WHAT WAS LEARNED
Both tumor classification systems had similar monotonicity and homogeneity. However, BWH was found to be superior to AJCC 8 and had a higher specificity (93%) and positive-predictive value (30%) for identifying cases at risk for metastasis and death. “Although AJCC 8 is an improvement over AJCC 7, the T2 and T3 groups have significant overlap. This creates a large heterogeneous group of tumors with similar risks — approximately 12% to 14% risk of nodal metastasis. This limits utilization of the staging system to guide work-up and treatment since it would require diagnostic studies and advanced treatment in a lot of tumors,” Dr Ruiz explained in an interview with Oncology Nurse Advisor.
The AJCC 8 has a large heterogeneous T2/T3 group (23%), which has an approximate 13% risk of nodal metastasis and an 8% risk of disease-specific death. However, in comparing AJCC 8 to BWH, the researchers found that most poor outcomes (70% of nodal metastasis and 92% of disease-specific death) were confined to just 9% of patients with BWH T2b/T3 tumors. The study also showed that AJCC 8 classified twice as many tumors as high tumor class compared with BWH (18% vs 9%).
The BWH was found to be superior in predicting nodal metastasis and disease-specific death; however, no differences were observed for local recurrence and overall survival. “The BWH staging system captures similar numbers of poor outcomes in the higher stages (ie, T2b and T3), but half the number of tumors are classified as higher-stage tumors compared with the higher stages of AJCC 8. This improves the positive predictive value of the system. This point combined with the fact that there is no overlap in the confidence intervals and so the risks of poor outcomes in BWH T2a and T2b are distinct, thus allowing for better utilization of the system in clinical practice,” said Dr Ruiz.
IMPLICATIONS FOR NURSES
The researchers note that a primary limitation of the current analysis is that it is based on a single institution cohort. This may be of particular importance because the measurement of perineural invasion may not be uniformly measured at all medical facilities. Therefore, an improvement in standardization is needed before these 2 tumor classification systems can be fully investigated in multicenter studies.
The current study demonstrated that AJCC 8 and BWH high tumor classes capture most poor outcomes. However, it also showed that AJCC 8 classifies twice as many tumors in a high tumor class. Dr Ruiz and colleagues concluded that the adoption of the BWH tumor classification system may minimize the number of patients recommended for radiologic evaluation, close surveillance, and possible adjuvant therapy without misidentifying patients at risk for recurrence, metastasis, and death.
“Utilization of the BWH staging system allows identification of 70% of poor outcomes in the higher stages. Tumors staged as BWH T2b/T3 may benefit from radiologic imaging and closer surveillance. A subset may need adjuvant therapy as well. Nurses in our clinical practice are very helpful with identifying patients at high risk for poor outcomes,” said Dr Ruiz.
Stamell Ruiz E, Karia PS, Besaw R, Schmults CD. Performance of the American Joint Committee on Cancer Staging Manual, 8th Edition vs the Brigham and Women’s Hospital Tumor Classification System for Cutaneous Squamous Cell Carcinoma. JAMA Dermatol. 2019;155(7):819-825.
This article originally appeared on Oncology Nurse Advisor