Meeting News CoveragePerspective

Mastectomy improves survival in younger, BRCA-positive women with ovarian cancer

Prophylactic mastectomy offered a modest survival gain at an acceptable cost increase over annual screening for BRCA-positive women diagnosed with ovarian cancer before age 60 years, according to data presented at the Society for Gynecologic Oncology Annual Meeting.

However, mastectomy did not appear financially or medically prudent for women diagnosed with ovarian cancer after age 60 years, results showed.

Society of Gynecologic Oncology guidelines recommend genetic testing for all women diagnosed with ovarian cancer. These women also should be informed of options to reduce their breast cancer risk, according to study background.

Thus, Charlotte R. Gamble, MD, obstetrics and gynecology resident at Duke University Medical Center, and colleagues sought to determine whether prophylactic mastectomy offered survival and financial gains compared with annual breast screening for women with ovarian cancer and a germline BRCA mutation.

The researchers constructed a decision model that compared survival and costs of mastectomy vs. annual MRI and mammography for mutation-positive women newly diagnosed with stage II to stage IV ovarian cancer.

They used SEER data to assess disease-specific survival for ovarian cancer and breast cancer, and examined four ages — 40 years, 50 years, 60 years and 70 years — at the time of ovarian cancer diagnosis.

Key study endpoints included mean cost, mean OS and cost-effectiveness by strategy.

Prophylactic mastectomy would lead to a survival advantage of 8 months over breast cancer screening for a BRCA1 mutation carrier diagnosed with ovarian cancer at 40 years, according to the decision model. Further, mastectomy appeared cost-effective for women diagnosed at this age, with an incremental cost-effectiveness ratio (ICER) of $12,298 per year of life saved.

Women diagnosed at 50 years would achieve a survival gain of 6 months with mastectomy, with an ICER of $24,255.

The survival gains were 3 months (ICER = $56,881) for women diagnosed with ovarian cancer at 60 years, and 1.5 months (ICER = $143,207) for women diagnosed at 70 years.

Among BRCA2 carriers, mastectomy conferred a survival benefit for all ages studied (40 years, 7 months; 50 years, 5 months; 60 years, 3 months; 70 years, 2 months).

Mastectomy also appeared cost-effective for women with BRCA2 mutations diagnosed with ovarian cancer at or before the age of 60 years. However, the researchers did not consider it cost-effective for women diagnosed at 70 years (ICER = $119,557).

The model showed a 99% probability that mastectomy would cost less than $100,000 per year of life saved in a woman diagnosed at 40 years. This cost decreased 24% in BRCA1 carriers and 36% in BRCA2 carriers by age 70 years.

“For women with ovarian cancer diagnosed before age 60 years and who are at high genetic risk, risk-reducing mastectomy achieves modest life expectancy gains, with an acceptable cost increase compared to annual breast screening,” Gamble and colleagues wrote. “Above age 60 years at ovarian cancer diagnosis, mastectomy is unlikely to be cost-effective, with diminishing gains in life expectancy.” – by Cameron Kelsall

Reference:

Gamble CR, et al. Abstract 141. Presented at: Society of Gynecologic Oncology Annual Meeting; March 19-22, 2016; San Diego.

Disclosure: Gamble reports no relevant financial disclosures. HemOnc Today could not confirm the other researchers’ relevant financial disclosures at the time of reporting.

Perspective
Banu Arun, MD

Banu Arun

  • Women who harbor deleterious germline mutations are at significantly increased risk for breast cancer (up to 80%) and ovarian cancer (up to 45%). Although risk–benefit discussion of preventive surgeries ― bilateral mastectomy or bilateral salpingo-oophorectomy ― for unaffected individuals is easier, it is rather difficult for individuals who are affected with breast cancer, ovarian cancer or any other cancer, as they have a competing cause for outcome: mortality from their current cancer.

    This study asks this important question: Do patients with ovarian cancer benefit from preventive bilateral mastectomy vs. breast screening? What is the cost-effectiveness?

    The researchers concluded that, for women with ovarian cancer diagnosed before the age of 60 years, preventive bilateral mastectomy shows modest life expectancy gains with an acceptable cost increase compared with annual breast screening.

    The results of this study are interesting, but they are based on modeling. Hence, prospective validation would be helpful. There are limited data on the effect of preventive surgeries and survival benefit for BRCA mutation carriers.

    Although a study has shown that bilateral salpingo-oophorectomy can decrease all-cause mortality by 77% in BRCA mutations carriers, a survival benefit from bilateral preventive mastectomy so far has not been shown. Further, studies in women with unilateral breast cancer have not shown a survival benefit from contralateral preventive mastectomy. Therefore, further studies need to examine the value of preventive mastectomy vs. breast screening in patients with ovarian cancer who have a deleterious BRCA germline mutation.

    Finally, in the current study, breast-screening modality is not well described. If the analysis was made based on mammography, the outcome might be different, as now we are also including breast MRI as a breast-screening modality.

    • Banu Arun, MD
    • The University of Texas MD Anderson Cancer
  • Disclosures: Arun reports no relevant financial disclosures.