THURSDAY, Jan. 20 (HealthDay News) -- The rate of depression among cancer patients may be lower than previously believed, a new study indicates.

An international team of researchers analyzed 94 studies involving more than 14,000 patients and found that about one-sixth of cancer patients suffer depression and about one-third have a more widely defined mood disorder.

Only modest rates of depression and anxiety occurred in cancer patients in the first five years after diagnosis, which suggests that depression is not inevitable in these patients, the researchers said.

Only when it was combined with other mood disorders was depression common, occurring in 30 percent of hospitalized cancer patients.

The study is published online Jan. 19 in The Lancet Oncology.

Rates of depression and anxiety were not significantly different between patients receiving palliative care (care designed to ease pain and increase comfort in patients with terminal cancer) or non-palliative care (care designed to fight the cancer while easing symptoms). This suggests that the effects that differences in cancer care settings and possibly cancer stage have on depression may have been previously overemphasized, the researchers said in a journal news release.

They also concluded that cancer patients' age and sex do not influence their risk of depression.

"Although these rates (of depression) are modest, this group of patients should not be overlooked. Improvements in survival and high prevalence of most cancers actually increase rates of depression, amounting to what we estimate to be 340,000 people in the UK and 2 million in the USA with major depression and cancer at any time," noted the researchers in the release.

"Our study shows that depression alone is not as common as previously thought in cancer settings, occurring in one in six patients, about the same as the rate seen in primary care settings. Although depression remains an important and overlooked complication of cancer, clinicians must also be vigilant for other related emotional problems such as anxiety, adjustment disorder or simply any form of significant distress," concluded the researchers, who stressed that "there is still an urgent need" for screening programs to detect depression, anxiety and mood disorders among cancer patients.

More information

The U.S. National Cancer Institute has more about cancer patients and depression.