Cancer

Overview of cancer

Systemic diseases of different degrees are common in adults and children. In the benign stages, they can be treated and cured through minimum medical interventions. Some of the diseases that are self-limiting in nature resolve with time. But some other diseases that take serious forms do not cure even after advanced medical procedures.Cancer is the end-stage of these types of diseases.

It is marked by the generation and uncontrolled spread of malignant cells.  A large part of the world population is suffering from this condition, which in most cases is irreversible.

What is cancer?

Cancer is defined as the presence of excess cells in some organ(s) of the body, which leads to organ enlargement and failure.

These cells are distinguishable from the normal cells in some aberrant characteristics.

Cancer occurs when the rate of generation of new cells exceeds the rate of destruction of the old cells. This condition is also known as malignancy.

Studies have also shown that in some of these cases, the old cells live even after the normal lifespan is over. This, along with an overproduction of new cells causes organ enlargement.

At the onset, the abnormal cells stay at their site of origin and do not spread elsewhere. With the gradual progression of the disease, the cells start spreading to the adjoining or the remote organs and tissues, inhibiting the actions of the cells therein. This phenomenon is known as metastasis. Once this stage is reached, the disease becomes almost incurable and the life-expectancy of the patients is severely impacted. This article will discuss different types of cancers and will also focus on their diagnosis and treatment techniques.

Breast Cancer

Breast cancer is the pathological condition in which cells within the breast grow abnormally and uncontrollably and lead to the formation of masses or lumps called “tumors”. Some other varieties of breast cancer originate from the milk-producing glands. Nearly 50% of breast cancer cases are reported in underdeveloped countries and 58% of death cases are reported in these countries annually.

What are the possible causes of breast cancer?

Numerous environmental and physiological factors account for breast cancer in women. These are elaborated below-

• A familial history of breast cancer
• Mutations in the BRCA, ATM, and PTEN genes
• An abnormal increase in breast tissue density
• Long-term exposure to strong radiations
• Overuse of birth control pills
• Excess alcohol and tobacco intake
• Presence of excess fat tissues
• Having no child or having a child after the age of 30
• Exposure to harmful chemicals such as Polychlorinated Biphenyls (PCBs)
• Hormonal therapies to treat osteoporosis
• Having menstruation before the age of 12 or menopause after the age of 15

What are the main symptoms of breast cancer?

Breast cancer symptoms are very subtle in the premature stages. But with the gradual progress of the disease, the fowling symptoms may be observed-

• Breast swelling and inflammation
• Breast tenderness and sensitivity
• Nipple retraction
• Formation of solid lumps in the breasts
• Abnormal nipple discharge
• Nipple eczema

What are the different types of breast cancer?

It is mainly of two types-

• Ductal carcinoma: It is caused due to cancerous cell growth in the inner linings of the milk-carrying ducts.
• Lobular carcinoma: It originates in the milk-producing glands of the breast called lobules.

Cervical Cancer

Cervical cancer is defined as the abnormal cell growth and proliferation in the cervix that leads to the formation of solidified mass called tumors.

It is mainly catalyzed by the Human Papilloma Virus (HPV).

According to statistics produced by the American Cancer Society, each year, more than 2,70,000 women die from cervical cancer (low and middle income countries)

What causes cervical cancer?

The following factors may trigger cervical cancer.

• Smoking
• Lack of immunity
• Chlamydia infection
• Obesity
• Unprotected sexual intercourse
• Giving birth to three or more children

How to tell if a woman has cervical cancer?

Cervical cancer is identifiable if the following symptoms are present-

• Vaginal bleeding and spotting
• Strong-smelling vaginal discharge
• Painful intercourse
• Post-coital spotting
• Pain in the lower abdomen and pelvic region

Do you know the different types?

Based on the nature of the malignancy, cervical cancer is of the following types-

• Microinvasive cervical cancer: Here the cancerous cells only break through the bottom layer of the cervical lining.
• Invasive cervical cancer: The cancerous cells are transmitted from the outer layer of the cervix to the inner layer of tissues.

Liver Cancer

Liver cancer refers to the condition in which abnormal cell growth occurs within the liver giving rise to tumours (solidified mass of cells and tissues) which may spread to different parts of the body.

Based on the reports compiled by American Liver Foundation, about 80% of liver cancer cases are reported due to Hepatocellular Carcinoma.

