Obesity affects survival odds for ovarian cancer

According to research in the U.S. obese women get more aggressive ovarian cancers, have a shorter time before the cancer recurs and a shorter survival compared to women who are not obese.

Ovarian cancer can occur at any age, but is most common after the menopause. A woman's risk of getting ovarian cancer during her lifetime is about 1 in 58. The risk of getting this cancer and dying from it is 1 in 98.

Ovarian cancers are difficult to diagnose and by the time it is diagnosed, most women are in the late stages of the disease and about 70% die within five years, making it one of the most lethal cancers.

This is not the first time that obesity has been implicated in increasing the risk for developing certain cancers and obesity has also been linked with worse outcomes for some patients with cancer.

Other studies have found a compound called insulin-like growth factor 1 (IGF-1) is more evident in obese people than those who are slimmer and IGF-1 correlates with increased breast cancer risk in women.

This study however suggests fat tissue might also affect how a tumour progresses and the researchers believe fat cells excrete a hormone or protein that makes ovarian cancer cells grow more aggressively.

The researchers from the Cedars-Sinai Medical Research Center in California recently carried out an evaluation from data on body mass index and outcomes among patients diagnosed with ovarian cancer.

In a study which involved 216 patients the researchers looked at the disease course of epithelial ovarian cancer - the most common type of ovarian tumours, accounting for 90% of cases. They all had various stages of ovarian cancer and underwent surgery for their cancer at Cedars Sinai Medical Center between 1996 and 2003.

The team found that of the 149 patients diagnosed with advanced ovarian cancer, those with an increased body weight had a significantly reduced time before a cancer recurrence and a decreased survival time.

The researchers say this indicates that patients with advanced ovarian cancer have a significantly worse outcome if they are obese.

The results add support to a growing body of evidence that obesity is associated with worse outcomes among patients with cancer and experts agree that maintaining a healthy weight is one of the best ways to reduce the chances of getting cancer.

Lead researcher Dr. Andrew Li says the study is the first to identify weight as an independent factor in ovarian cancer, in disease progression and overall survival, which he says suggests there is an element in the fat tissue itself that influences the outcome of the disease in obese women.

Dr. Li says the next step will be to examine exactly how fat might influence tumour growth.

The research is published in the online version of the journal Cancer.