Original article
Brigham and Women's Hospital tumor classification system for basal cell carcinoma identifies patients with risk of metastasis and death

https://doi.org/10.1016/j.jaad.2021.01.052Get rights and content

Background

Despite approximately 4400 locally advanced US cases annually, high-stage basal cell carcinoma (BCC) is ill-defined.

Objective

To develop a tumor (T) staging system for BCC that will predict metastasis/death and compare its performance with that of the American Joint Committee on Cancer 8th edition (AJCC8) T-staging system.

Methods

Brigham and Women's Hospital (BWH) T staging was developed from a previously published nested cohort of 488 primary BCCs. Tumors were staged via BWH and AJCC8 T-staging systems, and predictions of metastasis and/or death were compared.

Results

The BWH and AJCC8 T-staging systems both captured all metastases/deaths in high T stages (BWH, T2; AJCC8, T3/T4). BWH T2 included 54% fewer cases ≥2 cm than AJCC8 T3/T4. BWH had a higher specificity (0.92 vs 0.80; P < .001) and positive predictive value (24% vs 11%, P < .001) for identifying cases at risk for metastasis/death, and the C-statistic was superior for BWH (P < .001). The BWH T2 10-year cumulative incidence of metastasis/death was 37% (95% confidence interval, 21%-60%).

Limitations

Two-center cohort.

Conclusions

BWH and AJCC 8 BCC staging both capture all metastases and deaths in the upper stages. However, BWH staging does so in half the number of cases, thus minimizing inappropriate up-staging. The risk of metastasis or death in BWH T2 BCC is sufficient to warrant surveillance for recurrence and clinical trials of adjuvant therapy.

Section snippets

Methods

Data collection procedures have been previously published.8 In brief, a cohort was assembled of all histologically confirmed, dermally invasive primary BCCs at Brigham and Women's Hospital (BWH) and Massachusetts General Hospital between 2000 and 2009, including all BCCs with a tumor diameter of 2 cm or greater (n = 244) and an equal number of randomly selected BCCs of less than 2 cm, for a total cohort of 488 cases. Superficial BCCs were excluded because they are characterized by minimal

Results

The Supplemental Table I (available via Mendeley at https://doi.org/10.17632/pxf2g7yjsf.1) details the characteristics of the cohort, which included 388 patients and 488 tumors that gave rise to 12 M/Ds. The average age at time of BCC diagnosis was 65.2 years, and the median follow-up was 84.5 months (interquartile range, 35-122.5). The majority of patients were men (54%), and the majority of tumors were located on the head/neck (62%) and treated via Mohs micrographic surgery (61%). There were

Discussion

The proposed BWH T-staging system for BCC identifies a subset of BCCs with a clinically significant risk of M/D as designated by the T2 stage. Tumors classified as BWH T2 are at least 2 cm in diameter with 2 or more of the following risk factors: head/neck location, tumor diameter of 4 cm or greater, or depth beyond fat. Although all cases of M/D arose from high-stage BCC tumors, as classified by either staging system (BWH T2 or AJCC 8 T3/T4), BWH T staging had greater specificity (92% vs 80%)

Conflicts of interest

None disclosed.

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    • Cited by (0)

    Funding sources: Supported by Genentech, Inc, which provided an unrestricted grant for the conduct of this study.

    IRB approval status: The Partners Human Research Committee approved this study.

    Reprints not available from the authors.

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    © 2021 by the American Academy of Dermatology, Inc.