Patient, Tumor, and Care Characteristics
The study enrolled 1253 eligible patients with 1585primary NMSCs treated with destruction, excision, or Mohs surgery. Follow-up information was available for 1174 patients (93.7%) with 1488 tumors (93.8%) (). Patients lost to follow-up were similar to those with follow-up in most features but were more likely to be female (38% vs. 26%), to have worse mental health status (median SF-12 Mental Component Score 41.2 vs 51.5), and to have BCC rather than SCC (89% vs 75%).
Flow Diagram. Derivation of analytic cohort from consecutive patients diagnosed with NMSC during 1999–2000.
Patients, tumors, and care differed in the treatment groups (). For example, tumors treated with destruction were much less likely to be located in the H-zone of the face, and much less likely to have histological risk factors for recurrence(NCCN, 2011
). Tumors treated with Mohs surgery were smaller, and much more likely to be located in the H-zone of the face.
Characteristics of 1174 patients with 1488 nonmelanoma skin cancers treated with destruction, excision, or Mohs surgery1,2
Size of excisional margins was available for 289 tumors (50.6% of excised tumors); the median margin size was 3.0 mm (IQR 3.0 –.0). Tumor remained at the margins of the excised specimen for 29 tumors (5.1%). Of these tumors, 2 were re-treated with destruction, 11 with additional excisions, 7 with Mohs surgery, and 9 tumors were not re-treated.
The overall median follow-up time after treatment was 7.4 years (3.0–8.8); follow-up duration did not differ (P=0.16) among treatment groups. 652 patients were alive in December 2011 [median follow-up time, 8.5 (7.3, 9.2) years] and 522 had died [median follow-up time, 3.9 (1.6, 7.0) years].
328 patients (41.6% of those alive) with 396 tumors (40.4%) consented to examinations by the study dermatologist. Examined patients and tumors were similar (all P-values>0.1) to those not examined in almost all features, but examined patients had better mental health status (median Mental Component Scores 53.7 vs. 50.0, P=0.002]. Recurrence was suspected in 35 (9%) examined tumor locations. Based on subsequent medical record review, 24 were determined not to be recurrent, 8 were verified to be recurrent, none was probably recurrent, and for 3 tumors, recurrence was uncertain (for these tumors, the study dermatologist had judged the likelihood of recurrence as <20% for two tumors, and 21–40% for one tumor).
Fifty tumors recurred, and three tumors probably recurred. Overall, the unadjusted 5-year recurrence rate was 3.3% [95% CI 2.3, 4.4]. Unadjusted 5-year recurrence rates did not differ significantly (P=0.26) among treatments: 4.9% [2.3, 7.4]after destruction, 3.5% [1.8, 5.2] after excision, and 2.1% [0.6, 3.5], after Mohs surgery.
The median time of detection of recurrence was 3.9 years (1.8–5.3), and did not differ (P>0.11) at the two clinical sites or among treatment groups. depicts the cumulative incidence of recurrence in the treatment groups.
Figure 2a, b, c
a). Cumulative incidence of recurrence among 667 patients with857 NMSCs at the university site. No statistically significant difference (P=0.09) detected in tumors treated with destruction, excision, or Mohs surgery.
The median surgical margin size for excised tumors that recurred was 3.0 mm (3.0-3.0) and for excised tumors that did not recur was 3.0 mm (IQR 3.0–4.0). One of the recurrences occurred after an incomplete excision; this tumor had been subsequently treated with a second excision.
reports 5-year recurrence rates in clinical subgroups. Few characteristics were significantly related to tumor recurrence, including characteristics conventionally considered high-risk.(NCCN, 2011
) Overall, tumors in patients with a history of HIV, in those with multiple NMSCs at presentation, and in those who visited dermatology more often were more likely (P<0.01) to recur.
Mean NMSC recurrence rates five years after treatment in clinical subgroups
contains 5-year recurrence rates after each treatment, in subgroups conventionally considered high-risk.(NCCN, 2011
) There were few differences in the recurrence rates; at the university site recurrence was less likely after Mohs surgery for tumors located in the H-zone of the face (P=0.05), and was somewhat more likely after destruction for invasive tumors (P=0.04).
NMSC recurrence rates five years after different treatments, in subgroups of tumors conventionally believed to be high-risk for recurrence
The final Cox proportional hazard model adjusted for history of HIV infection, multiple NMSCs at presentation, tumor location in the H-zone of the face, histological subtype and invasiveness, and >2 annual dermatology visits during the follow-up period; for analyses of the entire sample, clinical site was also included. Adjusted 5-year recurrence rates were 2.8% [1.8, 3.8] overall, 3.8% [1.4, 6.1] after destruction, 3.3%[1.6, 4.9] after excision, and 1.7% [0.4, 3.0] after Mohs surgery (P=0.26) (Table S1
Comparison of recurrence rates after excision or Mohs surgery
The difference in recurrence rates between excision and Mohs surgery was 1.6% [−0.1, 3.0]. There was no statistically significant difference in the hazard of tumor recurrence after Mohs surgery compared to excision in any of the adjusted models (by site, in the overall sample, and in propensity-matched pairs), which are described in .
Hazard of recurrence after treatment in NMSCs treated with Mohs surgery compared to excision