Maintenance Olaparib: — Taking a Drug When There Is No Visible Cancer

Chemotherapy targets cancer cells that are visible and active, but microscopic cells can remain after even a good response — too small for any scan to detect. These are the cells most likely to cause the cancer to return. Olaparib targets those residual cells during the period when they are most vulnerable, rather than waiting for visible regrowth before acting. The fact that your chemotherapy worked is what makes you a good candidate for maintenance: there is a response worth sustaining.

The duration depends on your cancer type, your response, and the guidance your oncologist is following. Your team will set a planned course length when they start your treatment and will reassess at each follow-up. Ask your oncologist to tell you the intended duration at the start, so you have a clear horizon, and to explain what would change that plan. Scans and blood tests are part of how they monitor whether to continue.

Not from how you feel day to day, and that can be unsettling. Maintenance therapy works silently, at the level of cells rather than symptoms. Your team monitors with regular scans and blood tests — these are how you and they know the treatment is doing its job. Feeling well is a good sign but not the measure your team uses; follow-up appointments are. If the cancer were to start growing despite olaparib, scans would detect it.

No. Olaparib is a targeted therapy, not chemotherapy. Chemotherapy attacks rapidly dividing cells broadly across the body, which is why its side effects follow a familiar pattern. Olaparib works by blocking a specific enzyme that BRCA-mutated cancer cells depend on to survive. It has its own side effect profile — which your team will explain — but it is a different class of treatment with a different mechanism and a different experience for most people taking it.

The side effects most commonly reported with olaparib, according to NCCN guidance, include fatigue, nausea, and a drop in blood cell counts — particularly red blood cells, which can cause anaemia. Most are manageable, and your team will check your blood counts regularly while you are on treatment. Tell your team about any new symptom rather than deciding whether it is worth mentioning. Serious side effects are less common but need to be ruled out, which is why the monitoring appointments matter.

Feeling well does not mean the olaparib has finished its work or that you no longer need it. The drug works continuously at the cellular level, and stopping early removes the protection it provides during the maintenance period. If side effects are making it hard to continue, that is a conversation to have with your oncologist — there are often ways to manage them, including dose adjustments. Do not stop without telling your team, even for a few days.