What predisposes a person with liver cancer?

• Hepatitis C or Hepatitis B infection
• Liver cirrhosis
• Metabolic disorders
• Alcohol and tobacco abuse
• Toxic agents like Aflatoxins, Vinyl chloride, and Thorium dioxide
• Overuse of anabolic steroids

When do you know you have liver cancer?

The following symptoms generally serve as warning signs-

• Pain in the upper right portion of the abdomen
• Presence of a lump below the left rib
• Yellowish discoloration of skin and eyes

How many types are there?

Liver cancer has the following subtypes-

• Primary liver cancer: It originates in the liver itself. It is of four types- Hepatocellular carcinoma, Intrahepatic cholangiocarcinoma, Angiosarcoma, and Hepatoblastoma.
• Secondary liver cancer: The primary site is the liver but they are found in the pancreas, stomach, breast, lung, and colon. 

Lung Cancer

Lung cancer is defined as the abnormal and uncontrolled growth of cells within the lung leading to the formation of tumors.

Causes of lung cancer

The following conditions can cause lung cancer-

• Tobacco and alcohol consumption
• Exposure to asbestos
• Direct exposure to radon
• Beta-carotene supplements
• Mutations in the EGFR, KRAS, MET, LKB1 genes

Know the signs of lung cancer

Following are some of the warning signs-

• A persistent cough
• Brownish or reddish sputum
• Chest pain and discomfort
• Breathlessness or wheezy breathing

Know the common types

Two types of lung cancers are identified-

• Small cell lung cancer (SCLC): The cancerous lumps are formed of small round cells.
• Non-small cell lung cancer (NSCLC): It accounts for 80% of all lung cancer cases. 

Ovarian Cancer

Ovarian cancer is the medical term for abnormal and uncontrollable cell growth within the ovary. It occurs due to the abnormal growth of any of the three types of cells- epithelial cells, germ cells and stromal cells.

Why does ovarian cancer occur?

Given below are some of the causes of ovarian cancer-

• Reduction in the levels of estrogen and progesterone
• Obesity
• Overuse of fertility drugs such as clomiphene citrate
• Hormone replacement therapies

What are the main symptoms?

Ovarian cancer manifests as-

• Vaginal bleeding and spotting
• Abdominal bloating
• Bowel obstruction due to growth of a mass in the abdomen

What are the different types of ovarian cancer?

Research studies conducted over the years have shown the existence of three types of ovarian tumors

• Epithelial ovarian tumors: They originate from the cells that form the outer layer of the ovary.
• Germ cell ovarian tumors: They are of three types- Teratoma, Dysgerminoma and
• Stromal cell ovarian carcinoma: These tumors produce excess quantities of estrogen and at times androgen.

Pancreatic Cancer

Pancreatic cancer is the medical condition in which abnormal cell growth occurs in the pancreas leading to the formation of solidified mass (tumors). Either the exocrine or the endocrine or both types of pancreatic cells are affected by this type of cancer.

What causes it?

The main causes of pancreatic cancer are as follows-

• Aging
• Substance abuse
• Mutations in the PRSS1 gene
• Toxicity
• Limited physical activities

What are the main signs?

The main signs of pancreatic cancer are as follows-

• Yellowish discoloration of the skin and the sclera
• Tarry stool
• Brownish urine with a strong smell
• Occurrence of blood clots (Venous Thromboembolism)
• Diarrhoea and cramps
• Enlargement of gallbladder or liver
• Indigestion and heartburn

What are the different types?

The two main types of pancreatic cancer are-

• Exocrine pancreatic cancer: It affects the cells present in exocrine glands and ducts.
• Endocrine pancreatic cancer: Occurs mostly in the islet cells. 

Throat Cancer

Throat cancer is a collective term for laryngeal and hypopharyngeal cancers that mainly arise from the lower portions of the throat due to abnormal and proliferative cell growth in those regions.

What causes throat cancer?

Following are the main causes of throat cancer-

• Tobacco and alcohol abuse
• Viral infections
• Inherited conditions such as Fanconi anemia and Dyskeratosis congenital
• Mutations in the tumor suppressor genes TP53 and p16
• Inhaling particulates and pollutants
• Poor immunity
• HIV infection in the past
• Exposure to X-rays and other ionizing radiations

What are the symptoms of throat cancer?

