Deep Shave Removal of Suspected Basal Cell Carcinoma: A Prospective Study

Abstract

BACKGROUND

Diagnosis and treatment of basal cell carcinoma (BCC) in the same visit by shave removal may decrease health care spending and promote patient satisfaction.

OBJECTIVE

To prospectively evaluate deep shave removal of lesions clinically suspicious for low-risk BCC on the trunk or extremities in immunocompetent patients.

MATERIALS AND METHODS

Deep shave removal with the intent to remove the entire tumor was performed from January 2015 to June 2016, and patients were followed prospectively for clinical evidence of tumor recurrence.

RESULTS

Seventy-seven lesions were removed from 51 patients, including 29 (37%) superficial and nodular BCCs, 27 (35%) superficial BCCs, 16 (21%) nodular BCCs, and 5 (6%) non-BCCs. Fifteen BCCs (21%) had positive residual margins after deep shave removal, which was significantly more likely to occur in nodular compared with superficial BCCs (odds ratio 5 7.8, 95% confidence interval 5 1.4–43), and underwent re-excision. Fourteen specimens initially reported to have negative margins after deep shave underwent resectioning, which revealed positive margins in 4 specimens (28.6%). No BCCs have recurred clinically after an average follow-up of 50 months (SE 3.2).

CONCLUSION

Consider deep shave removal for low-risk BCCs on the trunk or extremities in immunocompetent patients hoping to avoid a second treatment visit.

Basal cell carcinoma (BCC), the most common type of skin cancer, occurs in approximately 2 million Americans annually with an incidence that continues to rise.^1,2 Traditionally, clinically suspicious BCCs are diagnosed initially with partial biopsy, requiring patients to return to clinic for definitive treatment. Treatment depends on the anatomic location, size, and histological subtype of the tumor, with treatment options including excision, Mohs micrographic surgery, electrodessication and curettage (ED&C), laser ablation, and topical therapy. Considering the rising incidence of BCC, separate clinic visits for diagnosis and treatment amplify the increasing demand and wait time for dermatology services and do so at a significant cost—BCC is the fifth most costly cancer to Medicare.³

Initial deep shave at the time of diagnosis with the intent to remove the entire tumor is a promising option to diagnose and expedite treatment. Cost analysis of “detect-and-treat” versus traditional management schemes suggests an average cost saving of 21% per lesion treated with shave removal at the time of clinical diagnosis.⁴ A simplified approach has the potential to decrease health care spending, increase access to dermatology services, and promote patient satisfaction.

Deep shave removal, also known as tangential shave removal, is already used by some in practice but limited data exist to evaluate its use. A retrospective study of 182 lesions clinically suspicious for primary superficial or nodular BCC on the trunk or extremities reported a high diagnostic accuracy (99%) and low recurrence rate (0.5%) following shave removal after an average follow-up of 5.2 years.⁵ However, this study included a small patient number (20), and only 22% of BCCs in this study had a nodular component.⁶

One concern about using deep shave removal is the potentially low accuracy of reporting margin status after BCC shave removal. Subsequent analysis of shave biopsy specimens originally reported to have negative margins revealed positive margins in 28% and 44% of tumors.^7,8 However, these studies were all retrospective and did not specify whether the intent of the biopsy was to remove the tumor.

The authors prospectively evaluated deep shave removal as a diagnostic and treatment modality for low-risk, primary BCCs on the trunk or extremities in immunocompetent patients.

Methods

This study was approved by the University of Pittsburgh institutional review board. Study enrolment occurred from January 2015 to June 2016 at the University of Pittsburgh Medical Center Department of Dermatology. Patients with lesions less than 2 cm in diameter that were clinically suspicious for superficial and/or nodular BCC on the trunk or extremities were asked to participate in this study. Lesions clinically suspicious for recurrent BCC, more aggressive subtypes like morpheaform BCC, and lesions on the face, hands, feet, or genitals were excluded. High-risk patients with a history of immunosuppression or prior radiation at the site were also excluded.

Patients who consented to the study underwent deep shave removal of the suspicious lesion using a flexible razor blade (DermaBlade) with a 2-mm peripheral margins around the clinical borders of the lesion to the level of the mid-dermis. The procedure was performed by a dermatology resident or attending. Biopsy specimens were examined by the University of Pittsburgh Medical Center Department of Dermatopathology using standard bread-loaf sectioning technique at 3-mm intervals with margin analysis. Lesions with positive margins after deep shave removal underwent standard re-excision with 4-mm margins. Patients were advised to follow-up every 6 to 12 months, per standard of care.

