21 February 2022, Monday

Importance of Bone Cancer Biopsy

Biopsy is a minor surgical procedure in which a small piece of the tumor tissue is sampled and sent for evaluation to a pathologist, who examines it under a microscope to establish its exact histological identity/name (diagnosis).

An improperly done biopsy can affect the future treatment of the disease, especially if it turns out to be a sarcoma. Leaving behind the biopsy scar and track, at the time of definitive surgery for the removal of a sarcoma, increases the risk of local recurrence of the disease significantly.

It is therefore, very important that the biopsy is conducted in a well-planned and careful manner, ensuring the least possible contamination of the normal tissues forming the biopsy track, with the tumor tissue/cells.

It is also equally important that the biopsy site is placed in an ideal location, which would allow the scar and track of the biopsy to be easily included for excision, along with the tumor, during the definitive surgery. Biopsy is therefore, best done by a surgeon who is experienced in bone tumor treatment.

Biopsy is a minor surgical procedure in which a small piece of the tumor tissue is sampled and sent to the laboratory for evaluation by a pathologist. The pathologist, after processing the tissue sample, examines thin slices of it under a microscope to identify whether it is cancerous tissue and if so, what type of cancer it is, i.e. its exact histological identity/name (diagnosis).

The pathologist can find out whether it is primary bone cancer or secondary bone cancer. In cases of primary malignant tumor of bone (sarcoma), the pathologist, other than identifying the exact type of sarcoma, can also opine on the grade of the tumor (whenever relevant), which is of value in ‘staging’ the disease.

In case of secondary bone cancer, the pathologist can often identify the source of the cancer (i.e. in which distant organ, the cancer originated from), which helps in localizing the primary source cancer, and thus in initiating effective treatment.

An improperly done biopsy can affect the future treatment of the disease, especially if it turns out to be a primary malignant bone tumor. It is a rule in musculoskeletal tumor surgery to remove the scar of biopsy along with the biopsy track (with a margin of surrounding normal tissue) en masse with the tumor, during the definitive surgery for a sarcoma, as it is considered to be a contaminated zone (an area which has come in contact with tumor tissue and therefore, could now be seeded with tumor cells).

It is well documented that, leaving behind the biopsy scar and track, at the time of the definitive surgery for the removal of a sarcoma, increases the risk of local recurrence of the disease significantly.

This makes it essential that the biopsy is conducted in a well-planned and careful manner, ensuring the least possible contamination of the normal tissues forming the biopsy track (tissues through which the biopsy track cuts through) with the tumor tissue/cells.

It is vital that the biopsy incision is placed in an ideal location, which would allow the biopsy scar and track to be easily included for removal, along with the tumor, during the definitive surgery.

An MRI is very helpful in planning the optimal location and approach of the biopsy. An incorrect biopsy location/approach, or an improperly done biopsy, may force the surgeon to remove important tissues (which could otherwise have been saved) along with the tumor, just to include the biopsy scar and track in the resection (to achieve en bloc excision with a wide margin).

This could either result in a loss of useful function, or may necessitate complex reconstruction procedures, involving plastic surgeons, vascular surgeons, etc., to attempt to restore useful function and/or save the limb.

It is well documented that, in some unfortunate situations, a poorly done biopsy procedure may leave no treatment option except amputation, in an otherwise perfectly salvageable extremity. Biopsy is therefore, best done by a surgeon with experience in bone tumor treatment.

Several biopsy techniques are available, including fine needle aspiration biopsy, core needle biopsy, incisional biopsy, excisional biopsy, etc. Biopsy for bone tumors is generally done as a small open surgery (Open Biopsy), or with the help of special biopsy needles (Core Needle Biopsy).

Between the two, Core Needle Biopsy is generally the preferred method for doing a biopsy as it is a simple, reliable, minimally invasive, safe and quick procedure. The correct method for your situation is best decided by your doctor.

Further Reads:

1. Core Needle Biopsy (CNB) and Open Biopsy (OB): Which is better and why?