Rare Ovarian Cancer More Difficult to
Treat
Low-Grade Serous Carcinoma Resists
Chemotherapy
A rare type of ovarian cancer,
recurrent low-grade serous carcinoma, does not respond well to chemotherapy and
is more difficult to treat than more common high-grade ovarian cancers, study
results say.
The research, conducted at
M. D. Anderson, was reported in March during the Society of Gynecologic
Oncologists Annual Meeting on Women's Cancers.
Significance of
research
This retrospective study is the first to look at how low-grade
recurrent ovarian tumors respond to chemotherapy.
The results support a growing body
of research that shows low-grade ovarian tumors behave differently than other
ovarian cancer tumors and are more resistant to chemotherapy than other ovarian
cancers, says lead author David Gershenson, M.D., professor and chair of
M. D. Anderson?s Department of Gynecologic Oncology.
Low-grade serous carcinoma
represents about 10% of serous ovarian cancers.
Background
Because low-grade serous ovarian
cancer is so resistant to treatment, a standard of care does not exist.
In addition, there is no universal
grading system for the cancer. Consequently, there are variations in classifying
and treating the disease.
Research
methods
Researchers searched patient
databases to identify women treated for recurrent low-grade serous carcinoma of
the ovary at M. D. Anderson from 1990 through 2007.
Primary
results
The database search revealed 52
patients who had one or more of 98 different chemotherapy regimens including
platinum-based chemotherapies in which patients were sensitive (more responsive)
and resistant (unresponsive) to treatment.
The researchers found that
the:
- Overall response rate was
4%
- Response rate in
platinum-sensitive disease was 6%
- Overall response rate in
platinum-resistant disease was 2%
Of all the treatments, 62%
stabilized the disease for a median of 22 weeks.
Additional
results
Gershenson said these results
compare unfavorably to treatment of more common ovarian cancers.
"It is unclear whether the high
rate of stable disease is more reflective of tumor biology of low-grade serous
carcinoma of the ovary or of the therapy regimen administered,? he
says.
What?s
next?
Since these tumors do not respond
well to conventional chemotherapies, new agents to treat them must be identified
and tested, Gershenson says.
Hormonal therapy, which has shown
some activity against low-grade serous carcinoma, warrants further exploration,
he says. M. D. Anderson plans a detailed analysis of its experience with
hormonal therapy in the near future.
Recognizing the need for more
research, the Gynecologic Oncology Group, a National Cancer Institute-funded
cooperative group, recently established a
rare tumor committee that has initiated a separate series of clinical trials for
recurrent low-grade serous carcinoma, as well as for other rare ovarian
cancers.
Adapted by Dawn Dorsey
from an M. D. Anderson news release
M. D. Anderson
resources:
Ovarian cancer
David M. Gershenson, M.D.
Gynecologic Oncology Center
Department of Gynecologic
Oncology
Other
resources:
Overview: Ovarian cancer (American Cancer Society)
Gynecologic Oncology
Group