Study provides new hope for patients with recurrent ovarian cancer
The findings, published in JAMA Oncology, challenge the current practice of continuing targeted maintenance therapy (PARP inhibitor therapy) until the cancer returns or side effects become unacceptable. The study suggests that for a small group of “exceptional responders”, ongoing treatment may not always be necessary.
Researchers studied 320 women from 41 centres across 14 countries who had recurrent ovarian cancer and had remained free of disease progression for at least five years after starting PARP inhibitor therapy. They were followed for an average of nearly seven years.
The results were encouraging. Almost 89% of patients were still free from cancer progression after 7.5 years, while nearly 79% remained progression-free after 10 years. More than 90% were still alive at long-term follow-up.
Importantly, women who stopped treatment for reasons other than cancer progression appeared to do just as well as those who stayed on treatment. Ten years after starting therapy, 90% of women who had stopped treatment remained free of progression, compared with 73% of those who continued.
Lead investigators Professor Michael Friedlander and Associate Professor Yeh Chen Lee, medical oncologists at the Royal Hospital for Women, said the study was prompted by a question doctors increasingly faced as some patients remained well for many years.
“When these treatments were first introduced, no one expected that some patients would respond so well for so long,” they said.
Doctors around the world have taken very different approaches when managing these patients. Some stop treatment after five years, others after 10 years, while some continue treatment indefinitely because there has been little evidence to guide decisions.
The study also provided reassurance about the long-term safety of treatment. While many patients needed their dose reduced because of side effects, fewer than 7% stopped treatment because of toxicity. Serious blood disorders were rare, affecting just five patients (1.6%).
Professors Friedlander and Lee said the findings support discussions about whether treatment can be stopped in carefully selected patients who have remained cancer-free for many years.
They stressed that the study does not prove treatment must be stopped, nor does it identify the ideal treatment duration. However, it provides doctors and patients with much-needed information when considering their options.
Researchers say the findings also raise the possibility that some patients may achieve what is known as a “functional cure”, meaning the cancer remains under control without ongoing treatment and patients can enjoy a normal or near-normal quality of life.
Professors Friedlander and Lee urged caution, noting that it is still impossible to know whether tiny amounts of undetectable cancer remain in some patients. However, the study offers new hope for women with recurrent ovarian cancer and may help shape future treatment decisions. They also acknowledged the enormous effort by Dr Lucy Haggstrom who was instrumental in the conduct of the study.
28 July 2026
