IMPORTANCE Cutaneous squamous cell carcinoma (cSCC) has metastatic potential, but the prognostic value of current staging systems in nonselected patients is uncertain. OBJECTIVE To assess the effect of risk factors for metastasis and to evaluate validity and usefulness of 4 staging systems for cSCC using population-based data. DESIGN, SETTING, AND PARTICIPANTS This was a nationwide, population-based, nested case-control study. The Cancer Registry of Norway, which receives compulsory data on all cancers in the Norwegian population of approximately 5.2 million inhabitants. All patients diagnosed as having a primary invasive cSCC in the period 2000 to 2004 (n = 6721) were identified. Of these, 112 patients were diagnosed with metastasis within 5 years. As control patients, 112 patients with cSCC without metastases, matched for sex and age at diagnosis, were identified by random. Clinical data and biopsy specimens of primary cSCC were collected for all 224 patients. The biopsies were reexamined histologically by an experienced pathologist using well-established criteria for cSCC, yielding 103 patients with metastasis (cases) and 81 cSCC without metastasis (controls). Variables necessary for accurate staging were not assessable in 26 patients (14.1%); multiple imputation was therefore performed. MAIN OUTCOMES AND MEASURES The ability of 4 cSCC staging systems (ie, the American Joint Committee on Cancer, 7th edition [AJCC 7] staging system, the staging system used by Breuninger et al, the Brigham and Women's Hospital [BWH] staging system, and the AJCC, 8th edition [AJCC 8] staging systems) to identify patients who developed metastasis with 5 years of follow-up. External validation was performed by logistic regression, discrimination (sensitivity, specificity, proportion correctly classified, concordance index), and calibration (R 2 , Hosmer-Lemeshow test, plots) statistics. RESULTS Of 6721 patients; 3674 (54.7%) were men, and 3047 (45.3%) were women, with a mean age at diagnosis of 78 years. Of the 103 patients with cSCC diagnosed with metastasis within 5 years, 60 [58.3%] were men, and mean [SD] age 72.7 [13.5] years. Of the 81 patients with cSCC without metastasis, 51 [63.0%] were men, and mean [SD] age 74.6 [11.7] 15 years. The staging systems distinguished poorly to moderately between patients who developed metastasis and those who did not. The ability to cluster patients with similar outcomes within the same staging category was low, particularly when using the AJCC 7 system. Using the AJCC 7 system, the risk of metastasis for T2 patientswasmorethan5-fold,comparedwithT1patients(OR,5.55;95%CI,2.24-13.75).Inthesystem usedbyBreuningeretal,high-riskcategoriesfordiameterandtumorthicknessandtheBWHsystem's T2b category collected relatively homogeneous groups. In the systems used by Breuninger et al and Brigham-Women's Hospital, risk of metastasis was significantly elevated with increasing stage or risk category. Using the system by Breuninger et al, the risk of metastasis was 3-fold for tumors in the high co-risk factor ...

The high risk of skin cancer after organ transplantation is a major clinical challenge and well documented, but reports on temporal trends in the risk of posttransplant cutaneous squamous cell carcinoma (SCC) are few and appear contradictory. OBJECTIVE To study temporal trends for the risk of skin cancer, particularly SCC, after organ transplantation. DESIGN, SETTING, AND PARTICIPANTS Population-based, nationwide, prospective cohort study of 8026 patients receiving a kidney, heart, lung, or liver transplant in Norway from 1968 through 2012 using patient data linked to a national cancer registry. The study was conducted in a large organ transplantation center that serves the entire Norwegian population of approximately 5.2 million. EXPOSURES Receiving a solid organ transplant owing to late-stage organ failure, followed by long-term immunosuppressive treatment according to graft-specific treatment protocols. MAIN OUTCOMES AND MEASURES Occurrence of first posttransplant SCC, melanoma, or Kaposi sarcoma of the skin. Risk of skin cancer was analyzed using standardized incidence ratios (SIRs) and, for SCC, multivariable Poisson regression analysis of SIR ratios, adjusting for 5-year time period of transplantation, different follow-up time, age, sex, and type of organ. RESULTS The study cohort included 8026 organ transplant recipients, 5224 men (65.1%), with a mean age at transplantation of 48.5 years. Median follow-up time was 6.7 years per recipient; total follow-up time, 69 590 person-years. The overall SIRs for SCC, melanoma, and Kaposi sarcoma were 51.9 (95% CI, 48.4-55.5), 2.4 (95% CI, 1.9-3.0), and 54.9 (95% CI, 27.4-98.2), respectively. In those who underwent transplantation in the 1983-1987 period, the unadjusted SIR for SCC was 102.7 (95%, 85.8-122.1), declining to 21.6 (95% CI, 16.8-27.0) in those who underwent transplantation in the 2003-2007 period. Adjusting for different follow-up times and background population risks, as well as age, graft organ, and sex, a decline in the SIR for SCC was found, with SIR peaking in patients who underwent transplantation in the 1983-1987 period and later declining to less than half in patients who

Folliculotropic mycosis fungoides is a variant of cutaneous T-cell lymphoma with distinct clinicopathological features. We describe here the clinical presentation, pathology findings and treatment outcome in 15 Norwegian patients. All patients were diagnosed between 1997 and 2010 at Oslo University Hospital. A spectrum of skin lesions, both typical and atypical, such as leonine facies, acneiform lesions, psoriasiform plaques, purulent ulcerations and cystic milia-like lesions for mycosis fungoides, were seen. Histological examination revealed characteristic infiltration of hair follicles with neoplastic T cells associated with partial destruction of the former. A CD4+ immunophenotype of the neoplastic T cells with loss of one or more T-cell markers was demonstrated. In general, the patients were given more aggressive therapeutic regimens than those with conventional mycosis fungoides, and showed a trend towards more rapid disease progression. In conclusion, this case series confirms the distinct clinical and histological features of folliculotropic mycosis fungoides.