COMET trial finds quality of life similar among patients with low- risk DCIS whether they received active monitoring or surgery

(Press-News.org) SAN ANTONIO – Patients with low-risk ductal carcinoma in situ (DCIS) who underwent active monitoring reported comparable physical, emotional, and psychological outcomes to patients who received upfront treatment, according to results from the COMET clinical trial presented at the San Antonio Breast Cancer Symposium (SABCS), held December 10-13, 2024.

The results of this study were simultaneously published in JAMA Oncology.

“Active monitoring” is a strategy in which patients are monitored closely, with surgery reserved for those patients who develop cancer.

A steady increase in mammography and other breast cancer screening methods has led to the identification of more cases of DCIS, a noninvasive form of breast cancer. However, because anywhere between 25% and 60% of cases progress to invasive cancer, determining how best to treat DCIS can be controversial. In the primary analysis of the COMET trial, also presented at SABCS, researchers found that active monitoring of patients with low-risk DCIS resulted in comparable rates of invasive ipsilateral (same breast) breast cancer diagnosis as upfront standard-of-care treatment.

But a common concern with treatment de-escalation is that patients may feel more anxious about their cancer worsening or returning, explained Ann Partridge, MD, MPH, interim chair of the Department of Medical Oncology at Dana-Farber Cancer Institute and a professor at Harvard Medical School, who presented a secondary analysis of the COMET trial evaluating how active monitoring compares with upfront treatment with regard to quality of life.

“It is critical that we understand how women feel when they are living with an active-monitoring approach and how it impacts on their overall quality of life, psychosocial health, worries about DCIS, anxiety and depression, and other related symptoms,” Partridge said.

Partridge and colleagues evaluated patient-reported outcomes from the COMET study, which enrolled 995 patients with grade 1 or 2, hormone receptor-positive, HER2-negative DCIS with no evidence of microinvasive or invasive disease. They randomly assigned 484 patients to undergo active monitoring and 473 patients to receive guideline-concordant care consisting of surgery with or without adjuvant radiation. Patients in the active monitoring arm could elect to have surgery at any time, and surgery was required if the tumor showed signs of invasive progression. Patients in both treatment arms were allowed to receive endocrine therapy, if desired.

Patients were asked to complete several clinically validated questionnaires at baseline, six months, one year, and every subsequent year after treatment assignment. Questionnaires were designed to assess health-related quality of life (including both physical and mental components), anxiety, depression, worry about DCIS, and breast cancer treatment-related symptoms, including pain. Patients who responded to at least one survey were included in the study.

Overall health-related quality of life remained stable from baseline to two years and did not differ significantly between the two treatment arms. There were also no significant differences in anxiety scores and worry about DCIS over time. While depression scores were not significantly different between the two treatment arms, there was a trend toward higher depression scores and a higher probability of depression over time in the guideline-concordant care arm compared to the active monitoring arm.

The physical functioning scores for health-related quality of life differed significantly over time between arms with lower average scores among patients in the active monitoring arm than patients in the guideline-concordant care arm. However, because 29% of patients overall did not adhere to their assigned treatment arm, the investigators conducted a separate analysis of patients who received their assigned treatment. In this analysis, average physical scores were transiently and significantly lower over time among patients who received guideline-concordant care than among those who received active monitoring; those in the guideline-concordant care arm reported a significantly greater burden from arm problems, breast pain, and sensory disturbances (i.e., numbness) on average, though mean differences resolved by two years.

When the researchers normalized scores based on race, age, tumor grade, and use of endocrine therapy, no significant differences in physical functioning over time were observed between the two treatment arms.

Partridge viewed the similarities in lived experiences between the two treatment arms as encouraging, demonstrating that neither approach had a markedly negative impact on patients’ quality of life.

“The data suggest that, in the short term, active monitoring is a reasonable approach in terms of patient experience,” she said. “If longer-term data hold up, this approach could be considered as a management option for women with low-risk DCIS.”

Limitations of this study include underrepresentation of women from racial and ethnic minority groups, the exclusion of patients under age 40, and a relatively short follow-up period of two years.

Data on primary outcomes from the COMET trial are available in another press release.

Funding for this study was provided by the Patient-Centered Outcomes Research Institute, the Breast Cancer Research Foundation, the Rising Tide Foundation, the National Cancer Institute of the National Institutes of Health, the University Cancer Research Fund of North Carolina, and Alliance Foundation Trials. Partridge declares no conflicts of interest.

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