WEDNESDAY, Jan. 15, 2003 (HealthDayNews) -- Women with advanced ovarian cancer whose tumors contain T-cells live longer than women whose tumors lack these important infection-fighting white blood cells.
The findings, which appear in tomorrow's issue of The New England Journal of Medicine, may one day change the way treatments are structured for ovarian cancer patients.
According to the American Cancer Society, more than 14,000 women die of ovarian cancer every year. As with other cancers, the survival odds increase dramatically the earlier the malignancy is caught. If the cancer has not spread beyond the ovaries, 95 percent of women will still be alive in five years. Overall, however, only slightly more than half the women diagnosed with ovarian cancer will survive beyond five years.
Although there has already been a lot of work involving tumor-infiltrating T- cells, particularly with other types of cancers, the prognosis for patients was unclear.
"As far as ovarian cancer was concerned, people have demonstrated that tumor-infiltrated lymphocytes [white blood cells] could indicate tumor immune response, but no one knew if they played a role in determining [the] course of the disease," says Dr. George Coukos, senior study author and director of the gynecologic malignancy research programs at the University of Pennsylvania. "What we are showing for the first time is that, indeed, tumor-infiltrating lymphocytes that indicate tumor immune response play an important role. They have a dramatic effect."
In this study, the researchers evaluated 186 frozen tissue specimens from advanced ovarian carcinomas to see whether the T-cells were present.
The results were striking: The five-year overall survival rate for patients whose tumors contained T-cells was 38 percent. For patients who did not have the cells, that number plummeted to 4.5 percent.
Women with tumor-infiltrating T-cells lived without a progression of their cancer for almost four times as long as patients without the telltale cells. Their survival rate was 2.8 times longer.
The results held fast regardless of what kind of treatment the woman had received. "We found that the prognostic power of lymphocytes is completely independent of chemotherapy and surgery," Coukos says.
The news was even better for a subset of patients who had their tumors surgically removed and who had a complete response to chemotherapy. "If these patients also had lymphocytes, the long-term survival is extraordinary," Coukos says. "We found up to a 70 percent survival rate at 10 years, which is unheard of in ovarian carcinoma."
What does this mean for cancer patients? "We have a new marker that can predict the outcome," Coukos says. "The idea is that it can potentially help us to tailor the therapies for specific patients. Right now, we're treating everybody the same way and people may respond well but they may not respond and then we're stuck."
Some courses of chemotherapy suppress the immune system while others don't. The presence or absence of T-cells could influence which type to use.
An added advantage is that the test to determine the presence of lymphocytes is a simple one. "Any pathology lab can do it," Coukos says.
"That is the first step. It opens a huge door basically to new therapeutics," Coukos says. "It really provides a strong rationale that we should be very actively looking for immune therapies in ovarian cancer. What we are really showing is that there is an immune response and that that immune response makes a difference."
The next goal is to reproduce the 70 percent survival rate found in that subset of patients in all patients. "We need to try to make everybody look that good," Coukos says.
However, don't look for these improvements tomorrow.
"It's a good piece of work, but these results are very preliminary," cautions Dr. Giuseppe Del Priore, assistant director of gynecologic oncology at New York University Medical Center and director of the Cancer and Fertility Society. "Vaccine trials in many sites like melanoma have been somewhat successful, but in other tumors, not so successful. Even direct infusion of these types of cells into patients has not been universally successful."
"We proceed in tiny steps," he adds. "There is not going to be a home run hit anytime soon in ovarian cancer, but that doesn't mean we shouldn't stop trying and keep advancing slowly."
More information
For more on ovarian cancer, visit the National Cancer Institute or the American Cancer Society.
