While definitions differ between regions, countries, and agencies, the National Cancer Institute defines rare cancers as those diagnosed in less than fifteen per 100,000 people annually. These malignancies, as a group, pose unique clinical challenges. Research becomes difficult because the number of cases of any particular rare cancer remains low. These factors have led to inadequate strategies for diagnosing, treating, and developing preventative measures for many rare cancers.
In addition to having a lower five-year survival rate compared to common cancers, the poor understanding of rare cancers makes it more difficult for patients to make informed decisions about their healthcare. Not surprisingly, this type of added emotional stress could likely have psychological outcomes for patients with rare cancer diagnoses.
A team of researchers from the National University of Singapore became concerned by the substantial percentage of cumulative cases of rare cancers, which account for up to 25% of all cancer diagnoses. This alarming trend prompted them to investigate the psychological impact of a rare cancer diagnosis through a meta-analysis, they recently published their results in the journal E Clinical Medicine.
The study applied an even stricter definition of rare cancer, as put forth by the Surveillance of Rare Cancers in Europe (RARECARE) where an incidence of less than six per 100,000 people annually is considered rare. The authors searched for peer-reviewed studies published between 2000 and January 2024 that evaluated psychological factors in patients with rare cancers. Specifically, the researchers looked for reports of depression, anxiety, suicide, and post-traumatic stress disorder (PTSD).
The systemic review of the literature revealed 32 studies fitting the criteria. In total, this resulted in 57,470 patients diagnosed with rare cancers. The meta-analysis found that patients with rare cancer had a significantly increased risk of experiencing psychological outcomes. Compared to healthy controls, patients with rare cancer had over 2.5 times higher risk of depression and anxiety.
Moreover, the study revealed a distressing finding-patients with rare cancer had a high rate of suicide, with 315 cases per 100,000 person-years. The researchers also reported high incidences of depression (175), anxiety (20%), and PTSD (18%) among patients with rare cancers. Importantly, the reported rates of suicide and PTSD among patients with rare cancers were significantly higher than in patients with common cancers, underscoring the urgent need for more research and intervention strategies.
The researchers also used the data to identify some risk factors for negative psychological outcomes. They found that patients with advanced disease, those who underwent chemotherapy, and those with lower incomes or social statuses exhibited a higher risk of experiencing psychological outcomes.
The authors conclude that the results of their study underscore the critical need for doctors and healthcare providers to identify patients at risk for adverse psychological outcomes. This understanding of the impact of psychological stressors on patients with rare cancer should drive further research into appropriate diagnostic and intervention strategies, which are crucial to best support these patients.
Sources: E Clinical Medicine, Eur J Cancer