Cancer diagnosis often causes tears and sadness in the heart of the patient and sometimes family. Nobody wants to hear this sentence from his doctor: “I’m sorry, you have cancer”. But it happens sometimes. Tears and sadness will not help. In fact, they will do more harm than good. Important is to face the disease and successfully fight it back.
The diagnosis can occur by hazard during a medical exam for another health issue or due to warning signs that you experience and search for medical care. Whether you experience typical cancer symptoms suggestive to the disease or learn you may have it following screening tests, different tests should be performed to confirm or rule out the presence of a malignant tumor in your body. Cancer diagnosis statistics are on the rise on most parts of the world; the chance for someone to have is not so low.
According to latest cancer diagnosis statistics by the American Cancer Society (ACS), it is estimated that the numbers of new cancer cases diagnosed and deaths in the USA in 2014 were about 1,665,540 and 585,720 successively. These figures make cancer the second most common cause of death in the US, accounting for nearly 1 of every 4 deaths.
Diagnostic procedures are not only important to confirm you have cancer but also to determine the nature of the tumor, as well as its degree of evolution in the primary site and possible presence of distant metastases. All these elements are essential to the establishment of an appropriate treatment. For more information, please see cancer diagnosis and treatment.
Any cancer diagnosis begins with a careful clinical exam, usually followed by prescription of a blood test, medical imaging exams, and biopsy. Blood exams prescribed as part of a cancer diagnosis may include complete blood count (CBC), blood protein testing, circulating tumor cell tests, and most importantly tumor marker tests.
What Is A Tumor Marker?
Also called serum markers or biomarkers, tumor markers are molecules produced in excess by certain cancer cells. For instance, the most common tumor markers for colorectal cancer diagnosis are carcinoembryonic antigen (CEA) and CA 19-9; in case of ovarian and breast cancer diagnosis, common biomarkers are human epidermal growth factor receptor 2 (HER2), cancer antigen 15-3 (CA 15-3), cancer antigen 27.29 (CA 27.29); carcinoembryonic antigen (CEA); PSA (Prostate Specific Antigen) for prostate cancer diagnosis; AFP (alpha-fetoprotein) for liver cancer; CA 125 for ovarian or endometrial cancer diagnosis.
When these tumor markers are synthesized by healthy cells they are usually in small quantities. Thus, when their concentration rises in your blood or urine, this may correspond to the development, recurrence, or metastasis of a tumor. However, increasing the concentration of a tumor marker is not sufficient to confirm a diagnosis: other pathologies, benign or malignant, can lead to the same effect. Similarly, normal finding tumor markers in your blood or urine is not reliable criteria to exclude diagnosis of cancer.
What Medical Imaging Exams Used In Cancer Diagnosis?
Medical imaging is now the leading cancer diagnostic tool. It allows a health professional to obtain images, more or less accurate, depending on the technique used, of internal organs and thus visualize the presence of any tumor. These images provide information on the location, size and evolutionary stage of the cancer. In addition to their diagnostic value, they are necessary to establish a therapeutic strategy to successfully fight the disease. Medical imaging techniques include many procedures, among them include:
Ultrasound (Ultrasound scanning or Sonography) – this diagnostic medical sonography involves the use of high-frequency sound waves. It allows to examining most of the abdominal organs: liver, pancreas, gall bladder, kidneys, ovaries, uterus, and others. To get better images, it is sometimes necessary to introduce the ultrasound probe into a body cavity (vagina, rectum or esophagus) in order to bring the small transducer closer to the organ to be examined.
Radiography – this imaging technique is used primarily to examine the thorax, abdomen and breasts (mammogram). It is based on the use of electromagnetic radiation or X-rays to view internal organs of the body. In some cases, the examination is performed after injection of a “contrast agent”, in order to obtain accurate images of the organ to be examined.
CAT scan (or just CT) – this is a procedure which also require the uses of X-rays to view the internal structure of the body. However, it allows the production of much finer pictures than radiography. With this technique, a specialist cannot obtain a single plane image but a series of images corresponding to the same sections of the examined organ. Thanks to CAT scan, it is possible to reconstitute an image in three relatively accurate dimensions of the organ and anomalies entailed. Injection of a contrast medium (contrast agent) precedes the exam to allow better image.
MRI (Magnetic Resonance Imaging) – MRI is a more sophisticated diagnostic procedure often recommended in cancer diagnosis. It requires the use magnetic field and radio waves to examine organs that are soft and rich in water like the brain. It is based on the use of magnetic fields that act on hydrogen molecules present in the tissue. It leads to obtaining very precise three-dimensional images of the organ.
PET scan (or Positron Emission Tomography Scan) – this is a dynamic imaging technique which allows a healthcare professional or a nuclear medicine scientist to visualize the functioning of organs. Its principle involves the use of a scanner (camera) and injection of a radioactive molecule (radiopharmaceutical) that will “mark” the fast-growing cells of the body, mainly the cancer cells. The malignant tissues usually appear ‘brighter’ than healthy tissues on the images. PET scans are mainly used in the assessment and diagnostic of cancers, neurological (brain) diseases and cardiovascular disease.
Scintigraphy – this is another diagnostic method used to visualize the activity of cells of some organs: heart, thyroid, lungs, bones… During the procedure, the specialist injects a radioactive substance that will broadcast to the diseased organ to be examined. This tracer is then detected using a scintillation camera (gamma camera) that can reconstruct a two-dimensional image of the organ.
What Is Endoscopy and How It Is Used in Cancer Diagnosis?
Endoscopy is a medical (also industrial) imaging method used to explore and visualize the inside or interior of conduit or body cavities inaccessible to the eye. The procedure usually involves an endoscope which comprises an optical tube equipped with a lighting system. Coupled to a miniaturized video camera, the system can thus transmit the image taken onto a screen. During the endoscopic procedure, the specialist can also take samples for analysis (biopsy).
Endoscopy may be used whether for diagnosis or for treating a disease (endoscopic surgery). Endoscopy is a generic term that can have different names depending on the organ being treated or examined. For instance, bronchoscopy means exploration of bronchi; colonoscopy, visualizing the inside of the colon; cystoscopy, examination of the bladder; gastroscopy, examination of the inside of the esophagus or stomach, etc.
What Is Biopsy and How It Is Used in Cancer Diagnosis?
Biopsy consists of taking a tissue sample suspected to be cancerous for analysis under microscope. This examination is almost always necessary for diagnosis of cancer. This is the most accurate way to determine if a tumor is benign or malignant and, where applicable, to determine the type of cancer with which the patient is diagnosed. This information is essential to choose the most appropriate therapeutic strategy or consider a treatment option.
Treatment of cancer varies depending on the severity of the tumor, the variety of cancer cells and its extent in the body. Cancers can have very different characteristics depending on their level of involvement, whether or not the tumor affects some nearby or remote tissues. Since all malignant tumors treatments are not the same, it is essential to know precisely what condition it is. Please see cancer treatment options for more information.