HEALTH PROFESSIONAL · SOURCE READING
Surgical excision with margin evaluation
Source: Skin Cancer Treatment (PDQ®)–Health Professional Version, National Cancer Institute.
Source updated: May 12, 2025 · Captured 2026-09-09.
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A traditional surgical treatment, surgical excision with margin evaluation usually relies on surgical margins ranging from 3 mm to 10 mm, depending on the diameter of the tumor. Re-excision may be required if the surgical margin is found to be inadequate on permanent sectioning. In one trial, 35 of 199 primary BCCs (18%) were incompletely excised by the initial surgery and underwent a re-excision.[12] In addition, many laboratories examine only a small fraction of the total tumor margin pathologically. Therefore, the declaration of tumor-free margins can be subject to sampling error.[13]
In randomized trials, excision has been compared with radiation therapy, Mohs micrographic surgery, photodynamic therapy (PDT), and cryosurgery.
Evidence (surgical excision with margin evaluation):
In a single-center trial, 360 patients with facial BCCs smaller than 4 cm in diameter were randomly assigned to undergo either surgical excision or radiation therapy (55% interstitial brachytherapy, 33% contact radiation therapy, and 12% conventional external-beam radiation therapy [EBRT]).[14][Level of evidence B1] Excisional margins, assessed by frozen section during the procedure in 91% of cases, had to be at least 2 mm, with re-excision if necessary. Thirteen patients were not treated and were dropped from the analysis.
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In a single-center trial, 360 patients with facial BCCs smaller than 4 cm in diameter were randomly assigned to undergo either surgical excision or radiation therapy (55% interstitial brachytherapy, 33% contact radiation therapy, and 12% conventional external-beam radiation therapy [EBRT]).[14][Level of evidence B1] Excisional margins, assessed by frozen section during the procedure in 91% of cases, had to be at least 2 mm, with re-excision if necessary. Thirteen patients were not treated and were dropped from the analysis.
At 4 years (mean follow-up of 41 months), the actuarial failure rates (confirmed persistent or recurrent tumor) were 0.7% in the surgery arm and 7.5% in the radiation therapy arm (P = .003).[15][Level of evidence B1]
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In a single-center trial, 360 patients with facial BCCs smaller than 4 cm in diameter were randomly assigned to undergo either surgical excision or radiation therapy (55% interstitial brachytherapy, 33% contact radiation therapy, and 12% conventional external-beam radiation therapy [EBRT]).[14][Level of evidence B1] Excisional margins, assessed by frozen section during the procedure in 91% of cases, had to be at least 2 mm, with re-excision if necessary. Thirteen patients were not treated and were dropped from the analysis.
The cosmetic results were also rated as better after surgery by both patients and dermatologists, and also by three independent professionals. At 4 years, 87% of surgery patients rated cosmesis as good, versus 69% of radiation therapy patients.[15]
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In a two-center, intent-to-treat analysis, 374 patients with 408 primary facial BCCs were randomly assigned to undergo either surgical excision or Mohs micrographic surgery with at least a 3-mm margin around the visible tumor until there were no positive margins in either case.[12][Level of evidence B1]
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In a two-center, intent-to-treat analysis, 374 patients with 408 primary facial BCCs were randomly assigned to undergo either surgical excision or Mohs micrographic surgery with at least a 3-mm margin around the visible tumor until there were no positive margins in either case.[12][Level of evidence B1]
After 30 months of follow-up, the recurrence rate was 5 out of 171 tumors (3%) in the excision group and 3 out of 160 (2%) in the Mohs micrographic surgery group (absolute difference, 1%; 95% confidence interval [CI], -2.5% to +3.7%; P = .724). There was no difference in complication rates, and overall cosmetic outcomes were similar.[12][Level of evidence B1]
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In a two-center, intent-to-treat analysis, 374 patients with 408 primary facial BCCs were randomly assigned to undergo either surgical excision or Mohs micrographic surgery with at least a 3-mm margin around the visible tumor until there were no positive margins in either case.[12][Level of evidence B1]
Total operative costs were nearly twice as high in the Mohs group (405.79 Euros vs. 216.86 Euros; P < .001).
A multicenter randomized trial included 101 adults with previously untreated nodular skin BCCs, excluding lesions of the midface, orbital areas, and ears. Patients were treated with either excision (at least 5-mm margins) or PDT using topical methyl aminolevulinate cream (160 mg/g) followed by red-light exposure (wavelength 570–670 nm, 75 J/cm2) twice, 7 days apart.[16][Level of evidence B3] A per-protocol/per-lesion analysis was performed on the 97 patients who had an excision or at least one cycle of PDT.
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A multicenter randomized trial included 101 adults with previously untreated nodular skin BCCs, excluding lesions of the midface, orbital areas, and ears. Patients were treated with either excision (at least 5-mm margins) or PDT using topical methyl aminolevulinate cream (160 mg/g) followed by red-light exposure (wavelength 570–670 nm, 75 J/cm2) twice, 7 days apart.[16][Level of evidence B3] A per-protocol/per-lesion analysis was performed on the 97 patients who had an excision or at least one cycle of PDT.
At 3 months, the complete response (CR) rate was 98% of lesions (51 of 52) in the surgery group versus 91% of lesions (48 of 53) in the PDT group (P = .25). CR rates assessed at 12 months were 96% for the surgery group versus 83% for the PDT group (P = .15).[16][Level of evidence B3] The investigators interpreted the results as noninferiority of PDT, but the study may have been underpowered.
Source links and citations
A multicenter randomized trial included 101 adults with previously untreated nodular skin BCCs, excluding lesions of the midface, orbital areas, and ears. Patients were treated with either excision (at least 5-mm margins) or PDT using topical methyl aminolevulinate cream (160 mg/g) followed by red-light exposure (wavelength 570–670 nm, 75 J/cm2) twice, 7 days apart.[16][Level of evidence B3] A per-protocol/per-lesion analysis was performed on the 97 patients who had an excision or at least one cycle of PDT.
Both the investigators and the patients rated the cosmetic results as either excellent or good in a higher proportion of PDT treatments at each time point of follow-up. At 12 months, patient ratings of excellent or good were 98% in the PDT group versus 84% in the surgery group (P = .03), and investigator ratings were 79% versus 38% (P = .001).
In a randomized single-center trial, 96 primary BCCs (patient number unclear) smaller than 2 cm in diameter involving the head and neck area were randomly assigned to either excision with a 3-mm safe margin or cryosurgery (i.e., curettage plus two freeze-thaw cycles by liquid nitrogen spray gun).[17][Level of evidence B3]
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In a randomized single-center trial, 96 primary BCCs (patient number unclear) smaller than 2 cm in diameter involving the head and neck area were randomly assigned to either excision with a 3-mm safe margin or cryosurgery (i.e., curettage plus two freeze-thaw cycles by liquid nitrogen spray gun).[17][Level of evidence B3]
At 1 year, there were no recurrences in the excision group versus three recurrences in the cryosurgery group (P = NS), but this is a very short follow-up time.[17][Level of evidence B3]
Source links and citations
In a randomized single-center trial, 96 primary BCCs (patient number unclear) smaller than 2 cm in diameter involving the head and neck area were randomly assigned to either excision with a 3-mm safe margin or cryosurgery (i.e., curettage plus two freeze-thaw cycles by liquid nitrogen spray gun).[17][Level of evidence B3]
Patients and five independent professionals who were blinded to the treatment arm rated the cosmetic outcomes. Their overall assessments favored excision.
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