What is Cancer and Its Different Types?

Cancer is a complex and diverse group of diseases characterised by the uncontrolled growth and spread of abnormal cells in the body. It can affect any part of the body, leading to various types of cancer. While each cancer type is unique, they all share a common characteristic: the disruption of normal cell function.

Cancer is a significant global health concern, affecting millions of lives each year. According to the World Health Organization (WHO), cancer is a leading cause of death worldwide. In 2020 alone, there were an estimated 19.3 million new cancer cases and 10 million cancer-related deaths globally. These staggering numbers illustrate the urgency for continued research, prevention efforts, and advancements in cancer treatments.
Cancer does not discriminate – it can affect anyone regardless of age, gender or geography. The incidence of cancer varies across different regions and populations. In India, for example, studies have shown that lung, breast, cervical and oral cancers are among the most prevalent cancer types.

Common Cancer Categories

When it comes to cancer, various types can affect different parts of the body. Understanding these different categories is crucial for early detection, prevention, and treatment. In this section, let's explore the common cancer categories, including carcinomas, sarcomas, leukaemias, lymphomas and myeloma.

Carcinomas

Carcinomas are the most common type of cancer and originate in the epithelial tissues that line the internal and external surfaces of the body. They can affect various organs such as the skin, lungs, breasts, prostate, colon and pancreas. Approximately 80 to 90 per cent of all cancer cases fall into the category of carcinomas. Some well-known subtypes include basal cell carcinoma, squamous cell carcinoma and adenocarcinoma.

Sarcomas

Sarcomas develop in the soft tissues such as muscles, fat, blood vessels, nerves, tendons, and ligaments. They can also form in the bones. Sarcomas are relatively rare compared to carcinomas and account for less than 1 per cent of all cancers. Examples of sarcoma include osteosarcoma (bone), leiomyosarcoma (smooth muscle), liposarcoma (fat) and angiosarcoma (blood vessels).

Leukemias

Leukemias are cancers that affect the blood and bone marrow. They occur when abnormal white blood cells multiply uncontrollably. Leukaemias are divided into four main types: acute lymphoblastic leukaemia (ALL), chronic lymphocytic leukaemia (CLL), acute myeloid leukaemia (AML) and chronic myeloid leukaemia (CML). These cancers can impact the body's ability to fight infections due to a compromised immune system.

Lymphomas

Lymphomas arise from cells of the lymphatic system, which is responsible for maintaining the body's immune response. They can be classified into two main types: Hodgkin lymphoma and non-Hodgkin lymphoma. Lymphomas typically begin in the lymph nodes or other lymphoid tissues and can spread to other parts of the body if left untreated.

Myeloma

Myeloma, also known as multiple myeloma, affects plasma cells found in bone marrow This cancer disrupts the production of normal blood cells, leading to weakened immunity and an increased risk of infections. Myeloma primarily affects older adults and often presents with symptoms such as bone pain, fatigue and recurrent infections.

Common Cancer Types

While there are numerous cancer types, let's take a closer look at some of the most prevalent ones.

Breast Cancer

Breast cancer is the most common cancer that affects women, but men can also develop it. It occurs when abnormal cells in the breast tissue start multiplying and forming a tumour. Early detection through regular self-exams and mammograms can significantly improve treatment outcomes.

Lung Cancer

Lung cancer is one of the leading causes of cancer-related deaths globally. It develops when abnormal cells in the lungs divide and grow uncontrollably, forming tumours.

Smoking is the primary risk factor for developing lung cancer, accounting for roughly 85% of cases.

Prostate Cancer

Prostate cancer is specific to men and affects the prostate gland, which produces seminal fluid. It usually grows slowly and may not cause symptoms in its early stages. Regular prostate-specific antigen (PSA) screenings are essential for detecting prostate cancer early on.

Colorectal Cancer

Colorectal cancer refers to cancers that start in either the colon or rectum. It typically begins as small polyps, which can become cancerous over time. Regular screenings such as colonoscopies can help identify and remove polyps before they turn into cancer.

Skin Cancer

Skin cancer is the most common type of cancer worldwide. Exposure to ultraviolet (UV) radiation from the sun or tanning beds is a significant risk factor. Self-examination for any changes in moles or new growths on the skin can aid in early detection.

Ovarian Cancer

Ovarian cancer affects the ovaries, which produce eggs and female hormones. It is often diagnosed at an advanced stage due to the absence of noticeable early symptoms. Being aware of potential symptoms like abdominal bloating, pelvic pain, or changes in bowel habits is crucial.

Pancreatic Cancer

Pancreatic cancer arises when abnormal cells in the pancreas start multiplying rapidly. It is one of the most aggressive types of cancer, with a low survival rate. Early detection plays a vital role in treatment options and outcomes.

Brain tumours

Brain tumours can be either benign (non-cancerous) or malignant (cancerous). Symptoms vary depending on the tumour's location and size but may include headaches, seizures, or changes in behaviour.

