Sentinel Node Biopsy May Be Underused for High-Risk Squamous Cell Carcinoma
NEW YORK (Reuters Health) – Sentinel lymph node biopsy (SLNB) is underused and prophylactic lymph node dissection overused in high-risk squamous cell carcinoma (SCC), researchers suggest.
“Cutaneous SCC is the second most common cancer worldwide and has displayed a sharp increase in incidence during the last two decades,” Dr. Ashley Wysong of the University of Southern California, Los Angeles told Reuters Health.
Although SCC generally is characterized by low morbidity and mortality, “a subset of cases have elevated local recurrence, metastasis, and death,” she said by email. “The single most important predictor of mortality in patients with SCC is the development of lymph node metastasis.”
“Updates to SCC staging . . . identify a subset of patients, T2b and T3, with a 30%-50% risk of occult lymph node metastasis found on SLNB,” she noted. “Despite this, there remains a lack of standardization in the work-up and management of these patients.”
“In melanoma,” she noted, “it is standard of care to offer SLNB for patients with T1b melanoma, (which has) an SLNB positivity rate of 7%-10%.”
To investigate the use of SLNB in SCC, Dr. Wysong and colleagues created a database of all high-risk patients with the disease treated at UCLA since 2006. Patient and tumor characteristics were documented, as were treatment modality and whether SLNB was performed.
Preliminary data suggest that less than 0.1% of patients with high-risk SCC tumors underwent SLNB, according to the authors’ research letter in JAMA Dermatology, online November 15.
By contrast, 14% underwent complete lymph node dissections, of which slightly more than half (56.7%) had microscopic metastasis to local lymph nodes. The rest (43.3%) were free of metastasis.
“Overall, we found prophylactic lymph node dissection to be overused and SLNB underused in high-risk SCC,” the authors concluded. “Future prospective studies are needed to further elucidate the use of SLNB in SCC.”
Three experts commented on the findings in emails to Reuters Health.
Dr. Richard Keidan, director of the Multidisciplinary Melanoma and Skin Cancer Clinic at Beaumont Hospital in Royal Oak, Michigan, observed, “SLNB should essentially eliminate and replace the use of an elective lymphadenectomy, thereby saving many patients a major operation that offers no benefit when the pathology is negative.”
“I strongly agree that lymphadenectomy should not be used in high-risk patients with clinically negative nodes (and agree) that SLNB is significantly underused in patients with SCC,” he said.
Dr. Vernon Sondak, Chair, Department of Cutaneous Oncology at Moffitt Cancer Center in Tampa, stated categorically, “I personally don’t believe in and do not utilize SLNB for cutaneous SCC.”