In November 2021, charts were reviewed for evidence of recurrence in each patient, including dermatology visit notes and all dermatopathology reports. If a new BCC was biopsied from a site close to the original lesion, photographs from the original and new biopsy sites were compared to determine whether the biopsies originated from different sites.

To further investigate margin status, 14 specimens with reported negative margins after deep shave removal were randomly selected for serial resectioning at 100 to 150 μm to exhaust the blocks. Additionally, to evaluate for residual tumor in re-excisions after deep shave removal with positive margins, 11 re-excision specimens with no residual tumor reported were resectioned at this interval as well.

Results

Fifty-one patients were followed prospectively after deep shave removal of 77 lesions (Table 1). Patients were predominantly male (69%) and ranged in age from 38 to 89 years (median = 72 years, SD = 12). Most patients (35, 69%) had 1 lesion removed, whereas 9 (18%), 3 (6%), and 4 (8%) patients had 2, 3, and 4 lesions removed, respectively. Most lesions measured between 5 and 10 mm in maximal diameter (median = 7 mm, SD = 2.5 mm).

TABLE 1.

Characteristics of Study Population (n = 51)

Characteristic	No. (%)
Sex
Male	35 (69)
Female	16 (31)
Age (yr)
40–59	9 (18)
60–79	35 (69)
>80	7 (14)
Median	72 (SD = 12)
Number of lesions removed
1	35 (67)
2	9 (18)
3	3 (6)
4	4 (8)

As shown in Table 2, lesions were most commonly removed from the back (50, 65%), followed by the chest or abdomen (15, 18%), upper extremity (11, 14%), and lower extremity (2, 3%). Pathology of the removed lesions demonstrated the following histological subtypes: 29 (37%) superficial and nodular BCC, 27 (35%) superficial BCC, 16 (21%) nodular BCC, and 5 (6%) non-BCC. The 5 non-BCC lesions were clinically suspicious for BCC but pathology upon removal revealed seborrheic keratosis, lichen planus-like keratosis, or epithelial sheath neuroma.

TABLE 2.

Lesion Characteristics (n = 77)

Characteristic	No. (%)
Location
Back	50 (65)
Chest or abdomen	15 (18)
Upper extremity	11 (14)
Lower extremity	2 (3)
Lesion diameter (mm*)
<5	11 (16)
5–9.9	51 (73)
10–14.9	7 (10)
>15	1 (1)
Histologic subtypes
Superficial	27 (35)
Nodular	16 (21)
Superficial and nodular	29 (38)
Not BCC	5 (6)

^*By largest dimension.

BCC, basal cell carcinoma.

After the initial deep shave removal, 15 cases (21%) had positive residual margins (Table 3), most of which demonstrated superficial and nodular histology (7, 47%), followed by nodular (6, 40%) and superficial (2, 13%). Of the 15 lesions with positive margins, 10 (67%) were removed from the back, 3 (20%) from the chest or abdomen, and 2 (13%) from the upper extremity. Residual BCC involved the lateral (5, 33%), deep (8, 53%), and both deep and lateral (2, 13%) margins. After re-excision, 14 of 15 specimens (93%) showed no residual BCC. The remaining 1 nodular BCC required a second excision to achieve clear margins after the first excision had persistent positive lateral margins.

TABLE 3.

Characteristics of Lesions With Positive Residual Margins After Initial Deep Shave (n = 15)

Characteristic	No. (%)
Location
Back	10 (67)
Chest or abdomen	3 (20)
Upper extremity	2 (13)
Lower extremity	0 (0)
Histologic subtype
Superficial and nodular	7 (47)
Nodular	6 (40)
Superficial	2 (13)
Involved margin(s)
Lateral	5 (33)
Deep	8 (53)
Lateral and deep	2 (13)

Nodular and mixed superficial and nodular BCCs were more likely to have positive margins after deep shave removal than superficial BCCs (odds ratio = 7.8, 95% confidence interval [CI] = 1.4–43 for nodular and odds ratio = 4.1, 95% CI = 0.9–18 for superficial and nodular). Lesions at least 1 cm in size were more likely to have positive margins compared with lesions smaller than 1 cm (odds ratio = 2.55, 95% CI = 0.45–14.4). However, this result was not statistically significant. Lesion location, patient age, and patient gender were not significantly associated with an increased risk of positive margins.

