At the International Meeting for Advanced Spine Techniques (IMAST; 16–19 September, Valencia, Spain), Kazuya Shinmura (Orthopaedic Surgery, Kanazawa University Medical School, Kanazawa, Japan) told delegates that implanting tumour tissue that has been treated with liquid nitrogen into the armpits of patients who have undergone posterior decompression and stabilisation for the management of metastatic spinal tumours is associated with enhanced anti-tumour immunity without tumour growth at the site of implantation.
Shinmura commented that posterior decompression and stabilisation for the management of spinal cord compression that occurs as the result of metastatic spinal tumours is associated with a significant increase in the ability to walk compared with radiotherapy alone (p=0.002). However he added that, after decompression and stabilisation, local recurrence is a “concern” in patients with prolonged survival and that the stress of surgery may supress anti-tumour immunity and “cancer progression may be promoted”.
“We developed a new technique of implanting a tumour frozen in liquid nitrogen after posterior decompression and stabilisation with the aim of enhancing anti-tumour immunity in order to prolong the survival period of the patient,” Shinmura commented. He explained that after a posterior decompression and stabilisation procedure, tumour tissue from the removed metastatic spinal tumour is immersed in liquid nitrogen (-196 degrees) for 20 minutes and subsequently implanted into the subcutaneous tissue of a patient’s armpit. The aim of the present study was to evaluate the anti-tumour immunity enhancing effect of the technique.
In the study, 19 patients underwent decompression and stabilisation for management of spinal cord compression due to metastatic spinal tumours. Of these, 15 underwent the new technique with the remaining four patients acting as controls. Shinmura said: “To evaluate the immunity-enhancing effect, plasma cytokines (interferon-y and interleukin-12) were analysed before surgery and one month after surgery. Interferon-y and interleukin-12, produced by the immune system, induce an anti-tumour effect.”
One month after surgery, interferon-y had not increased in any of the patients in the control group but had increased in 11 of the patients in the new technique group—in this group, the mean rate of increase was 279%. Also, 11 patients in the new technique group had an increase in interleukin-12 (an average increase of 493%) compared with four patients in the control group (an average increase of 18.5%). Tumour growth was not observed at the armpit in patients in the new technique group.
Shinmura concluded: “Implantation of a liquid nitrogen-treated tumour enhanced anti-tumour immunity after surgery.”