Ovarian cancer, one of the most deadly forms, is made worse by obesity, researchers have found. Time before recurrence and survival rates are both shorter for obese women who suffer from this disease.

Investigators found that obese ovarian cancer patients suffered recurrence of the disease and died sooner than their normal-weight counterparts.

The researchers reviewed the medical records of 216 women who had epithelial ovarian cancer, 8 percent of whom were underweight. Fifty percent were in the normal weight category, 26 percent were overweight, and 16 percent were obese. Obesity is defined as having a body mass index of 30 or higher.

Those patients who were in the overweight category, defined as having a BMI of 25 or higher, were found to experience shorter disease-free survival times than women with lower BMIs. As BMI increased, so did the chance of death from the cancer.

Ovarian cancer typically has a poor prognosis. In most cases, it is not diagnosed until the advanced stages, and more than two-thirds of afflicted women die within five years.

Principal investigator Andrew Li of the Cedars-Sinai Women's Cancer Research Institute in Los Angeles suggested that fat tissue may have characteristics that influence the outcome of the disease.

The study is the first to identify weight as an independent factor in the progress of ovarian cancer as well as the overall chance of survival, he noted. Li is also assistant professor-in-residence at the UCLA David Geffen School of Medicine.

About one in 60 women are stricken with ovarian cancer in the US, while about one in three adults over 20 are obese.

Obesity has been linked to endometrial cancer as well as cancers of the kidney, breast and colon. Earlier studies also have shown that obesity affects the development and progression of uterine and colorectal cancers.

Further studies are needed, Dr. Li said, to examine the relationship of obesity and ovarian cancer more closely, as well as to determine the biological mechanisms that influence tumor growth.

Ovarian cancer accounts for approximately 4 percent of all women's cancers and is the fourth leading cause of cancer-related death among women in the United States, according to the National Cancer Institute.

The incidence rate for ovarian cancer has been slowly declining since the early 1990s.

However, ovarian cancer still has the highest mortality of all cancers of the female reproductive system.

White women have higher incidence and mortality rates than other racial and ethnic groups.

It is estimated that approximately $2.2 billion is spent in the United States each year on treatment of ovarian cancer, the NCI concludes.