A breast cancer patient, visibly distressed by sudden hot flushes during her appointment, prompts me to halt my explanation. “Doctor, stop! I can’t process a thing,” she commands. As time stands still, I witness the onset of a hot flush begin with a flush across her face, spreading to her neck and chest, which is exposed by her tank top despite the cold winter morning. Beads of sweat form on her forehead, and her ears radiate heat, transforming her composed demeanor into one of palpable frustration, reminiscent of a firefighter fighting an inferno but ultimately waiting it out. “Sorry about that,” she grimaces.
The entire episode lasts around two minutes, offering a vivid example of one of the common side effects of anti-oestrogen therapy for breast cancer patients. When I ask how often she experiences these flushes, she shrugs and replies, “A dozen times on a good day.”
Approximately 75% of breast cancers are oestrogen-receptor positive, which means oestrogen stimulates the cancer cells. Treatment typically involves methods that suppress oestrogen, such as pills, injections, or ovariectomies, which induce menopause in younger women and enhance oestrogen suppression in those who are already menopausal.
With over 20,000 ovarian cancer cases diagnosed annually in Australia and two million cases worldwide, anti-oestrogen medications are critical in oncology—analogous to penicillin in its importance. Each week, I prescribe, renew, and replace these medications. However, while oncologists routinely mention the potential for hot flushes, the intense ordeal many patients endure often goes unexplained.
This omission begs the question: why?
Women recovering from rigorous chemotherapy and radiation treatments often cling to the hope of never undergoing such experiences again, while those with metastatic breast cancer harbor the hope of managing their illness for years, despite its incurable nature. Each patient requires a personalized discussion about their risks, yet many receive the broad-stroke message: “There is an effective medication to reduce recurrence risk and improve survival. Over the course of years, you might experience hot flushes, stiff joints, disturbed sleep, low mood, weight gain, and sexual dysfunction.” It resembles a punishment following an already harsh diagnosis. Nevertheless, oncologists strive to promote adherence to effective medications, hoping side effects will either not emerge or can be managed.
Vasomotor symptoms, which include hot flushes, affect up to 90% of breast cancer patients and can be particularly severe. Moreover, nearly half of women prescribed anti-oestrogen medications discontinue their use, with many simply not reporting their choice. Every oncologist has felt the disappointment when a high-risk patient opts against treatment, fully aware of what has led to that decision.
The frustration of limited effective treatment options for hot flushes is palpable. Despite a multitude of advertised solutions—cognitive behavioral therapy, acupuncture, hypnosis, dietary changes, exercise, and off-label use of antidepressants and anticonvulsants—none have proven significantly effective.
Adding to the complexity is the irony of using one medication to counteract the side effects of another, often leading to weight gain and its complications. Consequently, many women endure the ongoing repercussions of breast cancer.
Yet, there is a glimmer of hope. A randomized controlled trial recently revealed that a once-daily pill, Elinzanetant, significantly reduced the frequency of hot flushes in women undergoing anti-oestrogen therapy for breast cancer. This treatment works by influencing the brain’s temperature regulation signals.
In the trial’s baseline, women reported an average of a dozen hot flush episodes daily. By the end of the first month, 61% of those on the active medication noted a reduction of at least 50% in the frequency of moderate-to-severe hot flushes, compared to 27% on the placebo. Improvements in sleep quality and overall life satisfaction were also reported. Transitioning participants from placebo to the active medication mirrored these outcomes.
As with any medication, side effects are inherent. While more than 60% of participants from both groups experienced mild adverse events, severe reactions were rare. Symptoms such as sleepiness, fatigue, and diarrhea were noted more frequently in the group receiving the active treatment, but these may also be attributed to cancer therapy. Remarkably, over 90% of women who completed a year of the treatment chose to continue for an optional additional two years, indicating a high level of acceptance.
The drug has not yet received approval, and oncologists are seeking further information before prescribing it broadly. Concerns also remain regarding its effectiveness across diverse populations, as 88% of trial participants were white. It will be crucial to determine if this treatment improves adherence to the primary medication aimed at reducing cancer risk, a key goal of the prescription.
Finally, the rigorous selection and monitoring of clinical trial participants raises questions about how well real-world experiences will reflect those observed in trials; discrepancies are common.
As my patient leaves today, I commend her resolve to endure difficult treatment. She smiles, appreciative of the recognition, though she has only been in treatment for two years. I allow myself to hope for a future where relief from such trials is possible.