Depression treatment does not improve cancer survival
medwireNews: Use of a depression treatment program does not improve survival in patients with cancer and comorbid major depression, even though it was highly effective in reducing depressive symptoms, UK researchers report.
Compared with usual care, the Depression Care for People with Cancer (DCPC) program significantly reduced comorbid major depression at 24 weeks among 500 participants of the SMaRT Oncology-2 trial, as defined by the proportion who achieved a 50% reduction in the Symptom Check List-20 Depression subscale (62 vs 17%). All participants had cancers with a good prognosis.
The DCPC program – which consisted of collaborative pharmacologic and psychologic care delivered by a team of cancer nurses, psychiatrists, oncologists, and primary care physicians – also significantly reduced depression severity scores over 32 weeks among 142 participants of the SMaRT Oncology-3 study, who had lung cancer with a poor prognosis.
But after median follow-up periods of 5 years for SMaRT Oncology-2 and 1 year for SMaRT Oncology-3, there was no significant difference in mortality between the patients who were randomly assigned to follow the DCPC program and those who were assigned to receive usual care.
Specifically, in SMaRT Oncology-2 the mortality rate was 27% in both the DCPC and usual care groups, while the corresponding figures for SMaRT Oncology-3 were 76% and 84%. More than 80% of deaths in all four groups were cancer-related and none were attributed to suicide.
Writing in The Lancet Psychiatry, Michael Sharpe (University of Oxford) and co-authors conclude: “Despite there being no notable effect on length of life, the beneficial effect of treatment of depression on quality of life provides sufficient reason to make this an important part of cancer care.”
In an accompanying comment, Alex Mitchell, from the University of Leicester in the UK, examines why treating depression does not improve cancer survival, despite observational studies showing that “patients with depression have a higher incidence of specific cancers and have a worse prognosis” than patients without depression.
He suggests that the reason could be methodological, with a larger study and longer follow-up period needed to show a differential effect, or it could be that “depression treatment in a trial only represents a small fraction of a patient’s life living with depression, and furthermore, neither medical nor psychiatric care is controlled or monitored after such a trial ends.”
Mitchell also suggests that depression might only influence survival in specific cohorts such as those with early-stage cancer, younger patients, and patients who develop depression after their cancer is diagnosed.
He concludes that “differences in cancer survival are unlikely to be corrected in randomised trials in patients with depression, but that should not detract from the message that depression remains a key target for prompt recognition and appropriate treatment, including the urgent necessity to reduce any inequalities in cancer care related to patients’ pre-existing or current mental ill health.”
By Laura Cowen
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