Traditionally, biopsies involve the removal of tissue in order to examine it for disease. Samples of tissue can be obtained from any part of the body and may involve using a needle placed through the skin (percutaneous needle biopsy) or by using ultrasound, x-ray, CT, or MRI imaging guidance. In addition, the biopsy can also involve surgically removing an entire lump or nodule for examination.
For cancer patients, the tissue biopsy is a standard procedure used to pinpoint a cancer’s mutations and degree of malignancy. The biopsy of the tissue is important for obtaining valuable information on the unique attributes of a patient’s cancer.
Advantages of the tissue biopsy:
Currently, the primary advantage of tissue biopsy is that it remains the gold standard for the confirmation, diagnosis, and determination of the characteristics of various diseases, including cancers. Most pathologists rely on performing a tissue biopsy to diagnose a disease and they are trained specifically to perform various cytological tests on the submitted tissue specimen.
Limitations of the tissue biopsy:
- Might involve more invasive procedures - Tissue biopsies may not always be easily obtained and often may involve the use of more invasive procedures. Some cancers may be hidden deep inside the body or may be in critical organs providing a physical challenge, as well as possible danger to the patient.
- Samples may be insufficient and need repeating - In some cases, the amount of tissue obtained from a needle biopsy may not be sufficient and the biopsy may have to be repeated.
- Can be labor intensive and time-consuming - Doing a standard tissue biopsy would probably only take a few days if the diagnosis is fairly straight forward, but processing for cancer treatment could take longer because of the need to characterize the cancer cells, responses to treatment, etc. Tissue sampling and reporting may be a labor-intensive process and may take valuable time. The median time of processing a biopsy sample is approximately 27 days for those who have received treatment and 12 days for those who are newly diagnosed*. In addition, other specialized tests may need to be performed on the tissue sample to render a pathology report.
- May not reflect the characteristics of the entire tumor - A tissue sample may not be indicative of the entire tumor landscape so that mutations may not be present throughout the entire tumor. Because of intratumor heterogeneity, the biopsy result from the sampling may lead to an underestimation of the tumor genomics.
- Can be a costly procedure - Tissue biopsies can be expensive and may cause additional health complications for the patient undergoing treatment. Cost does vary depending on the location of the tumor; however, typically the cost can be in the thousands of dollars*. Cost is high due to various tissue preparation costs, test costs, pathologist interpretation fees, other specialty tests.