New treatment of advanced rectal cancer leads to fewer distant metastases

8 December 2020• PRESSRELEASE

The risk of recurrence of rectal cancer is less if a patient received short-course radiotherapy and subsequent chemotherapy prior to surgery. This is shown by an international study coordinated by the Leiden University Medical Center, University Medical Center Groningen, Karolinska Institutet and Uppsala Universitet from Sweden. The researchers expect that these results will lead to changes in the current standard treatment of advanced rectal cancer. The results will be published on the 7th of December in The Lancet Oncology.

Together with more than fifty other hospitals, the researchers investigated whether a different treatment strategy for rectal cancer could lead to fewer metastases elsewhere in the body. Current treatment for advanced rectal cancer consists of six weeks of radiotherapy combined with a low dose of chemotherapy. Subsequently, the tumour is surgically removed. With this new treatment, the patient receives one week of radiotherapy followed by 18 weeks of chemotherapy. Afterwards, surgery will be performed.

Tackling distant metastases at an early stage

"Radiotherapy with low doses of chemotherapy ensures that the tumour is as small as possible and therefore easier to remove during surgery. Besides, chemotherapy kills tumour cells that form metastases," says radiotherapist at LUMC and Antoni van Leeuwenhoek Corrie Marijnen.

"By providing chemotherapy before surgery, we tackle possible metastases at an early stage. In the meantime, the effect of the radiotherapy will be prolonged irradiation can continue for longer, allowing the tumour to become even smaller before surgery".  

Less recurrence

"We have treated a total of 920 patients from seven countries with advanced rectal cancer according to the standard or new treatment. Then we monitored them for years," explains oncological surgeon at LUMC Cock van de Velde. During the years after treatment, patients who received the new treatment strategy developed fewer distant metastases.  "After 3 years, this was 20% of patients, compared to 27% of patients receiving the standard treatment. 

In addition, the researchers discovered that the new strategy made the tumour so small that in 28% of the patients, tumour cells could no longer be found in the rectum and surrounding lymph nodes. In the standard treatment, this was only in 14% of patients. It is possible that surgery could be omitted in these patients in the future. However, more research is needed for this.

Less hospital visits

Although the results are positive, patients reported more side effects. This is because the chemotherapy is tougher. "However, these side effects did not prevent patients from having surgery. The number of post-treatment complications was similar in both groups," explains UMCG oncological surgeon Boudewijn van Etten.

"An additional advantage of the new treatment is that hospital visits are less often needed. With the standard treatment the patients visits the hospital 25 to 28 times and with the experimental treatment this is only 12 times".

New standard

Years of research are needed to prove that a new treatment is effective. Already in 2006 there was a 'proof of concept', says Geke Hospers, medical oncologist at the UMCG. With the efforts of many institutes and a grant from Dutch Cancer Society, it has finally been possible to demonstrate the effect of this treatment. 

"We expect that steps will be taken to turn this experimental treatment into a standard treatment. Treatment of the patient prior to surgery is a leading treatment strategy for this form of rectal cancer, if possible, with no need for surgery as a possible additional option in the future".

The entire study can be found in Lancet Oncology.

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