Weekly chemotherapy no better than three-weekly chemotherapy for people with ovarian cancer

09 Jun 2022

Having chemotherapy every week does not improve survival for people with ovarian cancer compared to having it once every three weeks, according to the long-term results of the ICON8 trial. These results were published yesterday in The Lancet Oncology journal.

ICON8 was a large international trial looking at whether having smaller doses of chemotherapy more often could offer additional benefit for people with epithelial ovarian, fallopian tube, or primary peritoneal cancer. Ovarian cancer is usually treated with two chemotherapy drugs, which are given once every three weeks.

These latest results are in line with previous results from ICON8, which showed that weekly chemotherapy was no better at preventing the cancer returning or getting worse than having it every three weeks.

People who agreed to take part in ICON8 were allocated at random to one of three groups:

  • Standard chemotherapy with the drugs carboplatin and paclitaxel, given once every three weeks, for a total of 18 weeks
  • Weekly chemotherapy, with carboplatin still given every three weeks, but with paclitaxel given once a week (at a lower dose), for a total of 18 weeks
  • Weekly chemotherapy, with both carboplatin and paclitaxel given once a week (at a lower dose), for a total of 18 weeks

The chemotherapy was given either after surgery, or for nine weeks before and nine weeks after surgery.

1566 people took part in the study, joining between June 2011 and November 2014. Most were from the UK, but some people from South Korea, the Republic of Ireland, Mexico, Australia and New Zealand also took part.

On average, people in the trial lived for around four years from randomisation, with no evidence of a difference between the groups. This is more than a year longer than the forecasted average survival time when the trial was designed, probably reflecting general improvements in standards of care.

Having smaller doses of chemotherapy weekly did not reduce side-effects compared to having bigger doses once every three weeks.

These results will not change the way that future patients are treated. But they help doctors to understand more about how chemotherapy should be given to women with ovarian cancer. This may help them find other, better ways to treat ovarian cancer in the future.

A follow-on trial is now running called ICON8B. ICON8B is looking at whether weekly chemotherapy is better than three-weekly chemotherapy for women who are receiving the drug bevacizumab (also known as Avastin) in addition to chemotherapy. ICON8B has now finished recruiting patients, and is following them up to see how they do. We expect to know the ICON8B results in 2023.

The ICON8 trial was funded by Cancer Research UK.


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