Immunotherapy
May Prolong Survival for Advanced Ovarian Cancer Patients
May / June 2003
Researchers from the Abramson Cancer Center of the University
of Pennsylvania and the Center on Women’s Health at
the University of Pennsylvania School of Medicine have found
genetic markers that may improve the prognosis for patients
with advanced ovarian carcinoma. The presence of one type
of immune cell (tumor-infiltrating lymphocytes) can predict
the length of remission after chemotherapy and the overall
survival rates of patients with ovarian cancer. This discovery
establishes for the first time the importance of the body’s
natural immunomechanisms, which recognize and attack the tumor,
in the fight against ovarian cancer.
The prognosis for ovarian cancer is primarily based upon
the extent of surgical removal of the tumor and the degree
of differentiation of the tumor cells. The presence of T-cells
in the tumor can now predict a more favorable outcome for
the patient. According to the Penn study, the five-year survival
rate of patients whose tumors were infiltrated by lymphocytes
was 38 percent, as compared to 4.5 percent for patients whose
tumors lacked these lymphocytes.
In addition, only patients
with these tumor-infiltrating lymphocytes survived beyond
five years. “Moreover, a subset of patients who had
optimal surgical resection, complete response to chemotherapy,
and evidence of antitumor response, experienced up to a 70
percent survival at ten years - a remarkable survival
rate for advanced ovarian cancer,” says George
Coukos, MD, PhD, gynecologic oncologist in Penn’s
Department of Obstetrics and Gynecology.
In the past, immunotherapy has been used for ovarian cancer
with little success. “We are much more sophisticated
in understanding why past treatments have failed and know
how to better prepare T-cells,” explains Dr. Coukos.
Data shows that possibly half of the patient population has
T-cells present in their tumors. For those patients without
the presence of T-cells, progress is being made to enhance
tumor response by vaccination. “Vaccines have been tested
in ovarian cancer without much success,” says Dr. Coukos,
“however, huge progress has been made in the last ten
years to understand how to prepare very powerful vaccines.”
Although immunotherapy is still experimental for ovarian
cancer, present research is promising. Recently, the National
Cancer Institute demonstrated a method of preparing T-cells
from tumor infiltrating T-cells in melanoma, which can give
spectacular results. “This proves the concept that immune
therapies have evolved,” explains Dr. Coukos. There
are four major types of immune therapy including vaccine therapy,
adoptive therapy with T lymphocytes, antibody-based therapy,
and cytokine therapy.
“Although the specific details need to be configured,
I anticipate that immunotherapy in combination with surgery
and chemotherapy will become a standard of care for ovarian
cancer,” adds Dr. Coukos. Critical for the most successful
treatment for gynecologic cancer is appropriate surgery to
debulk and stage the tumor. Studies have shown that a gynecologic
oncologist performs the correct surgery in 95 percent of patients
as compared to a general surgeon who will do this in 50 percent
of patients.
“Ideally, a woman needs the presence of T-cells, optimal
surgical debulking and effective chemotherapy for long-term
survival of advanced ovarian cancer. Primary care physicians
play a pivotal role in a patient’s outcome. Guiding
their patients who present with an ovarian mass to the appropriate
surgeon will enable them to receive the highest level of care
for their disease and take advantage of innovative therapies,”
adds Dr. Coukos.
|
