medwireNews: An inexpensive, commercially available dexamethasone mouthwash substantially reduces the incidence and severity of stomatitis in patients receiving everolimus and exemestane for breast cancer, US study data show.
Hope Rugo (University of California San Francisco, USA) and co-researchers say the findings from their SWISH trial could represent “a new standard of oral care for patients receiving everolimus and exemestane therapy.”
They found that using 10 mL of an alcohol-free mouthwash containing 0.5 mg dexamethasone per 5 mL, four times daily for 8 weeks, alongside treatment with everolimus and exemestane for metastatic hormone receptor-positive, HER2-negative breast cancer, reduced the proportion of all-grade stomatitis by 61% and grade 2 or worse stomatitis by 91% compared with historic controls from the BOLERO-2 trial who received the same chemotherapy without the mouthwash.
At 8 weeks, a time by which the researchers say the vast majority of everolimus-related stomatitis will be apparent, 2% of 85 patients who used the dexamethasone mouthwash had experienced grade 2 or worse stomatitis compared with 27% of 482 patients in the BOLERO-2 study.
In addition, the median everolimus dose intensity was higher in the SWISH trial than in BOLERO-2, at 10.0 versus 8.6 mg, which Rugo et al suggest “might be a consequence of the reduced incidence of stomatitis, as well as the fact that dexamethasone mouthwash treatment was well tolerated with minimal toxicity.”
Writing in The Lancet Oncology, the researchers say their findings reinforce “the importance of prophylaxis initiation concurrent with everolimus and exemestane treatment and the rationale for an early and short-term intervention.”
“As such, a reasonable approach based on these data would be to use the steroid-based mouthwash for the first two to four cycles of everolimus and exemestane treatment and then on an as-needed basis for signs or symptoms of stomatitis,” they conclude.
However, in an accompanying comment Laura Spring and Aditya Bardia, both from Harvard Medical School in Boston, Massachusetts, USA, point out that the women included in the SWISH and BOLERO-2 trials do not represent “the current population of patients with hormone receptor-positive metastatic breast cancer,” as everolimus and exemestane are no longer used as a first-line therapy.
They say almost all patients with hormone receptor-positive metastatic breast cancer are now treated with “the combination of a CDK 4/6 inhibitor and endocrine therapy before consideration of everolimus and exemestane treatment, and the effect of previous CDK 4/6 inhibitor treatment as a risk factor for developing everolimus-induced oral mucositis is unclear.”
Nonetheless, they write: “On the basis of the SWISH trial, the use of prophylactic dexamethasone mouthwash should be considered a potential option for the prevention of everolimus-induced oral mucositis.”
Spring and Bardia comment that “in the era of targeted therapies and precision medicine, studies such as the SWISH trial, dedicated to the mitigation of adverse effects from targeted therapies to improve quality of life and tolerability, are particularly refreshing.”
By Laura Cowen
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