van Winden MEC, Hetterschijt CRM, Bronkhorst EM, et al. - According to this observational cohort study, watchful waiting (WW) was an appropriate approach in several patients in this cohort study of patients with basal cell carcinoma (BCC), especially those with asymptomatic nodular or superficial BCCs and a limited life expectancy. Patients should be followed up on a regular basis to see if a WW approach is still appropriate and if patients still prefer WW, as well as to reconsider the consequences of treatment and refraining from treatment.

• With a median (interquartile range [IQR]) follow-up of 9 (4-15) months, 280 BCCs were chosen for watchful waiting in 89 patients (47 men [53%] and 42 women [47%]).

• The included patients ranged in age from 73 to 88 years old.

• Patient-related factors or preferences (ie, prioritisation of comorbidities, severe frailty, or limited life expectancy) were reasons for initiating WW in 74 (83%) patients, followed by tumor-related factors (n = 49; 55%).

• For 35% and 46% of the patients, respectively, treatment-related and circumstantial reasons were important.

• A small percentage of tumors grew in size (47%).

• Tumor growth was linked to BCC subtype but not to initial tumor size or location.

• The estimated tumor diameter increase in 1 year for BCCs with at least an infiltrative/micronodular component was 4.46 mm and 1.06 mm for the remaining BCCs (only nodular/superficial component/clinical diagnosis).

• Tumor burden or potential tumor burden, resolved reason(s) for WW, and reevaluation of patient-related factors were the most common reasons for starting treatment.