I just came across something today that suggests a scientific explanation of how this could happen. Apoptosis is the "programmed form of cell death" in the body. There's a theory by Alan Bloom, in his book THE GLOBAL BRAIN, about one's "inner judge", that when it turns suicidal, due to being of "no further use to the group/species", it triggers this program...
en.wikipedia.org
A term used in Howard Bloom's Global Brain. Inner-judges are hard-wired biological bits that control hormone levels, kill brain cells, and so forth. The...
everything2.com
An explanation from an article at the link below, "Conformity, Diversity, and The Global Brain":
"Inner-judges are, according to Bloom, the equivalent of cellular mechanisms that encourage apoptosis (cell death). These judges, through some (rather poorly explained) system of hormones and chemicals, create a sometimes overwhelming feeling of despair in individuals who have failed to contribute to the group. Inner-judges are usually harsh, unforgiving critics who can encourage individuals to remove themselves from the progress of the group, either through suicide or through an inability to continue performing tasks."
I can't say I understand the heavy jargon, and I'm not sure if this is suggesting that depression causes cancer as much as it suggests a symbiotic relationship, but it's a start:
ABSTRACT:
"Based on our findings, we hypothesize that the mechanism of the interaction between HCC and depression may be related to cell death or apoptosis. Further studies are needed to verify this hypothesis."
Hepatocellular carcinoma is the third most common cause of cancer deaths worldwide [
1]. Due to various factors, including economic development and environmental factors, incidence is rapidly increasing across all age groups [
2]. Hepatitis B, hepatitis C, aflatoxin exposure, alcohol consumption, and smoking are HCC risk factors [
3]. Recent studies suggest that HCC is also associated with emotional and psychological factors. Numerous studies have reported high depression incidence in cancer patients. A Taiwanese prospective study involving 128 newly diagnosed HCC patients found that advanced Barcelona Clinic liver cancer stage, radiofrequency ablation therapy, or liver resection was most closely associated with worsening physical and psychological symptoms over time [
4]. Anxiety disorders and depression have also been associated with a significantly increased overall survival rate in HCC patients in a retrospective study involving 7304 patients treated for HCC from 1996 to 2010 [
5]. Thus, clinical professionals should pay attention to physical and psychological factors during treatment.
This study aimed to uncover the possible mechanism underlying the interaction between HCC and depression using bioinformatics. From our findings, we hypothesize that interaction between the two may exist in cell death/apoptosis. We also searched for drugs that can act on core genes and which may guide further research.
"Epidemiological investigation found that the prevalence of depression in cancer patients is higher than that in the general population [
14]. Cancer incidence is higher in patients with depression, and depression is linked to the increase in cancer-specific mortality, which is consistent with findings that depression and anxiety were significantly associated with increased risk of cancer (adjusted RR: 1.13, 95% CI: 1.06–1.19), cancer-specific mortality (1.21, 1.16–1.26), and all-cause mortality in cancer patients (1.24, 1.13–1.35) [
15]. The estimated absolute risk increases (ARIs) associated with depression and anxiety were 34.3 events/100,000 person years (15.8–50.2) for cancer incidence and 28.2 events/100,000 person years (21.5–34.9) for cancer-specific mortality. However, so far, we have seen more clinical observational and epidemiological survey data. The genetic mechanism of the interaction between HCC and depression has not been determined. Here, we used bioinformatics to identify genes that are co-expressed in HCC and depression and to identify the biological process, cellular component, molecular function, and signaling pathways involved. Using DGIdb database, we identified drugs that may be used in both."
There may be a mutually reinforcing relationship between hepatocellular carcinoma (HCC) and depression, but the mechanism is unknown. This study used bioinformatics to evaluate the relationship between HCC and depression at the genetic level. Genes associated ...
www.ncbi.nlm.nih.gov
Another article:
The link between depression and anxiety status and cancer outcomes has been well-documented but remains unclear. We comprehensively quantified the association between depression and anxiety defined by symptom scales or clinical diagnosis and the risk of cancer incidence, cancer-specific...
pubmed.ncbi.nlm.nih.gov
The link between depression and anxiety status and cancer outcomes has been well-documented but remains unclear. We comprehensively quantified the association between depression and anxiety defined by symptom scales or clinical diagnosis and the risk of cancer incidence, cancer-specific mortality, and all-cause mortality in cancer patients....Subgroup analyses demonstrated that clinically diagnosed depression and anxiety were related to higher cancer incidence, poorer cancer survival, and higher cancer-specific mortality. Psychological distress (symptoms of depression and anxiety) was related to higher cancer-specific mortality and poorer cancer survival but not to increased cancer incidence. Site-specific analyses indicated that overall, depression and anxiety were associated with an increased incidence risks for cancers of the lung, oral cavity, prostate and skin, a higher cancer-specific mortality risk for cancers of the lung, bladder, breast, colorectum, hematopoietic system, kidney and prostate, and an increased all-cause mortality risk in lung cancer patients.
These analyses suggest that depression and anxiety may have an etiologic role and prognostic impact on cancer, although there is potential reverse causality; Furthermore, there was substantial heterogeneity among the included studies, and
the results should be interpreted with caution. Early detection and effective intervention of depression and anxiety in cancer patients and the general population have public health and clinical importance.