Delaying chemotherapy can benefit women with relapsed ovarian cancer: Results of the EORTC 55955 trial

Results from a clinical trial funded by the Medical Research Council (MRC) and the European Organisation for Research and Treatment of Cancer (EORTC) show that women whose ovarian cancer has returned can delay chemotherapy treatment until symptoms appear without affecting their survival[1]. These findings will help patients make more informed decisions about their treatment and follow-up and could improve the quality of life for many women affected by ovarian cancer.

Ovarian cancer currently affects more than 6,000 women in the UK. Unfortunately for women with advanced forms of the disease, even when treated with chemotherapy, there is still an 80 per cent chance that the cancer will return. Relapsed cancer is frequently diagnosed by measuring a substance in the blood called CA125. If there is an increased level of CA125 it means that the cancer has come back and can be treated but usually cannot be cured.  Some doctors then treat patients with a second course of chemotherapy straight away.

The results of the trial show that if CA125 levels have increased and the cancer has returned, patients can choose not to start further chemotherapy until they start to feel symptoms such as pain, swelling or bloating without affecting how long they will live. This potentially offers women a better quality of life for longer; free from symptoms of their ovarian cancer and free of the debilitating side-effects of chemotherapy.

The randomised controlled trial OVO5, EORTC 55955, co-ordinated by the MRC’s Clinical Trials Unit and the European Organisation for Research and Treatment of Cancer (EORTC), was conducted in 16 sites in seven countries and included 1442 women. CA125 levels were measured every three months over an average of four and three quarter years. If a woman’s CA125 level reached twice that of normal levels, they were randomly assigned to one of two groups; one for immediate chemotherapy treatment and one where treatment was delayed until the first physical symptoms appeared.

Researchers could find no significant difference in survival between the two groups, with women surviving 25.7 months on average in the early treatment group, and 27.1 months for women whose treatment was delayed.

Professor Gordon Rustin from the Mount Vernon Cancer Centre and co-chief investigator of the study said: “We hope women affected by ovarian cancer will be reassured by the results of this trial. It is instinctive to want to diagnose and treat cancer that has returned straight away. However, the reality is that in many cases chemotherapy can worsen the quality of a woman’s life as much as cancer itself. We are pleased that this trial has provided robust evidence that not measuring CA125 levels routinely does not put women at a disadvantage. This will inform discussions between patients and doctors and help women make the right choices. Ovarian cancer is a devastating disease and trials like this show the benefit of empowering women to make the best decisions which can now be based on hard evidence.”

Dr Ann Marie Swart who led the trial from the MRC’s Clinical Trials Unit said: “This trial shows the importance of publicly funded research, tackling questions that really impact the lives of women with ovarian cancer that would otherwise go unanswered. Better treatments are also needed and we will continue to work with UK and international colleagues to improve the lives of women with ovarian cancer.”

Catherine Beveridge

Medical Research Council, London


[1] Gordon J S Rustin, Maria E L van der Burg, Clare L Griffin, David Guthrie, Alan Lamont, Gordon C Jayson, Gunnar Kristensen, César Mediola, Corneel Coens, Wendi Qian, Mahesh K B Parmar, Ann Marie Swart, for the MRC OV05 and EORTC 55955 investigators. Early versus delayed treatment of relapsed ovarian cancer (MRC OV05/EORTC 55955): a randomised trial. The Lancet 376: 1155-1163, 2010.

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