Cancer And Its Symptoms

Cancer is a class of diseases characterized by uncontrolled cell division and the ability of these cells to invade other tissues, either by direct growth into adjacent tissue or by migration of cells to distant sites . This unregulated growth is caused by damage to DNA, resulting in mutations to vital genes that control cell division, among other functions. One or more of these mutations, which can be inherited or acquired, can lead to uncontrolled cell division and tumor formation. Tumor refers to any abnormal mass of tissue, but may be either malignant or benign noncancerou. Only malignant tumors are capable of invading other tissues or metastasizing.

Cancer can cause many different symptoms, depending on the site and character of the malignancy and whether there is metastasis. A definitive diagnosis usually requires the microscopic examination of tissue obtained by biopsy. Once diagnosed, cancer is usually treated with surgery, chemotherapy and/or radiation.If untreated, most cancers eventually cause death; one of the leading causes of death in developed countries. Most cancers can be treated and many cured, especially if treatment begins early. Many forms of cancer are associated with environmental factors, which may be avoidable. Smoking tobacco leads to more cancers than any other environmental factor.

Signs and symptoms
Roughly, cancer symptoms can be divided into three groups:Local symptoms: unusual lumps or swelling tumo, hemorrhage bleeding, pain and/or ulceration. Compression of surrounding tissues may cause symptoms such as jaundice.
Symptoms of metastasis enlarged lymph nodes, cugh and hemoptysis, hepatomegaly enlarged liver bone pain, fracture of affected bones and neurological syptoms. Although advanced cancer may cause pin, it is usually not the first symptom.
Systemic symptoms: weight loss, poor appetite and cachexia , excessive sweating , anemia and specific paraneoplastic phenomena, i.e. specific conditions that are due to an active cancer, such as thrombosis or hormonal changes.
Every single item in the above list can be caused by a variety of conditions a list of which is referred to as the differential diagnosis Cancer may be a common or uncommon cause of each it

Biopsy
A cancer may be suspected for a variety of reasons, but the definitive diagnosis of most malignancies must be confirmed by microscopic examination of the cancerous cells by a pathologist. The procedure of obtaining cells and/or pieces of tissue, and their examination, is referred to as a biopsy. The tissue diagnosis indicates the type of cethat is proliferating, its , and its extent and size. Cytogenetic and immunohistochemistry tests may provide information about future behavior of the cancer and best treatment.All cancers can be cured if entirely removed, and sometimes this can be accomplished by the biopsy procedure. When the whole mass of abnormal tissue is removed, the borders of the sample are examined closely to see if all malignant tissue has tuly been excised. If the cancerhas spread to other sites in the body metastasis, complete surgical excision is impossible.The nature of the biopsy depends on the organ that is sampled. Many biopsies can happen on an outpatient basis. Biopsies of other organs are performed under anesthesia and require surgery.

Screening
Cancer screening is a test to detect unsuspected cancers in the population. Sceening tests suitable for large numbers of healthy people must be relatively affordable, safe, noninvasive procedures with acceptably low rates of false positive results. If signs of cancer are detected, more definitive and invasive followup tests are peformed to confirm the diagnosis.Screening for cancer can lead to earlier diagnosis. Early diagnosis may lead to extended life. A number of diferent screening tests have been developed.Breast cancer screeningcan be done by breast self-examination. Screening by regular mammograms detects tumors even earlier than self-examination, and many countries use it to systematically screen all middle-aged women. Colorectal cancer can be detected throuh fecal occult blood testing and colonscopy, which reduces both colon cancer incidence and mortalit, presumably through the detection and removal of premalignant polyps. Similarly, cervical cytology testing leads to the identification and excision of precancerous lesions. Over time, such testing has been followed by a dramatic reduction of cervical cancer incidence and mortality. Testicular self-examination is recommended for men beginning at the age of 15 years to detect teticular cancer. Prostatcancer can be screened for by a digital rectal exam along withprostate specific antigen blood testing

Screening for cancer is controversial in cases when it is not yet known if the test actually saves lives. The controversy arises when it is not clear if the benefits of screening outweigh the risks of follow-up diagnostic tests and cancer treatments. For example: when screening for prostate cancer, the PSA test may detect small cancers that would never become life threatening, but once detected will lead to treatment. This situation, called overdiagnosis, puts men at risk for complications from unnecessary treatment such as surgery or radiation. Followup procedures used to diagnose prostate cancer prostate biopsy may cause side effects, includinr intercourse. Similarly, for breast cancer, there have recently been criticisms that breast screening programs in some countries cause more problems than they solve. This is because screening of women in the general population will result in a large number of women with false positive results which require extensive follow-up investigations to exclude cancer, leading to having a high number-to-treat or number-to-screen to prevent or catch a single case of breast cancer early.

Cervical cancer screening via the Pap smear has the best cost-benefit profile of all the forms of cancer screening from a public health perspective as, as a cancer, it has clear risk factors (sexual contact), the natural progression of cervical cancer is that it normally spreads slowly over a number of years therefore giving more time for the screening program to catch it early and the test itself is easy to perform and relatively cheap.For these reasons, it is important that the benefits and risks of diagnostic procedures and treatment be taken into account when considering whether to undertake cancer screening.

Use of medical imaging to search for cancer in people without clear symptoms is similarly marred with problems. There is a significant risk of detection of what has been recently called an incidentaloma - a benign lesion that may be interpreted as a malignancy and be subjected to potentially dangerous investigations.