BOSTONPatients diagnosed with orbital lymphoma should have a
complete staging workup before radiation therapy, according to a Rare
Cancer Network presentation at the American Society for Therapeutic
Radiology and Oncology (ASTRO) annual meeting.
Radiation therapy was shown to be an effective treatment in a
retrospective study of 88 consecutive patients with orbital lymphoma
treated at 11 European institutions between 1980 and 1999, as
analyzed by Dr. Sylvie Martinet, the principal investigator. In
multivariate analysis, neither technique nor dose influenced
disease-free survival, but complete staging did, along with age less
than 65 and conjunctival localization.
Fewer Recurrences
Rene O. Mirimanoff, MD, professor of radiation oncology, University
of Lausanne and Centre Hospitalier Universitaire Vaudois, Lausanne,
Switzerland, and Dr. Martinet reported that the disease recurred in
one third of patients who did not have complete staging but in only
one eighth of those who did.
A full staging workup consists of chest x-ray, abdominal ultrasound
and/or thoracoabdominal CT scan, bone marrow assessment, CBC, and
LDH. Dr. Mirimanoff told ONI that a complete workup is
important because some of those patients may have lymphoma
elsewhere in the body.
All of the patients reviewed had Ann Arbor stage I or II primary
orbital lymphoma. The median age was 64. Complete remission was
achieved in 98% (86 patients) immediately after radiation therapy.
Five-year disease-free survival was 65%; 5-year overall survival was
76%. The median follow-up was 58 months.
Most of the patients had a single orbital localization: conjunctiva
(25), orbit (25), or eyelid (15). Surgical excision was performed in
29 patients, and 11 had chemotherapy in addition to radiation
therapy. Eighteen patients had a systemic relapse, and seven
developed metachron-ous contralateral eye involvement.
The most prominent late toxicities were cataracts and xerophthalmia.
There was no correlation between the development of cataracts and
lens shielding.
The study was conducted to find the most appropriate treatment for
the disease, which occurs too infrequently for a prospective clinical
trial to be performed.
Chemotherapy is not needed in the majority of cases, he
said, pointing to the research groups conclusion that
moderately low dose radiation therapyless than 34 Gy is
usually sufficient.
About 35 centers participate in the Rare Cancer Network, which was
started in 1993. Dr. Mirimanoff said its purpose is to help
researchers collect, analyze, and publish data on any type of
cancer so uncommon that there is no large series in the literature,
no more than 10 to 20
cases in any study. Unusual presentations of common cancers are
also eligible for investigation. Orbital lymphoma, for example,
accounts for only 10% to 15% of all orbital tumors and 1% of all
lymphomas, Dr. Mirimanoff said.
Any researcher at a member institution can initiate a study by
sending out an invitation asking other members whether they have
cases of a rare cancer and want to participate. In this manner, the
group hopes to collect enough cases to do meaningful retrospective
studies when a prospective trial is not possible.
No US institutions currently are members of the network, but Dr.
Mirimanoff welcomes new members and can be contacted at rmiriman@chuv.hospvd.ch.