Cryotherapy, or cryosurgery, is a procedure that freezes and destroys cancer cells using extremely cold liquid nitrogen or argon gas.

Cryosurgery may be used to kill cancer cells on your skin or within your body.

• For skin tumors, cryosurgery involves spraying or swabbing the cancerous area directly with liquid nitrogen. After the procedure, the frozen tissue forms a blister and then a scab, which typically falls off within three weeks.
• For tumors inside the body, the procedure is more complicated. Internal tumors are treated with cryotherapy using small needle-like probes called cryoprobes that are hollow and contain freezing-cold liquid nitrogen or argon gas. Once the procedure is complete, the immune system works to remove the dead cells through a process known as efferocytosis. Special phagocytic cells, which are part of the immune system, track these dead cells within the body and bind to them before engulfing them and finally breaking them down.

What cryosurgery is used for

Cryosurgery may be a treatment option for several types of cancer or cancer-related conditions, including:

• Retinoblastoma, when the tumor is very small (cancer of the eye)
• Early-stage basal cell and squamous cell carcinomas (skin cancer)
• Certain precancerous conditions of the skin (actinic keratosis) or cervix (cervical intraepithelial neoplasia)
• Certain cancerous or noncancerous bone tumors

In some situations, it may be an option for early-stage prostate cancer or liver cancer. Researchers continue to study how this treatment may help patients with other cancers, too.

What to expect with cryosurgery

The cryotherapy procedure, and what it entails, depends on its purpose and the treatment area.

Before cryosurgery, you may receive some kind of pain medication. Possible options include:

• General anesthesia to put you into a deep sleep
• Spinal anesthesia to numb your body below the waist
• Sedative to induce drowsiness
• Numbing medicine

Prostate cancer patients receiving cryosurgery need to have a catheter (a soft tube) inserted into the bladder before the procedure. The catheter stays in place for about three weeks after the procedure to help empty the bladder while the area heals.

Skin cryotherapy

During a skin procedure, your dermatologist applies liquid nitrogen directly to the area using a cotton swab or a spray bottle. When the liquid nitrogen is applied to the skin, you may feel some pain, although your doctor may likely numb the area with a topical medicine beforehand. The entire procedure lasts a few minutes and is usually performed in a doctor’s office.

After the procedure, your care team may give you instructions on how to care for the treated area, such as how to clean and protect the wound. The treated area usually turns into a blister in the hours following the procedure. Over the course of a few weeks, the blister turns into a scab, which eventually falls off.

Internal cryotherapy

During a cryotherapy procedure inside the body, the doctor inserts one or more needle-like probes directly through the skin or through a small incision. An imaging device, such as an ultrasound, is used to help guide the probes to the location of the cancer. The extremely cold temperature of the probes freezes and destroys cells in the area. Your body’s immune system then works to naturally remove the dead cells. The procedure generally takes one to three hours.

Since cryosurgery is relatively noninvasive compared with many other treatments, it generally requires a short recovery time. In some cases, you may need to stay at the hospital overnight after having cryosurgery, but many patients leave the same day.

Benefits of cryosurgery

Compared with regular surgery, cryosurgery is less invasive and typically comes with lower risks of pain, bleeding and other surgical complications.

Another benefit of the treatment is that it may be targeted at the cancerous area, causing minimal damage to healthy tissue in the region surrounding the tumor. It may also be used more than once and as part of a larger treatment plan that includes standard options such as surgery, radiation, chemotherapy and hormone therapy.

Risks and possible side effects of cryosurgery for different cancers

Prostate cancer:

• Blood in urine
• Swelling of the penis or scrotum
• Pain or soreness in the bladder and rectum
• Frequent urge to urinate
• Frequent urge to have a bowel movement
• Erectile dysfunction
• Trouble urinating
• Damage to the rectum
• Problems passing urine or controlling the bladder

In very rare cases, men may develop an abnormal tube that forms between the bladder and rectum (fistula) that lets urine flow into the rectum.

Liver cancer:

• Bile duct damage
• Blood vessel damage (which may result in heavy bleeding or infection)

Cervical intraepithelial neoplasia (a precancerous condition in the cervix):

• Cramping
• Pain
• Bleeding

Skin cancer:

• Scarring
• Swelling
• Loss of sensation (if nerve damage occurs)
• Pigmentation or hair loss in the treatment area (rare)

Bone tumors:

• Damage to nearby bones and fractures

Retinoblastoma:

• Swelling of the eye/eyelid
• Blind spots or temporary detachment of the retina

Results of cryosurgery

The benefits of cryosurgery depend on the type of cancer and how far it’s spread. Cryotherapy may target and destroy specific tumors successfully, but it may also miss or leave behind some microscopic cancerous cells, providing an opportunity for the cancer to continue to spread.

The long-term efficacy of cryosurgery as a treatment for cancer is disputed. More research is needed on cryosurgery and its ability to improve outcomes for people with cancer.

As a treatment for prostate cancer, cryosurgery may only be used on early-stage tumors that haven’t spread outside of the prostate. It isn’t considered a first-line treatment for prostate cancer and tends to be used when other treatments, such as radiation, have failed or when patients cannot receive more standard treatments. For example, cryosurgery may be an option for men who are older or have other health problems that make regular surgery riskier.

Similarly, cryotherapy is only used to treat retinoblastoma when the tumors are small and at the front of the eye. It isn’t considered an appropriate treatment on larger or more widespread tumors.