The major signs and symptoms are as follows-

• Cough with or without sputum
• Difficulty swallowing
• Hoarseness of voice

Testicular Cancer

Testicular cancer is a kind of malignancy that occurs due to an abnormal and proliferative growth of cells in the testicles. More than 90% of the testicular cancers originate from the germ cells (seminomas and non-seminomas) that are responsible for the production of sperm. Chance of survival from testicular cancer is 95%, only if the disease is detected at stage I.

What causes testicular cancer?

Testicular cancer mainly arises from the diseases of the testes. The general causes are as follows-

• A congenital condition wherein one or both the testicles are outside the scrotum or partially within the scrotum (Cryptorchidism)
• A history of testicular diseases
• Presence of pre-cancerous cells (Intratubular Germ Cell Neoplasia ) in the testicles
• Infertility
• Genetic disorders (presence of extra copies of chromosome 12)
• Being a white native American
• Mechanical injury to the testes
• HIV infection

How to tell if one has the disease?

The following symptoms may help identify testicular cancer-

• One testis may appear larger than the other
• Swelling and lump formation in the testes
• Pain and pressure in the testes, scrotum and lower abdomen

Types

Seminomas: The cells originate from the germ cells of the testicles and are located in the mediastinum or other extra-gonadal locations.

Non-seminomas: They may or may not be of germ-cell origin.

Prostate Cancer

Prostate cancer is the pathological condition in which cells within the prostate gland show abnormal growth and start multiplying rapidly, giving rise to tumors. African American men have a 60% chance of developing prostate cancer in their lifetime than Caucasian men and are 2.5 times more likely to die from the disease.

What are the causes?

• Loss of function of the prostate glands with age
• Being of African American or Carribean origin
• A familial history of prostate cancer
• Overconsumption of red meat, dairy products, and calcium
• Obesity
• Tobacco smoking
• Chemical toxicity
• Benign Prostate Hyperplasia (BPH) or Prostatitis
• Sexually Transmitted Diseases (Chlamydia or Gonorrhoea)
• Vasectomy

Symptoms of prostate cancer

• Painful urination
• Feeling of bladder fullness
• Erectile dysfunctions
• Loss of bladder control 

What are the diagnostic tests available for different types of cancer?

The laboratory examinations for different types of cancer are given below-

• Breast cancer: Mammogram, Breast ultrasound, Breast MRI, Ductogram, Biopsy
• Cervical cancer: Pap test, Colposcopy, Cervical Cancer
• Liver cancer: Ultrasonography, CT scan, Angiography, MRI, liver biopsy
• Lung cancer: Sputum cytology, Chest X-ray, CT scan, Lung Biopsy
• Ovarian cancer: Laparoscopy, Blood Test, Biopsy, MRI, Ultrasound, CT scans
• Pancreatic cancer: CT scan of the pancreas, MR cholangiopancreatography, MR angiography, Endoscopic Ultrasound (EUS)
• Throat cancer: Laryngoscopy, Panendoscopy
• Testicular cancer: PET scan, Ultrasound of testes
• Prostate cancer: Digital Rectal Examination, Prostate Specific Antigen Blood Test, Transrectal Ultrasound, Prostate biopsy

Treatment & Prevention

The treatment protocol for cancer depends on the type of cancer, the degree of spread, organ/s affected, and the age and health of the patient.  Cancer patients are usually administered a combination of surgeries, therapies, and palliative care modules for treating or managing the symptoms. Surgery includes complete removal of the cancer-affected organ if it is possible to do so without affecting the healthy organs. But this can be only done if the disease hasn’t spread to other parts of the body. Radiation therapy uses high energy gamma rays to destroy targeted cancer cells. Chemotherapy involves the injection of toxic chemicals which interfere with the division of cancer cells and prevent it from spreading. Immunotherapy and hormonal therapy are aimed at enhancing the body’s immunity and balancing the hormonal level respectively.

Lifestyle improvements can prevent a large number of cancers. These include no smoking or drinking, maintain a healthy BMI, eliminating tobacco consumption, vaccinations (cervical cancer), and leading a physically active lifestyle.

Till date, there is no absolute cure for cancer. Chemotherapy is provided to the patients for a particular duration in order to increase the life expectancy. This method, however, has several systemic complications. The current research works are being directed towards devising effective means of treatment for these patients and reduce the global burden of cancer.

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