Growth Disturbances and Neoplasia

Introduction:

The neoplastic cells take their nutrition from the host body. The needed nutrients and lack of growth control stimuli together help in the proliferation of cells into tumor masses. The disease cancer has turned into a forever nightmare in the medical dictionary. However, the case is not the same for all cancers. Modern science has cures for cancers at early detection stages.

What Are the Various Types of Neoplasm?

Neoplasms are tumor growths that depend on the host body's nutrition and blood supply. These tumors are cancerous. The word cancer is taken from a Latin word for crab. Hence it shows the characteristic of crabs showing greater adherence to any surface they attach. Depending on the nature of neoplasms, they are divided into

1. Benign: Mostly, they are localized tumors of less threat. They are mostly curable. For example, benign epithelial neoplasms like adenomas and papillomas.

2. Malignant: These tumors spread to distant sites and are life-threatening. Early diagnosis can be helpful for a cure. For example, fibrosarcoma and squamous cell carcinoma.

Tumors are distinguished based on cellular differentiation and anaplasia, growth rate, local invasion, and metaplasia.

What Are Differentiation and Anaplasia?

• Differentiation: It is the ability of cells to replicate into similar morphology and functionality of their forebears.

• Anaplasia: It is the absence of differentiation or dedifferentiation. It is the loss of functional and structural differentiation. This condition leads to malignancies. It shows differences in cell size and hyperchromatic nuclei.

How Does the Rate of Growth Affect the Tumor Growth?

Benign tumor cells grow slowly, whereas malignant growth is faster and spreads. But there are exceptions as well. During pregnancy, the circulation of estrogen is high. After delivery, the cessation of this large mass can give rise to atrophy or fibrocalcific structure. In malignant growth of tumors, it could be an aggressive or slower growth over time. Even more, there are cancer cases like choriocarcinomas, which have completely disappeared over time.

How Does Cancer Spread to Other Parts of the Body?

The spread of cancer to a distant part of the body is known as metastasis. These are also known as secondary tumors. Not all cancers metastasize. Certain tumor cells are highly invasive but rarely metastasize. For example, basal cell carcinoma of the skin and central nervous system tumors. Metastasis could be due to the following:

• Invasion or dissemination of neoplastic cells into the body.

• Spreading through the lymphatic system.

• Spreading through the bloodstream.

The spread of cancer through the hematogenous system is the most dangerous. The liver and lungs are the most common sites for hematogenous dissemination.

What Are the Examples of Metastatic Cancer?

One of the most common metastases seen is in lung carcinomas. It spreads to bronchial lymph nodes, then to tracheobronchial and hilar nodes. Carcinoma of the breast arises in the upper outer quadrant. It then spreads to axillary nodes. The medial lesion may spread through the internal mammary artery. Cancer of the prostate spreads to the bone. Neuroblastomas spread to the liver and bones.

What Are the Predisposing Factors Leading to Cancer?

Besides cellular and molecular changes, various epidemiological conditions also contribute to cancer. Factors influencing neoplasms are

• Rate of Incidence: Lung cancer is the most common neoplasm. Leukemia is the most common childhood cancer. The rate of mortality in men is higher than in women. The most common neoplasia seen in men is in the prostate and lungs. In women, the most common neoplasms are in the breasts and lungs.

• Geographic Factors: The mortality rate due to breast cancer is higher in the United States and Europe. The death rate for stomach cancer is higher in the Chinese population. Neoplasm of the liver is prevalent in Africans. Environmental carcinogens like asbestos, ultraviolet radiation, and atmospheric pollutants also play a crucial role in oncogenesis.

• Age: The rate of cervical cancer is higher in females with multiple sexual partners and the age of intercourse. It is passed due to venereal transmission of the oncogenic virus. The higher the age, the higher the risk of cancer. In children, the prevalence of cancer is seen more under the age group of fifteen years.

• Heredity: Lung cancer is mostly associated with cigarette smokers. But the rate of lung cancer is high among non-smokers due to familial or hereditary predispositions. Other examples are carcinoma of the breast, brain, and colon.

