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1st
appeared 17 May 1999
Melanoma Patients' Sentinel Lymph Nodes Play
Strong Role in Disease Prognosis, UCSF Study Finds
Researchers at UC San Francisco report that melanoma patients whose cancer has spread to
their sentinel lymph nodes (SLNs) have a greater chance of experiencing disease recurrence
and mortality compared to those whose cancer has not advanced to their SLNs.
 The sentinel lymph node (SLN) earned its name because it is the first region in
a person's body that receives cancer cells from the place where the disease originated.
After cancer cells drain to the SLN, the disease may spread, or metastasize, to other
regions of the body. Lymph nodes are the body's first line of defense against infections
and cancers. They produce infection-fighting lymphocytes that are distributed via the
lymphatic system that functions as a channel of freeways throughout the body.
"Sentinel lymph nodes are a strong marker for predicting a patient's outcomes in
regards to disease recurrence and death due to advanced melanoma," says Stanley P.L.
Leong, UCSF professor of surgery and director of the Sentinel Lymph Node program in the
UCSF Cancer Center. "We found that patients who have a positive SLN biopsy are more
likely to experience a disease recurrence and die from melanoma than those with a negative
SLN biopsy."
Leong presented data on the role of SLNs in melanoma on Saturday, May 15, at the American
Society for Clinical Oncology (ASCO) meeting.
During the UCSF study, a total of 358 advanced melanoma patients underwent a selective SLN
dissection and were followed for a median period of 546 days. Leong reports that for
patients whose cancer spread to their SLNs and therefore had a positive SLN biopsy (63),
78 percent had no evidence of disease and 22 percent experienced recurrent melanoma.
Eighty-six percent of these patients remained alive and 14 percent (9) died from melanoma
by the end of the study.
For patients with negative SLNs (295), 93 percent showed no evidence of disease and 7
percent developed a recurrence of the disease. Ninety-seven percent of these patients
remained alive and 3 percent (9) died by the end of the study. Of the nine deceased
patients, 44 percent died of melanoma and 56 percent died of causes unrelated to the
disease.
Study participants underwent a SLN dissection using selective techniques called
preoperative lymphoscintigraphy and intraoperative lymphatic mapping. These procedures
allow surgeons to pinpoint the SLN where cancer potentially could have spread (only 18
percent of all melanoma spreads to a person's lymph nodes) by injecting a blue dye and/or
radiocolloid substance that enters lymphatic capillaries and concentrates in the SLNs. A
hand-held gamma probe can be used to further identify a radiolabeled SLN.
"Selective sentinel lymph node dissection helped to solve a clinical dilemma by
providing us with the necessary information regarding the status of a patient's cancer
without having to remove all of a person's lymph nodes," Leong says. "A
selective SLN dissection functions like a staging procedure for melanoma because the
results tell us what a patient's next treatment steps should be to manage their
disease."
He adds that a patient who has negative SLN biopsy can be assured that the likelihood of
their disease recurring or spreading to other parts of the body is very low; therefore,
experiencing great psychological relief.
"We now know the relationship between positive SLN biopsies and disease recurrence
and mortality rates," Leong says. "In future clinical trials, we aim to
determine if SLN biopsies will also enhance survival rates in patients."
Links:
UCSF Cancer Center
American Society for Clinical Oncology
Source: Abby Sinnott, News Services |
