies have shown that heredity is one of the recognizable components causing cancer. Persons suffering from Down’s syndrome do have chances of developing leukemia and testicular cancer. Mutations in retinoblastoma genes can cause cancer of the retina.²² Apart from these certain chemicals like benzene, poisonous mushrooms and a number of unknown substances can cause cancer.

Diagnosis of of cancer

Diagnosis of cancer is done by observing the symptoms shown by the patient. The physician may suggest blood tests, endoscopy, X-ray, ultrasonography, CT scan or MRI scan to find out the location and size of the tumor.

Confirmatory tests are done through biopsy which involves microscopic examination of the samples from the suspected area. Biopsies are painful and are conducted in the presence of local anesthesia. Biopsies involve cutting out a piece of tissue from the suspected area with the help of a scalpel.²³ Pathological examination of the biopsy helps us to know whether the tumor is ‘benign’ or ‘malignant’.

After the diagnosis, staging tests are done to know the location, growth of cancerous cell to the nearby structures and spread to different parts of the body. CT scan is done to detect cancer in different parts of the body like liver, lungs, brain, lymph nodes etc. MRI scan is done to detect cancer of the brain, bone and spinal cord.

Treatment of cancer

Treatment of cancer

As cancer refers to a class of diseases, treatment of cancer depends on the type of cancer, location and the stage of cancer. 

How to cope up with chemotherapy side effects

Side-effects are closely associated with all chemotherapy treatments. However, the severity of side-effects vary from the fact kind of chemotherapy being taken.

Management of cancer

Prevention of cancer
Prevention is the best way to reduce the risk of cancer. Risk factors can be prevented depending on the specific kind of cancer.  

Management of pain in the cancer
Cancer is associated with a lot of pain. Hence, symptomatic pain relief is very essential in cancer.