Eleven BCCs (15%) in 8 patients were lost to follow-up. Fifty-nine (82%), 53 (74%), and 37 (51%) BCCs were evaluated at 1, 3, and 5 years after deep shave removal, respectively. To date, the authors have noted no clinical evidence of BCC recurrence after an average of 50 months (standard error (SE) 3.2) of follow-up. Excluding those lost to follow-up, the average follow-up duration was 59 months (SE 2.3).

Among the 14 specimens with reported negative margins after deep shave removal that were randomly selected for serial resectioning, an average of 12 slides (SE 1.1) were reviewed per specimen. Positive margins were newly identified upon resectioning in 4 of 14 specimens (28.6%). Three of these specimens were superficial BCC found to have positive lateral margins, and 1 was a superficial and nodular BCC found to have positive lateral and deep margins. One patient with newly identified positive lateral margins on resectioning was lost to follow-up. The remaining 3 patients have been followed in the authors’ department for an average of 66 months (SE 7.4) without clinical evidence of recurrence.

Among the 11 re-excision specimens that reported no residual tumor from patients with positive margins after initial deep shave removal, an average of 43 slides (SE 3.4) were reviewed per specimen. One of 11 specimens (9%) was found to have residual BCC (positive lateral margin) identified on further resectioning. However, the positive margin was not contiguous with the scar from deep shave removal, so this tumor focus was hypothesized to represent a new primary superficial BCC incidentally excised adjacent to the original tumor. This patient was followed in the authors’ department for 9 months and then with a dermatologist outside of the authors’ system for a total of 52 months without clinical evidence of recurrence.

Discussion

The results of this study support deep shave removal as a diagnostic and treatment modality for low-risk, small (<2 cm), primary BCCs on the trunk or extremities in immunocompetent patients who prefer to avoid a second treatment visit. Consistent with previous studies, the physicians of this study identified clinically suspicious BCCs as appropriate for this method with high diagnostic accuracy.^4,5,9 This management approach expedites BCC treatment and has been estimated to decrease treatment cost by an estimated 21% per lesion.⁴ Increased efficiency of care may also improve practice productivity by allowing practices to fill spots with new patient appointments and expand access to dermatologic services.¹⁰ Furthermore, patients may be more satisfied when their skin cancer is diagnosed and treated in the same visit, eliminating the burden associated with attending a second visit (including transportation and time off of work) and with caring for a second procedural site.

Shave biopsy followed by ED&C is another option for diagnosing and treating BCCs in the same visit with a similar cosmetic outcome.⁹ Recurrence after ED&C is relatively low, ranging from 1.6% to 6.9%.^11–14 Deep shave removal has the added benefit of allowing histologic evaluation of treatment margins. In contrast to shave biopsy followed by ED&C, deep shave removal does not destroy surrounding tissue. If necessary for lesions that clinically mimic BCC, such as amelanotic melanoma, additional staging information may be obtained from re-excision specimens.

It is important to note, however, that histologic assessment of margin status after deep shave removal has its limitations. Standard “bread-loaf” sectioning assesses less than 1% of the true tissue margin. Although grossly positive margins requiring re-excision may be identified, smaller tumor islands involving the margin may not be captured. Deep shave removal includes 2 mm lateral margins around the clinical borders of the lesion to the level of the mid-dermis, which is narrower and shallower than a standard excision, thus increasing the risk of positive margins. In the present study, 21% of lesions had positive residual margins after deep shave removal requiring re-excision, which was more likely to occur in BCCs with a nodular component and in BCCs 1 cm or greater in size, although the latter was not statistically significant. Interestingly, additional resectioning at 100 to 150 μm of 14 randomly selected deep shave removal specimens that were initially reported to have negative margins revealed positive margins in 4 specimens (28.6%). Despite the intent to remove the entire tumor via deep shave, this finding is consistent with other retrospective studies revealing false-negative margins in 28% to 44% of BCC shave specimens upon subsequent analysis.^7,8 Due to monetary and time constraints, it would not be feasible to thoroughly section every deep shave specimen at 100 to 150 μm in routine practice.

