Stressful childhood events may increase skin cancer risk
A number of research papers have reported an association between stress and both increased cancer risk and decreased cancer survival. Now, a study has linked stressful childhood events with an increased risk of the commonest form of skin cancer: basal cell carcinoma. The study results were presented in the June issue of the Archives of General Psychiatry.
The authors noted that emotional maltreatment of a child can have a long-term impact on the immune system that can be aggravated by other stressful events that when the child reaches adulthood. They add that childhood maltreatment has been associated with elevated inflammation and higher antibody titers to herpes simplex virus type 1 (reflecting poorer cellular immune function) and has also been linked to multiple diseases, including cancer. They explain that immune dysregulation is a likely contributor to these effects and that the immune system plays a major role in basal cell carcinoma appearance and progression.
The authors designed a study to evaluate the association between basal cell carcinoma and recent severe life events, childhood parental emotional maltreatment, depression, and messenger RNA (mRNA) coding for immune markers associated with basal cell carcinoma tumor progression and regression.
The study group was comprised of 91 patients with basal cell carcinoma (ages, 23-92 years) who had a previous suffered a previous basal cell carcinoma. They collected data from the patients regarding early parent-child experiences, severe life events in the past year as assessed by the Life Events and Difficulties Schedule, depression, and mRNA for immune markers associated with basal cell carcinoma progression and regression.
The main outcome measures were the expression of four basal cell carcinoma RNA tumor markers: CD25, CD3ϵ, intercellular adhesion molecule 1, and CD68. These markers were assessed in basal cell carcinoma biopsy specimens. These markers have been linked to basal cell carcinoma tumor progression and regression.
The investigators found that both maternal and paternal emotional maltreatment interacted with the occurrence of severe life events to predict the local immune response to the tumor. Among basal cell carcinoma patients who had experienced a severe life event within the past year, and those who were emotionally maltreated by their mothers or fathers as children had a poorer immune response to the cancer. Emotional maltreatment was unrelated to basal cell carcinoma immune responses among those who did not experience a severe life event. Furthermore, depressive symptoms were not associated with the local tumor immune response.
The authors concluded that troubled early parent-child relationships, in combination with a severe life event in the past year, predicted immune responses to a basal cell carcinoma. The immunoreactivity observed in cancers themselves and the surrounding tissue reflects an anti–tumor-specific immune response that can be altered by stress.
Skin cancer, which the most common cancer in the US, is more prevalent than all other malignant tumors combined. The incidence of basal cell carcinoma, the most common skin cancer, has been doubling every 14 years. The risk of subsequent basal cell carcinomas after an initial tumor is significant; 44% of patients develop new cancers within three years. Risk factors for the first episode of cancer include age, childhood sun exposure, fair skin, and male sex; however, subsequent tumors are not reliably related to these factors.
Reference: Archives of General Psychiatry