Tumor recurrence of keratinocyte carcinomas judged appropriate for Mohs micrographic surgery using Appropriate Use Criteria.

BACKGROUND: The use of Mohs micrographic surgery (MMS) has increased greatly to treat basal cell and cutaneous squamous cell carcinomas (keratinocyte carcinoma [KC]), and consensus-based Appropriate Use Criteria (AUC) were developed to identify tumors for which MMS is appropriate. OBJECTIVE: We sought to compare recurrence rates after different treatments in tumors judged appropriate for MMS. METHODS: We used data from an observational prospective cohort study and retrospectively categorized consecutive tumors as appropriate for MMS according to the AUC. Among appropriate tumors, we used survival analyses to compare 5-year recurrence rates after treatments. RESULTS: Among tumors appropriate for MMS (N = 1483), adjusted 5-year recurrence rates were 2.9% (range, 1.4-4.3%) after MMS, 5.5% (range, 3.1-7.9%) after excision, 4.0% (range, 0.6-7.2%) after destruction, and 5.9% (range, 1.5-10.2%) after other treatments. In tumors treated only with MMS or excision (the most similar subgroups), the adjusted hazard ratio of 5-year recurrence after MMS was 0.6 (95% confidence interval, 0.3-1.0; P = .06). LIMITATIONS: This study is limited by its uncertain generalizability, lack of randomization, and unmeasured characteristics. CONCLUSION: The AUC identified tumors for which recurrence would be less common after MMS than after excision, but the absolute difference in recurrence rates was small.

Timing of subsequent new tumors in patients who present with basal cell carcinoma or cutaneous squamous cell carcinoma.

IMPORTANCE: Patients with basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (SCC) (often termed nonmelanoma skin cancer or keratinocyte carcinoma [KC]) often develop new KCs, but information is limited on the frequency and timing of these subsequent tumors. This information is crucial to guide follow-up care. OBJECTIVE: To determine the timing of subsequent new KCs in patients who present with KC. DESIGN, SETTING, AND PARTICIPANTS: We enrolled a consecutive cohort of 1426 patients diagnosed as having biopsy-proven KC from January 1, 1999, through December 31, 2000, in a university dermatology practice and its affiliated Department of Veterans Affairs dermatology service. After exclusion of patients with basal cell nevus syndrome and immunocompromise, 1284 patients (90.0%) were followed up prospectively for a mean of 5.7 (range, 0-12.3) years. MAIN OUTCOMES AND MEASURES: We assessed the risks for subsequent KCs over time using single-failure and multiple-failure models. We separately assessed outcomes after first lifetime KCs and after nonfirst lifetime KCs. We also performed secondary analyses of the risk for a subsequent BCC after a prior BCC diagnosis and the risk for a subsequent SCC after a prior SCC diagnosis. RESULTS: The risk for a subsequent KC was substantially lower after the first lifetime KC diagnosis: 14.5% (95% CI, 11.9%-17.7%) at 1 year, 31.1% (95% CI, 27.3%-35.3%) at 3 years, and 40.7% (95% CI, 36.5%-45.2%) at 5 years, than after a nonfirst KC: 43.9% (95% CI, 42.0%-45.9%) at 1 year, 71.1% (95% CI, 69.1%-73.0%) at 3 years, and 82.0% (95% CI, 80.2%-83.7%) at 5 years. Secondary analyses of the risks for a subsequent BCC after a prior BCC diagnosis and of a subsequent SCC after a prior SCC diagnosis yielded results consistent with the analyses for the pooled KC sample. CONCLUSIONS AND RELEVANCE: Although all patients with KC are assumed to be at high risk for subsequent tumors, a subset may not develop another KC after their first tumor. Whether these findings are related to biological or behavioral differences or to differences in health care services should be investigated further to inform and improve care. Ongoing routine screening for subsequent KC may not be indicated for all patients with KC. Skin cancer screening can be improved with a better understanding of the course and frequency of subsequent KC diagnoses.

Tumor recurrence 5 years after treatment of cutaneous basal cell carcinoma and squamous cell carcinoma.

