For most cutaneous basal cell and squamous cell carcinomas (nonmelanoma skin cancers [NMSC]) 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 NMSC treated with the most common treatments in two practices in 1999–2000. Recurrence was determined from medical records by observers blinded to treatment type. 24.3% of tumors (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). Follow-up was available for 1174 patients with 1488 tumors (93.8%) at median 7.4 years; 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 NMSC were at least 95% effective, and further studies are needed to guide therapeutic choices for different clinical subgroups.

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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.

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, deter-mined 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.

Activation of the innate immune receptor NLRP1B leads to the formation of an inflammasome, which induces autoproteolytic processing of pro-caspase-1, and ultimately to the release of inflammatory cytokines and to the execution of pyroptosis. One of the signals to which NLRP1B responds is metabolic stress that occurs in cells deprived of glucose or treated with metabolic inhibitors. NLRP1B might therefore sense microbial infection, as intracellular pathogens such as Listeria monocytogenes and Shigella flexneri cause metabolic stress as a result of nutrient scavenging and host cell damage. Here we addressed whether these pathogens activate the NLRP1B inflammasome. We found that Listeria infection activated the NLRP1B inflammasome in a reconstituted fibroblast model. Activation of NLRP1B by Listeria was diminished in an NLRP1B mutant shown previously to be defective at detecting energy stress and was dependent on the expression of listeriolysin O (LLO), a protein required for vacuolar escape. Infections of either Listeria or Shigella activated NLRP1B in the RAW264.7 murine macrophage line, which expresses endogenous NLRP1B. We conclude that NLRP1B senses cellular infection by distinct invasive pathogens.KEYWORDS Listeria monocytogenes, NLRP1B, Shigella, caspase-1, inflammasome N LRP1B is a pattern recognition receptor that forms a multiprotein complex termed an inflammasome after it detects an activating signal (1). The NLRP1B inflammasome complex consists of multiple copies of NLRP1B and pro-caspase-1. The assembly of the complex leads to autoproteolysis of pro-caspase-1 and, consequently, to processing of inflammatory cytokines interleukin-1␤ (IL-1␤) and IL-18 and to a type of cell death called pyroptosis (2, 3). NLRP1B has four domains (2) (Fig. 1A). The N-terminal NACHT domain (a domain present in NAIP, CIITA, HET-E, and TP-1) is a nucleotide-binding domain that selfassociates. The leucine-rich repeat (LRR) domain is involved in autoinhibition (4, 5), and the function to find domain (FIIND) undergoes autoproteolytic processing, which facilitates inflammasome assembly (6-8). The C-terminal caspase-activating and recruitment domain (CARD) binds the CARD of pro-caspase-1 (4).Anthrax lethal toxin is the only known direct activator of murine NLRP1B (1). The proteolytic component of the toxin cleaves NLRP1B near its N terminus; this cleavage is sufficient to relieve autoinhibition and allow oligomerization (9-11). Depletion of intracellular ATP is another activator of NLRP1B but one that probably triggers inflammasome assembly indirectly (12). The N-terminal region of NLRP1B is not cleaved after depletion of ATP, and the FIIND of NLRP1B facilitated the detection of this signal instead (5). Thus, activation of NLRP1B occurs through at least two distinct mechanisms.The intracellular parasite Toxoplasma gondii is also detected by NLRP1B (13,14), although the direct signal has not been determined. It is possible that Toxoplasma infection causes a reduction in cytosolic ATP. Notably, the parasite cannot synthesiz...