CALCA and medullary thyroid gland carcinoma: Calcitonin levels > 100 pg/mL are highly predictive of medullary thyroid cancer (MTC), whereas concentrations > 500 pg/mL indicate multiple MTC metastases.[31] In conclusion, these results suggest that basal serum PCT levels may be elevated well above the sepsis cutoff in cancer patients, even in the absence of systemic bacterial infections.