Systemic hernial disease protects against cancer: an hypothesis.

Research by herniologists from around the world has shown that abdominal defects, in the adult, are not caused by wear and tear but systemic hernial disease (herniosis), a disorder of connective tissue which affects the extracellular matrix (ECM). Wound healing may be affected, leading to recurrences after hernia repair or primary incisional herniation. Women with genitourinary prolapse show signs of herniosis in the pelvis. Diverticulosis coli, commonly seen in the elderly, like hernia, was once attributed to stress and strain from constipation. It is now suspected that herniosis weakens the colonic ECM, allowing the mucosa to form diverticula by herniating alongside the vasa recta. Remarkably, clinical studies of Saint's triad extending over the past 60 years have repeatedly demonstrated a highly significant relationship between colonic diverticula and abdominal herniae. Krones et al. (Int J Colorectal Dis 21:18-24, 2006) reported that diverticula and cancer are rarely coincident in the colon, despite aging. Their data indicate that the two pathologies arise in different ECMs. Klinge et al. (Int J Colorectal Dis 22:515-520, 2007), quoting Paget (Lancet 1:571-573, 1889), "Tumor cells can like seeds only grow if they fall on congenial soil," suggested that certain genes prevent stromal malignancy by influencing the microenvironment to stop epithelia from becoming cancerous. Thus, damage to the colonic ECM from hernial disease is conducive to diverticulosis, but hostile for cancer. Hernial disease being systemic, a similar ECM should be present throughout the body. Coincident diverticulosis and herniae support this hypothesis. Its validation requires further research involving the lifetime risk of cancer in patients with and without hernia. Since smoking causes both herniation and cancer, data from indulgers will have to be analyzed separately from abstainers.