Kidney Cancer

Kidney cancer typically originates in the kidneys and can spread to other parts of the body. Blood in urine, back pain, or a lump in the abdomen are potential signs of kidney cancer.

Liver Cancer

Liver cancer can begin in the liver or spread from other organs. Chronic hepatitis B or C infections, excessive alcohol consumption, or certain genetic conditions increase the risk.

Thyroid Cancer

Thyroid cancer affects the thyroid gland located in the neck, which helps regulate metabolism. Most cases have an excellent prognosis with early detection and treatment.

Bladder Cancer

Bladder cancer starts in the bladder lining and can cause blood in urine or frequent urination. Smoking and exposure to certain chemicals are major risk factors.

Blood-Related Cancers

Blood-related cancers include leukaemia, lymphoma, and multiple myeloma. They originate from abnormal blood cells and affect various parts of the body's immune system.

Rare But Significant Cancer Types

When one thinks of cancer, the first types that often come to mind are breast, lung, and prostate cancer. While these are indeed prevalent, it's important to acknowledge that there are several other cancer types that, even though rare, can have a significant impact on those affected. Let's explore some rare but significant cancer types and their definition and prevalence.

Mesothelioma

Mesothelioma is a cancer type that affects the thin layer of tissue surrounding the lungs, heart, abdomen, and other organs. It is primarily caused by exposure to asbestos fibres.

Adrenal Cancer

Adrenal cancer originates in the adrenal glands, which are located on top of the kidneys.

It is a rare type of cancer affecting around 200 people in the US each year. Adrenal cancer typically affects adults aged 40 to 50 years.

Testicular Cancer

Testicular cancer occurs in the testicles, which are responsible for producing male hormones and sperm. It is the most common type of cancer among young men aged 15 to 35. The good news is that testicular cancer has one of the highest survival rates among all cancers.

Gallbladder Cancer

Gallbladder cancer originates in the gallbladder, a small organ located under the liver. It is more common in women than men and typically affects individuals over the age of 65.

Gallbladder cancer is relatively rare but can be aggressive and challenging to detect at early stages.

Bone Cancer

Bone cancer develops when abnormal cells grow uncontrollably in bones. It can occur at any age but is more common in children and adolescents. The prognosis for bone cancer varies depending on factors such as the type and stage of the cancer.

Eye Cancer

Eye cancer, also known as ocular melanoma, affects the cells that produce pigments in the eye. It is a rare form of cancer with an estimated incidence rate of 5 cases per million population. Early detection and treatment are crucial for preserving vision and improving outcomes.

Uterine Cancer

Uterine cancer, also called endometrial cancer, develops in the lining of the uterus. It is the most common gynecologic cancer and primarily affects postmenopausal women. Regular check-ups and awareness of symptoms can aid in early detection and successful treatment.

List of All Cancer Types

By understanding the different cancer types, one can increase our knowledge and awareness about this disease and take steps to prevent and detect it early.

Here are some of the different cancer types:

• Adrenal gland tumour: A rare type of cancer that forms in the adrenal glands, located on top of the kidneys.

• Anal cancer: Anal cancer is a type of cancer develops in the tissues of the anus and can occur in both men and women.

• Appendix cancer: While rare, cancers can also develop in the appendix, a small organ located near the large intestine.

• Childhood cancer: Cancer can affect children of all ages, with various types specific to pediatric patients. It's essential to be vigilant about any symptoms or changes in children's health.

• Colorectal cancer: This cancer affects the colon or rectum and is one of the most common cancers worldwide. Regular screenings can help detect it early.

• Oesophageal cancer: Oesophageal cancer occurs in the oesophagus, which connects the throat to the stomach. It is more common in older adults.

• Eyelid cancer: Skin cancers can develop on the eyelids, so it's crucial to protect one's eyes from harmful UV rays.

• Head and neck cancer: Cancers that affect the head and neck region include those in the mouth, throat, larynx (voice box), sinuses, and nasal cavity.

• HIV/AIDS-related cancer: People with weakened immune systems due to HIV/AIDS have an increased risk of developing certain cancers.

• Laryngeal and hypopharyngeal cancer: These cancers affect the voice box (larynx) and adjacent areas. They are often associated with smoking and excessive alcohol consumption.

• Myelodysplastic syndromes - MDS: This group of blood cancers affects the bone marrow and the production of healthy blood cells.

• Nasal cavity and paranasal sinus cancer: Nasal cavity and paranasal sinus cancer develop in the nasal cavity or the paranasal sinuses around the nose.

• Nasopharyngeal cancer: Nasopharyngeal cancer is a rare type of cancer that affects the nasopharynx, located behind the nose and above the back of the throat.

• Oral and oropharyngeal cancer: Cancers that affect the mouth, tongue, tonsils, and throat fall under this category. Regular dental check-ups can help detect early signs of oral cancer.

• Fallopian tube, and peritoneal cancer: These are rare types of cancer that primarily affect women's reproductive organs.

• Parathyroid cancer: This type of cancer develops in the parathyroid glands, which are responsible for regulating calcium levels in the body.