Although false-negative margins were identified in a subset of patients, there have been no clinically identified recurrences in the study cohort of authors after an average follow-up of over 4 years. The authors considered 2 hypotheses to address this finding. First, several studies have postulated that the host immune system involved in wound healing may mediate some degree of postprocedural tumor regression, although this topic remains controversial in the literature.¹⁵ Up to 20% to 40% of BCC biopsy specimens with positive margins on initial biopsy or excision show no residual tumor on second excision after additional histologic sectioning.^16–18 In the study cohort of the authors, 14 of 15 re-excisions did not reveal any residual tumor, including 10 of 11 specimens that were resectioned at 100 to 150 μm. The local immune response is thought to play a role in spontaneously regressing BCCs, which demonstrate increased infiltration of CD3⁺ and CD4⁺ T cells and increased expression of the interleukin-2 receptor compared with nonregressing BCCs.¹⁹ Similarly, wound healing induced by biopsy is theorized to promote tumor regression, which may decrease the likelihood of recurrence despite small tumor nests that persist after deep shave removal. This phenomenon may explain the lack of clinical recurrence of tumors that were found to have positive margins upon additional sectioning of the deep shave removal specimens.

Conversely, Spencer and colleagues²⁰ suggest that postprocedural inflammation does not clear residual BCC. The rates of tumor clearance in small (<1 cm), primary BCCs that were excised immediately after ED&C (75.9%) were comparable with those that were excised at 1 month after ED&C (78.6%). A similar study observed a small but not significant increase in tumor clearance of small (<1 cm), primary BCCs at 3 months after ED&C (83.3%) compared with immediately after ED&C (75.9%).²¹ However, the authors question why clinical recurrence rates are not higher if residual BCC is identified in 1 in 4 tumors after ED&C. Other theories are that enhanced immune surveillance or changes in stromal fibrosis during the wound healing remodeling phase induce delayed tumor clearance such that significant differences in tumor clearance rates were not captured in these relatively short-term studies.^20,21

Another possibility is that the authors have not yet identified BCCs that are going to recur during the average follow-up period of over 4 years. A large systematic review reported that 66% of recurrent BCCs are diagnosed within 3 years, 74% within 4 years, and 82% within 5 years, regardless of treatment modality.²² The follow-up duration of this study should have been long enough to capture most recurrences, but the possibility of recurrence in subsequent follow-up cannot be excluded.

This study used a flexible razor blade (DermaBlade), the preferred tool for shave procedures at the authors’ institution and by many dermatologists in routine clinical practice. Advantages of the DermaBlade include the blade’s sharpness, which is greater than that of a scalpel and its flexibility, allowing for fine control over the specimen’s width and depth.^23,24 However, the DermaBlade may produce more beveled edges than a scalpel, theoretically increasing the risk of positive lateral margins. After initial deep shave removal in this study, 15 of 72 BCCs (21%) had positive margins. The deep margin was most frequently involved (8, 53%), followed by the lateral margin (5, 33%) and both deep and lateral margins (2, 13%). In contrast, the study by Abramson and colleagues⁵ used a #15 blade scalpel for tangential shave removal and reported a lower rate of positive margins at 1.6% (3 of 182 lesions). However, direct conclusions about the efficacy of a DermaBlade versus scalpel for deep shave removal cannot be made based on these data because this study included more BCCs with a nodular component (58% vs 22% in Abramson and colleagues), which were significantly more likely than superficial BCCs to leave positive margins.

Additional limitations include a risk of overtreating nonmalignant lesions with a deep instead of superficial shave, although as previously mentioned, physicians select lesions appropriate for this method with high diagnostic accuracy. Deep shave removal was performed by several dermatology residents and attendings, thus introducing variability in procedural technique.

Conclusions

Deep shave removal allows for diagnosis and treatment in the same clinic visit but should be reserved for the appropriate tumor in the appropriate patient. Deep shave removal may be considered for low-risk, small (<2 cm), primary BCCs with clearly defined clinical margins on the trunk or extremities in immunocompetent patients who prefer to avoid a second treatment visit. No clinical evidence of tumor recurrence was observed in this study after an average follow-up of over 4 years. Even in patients whose biopsy samples demonstrated positive margins on resectioning, BCCs did not recur in the follow-up time of the study. Given the limitations of margin assessment with standard histologic sectioning, patients with a reliable history of follow-up are preferred to allow for long-term monitoring for recurrence.