Operate more often, better medicines
Previously, there was virtually no effective treatment for metastatic colorectal cancer. Thanks to new techniques and medicines, the survival chances of patients with this form of cancer have increased considerably. Oncologist Kees Punt talks about the developments in his field.
“Twenty-five years ago, half of patients with metastatic colorectal cancer had died within 7 to 8 months. That has been moved to more than 2 years. The 5-year survival of these patients has also increased, from less than 5 percent to 20 percent,” says Kees Punt, professor of medical oncology at the AMC in Amsterdam, who specializes in cancer of the gastrointestinal tract. “This is due to new effective drugs and because we are able to operate on more and more patients with metastases.”
Screening
He is happy that the bowel cancer screening for people over 55 has started. “As a result, the disease is detected earlier and earlier and metastatic colon cancer will occur much less in the long term.” 20 to 25 percent of people already have metastases at the first diagnosis. Colon cancer is usually the first to spread to the liver. This happens in about half of the patients. “For a long time, surgery was only possible if there were only one or two metastases, but now the determining factor is how much healthy liver is preserved after surgery. This is at least around 30 percent. However, the metastases should not be too close to the large blood vessels and bile ducts,” says Punt.
Before an operation, patients often first receive chemotherapy in combination with so-called targeted therapy to make the metastases smaller and therefore more accessible for surgery. Of the patients whose liver metastases have been surgically removed, 30 to 50 percent still live at least 5 years. “Actually, after 5 years we can speak of a cure,” says Punt, “because the chance that the disease will come back after that is small.”
New treatments and techniques
With regard to local treatments of the liver, various techniques are being explored as an alternative to surgery. For example, radiofrequency ablation (RFA, burning away the metastasis), stereotactic radiotherapy (precision irradiation), and radioembolization (injection of radioactive spheres into the liver). However, if metastases can be completely removed by surgery, this is still preferable. If surgery is not possible, the patient has no chance of recovery, but treatment with drugs does offer a clear survival benefit.
There are three types of effective chemotherapy (5FU or capecitabine, irinotecan, and oxaliplatin). In addition, there are several targeted drugs, such as bevacizumab, cetuximab and panitumumab. They inhibit specific growth signals from cancer cells. These agents are now part of the standard treatments. There are also new drugs such as aflibercept and regorafenib, the positioning of which is still being investigated.
“The challenge is to determine the right combination and sequence of medicines for each patient. In addition to certain patient characteristics, it is becoming increasingly clear that tumor characteristics are the most predictive of the efficacy of cancer drugs. We are moving towards tailor-made treatment for each patient, but we are not there yet, because a lot of research is still needed for that,” emphasizes Punt.
Sources):
- Plus Magazine