For most cutaneous basal cell and squamous cell carcinomas (nonmelanoma skin cancers (NMSCs)), data are insufficient to permit evidence-based choices among treatments. To compare tumor recurrence after treatments, we conducted a prospective cohort study of consecutive patients with primary NMSCs treated with the most common treatments, in two practices in 1999-2000. Recurrence was determined from medical records by observers blinded to treatment type. Follow-up was available for 1,174 patients with 1,488 tumors (93.8%) at median 7.4 years; of these tumors, 24.3% (N=361) were treated with destruction with electrodessication/curettage, 38.3% (N=571) with excision, and 37.4% (N=556) with histologically guided serial excision (Mohs surgery). The overall 5-year tumor recurrence rate (95% confidence interval) was 3.3% (2.3, 4.4). Unadjusted recurrence rates did not differ after 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 (P=0.26), and no difference was seen after adjustment for risk factors. In tumors treated only with excision or Mohs surgery, the hazard of recurrence was not significantly different, even after adjustment for propensity for treatment with Mohs surgery. These data indicate that common treatments for NMSCs were at least 95% effective, and further studies are needed to guide therapeutic choices for different clinical subgroups.

Treatment of nonfatal conditions at the end of life: nonmelanoma skin cancer.

IMPORTANCE: Nonmelanoma skin cancer (NMSC) is the most common cancer and predominantly affects older patients. Because NMSCs do not typically affect survival or short-term quality of life, the decision about whether and how to treat patients with limited life expectancy (LLE) is challenging, especially for asymptomatic tumors. OBJECTIVE: To compare treatment patterns and clinical outcomes of patients with NMSC with and without LLE. DESIGN, SETTING, AND PARTICIPANTS: A prospective cohort study of 1536 consecutive patients diagnosed with NMSC at 2 dermatology clinics: a university-based private practice and a Veterans Affairs Medical Center in San Francisco, California. Patients were recruited in 1999 through 2000 and followed up for a median of 9 years. A total of 1360 patients with 1739 tumors (90%) were included in the final analysis. Limited life expectancy was defined as patients either 85 years or older at the time of diagnosis or patients with multiple comorbidities (Charlson Comorbidity Index of ≥ 3). Treatment options included no treatment, destruction, or 2 types of surgery-elliptical excision or Mohs surgery. MAIN OUTCOMES AND MEASURES: Treatment type. RESULTS: Most NMSCs (69%) were treated surgically, regardless of patient life expectancy. The choice of surgery was not influenced by patient prognosis in univariate or multivariable models adjusted for tumor and patient characteristics. Many patients with LLE (43%) died within 5 years, none of NMSC. Tumor recurrence was rare (3.7% at 5 years [95% CI, 2.6%-4.7%]) in all patients. Although serious complications were unusual, approximately 20% of patients with LLE reported complications of therapy, compared with 15% of other patients. CONCLUSIONS AND RELEVANCE: Most NMSCs are treated surgically, regardless of the patient's life expectancy. Given the very low tumor recurrence rates and high mortality from causes unrelated to NMSC in patients with LLE, clinicians should consider whether these patients would prefer less invasive treatment strategies.

Recurrence after treatment of nonmelanoma skin cancer: a prospective cohort study.

OBJECTIVE: To determine long-term tumor recurrence rates after treatment of primary nonmelanoma skin cancer (NMSC). Data are currently insufficient to permit evidence-based choices among treatments for NMSC. DESIGN: Prospective study of an inception cohort observed for a median of 6.6 years after treatment. SETTING: Dermatology clinic at a Veterans Affairs hospital. Care was provided by dermatology resident or attending physicians. PATIENTS: Consecutive sample of all 495 patients with 616 primary NMSCs diagnosed in 1999 and 2000 and treated with electrodessication and curettage (ED&C), excision, or Mohs surgery. Follow-up was available for 608 tumors (99%). MAIN OUTCOME MEASURE: Tumor recurrence, determined by medical record review, with validation by clinical examination. RESULTS: The mean age at diagnosis was 71 years; 97% were men. Overall, 127 tumors were treated with ED&C (20.9%); 309 with excision (50.8%); and 172 with Mohs surgery (28.3%). Over the course of the study, 21 tumors recurred (3.5% [95% confidence interval (CI), 2.2%-5.2%]): 2 after ED&C (1.6% [95% CI, 0.2%-5.6%]), 13 after excision (4.2% [95% CI, 2.2%-7.1%]), and 6 after Mohs surgery (3.5% [95% CI, 1.3%-7.4%]). CONCLUSIONS: Recurrence of primary NMSC after treatment occurred in less than 5% of tumors. The recurrence rate after ED&C was lower than expected, and the recurrence rate after Mohs surgery was higher than expected. These findings may be related to the risk for recurrence in the treatment groups.