Non-Pharmacological Treatments for Cancer Pain: Minimally Invasive Procedures

Cancer pain severely impairs patients' quality of life. Some patients cannot achieve relief with medication alone, but pain can be controlled through minimally invasive procedures. Minimally invasive pain relief is a relatively new approach that has emerged in recent years; it is effective to some degree for neuropathic pain caused by tumor compression of nerves and for visceral pain caused by tumor compression of organs, with relatively few side effects.

It is especially suitable for patients who cannot tolerate the side effects of medication. In pancreatic cancer, for example, the celiac plexus is often compressed, causing severe pain, restricted posture, and a very poor quality of life. When such patients take common analgesics, they may experience nausea, vomiting, constipation, and a host of other side effects—so that the treatment itself adds new suffering—and the relief is short-lived. For these patients, celiac plexus neurolysis is worth considering.

Celiac plexus neurolysis is performed under CT guidance: a fine needle is inserted into the celiac plexus and a neurolytic agent is injected to block the pain caused by tumor compression of the nerves. Relief usually lasts about four months, and if the patient is still alive at that point, the procedure can be repeated with good effect.

Patients with bone metastases whose skeletal tissue has been invaded by tumor cells have unstable bones and are prone to nerve compromise and fracture; for them, percutaneous vertebroplasty is an option. It is a minimally invasive procedure that strengthens a vertebral body by injecting bone cement (polymethylmethacrylate) or artificial bone into the affected vertebra. Vertebroplasty alone usually provides about half a year of pain relief, but combined with other treatments the results are better.

For patients with a relatively favorable prognosis, such as those with breast cancer bone metastases, injecting bone cement improves quality of life and helps them tolerate other treatments. Such surgery often both improves quality of life and substantially prolongs survival.

Besides the above, another common method is patient-controlled analgesia (PCA) via intravenous or subcutaneous routes. A PCA pump loaded with an analgesic such as morphine is implanted, connected by catheter to the subcutaneous or venous system; when the patient feels pain, pressing the control delivers a set dose. This is mainly used for unstable pain, but because the procedure is technically demanding and expensive, it is not yet widely available in China.

Implantation of radioactive seeds is another minimally invasive pain-relieving procedure; its full name is "radioactive seed implantation therapy." It involves implanting a radiation source inside the tumor to destroy it. In the United States and other countries it has become a standard treatment for early prostate cancer, and in recent years it has also won favor among Chinese oncologists, pain specialists, and patients; it both relieves pain and suppresses tumor progression.

Ablation also belongs to minimally invasive surgery; common forms are microwave ablation and radiofrequency ablation. A thin needle is inserted into the lesion and the adjacent nerve tissue to block the nerve. Ablation can both block nerves and relieve pain and shrink the lesion. However, a number of patients, although pain is stopped, develop complications that are more distressing than the pain itself, so choosing ablation carries some risk.

Ablation is a form of neurolysis, which uses various methods to destroy nerves causing pathological pain. Besides ablation, neurolysis can be achieved through open surgery or injection of chemical agents. Neurolysis is irreversible: the destroyed nerve cannot recover, so it is usually reserved for cases in which medication and local nerve blocks have failed.

When conventional analgesia fails, cancer patients may consider minimally invasive pain procedures. Medical resources vary by region, and not every hospital offers them. Pain or oncology departments in general hospitals may provide relevant services; patients and families may consult nearby hospitals, weigh all factors, and choose an appropriate procedure on medical advice.