• Autosomal Recessive Syndromes of Defective Deoxyribonucleic Acid (DNA): Conditions like xeroderma pigmentosum in which DNA repair is defective.

• Acquired Preneoplastic Disorders: Conditions like villous adenomas of the colon are at high risk of transformation into colorectal carcinoma.

What Are the Diagnostic Tools to Detect Cancer?

• Biopsy: Removal of a small tumor section to be analyzed by a histopathologist. This is done to establish a precise diagnosis. It can be done using exfoliative cytology and interventional cytology like- fine needle aspiration.

• Hematology: The components of blood are studied. Any abnormal parameters can indicate a cancerous condition.

• Histopathology: It is the microscopic study of cells and tissues.

• Tumor Markers: The presence of a specific cancer-causing substance in the body. For example, neuron-specific enolase (NSE) helps detect neuroblastomas. Alpha-fetoprotein (AFP) is particularly high in patients with high germ cell tumors.

• Medical Imaging Techniques: These are:

  • X-ray: It is used to detect the site and extent of the tumor.

  • Computed Tomography (CT): A image of the internal body structure is obtained. Computers then process the image.

  • Magnetic Resonance Imaging (MRI): The biochemical activity of the tissue normally responds to magnetic forces. The presence of tumors may give abnormal signals.

  • Ultrasound: The image of internal organs is obtained using a sound wave medium.

What Are the Various Stages of Cancer?

• Benign: This is mostly non-cancerous and not spreading in nature. It is a mild condition.

• Malignant: This is cancerous condition, where the tumor grows uncontrollably and may destroy the normal tissue.

• In-Situ or Invasive or Localized: A tumor restricted to a single site.

• Metastasis: This is a tumor spreading to other body parts, distant from the original site.

• Staging: The diseased condition is categorized by how far it has spread. Such as the low stage, where the tumor is localized and easily resectable, and the high stage, where the tumor spreads rapidly (metastasis) and treatment depends on staging.

• Prognosis: It is the expected outcome of the disease, depending on the stage, age, and site.

• Remission: It is a condition where symptoms of cancer are no longer present.

• Relapse: During this stage, the disease recurs after a period of remission.

• Refractory: This is where cancer is resistant to treatment.

• Restaging: Patient is followed up to check for the progress of treatment.

• Follow-up: This is where the treatment is completed. The patient visits the physician to monitor and to ensure no recurrence of the disease.

What Are the Treatment Options for Cancer?

1. Curative Treatment: This is done to destroy cancer cells.

2. Palliative Treatment: The treatment which relieves the symptoms and pain.

3. Surgical Treatment: During this stage, various procedures are done, such as:

• Preoperative Chemotherapy: In this process, a drug is given to shrink the tumor before surgery.

• Complete Resection: At this stage, all of the tumors are removed during surgery. This is followed by radiotherapy to kill the remaining tumor cells.

• Prosthesis: It is an artificial implant used in conditions like amputated limbs.

• Endoprosthesis: Prosthesis which fits inside the body. For example, the replacement of the thigh bone (femur).

4. Radiotherapy: This is again classified into many types:

• External Radiation: Done outside the body using radiation from a machine. For example, skin lymphoma and breast cancer.

• Internal Radiation: Radiation given to tumor cells within the body. For example, brachytherapy.

• Fractions: These are smaller doses of radiation to reduce the risk of side effects. This is normally done one fraction per day.

• Hyperfractionated Radiotherapy: The administration of more than one fraction in a given day.

• Radiotherapy Field: The area towards which the radiation is directed.

• Total Body Irradiation: The total radiation achieved over the whole body. For example, the destruction of all malignant cells before the bone marrow transplant (BMT).

5. Chemotherapy: In this, mostly combination chemotherapy is used.

Conclusion:

Funding for cancer research and drug development is proposed. Various in vitro/ in vivo studies are done outside the human body for clinical trials. An attempt is made to conduct genetic, cellular, and chromosomal studies economically viable for the early detection and eradication of cancer. Healthcare workers should perform public health programs for cancer detection and screening, including rural and urban populations.