Sentinel Node Biopsy Plus Excision for Cutaneous Melanoma
Sentinel Node Biopsy Plus Excision for Cutaneous Melanoma
Prospectively collected data were extracted from the Melanoma Institute Australia (MIA) database. Patient selection for this retrospective assessment was based on eligibility for SNB at the MIA. Between 1992 and 2008, wide local excision (WLE) was performed in 5840 patients with a single primary melanoma 1.0 mm or more in thickness or when ulceration, Clark level IV or V invasion or a tumor mitotic rate 1 or more per millimeter square was recorded. SNB was discussed with nearly every patient in this study, but some chose not to have the additional procedure or were advised against SNB for reasons including medical comorbidities and advanced age. Lymphatic mapping for SLNB was performed in all patients prior to WLE. After WLE, 2909 (49.8%) patients underwent SNB and 2931 (50.2%) did not (OBS). Of the 5840 patients, 803 (13.7%) were enrolled in the randomized first MSLT-I and those randomized to WLE only did not have an SNB. Patients were excluded from the present study if they had multiple primary melanomas, extracutaneous melanoma, melanoma of the ear, incomplete follow-up, a SNB for recurrent melanoma, an elective lymph node dissection, or no immediate CLND when found to be SN-positive.
WLE was performed in all patients, with surgical clearance margins based on the Australian clinical practice guidelines. These recommend margins of 1 cm for melanomas less than 1.0 mm thick, 1 to 2 cm for melanomas 1.0 to 4.0 mm thick, and 2 cm for melanomas more than 4.0 mm thick. After WLE, 49.8% of patients underwent SNB, using a standard protocol that has been described in detail previously. After removal, the SNs were examined histopathologically as previously described. In patients found to be SN-positive, CLND was performed. Follow-up surveillance intervals of patients was according to clinician preference and varied over time.
Statistical analyses were performed with IBM SPSS (version 19.0, IBM Corp., Armonk, NY). Variables were coded and included in statistical analyses as reported in Table 1. Survival time was measured from date of definitive primary melanoma surgery to first disease recurrence for DFS, to first recurrence in the regional lymph node field for regional lymph node recurrence, to first relapse at a distant site for DMFS, and to last follow-up (censored) or death from melanoma for MSS. P values < 0.05 were considered statistically significant. Additional details of the statistical methods can be found in the Supplemental Methods section available at http://links.lww.com/SLA/A532.
Patients and Methods
Patients
Prospectively collected data were extracted from the Melanoma Institute Australia (MIA) database. Patient selection for this retrospective assessment was based on eligibility for SNB at the MIA. Between 1992 and 2008, wide local excision (WLE) was performed in 5840 patients with a single primary melanoma 1.0 mm or more in thickness or when ulceration, Clark level IV or V invasion or a tumor mitotic rate 1 or more per millimeter square was recorded. SNB was discussed with nearly every patient in this study, but some chose not to have the additional procedure or were advised against SNB for reasons including medical comorbidities and advanced age. Lymphatic mapping for SLNB was performed in all patients prior to WLE. After WLE, 2909 (49.8%) patients underwent SNB and 2931 (50.2%) did not (OBS). Of the 5840 patients, 803 (13.7%) were enrolled in the randomized first MSLT-I and those randomized to WLE only did not have an SNB. Patients were excluded from the present study if they had multiple primary melanomas, extracutaneous melanoma, melanoma of the ear, incomplete follow-up, a SNB for recurrent melanoma, an elective lymph node dissection, or no immediate CLND when found to be SN-positive.
Methods
WLE was performed in all patients, with surgical clearance margins based on the Australian clinical practice guidelines. These recommend margins of 1 cm for melanomas less than 1.0 mm thick, 1 to 2 cm for melanomas 1.0 to 4.0 mm thick, and 2 cm for melanomas more than 4.0 mm thick. After WLE, 49.8% of patients underwent SNB, using a standard protocol that has been described in detail previously. After removal, the SNs were examined histopathologically as previously described. In patients found to be SN-positive, CLND was performed. Follow-up surveillance intervals of patients was according to clinician preference and varied over time.
Statistics
Statistical analyses were performed with IBM SPSS (version 19.0, IBM Corp., Armonk, NY). Variables were coded and included in statistical analyses as reported in Table 1. Survival time was measured from date of definitive primary melanoma surgery to first disease recurrence for DFS, to first recurrence in the regional lymph node field for regional lymph node recurrence, to first relapse at a distant site for DMFS, and to last follow-up (censored) or death from melanoma for MSS. P values < 0.05 were considered statistically significant. Additional details of the statistical methods can be found in the Supplemental Methods section available at http://links.lww.com/SLA/A532.
