Cancer: Causes, Symptoms, Types & Tests

Cancer refers to an abnormal growth, including the spread of cells that develop and invade the body's tissues. It affects nearly any part of the body and comes in all sorts of types, with each one having its own set of symptoms, risk factors, and treatments. Early detection and investigation by a physician greatly improve treatment of cancer. 

Many symptoms that are associated with cancer, however, are also caused by infections, benign conditions, or other health issues. These symptoms, if they do not get better or go away, should be reviewed by your health care provider, not treated as cancer. Advanced diagnostic services offered in Molecular Diagnostics and Therapy assist in the evaluation and management of cancer when clinical needs dictate and are recommended by patients' care providers.

What Is Cancer?

Cancer is the result when genes within the cells begin to change in such a way that the cells begin to grow and multiply out of control. In normal cells, growth, division, and death take place in an orderly manner. If genetic alterations affect these processes, abnormal cells continue to multiply, rather than dying off. There are some cancers in which the cancer forms in the solid tissues of the body, and some cancers, such as leukemia, more often form in the tissues that make blood. 

Infiltrating the cells into surrounding tissue and, in some, cancer cells invade the blood or lymph system and travel to other parts of the body. If these spreads happen, it's called metastasis. There are over 100 varieties of cancers. Usually, these are more specific and are referred to by the organ or the tissue in which they grow, such as breast cancer, lung cancer, liver cancer, and prostate cancer.

What Causes Cancer?

There's no single cause of cancer. It occurs when harmful changes in the genes that control cell growth, division, repair, or death happen. This happens due to natural mistakes that happen in cell division, cancer-causing substances in the body, the environment, and inherent genes. Some factors raise the possibility of getting some cancers. These are age, smoking, tobacco, drinking, obesity, some infections, radiation, sunlight, some chemicals, long-term inflammation, and a family history of certain cancers. A risk factor increases the risk of cancer, but not everyone who has it actually gets the disease. Likewise, some individuals have no known risk factors for cancer.

Common Cancer Symptoms

Cancer's symptoms vary if the cancer is located in different places. Some cancers produce a prominent symptom, while others don't do anything in the early stages. Some symptoms include: a lump or swelling that does not make sense, cough or hoarse Voice, no apparent cause for unwanted weight loss, bleeding or unusual wounds, persistent or worsening symptoms of pain, needing to urinate more often or having an urge to urinate, difficulty swallowing or chewing, unexplained changes in a mole or in the skin, or frequently having fevers.

Some of the most common breast changes include changes in the nipple, skin changes, or a new lump. Other cancers result in blood in the urine, persistent digestive symptoms, or a change in the digestive process. The symptoms are not necessarily indicative of cancer. A lot of them are attributed to non-cancerous factors. Any symptoms that last for several weeks or get worse should be discussed with a doctor.

Types of Cancer

Cancer can be classified in several ways depending on where it begins and the type of cells involved.

Carcinoma

Carcinomas grow in epithelial cells that line the inside of many organs and form the lining of surfaces all over the body. Carcinomas may also occur in the breast, lung, colon/rectum, prostate, and numerous other types of cancer.

Sarcoma

Sarcomas occur in connective or supportive tissues, including bone, cartilage, fat, muscle, blood vessels, and other soft tissues.

Leukemia

Leukemia is also a cancer of blood-forming tissues, such as the bone marrow. Disrupts the formation and activity of blood cells.

Lymphoma

A cancer that starts in lymphocytes, a component of the immune system. The two main types of the disease are Hodgkin's and non-Hodgkin's.

Multiple Myeloma

Multiple myeloma arises from plasma cells, a group of cells within the bone marrow that are part of the immune system. Abnormal plasma cells multiply and interfere with normal blood-cell production and bone health.

How Is Cancer Diagnosed?

Not all cancers are diagnosed with a single test. A doctor typically begins by taking a medical history and conducting a physical exam, and recommends further lab work, imaging studies, or other tests if warranted based on the symptoms and suspected condition. A biopsy is sometimes necessary to verify the cancer. A biopsy is a procedure in which the doctor takes an abnormal tissue sample and sends it to a pathologist to be examined under a microscope. Further lab tests are also done on the tissue to see if it contains any particular kind or property of the cancer.

Common Cancer Tests

Blood Tests

Blood tests give information regarding the work of organs like the liver and kidneys, and the number of blood cells. Some blood tests also detect levels of tumor markers or other substances that give some extra information. But raised blood test results do not necessarily indicate a person has cancer, and normal levels do not automatically exclude cancer. Usually blood tests are performed in conjunction with other tests.

Imaging Tests

Imaging tests enable physicians to see inside the body for signs of abnormalities or tumors, or the presence of cancer occurring outside the primary tumor's location. Some of the imaging tests that are used depend on the suspected cancer; they involve ultrasound, X-ray, computed tomography (CT) scan, magnetic resonance imaging (MRI) scan, nuclear medicine imaging, bone scan, or PET scan.

CT Scan

A CT scan uses an X-ray computer that creates detailed cross-sectional images of the body. It is used to detect cancer and to assess nearby tissue and whether it has spread to other parts of the body.

MRI Scan

MRI is a technique that uses magnets and radio waves to produce detailed images of soft tissues. It is beneficial for examining spaces like the brain, spine, pelvis, and breast, as well as soft tissues.

PET Scan and PET-CT

PET is an imaging procedure that gives information regarding the function of tissues. Before the image is taken, a radiotracer is injected into the body, and regions that take up the tracer show up on the image. PET/CT is a combination of the two modalities: structural information from CT and functional information from PET. PET-CT is used to detect cancer, determine the size of the cancer, monitor the response to therapy, or assess for the presence of cancer recurrence depending on the type of cancer.

Biopsy

Biopsy is the removal of tissue or cells from an area that has an abnormal appearance. The sample is sent to the pathologist, who looks at it to see if there is cancer and, if so, the type and characteristics of the cancer. In most cases, biopsy is the final diagnosis for cancer.

Conclusion

Cancer is an umbrella term for a group of diseases that develop in any part of the body. It happens because of abnormal growth and multiplication of abnormal cells due to genetic changes. Risk factors are age, tobacco, certain infections, radiation, environmental exposures, inherited genetic changes, and more. The signs and symptoms of cancer are different in each person and also occur in people who don't have cancer. When there are persistent or unexplained symptoms, it is important to seek medical evaluation, not just brush off the details.

Generally, the diagnosis of cancer requires a combination of several tests: medical history, physical exam, lab tests, imaging tests, and, if necessary, biopsy. Imaging tests like computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET-CT) give valuable information about any abnormalities, and sometimes, a biopsy is needed to confirm the diagnosis and assess the disease's extent. Patients and healthcare providers benefit from Molecular Diagnosticsand Therapy’s advanced diagnostics that help them get the right diagnosis and the right treatment at the right time.