Relationship between loneliness and proangiogenic cytokines in newly diagnosed tumors of colon and rectum.
OBJECTIVE
To investigate the association of serum levels of proangiogenic cytokines with different indices of social support and loneliness by measuring the levels of expression of two important proangiogenic cytokines, vascular endothelial growth factor (VEGF), and interleukin-6 in tumors of colon and rectum. Lack of social support has been prospectively associated with cancer progression.


METHODS
Fifty-one newly diagnosed patients with colorectal tumors (mean age, 68.3 years) completed two measures of loneliness 1 to 2 days before their surgical treatment. The first was an explicit self-report questionnaire, which tapped into negative feelings as a result of low social support. The second was a standardized computer-based task, which measured loneliness implicitly. Immunohistochemical analyses were performed on tumor tissues post surgery to determine the expression of cytokines.


RESULTS
Logistic regression showed that higher levels of implicit loneliness independently predicted stronger expression of VEGF, controlling for Dukes stage and explicit loneliness, both of which were nonsignificant predictors. No significant relationships were found between the loneliness measures and interleukin-6.


CONCLUSIONS
The results of this study suggest VEGF to be an angiogenic mechanism through which loneliness may lead to worse cancer-related outcomes. Implications are discussed in terms of devising targeted psychosocial and immunotherapeutic interventions for cancer patients with low social support.
Nausheen
Bina
B
Division of Clinical Neurosciences, School of Medicine, University of Southampton, Royal South Hants Hospital, Brinton’s Terrace, Southampton, United Kingdom. bn1@soton.ac.uk
Carr
Norman J
NJ
Peveler
Robert C
RC
Moss-Morris
Rona
R
Verrill
Clare
C
Robbins
Elizabeth
E
Nugent
Karen P
KP
Baker
Alex M
AM
Judd
Mary
M
Gidron
Yori
Y
D015100:3,3'-Diaminobenzidine; D000324:Adrenocorticotropic Hormone; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015179:Colorectal Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000523:psychology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000097:blood; D008132:Loneliness / Q000523:psychology*; D008297:Male; D011379:Prognosis; D012720:Severity of Illness Index; D012944:Social Support; D013564:Sympathetic Nervous System; D047368:Tumor Burden; D042461:Vascular Endothelial Growth Factor A / Q000097:blood*
D015415:Biomarkers; D015850:Interleukin-6; D042461:Vascular Endothelial Growth Factor A; D015100:3,3'-Diaminobenzidine; D000324:Adrenocorticotropic Hormone