Women treated for depression before breast cancer diagnosis may have poorer survival

Women treated for depression before being diagnosed with early-stage breast cancer were at greater risk for receiving nonguideline treatment and had poorer overall and breast cancer–specific survival, according to a multivariable logistic regression analysis conducted in Denmark.

“Although not surprising, we found it disturbing to document that women with depression are at increased risk for not receiving guideline breast cancer treatment,” Nis P. Suppli, MD, PhD, at the Danish Cancer Society Research Center, told HemOnc Today. “Further, we documented that this group of women had decreased survival after diagnosis of breast cancer compared to women without depression.”

Suppli and colleagues aimed to determine whether prior treatment for depression is associated with breast cancer treatment in accordance with national guidelines. They also compared OS, breast cancer-specific survival and death by suicide among women who had and had not been treated for depression before breast cancer diagnosis.

“In our research groups we have a special interest in social inequality in health,” Suppli said. “It has been known for the past 10 years that the life expectancy of persons with psychiatric diseases is decreased by 10 to 15 years. Prior work has pointed to increased incidence of and poorer survival from somatic diseases as the main reasons for this increased mortality. Although the relative risk for death by suicide is increased by a factor 20, this only accounts for a smaller proportion of the absolute number of deaths.

“As breast cancer is a highly incident disease that is supposed to have structured, algorithm-based guideline treatments, we found it interesting to investigate if women with depression are actually treated according to guidelines and if they have similar survival after breast cancer compared to women without depression,” Suppli added.

Researchers identified 45,325 women diagnosed with early-stage breast cancer in Denmark between 1998 and 2011. Of those, 744 women (2%) had previously visited a hospital for depression and 6,068 (13%) had been treated with antidepressants. Women with previous cancer, except for nonmelanoma skin cancer, or previous major psychiatric disorders, except for unipolar depression, were excluded from the study.

Women who had been treated for depression prior to breast cancer diagnosis were significantly more likely to be older, have less education, live alone, have comorbid somatic disease, and have breast cancer diagnosed in later calendar years than those who did not.

After diagnosis, 80% of women who had previously been treated for depression used antidepressants, and 23% of women who were not previously treated for depression initiated the use of antidepressants.

Women who had been treated for depression before diagnosis were significantly more likely to receive nonguideline-adherent treatment (OR = 1.14; 95% CI, 1.03-1.27). They also had significantly worse OS (HR = 1.21; 95% CI, 1.14-1.28) and breast cancer–specific survival (HR = 1.11; 95% CI, 1.03-1.2) than those who had not been treated for depression.

Further, researchers reported significantly greater risk for death by suicide for women who had used antidepressants before diagnosis (HR = 5.38; 95% CI, 2.16-13.37) and women who previously had received hospital care for depression (HR = 19.81; 95% CI, 5.32-73.86).

Researchers noted that the small number of patients who had previously received hospital care for depression (n = 744) may have minimized the statistical power of the analysis.

“We know that receiving guideline treatment is paramount in improving the chance of survival,” Suppli said. “Thus, our results should remind all health care professionals that getting women with depression allocated to guideline breast cancer treatment and making sure that they have the resources to complete this treatment will improve their survival. That is, we have very good breast cancer treatments; however, women with depression are a vulnerable group at risk for not getting this guideline treatment, resulting in poor survival.

“Although the bad news was poorer survival after breast cancer among women with depression, the good news is that it is very likely that by ensuring allocation and adherence to guideline treatment, we will be able to ensure that this group of women improve their survival rate to that of women without depression.” – Chuck Gormley

For more information:

Nis P. Suppli, MD, PhD, can be reached at Danish Cancer Society Research Center, Strandboulevarden 49, 2100 Copenhagen, Denmark; email: suppli@cancer.dk.

Disclosure: Suppli reports no relevant financial disclosures. Other researchers report honoraria from or consultant/advisory roles with AstraZeneca, GE Healthcare, Lundbeck and Roche.