Chronic inflammation not linked to ovarian cancer

NEW YORK (Reuters Health) - The results of a study published in the International Journal of Cancer suggest that most factors that may cause inflammation of the ovaries are not associated with a statistically significant increased risk of ovarian cancer.

Chronic inflammation was first suggested as a possible mechanism in the development of epithelial ovarian cancer, which would explain the association between certain factors, such as pelvic inflammatory disease or the use of talcum powder in the pelvic area, and the risk of ovarian cancer, Dr. Penelope M. Webb and colleagues point out.

Epithelial ovarian tumors, which comprise up to 90 percent of all ovarian cancers, are formed in epithelial cells, cells that cover the outer surface of the ovary. Tumor types are generally named after the kind of cell from which they originate. Within the epithelial tumor category, ovarian cancers are further classified as serous, mucinous, endometrioid and clear cell types, with serous tumors being the most common.

The researchers, from the Queensland Institute of Medical Research, Brisbane, Australia, examined factors potentially linked to ovarian inflammation in 1,576 women with invasive tumors and low-malignant potential tumors and 1,509 comparison subjects from the general population.

The use of talcum powder in the pelvic region was associated with a statistically significant increased risk of all types of ovarian cancer combined. The increased risk was strongest for serous and endometrioid tumors, but the risk was only statistically significant for serous tumors.

No associations were observed between pelvic inflammatory disease, human papilloma virus infection or mumps and the overall risk of ovarian cancer. A history of genital herpes also not associated with an increased risk of ovarian cancer, Webb's team reports.

As in other studies, a history of endometriosis nearly doubled the risk of endometrioid tumors and more than doubled the risk of clear-cell ovarian tumors.

Endometriosis is a common condition in which tissue that lines the inside of the uterus (the endometrium), begins to grow in areas outside of the uterus, such as the bowel, the bladder or other surrounding structures. Symptoms include severe cramping, chronic lower back pain, heavy bleeding and infertility.

"Overall we conclude that chronic inflammation does not play a major role in the development of ovarian cancer," the investigators state.

SOURCE: International Journal of Cancer, January 2008.