CANCER

 

INTRODUCTION: Cancer is a disease process that begins when an abnormal cell is transformed by the genetic mutation of the cellular DNA. The abnormal cell forms a clone and begins to proliferate abnormally, ignoring growth-regulating signals in the environment surrounding the cell. The cells acquire invasive characteristics, and changes occur in surrounding tissues. The cells infiltrate these tissues and gain access to lymph and blood vessels, which carry the cells to other areas of the body. This phenomenon is called metastasis. In otherwards the cancer spread to other parts of the body.

DESCRIPTION OF CANCER: Cancerous cells are described as malignant neoplasms and are classified and named by tissue of origin. The failure of the immune system to promptly destroy abnormal cells permits these cells to grow too large to be managed by normal immune mechanisms. Certain categories of agents or factors implicated in carcinogenesis include viruses and bacteria, physical agents, chemical agents, genetic or familial factors, dietary factors, and hormonal agents.

CLINICAL MANIFESTATIONS: Cancerous cells spread from one organ or body part to another by invasion and metastasis; therefore, manifestations are related to the system affected and degree of disruption. Generally, cancer causes anemia, weakness, weight loss, and pain which is often in late stages. Symptoms are from tissue destruction and replacement with nonfunctional cancer tissue or overproductive cancer tissue such as, bone marrow disruption and anemia or excess adrenal steroid production; pressure on surrounding structures; increased metabolic demands; and disruption of production of blood cells.

ASSESSMENT AND DIAGNOSTIC METHODS: Screening to detect early cancer usually focuses on cancers with the highest incidence or those that have improved survival rates if diagnosed early. Examples of these cancers include breast, colorectal, cervical, endometrial, testicular, skin, and oropharyngeal cancers. Patients with suspected cancer undergo extensive testing to;

1) Determine the presence and extent of tumor.

2) Identify possible spread (metastasis) of disease or invasion of other body tissues.

3) Evaluate the function of involved and uninvolved body systems and organs.

4) Obtain tissue and cells for analysis, including evaluation of tumor stage and grade.

Diagnostic tests may include tumor marker identification, genetic profiling, imaging studies (mammography, magnetic resonance imaging [MRI], computed tomography [CT], fluoroscopy, ultrasonography, endoscopy, nuclear medicine imaging, positron emission tomography [PET], PET fusion, radioimmunoconjugates), and biopsy.

RELATED;

1.  THE ORIGIN OF CANCER

2.  PATHOLOGY

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