In the last decades, the incidence of thyroid cancer (TC) has more than doubled, but the disease-specific mortality rate was stable. To date 30-40% of all TC is represented by papillary microcarcinomas (mPTC), an indolent tumor, that probably remained undiagnosed before routine ultrasound use.
In 1993, Miyauchi was the first who hypothesized a conservative approach for low-risk mPTC and introduced the concept of active surveillance (AS) in its clinical management. The progression rate of mPTC during AS was low and delaying surgery did not impact on the efficacy of treatment or outcome. Since then, several authors from all over the world have reported their experience on AS in mPTCs.
As suggested by current guidelines, AS can be considered as an alternative to immediate surgery to avoid over-treatment in low-risk mPTC and may be the strategy to avoid complications from unnecessary surgery. In the last years, the AS inclusion criteria have been extended to both bigger tumors and to younger/healthier patients. The adoption of AS should take into consideration not only tumor characteristics, but also patient psychological profiles and medical team expertise.
Its safety and efficacy have been demonstrated in long-term outcome studies and in other types of tumors, however, scepticism in patients, families and physicians should be overcome by strong recommendations coming from scientific guidelines.
This review analyses the several and different experiences on AS and the potential obstacles in implementing it as a routine approach in mPTC patients.