Background One in six people with cancer will develop depression at some point in their care. Untreated depression affects quality of life, cancer care satisfaction and healthcare expenditure. Treatments for this vulnerable heterogenous population should be evidence based and specific. A common sentiment is that psychiatric research does not reflect the prevalence of patients with cancer and comorbid depression and is biased towards certain cancers, but this has not been empirically shown. Study selection and analysis A systematic review of studies on psychological and pharmacological treatments for depression in people with cancer was conducted. Of 4621 papers identified from a search of PubMed and PsycINFO up to 27 June 2020, 84 met inclusion criteria (eg, adults with cancer; depression diagnosis; treatment study) and comprised 6048 participants with depression with cancer. Findings Cancer types are not proportionally represented in depression research in accordance with their incidence. Breast cancer is over-represented (relative frequency in research 49.3%, but 11.7% of global cancer). Cancers of the head and neck and bone and soft tissue were close to parity. All other cancers are under-represented. Representativeness varied 40-fold across different cancers. Conclusions The evidence base for depression treatments is dominated by a single cancer. Given heterogeneity in cancer populations (eg, stage of illness; psychological impact; cancer treatments), it is possible that depression treatments may not have the same benefits and harms across all cancers, impeding the ability to offer people with different cancers the best depression treatment. While the dominant opinion within this research field is that a cancer bias exists, this is the first study to demonstrate as such.

中文翻译：

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癌症患者的抑郁症治疗研究并不反映癌症患病率：系统评价的结果。

背景 六分之一的癌症患者在护理过程中的某个阶段会患上抑郁症。未经治疗的抑郁症会影响生活质量、癌症护理满意度和医疗支出。针对这一弱势异质人群的治疗应以证据为基础且具体。人们普遍认为，精神病学研究不能反映癌症和共病抑郁症患者的患病率，并且偏向于某些癌症，但这尚未得到实证证明。研究选择和分析 对癌症患者抑郁症的心理和药物治疗研究进行了系统回顾。截至 2020 年 6 月 27 日，在 PubMed 和 PsycINFO 检索中确定的 4621 篇论文中，有 84 篇符合纳入标准（例如，患有癌症的成年人；抑郁症诊断；治疗研究），包括 6048 名患有癌症的抑郁症参与者。研究结果 抑郁症研究中癌症类型的代表性并不与其发病率成比例。乳腺癌的比例过高（研究中的相对频率为 49.3%，但占全球癌症的 11.7%）。头颈癌、骨癌和软组织癌的发病率接近相同。所有其他癌症的代表性均不足。不同癌症的代表性相差 40 倍。结论 抑郁症治疗的证据基础以单一癌症为主。鉴于癌症人群的异质性（例如疾病阶段、心理影响、癌症治疗），抑郁症治疗可能不会对所有癌症具有相同的益处和危害，从而阻碍了为不同癌症患者提供最佳抑郁症治疗的能力。虽然该研究领域的主流观点是存在癌症偏见，但这是第一项证明这一点的研究。