• Penile cancer: Although rare, penile cancer can occur in men. Maintaining good hygiene and regular check-ups can help with early detection.

• Pituitary gland tumour: Pituitary tumour that develop in the pituitary gland can disrupt hormone production and cause various health issues.

• Salivary gland cancer: Cancers that begin in the salivary glands, which produce saliva, fall under this category.

• Small bowel cancer: This type of cancer affects the small intestine and is relatively rare. Symptoms may include abdominal pain and unexplained weight loss.

• Stomach cancer: Also known as gastric cancer, it affects the stomach lining. Early diagnosis plays a crucial role in improving survival rates.

• Thymoma and thymic carcinoma: These rare tumours develop in the thymus gland, a part of our immune system located behind the breastbone.

• Vulvar cancer: Vulvar cancer affects the external genitalia of women and is usually detected through regular pelvic exams.

• Vaginal cancer: Vaginal cancer is a rare type of cancer that develops in the vagina, regular gynaecological check-ups are crucial for early detection.

• Werner syndrome: This rare genetic disorder increases the risk of various cancers and other age-related health issues.

• Kaposi sarcoma: Kaposi sarcoma often associated with HIV/AIDS, this cancer affects the skin, blood vessels, and internal organs.

• Male breast cancer: Although breast cancer is more common in women, in men breast cancer can also develop. Awareness about the signs and symptoms is important for early detection.

• Recurrent cancer: Sometimes, cancer may return after successful treatment. Regular follow-ups and monitoring are essential for detecting recurrent cancer.

Importance of Early Detection

Regular screenings are essential for early detection as they can identify cancer at its earliest stages when it is most treatable. For lung cancer, individuals with a history of smoking or exposure to secondhand smoke should be particularly vigilant about screening. Other cancer types, such as breast cancer, prostate cancer, and colorectal cancer, also have specific screening guidelines that should be followed based on age, gender, and other risk factors. Mammograms are recommended every one to two years for women aged 40 and above to detect breast cancer. Men aged 50 and above should discuss prostate cancer screening options with their doctors. Regular colonoscopies are advised for individuals aged 50 and above to detect colorectal cancer.

Early detection is crucial in the battle against cancer. By being proactive and seeking regular check-ups, one can increase our chances of detecting potential issues at their earliest stages. Remember, early detection can save lives. Let's take control of our health and prioritise regular screenings for cancer.

Frequently Asked Questions

1. What are the 4 stages of cancer?

Cancer is typically classified into four stages based on how far it has spread within the body.

• Stage 1 indicates a small tumour that has not yet invaded surrounding tissues.

• Stage 2 signifies a larger tumour or limited spread to nearby lymph nodes.

• Stage 3 represents extensive local invasion or regional lymph node involvement.

• Stage 4 indicates metastasis, where cancer has spread to distant organs.

2. When can cancer start?

Cancer can develop at any age but the risk of developing cancer increases with age. Certain cancers, such as childhood cancers, can occur early in life. Lifestyle factors such as smoking, poor diet, lack of physical activity, and exposure to certain chemicals or radiation can also increase the risk of developing cancer.

3. Is cancer genetic?

Some forms of cancer have a genetic component, meaning they can be inherited from family members. However, most cancers are not solely caused by genetics but are influenced by a combination of genetic and environmental factors.

4. How does cancer make you ill?

Cancer can make you ill in various ways depending on its location and stage. It may interfere with normal organ function, cause pain or discomfort, weaken the immune system, or lead to nutritional deficiencies due to changes in metabolism.

5. What are the risk factors for cancer?

The risk factors for developing cancer vary depending on the type of cancer. Common risk factors include tobacco use, excessive alcohol consumption, obesity, exposure to certain chemicals or radiation, family history of cancer and certain infections such as HPV or hepatitis.

6. What are the treatment methods available for cancer?

Cancer treatment options depend on the cancer type, stage and location. Treatment methods may include surgery, radiation therapy, chemotherapy, immunotherapy, targeted therapy, hormone therapy or a combination of these approaches.

7. How does chemotherapy work?

Chemotherapy uses drugs to kill cancer cells or prevent them from growing and dividing. It can be administered orally or intravenously and may be used as a standalone treatment or in conjunction with other therapies. Chemotherapy can have side effects but advancements in supportive care have improved its tolerability.

8. What is the main treatment for cancer?

The main cancer treatment depends on various factors such as cancer type, stage and patient characteristics. Surgery is often used to remove tumours and nearby lymph nodes if applicable. However, other treatments like radiation therapy or chemotherapy may also be used as the primary treatment modality.

9. What is Stage 5 cancer?

Cancer staging typically ranges from stage 0 to stage 4. There is no official "Stage 5" classification recognised in traditional cancer staging systems.

10. What is the best treatment for childhood cancer?

Childhood cancers require specialised care from pediatric oncologists who are experienced in treating these unique cases. The best treatment for childhood cancer depends on various factors like the type of cancer, stage of disease, and individual patient considerations. Treatments may include surgery, radiation therapy, chemotherapy, immunotherapy, or stem cell transplant.