Diagnosis of Cancer

The earlier cancer is diagnosed; the better is the prognosis of the condition

Diagnosing a tumor or cancer is a rather complicated procedure and involves highly accurate analysis of signs and symptoms by a medical practitioner. Observations based on physical examination and different test results from diagnostic tests performed on the patient[1] help confirm  the diagnosis. There are a number of cancers that are very difficult to diagnose owing to the similarity of their symptoms with various other medical conditions. There are a number of diagnostic tests used for confirming the presence of  cancer. The main types of tests used for making cancer diagnosis are as follows:

1) Biopsy techniques:

Biopsies are used for the retrieval of cells that are suspect for mutation so that they can be studied via microscopes. The study of examining and analyzing natural tissues with the help of a microscope is known as histopathology, or simply histology. The type of biopsy used on a particular patient is determined by the location of the cancer or tumor in the body, or the region from which the cells or the tissue will be retrieved for microscopic examination. Some of the most common methods of obtaining tissue include surgery, endoscopy or with the help of a needle.

2) Imaging examinations:

Imaging examinations are used for the detection of major or minor changes in the normal physiology and anatomy of a tissue, and for revealing masses that may be cancerous in nature inducing change or damage in the healthy tissues. Masses can either be malignant or benign. Some of the most common types of imaging techniques and tests include computerized tomography (CT scan), ultrasound imaging, magnetic resonance imaging (MRI), mammography, and positron emission tomography (PET).

3)  Blood tests:

Blood tests are used for the detection of substances that are produced by mutated cancer cells, these products are known as tumor markers. Blood tests can also indicate whether or not a particular organ is functioning optimally and normally. The development and progression of cancer can result from one of these abnormalities and malfunctions. Leukemia is the only form of cancer that can be diagnosed with the help of blood count results. Abnormal findings in blood tests in case of cancer can simply indicate the presence of a suspicious lesion in the body. It is for this reason that blood tests are generally done after or during a treatment, once the definite diagnosis has been established. The definitive diagnosis for cancer can only be established based on histological examination which can confirm whether the tissue is composed of mutated cancerous cells or not. It is important to note that blood tests and imaging techniques should not be used to form a definitive diagnosis for cancer, except in case of patients who are not fit to undergo a biopsy procedure.

Tumor Grade

Tumor grading is a specialized system that is used for the classification of cancerous cells based on: the abnormality of their appearance as observed under a microscope, and how rapidly they can spread and grow in the body. There are cancer cells which bear close resemblance to normal healthy cells of the body. They are known as low grade, or well differentiated cells. Cancerous cells which do not even remotely resemble the healthy cells from which they initially originated are known as high grade, poorly undifferentiated, or undifferentiated cells. All high grade cancer cells have the ability and potential to spread and grow more rapidly than low grade tumors. There are different grading systems designated for different types of cancers. Cancers that are malignant have the ability to spread to different parts of the body.

Cancer Treatment

The type of treatment that the patient should receive is dependent upon the stage and specific pathology of the cancer or the tumor that the patient has. Some other factors that play a vital role in the determination of treatment include age, general health of the patient, logistical consideration, socio-economic and family status, and other personal preferences. There are four basic modalities for treating cancer. These include chemotherapy, radiation therapies, surgery and biological therapies.

During some stage of cancer, almost 90% of all patients do undergo some form of surgical or invasive procedure. By far the most promising treatment for cancer is the removal of the cancerous tissue, which holds great potentials for complete cure. There are a number of surgeries that are only performed for the purpose of establishing a definitive diagnosis. The addition of more treatment modalities can enhance the chances of improving disease control, and pave the way for better survival. The combination of biological therapies, chemotherapy and radiation therapy is known as adjuvant therapy. Non-adjuvant therapy is one which is given to the patient prior to surgery for the purpose of shrinking the cancerous lesion in order to reduce the extent of the surgical procedure. It is much easier to treat a benign lesion or growth, commonly known as a “tumor” with the help of a surgical procedure if it is located in a part of the body that is accessible surgically.

Additional Resources:

Dollinger, Malia, et al. 2002. Everyone’s Guide to Cancer Therapy: How Cancer Is Diagnosed, Treated, and Managed Day to Day. 4th ed. Kansas City, MO: Andrews & McMeel.

This is a thick volume of over 800 pages covering diagnosis, treatment, supportive care, quality-of-life issues, and cancer advances. Overviews of 51 specific cancer types also are included. The text provides explanations of the theories behind cancer research and treatment, as well as practical information written in easy-to-understand language with instructive illustrations. The authors address issues such as getting second opinions and cancer information seeking on the Internet. The editors are well known cancer researchers and clinicians assisted by a 140-member board of medical advisers and contributing authors who are top specialists in all fields of cancer research and treatment.

Eyre, Harmon J., et al. 2002. Informed Decisions: The Complete Book of Cancer Diagnosis, Treatment, and Recovery. 2nd ed. Atlanta: American Cancer Society

Coleman, C. Norman. 2006. Understanding Cancer: A Patient’s Guide to Diagnosis, Prognosis, and Treatment. 2nd ed. Baltimore: Johns Hopkins University Press.

A professor of radiation oncology from Harvard Medical School guides patients through the decision-making process right after diagnosis and through the illness. Describing and explaining the various diagnostic tests and treatment options available, the book’s purpose is to help patients evaluate risks and benefits and make decisions together with their doctors. Checklists and case studies help to illustrate how cancer patients can play an active role in determining their own treatment plan.


[1] www.cancer.gov/cancertopics/factsheet/detection

This article was originally published on 7/12/2014 and last revision and update of it was 9/14/2015.