Study Shows Cryosurgery Extends Options for Liver Tumor Treatment and Improves Survival Rates in Patients

Data from Medical College of Wisconsin researchers show that the use of cryosurgery to freeze and kill liver tumors, either alone or with traditional surgical techniques, can improve the survival rates in patients with cancer tumors that have spread from the colon or rectum to the liver.

Cryosurgery uses liquid nitrogen at -360 F to turn tumors into iceballs, killing the cancer cells. The tumors are eventually absorbed by the body. Traditional surgery, or resection, for the spread of colorectal tumors has long been considered the best option for patients with 4 or fewer tumors meeting specified criteria.

Now the use of an intraoperational ultrasound probe during surgery increases the chances of detecting previously undiscovered liver tumors. And cryosurgery allows the treatment of liver lesions in otherwise inaccessible areas, with less destruction of normal liver tissue in the case of multiple tumors. The new study shows that resection and/or cryosurgery can safely and successfully be used to treat more than 4 liver tumors at one time with improved long-term survival.

"This report," says Medical College researcher Edward J. Quebbeman, MD, PhD, Professor of Surgery, "suggests that the new standard of care for the number of treatable lesions should be raised from 4 to at least 8, thus allowing more patients the opportunity for long-term, disease-free survival."

Medical College researcher James R. Wallace, MD, PhD, Assistant Professor of Surgery (Trauma & Critical Care), reported the study in the Journal Surgery. He was assisted by Medical College faculty Kathleen K. Christians, MD, Instructor of Surgery, (Trauma & Critical Care); Henry A. Pitt, MD, Chairman and Ausman Foundation Professor of Surgery; and Dr. Quebbeman.

From 1993 to 1999, 137 patients with liver metastases from colorectal cancer were examined. Treatment consisted of resection alone in 34, cryotherapy alone in 20, both treatments in 52. No treatment was possible in 31 patients. Survival rates were determined by the destruction of all identifiable tumors and were not statistically influenced by age, gender, type of therapy, or the number of tumors treated. In fact, study participants who had between 5 and 8 tumors had a long-term survival rate better than those with 1 to 4 tumors.

By the Numbers

Approximately 92 % of the patients in the study were white, 63.5 % were male, and the average age was 65.2 years (ranging from 36 to 85 years). Seventy-one percent of the patients received chemotherapy before beginning the study.

In 45 % of patients, the preoperative CT scan underestimated the number of liver tumors; additional tumors were found with the intraoperative ultrasound.

At the conclusion of surgery, 77 % were believed to be "cured" of their metastatic disease -- meaning that all tumors that could be uncovered were removed or destroyed. The average hospital stay for patients was 7.3 days.

The average diameter of tumors treated with cryosurgery was 3.4 cm; the largest was 5 cm. The average size of the tumors was larger in those treated with resection only: 6.5 cm, with the largest being 21 cm.

In those patients where a curative procedure was achieved, 86 % survived to 1 year and 29 % to 3 years, compared to 36 % and 5 % where a curative procedure could not be achieved. Of those patients with a curative procedure and fewer than 5 tumors, 31 % survived to 3 years; of those with a curative procedure and 5 to 8 tumors, 41 % survived to 3 years. Nationally, the 3-year survival rate without surgery is about 2%.

Thirty-five percent of the resection-only patients and 37 % of cryosurgery-only patients survived to 3 years, compared to 24 % of patients who had both procedures performed. Sixty percent of patients aged 30 to 59 years survived to 3 years compared to 37 % of those aged 60 to 89 years.

"Up to 80 % of patients are not considered candidates for traditional surgical resection under the current standard of care," Dr. Quebbeman says. "Our research shows that more patients with metastatic colorectal cancer can be safely and effectively treated with surgical therapy, including cryosurgery, thereby extending the long-term survival rates of patients with this disease."

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.