The drug (olaparib) is a PARP inhibitor, which suppresses the growth of cancerous tumours. As per Ovarian Cancer Canada,

PARP inhibitors target the ability of a cancer cell to repair its damaged DNA and either survive or die. PARP is a protein inside cells that helps repair damage to the cell DNA. If the cell can repair itself, it will survive and grow. If the cell cannot repair itself, it will die. So, the PARP "inhibitor" stops a cancer cell from repairing its DNA which causes cell death and prevents tumour growth.

In my case, olaparib appears to have done its job, as both my monthly CA125 tests and recent CT scan show no evidence of cancer recurrence. Equally important, my monthly blood work results and my own assessment of how I'm feeling suggest that my body has tolerated the drug well.

That said, olaparib is not without its risks. It may cause bone marrow problems called Myelodysplastic Syndrome (MDS) or Acute Myeloid Leukemia (AML). Dr. Faught estimated this risk at 1.5% and noted that the risk is likely to increase the longer a patient is on the drug.

In deciding whether to continue or discontinue olaparib, Dr. Faught noted that there is no evidence that staying on the drug would have a long-term benefit. What evidence does exist suggests that patients on the drug for up to 2 years enjoyed a residual benefit for the next 5 years. In the SOLO-1 Trial, patients with newly diagnosed advanced ovarian cancer and a BRCA mutation who had responded to platinum-based chemotherapy were randomly assigned to maintenance olaparib or placebo for up to 2 years. A 2023 update of the trial in the Journal of Clinical Oncology noted that new data from 2022 had confirmed earlier findings from 2020 and 2018 that "the benefit of maintenance olaparib extends well beyond its 2-year treatment cap in patients with newly diagnosed advanced ovarian cancer and a BRCA mutation." The benefits were these: 67.0% of the patients who had received olaparib for up to 2 years were still alive after 7 years, compared to 46.5% who had received a placebo. As well, 45.3% of the patients who had received olaparib for up to 2 years had not had a cancer recurrence after 7 years, compared to 20.6% who had received a placebo.

When I met with Dr. Faught in March 2024, I had been on olaparib for just over 3 years. Because there was no evidence of cancer recurrence (low and stable CA125, no sign of tumours on various scans) and no signs of toxicity (stable blood work and overall good health), Dr. Faught recommended that I continue on olaparib. "We don't want to rock the boat," he had said then.

However, now that I'm at 3¾ years on the drug with no evidence of disease, the risk of recurrence is quite low, Dr. Faught said. He estimated my risk of recurrence to be less than 10%. I almost cried when he said that, remembering that he had told me in August 2020 that the risk of recurrence in ovarian cancer is about 80%. And if I make it to 5 years with no evidence of disease, my risk of recurrence would be essentially 0%—I would be considered cured.

Dr. Faught did offer that I could remain on the drug for a full 4 years if I felt—as some patients do—that being on the drug provided additional assurance and peace of mind. But I'm more inclined to go with what the evidence shows. Though the evidence in this case is limited, I'm satisfied with Dr. Faught's recommendation and my decision. I proposed to Dr. Faught that I finish my current supply of olaparib and then stop taking the drug; Dr. Faught agreed. Based on the number of pills I have left, I will be finished just before Christmas.

My CA125 tests will move from monthly to every 3 months since my monthly blood work was more about monitoring my blood for signs of drug toxicity than it was about measuring the level of cancer antigen in my blood, which would not change that quickly.

I asked Dr. Faught about a scenario in which I experienced a recurrence after discontinuing olaparib. If this were to happen, I would likely need to go through chemotherapy again and possibly surgery. A decision on whether to restart olaparib could be made at that time. Dr. Faught did not rule it out.

Dr. Faught has been a wise and empathic presence throughout my cancer journey. He was the first oncologist I met in August 2020, after being unofficially diagnosed with ovarian cancer by an emergency department physician just a few weeks before. He was the doctor who informed me that a BRCA2 mutation had been found in the tumours removed during my ovarian cancer surgery, noting that it was good news overall. He was the specialist who advised me, after 3 years on the maintenance drug, to continue to take the medication because we didn't want to rock the boat. And he was the oncologist who walked me through the considerations that led to today's decision to phase out olaparib.

He spent considerable time with me this morning, patiently answering all my questions and gently reminding me that he had other patients to see. I left the hospital feeling grateful that I had been given all the information I needed to make a sound decision, including a clear recommendation from Dr. Faught and data to support that recommendation.