PURPOSE: Biochemical remission is the primary treatment goal in acromegaly. However, some patients experience biochemical discordance between growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels following multimodal therapy, complicating disease assessment and management. This study aims to identify predictive factors associated with post-therapeutic biochemical discrepancy.

METHODS: We conducted a retrospective monocentric analysis of 156 patients with GH-producing pituitary adenomas (PAs) who underwent transsphenoidal surgery between 1984 and 2017. Biochemical outcomes were classified into four groups: group 1 (biochemical remission), group 2 (isolated GH normalization), group 3 (isolated IGF-I normalization), and group 4 (persistent acromegaly). Predictive factors for biochemical discrepancy were assessed, including demographic data, tumor characteristics, medication, irradiation, follow up duration, and disease recurrence.

RESULTS: The median age of the cohort was 48.2 years, with a female predominance (61.5%). Most PAs were macroadenomas (79.6%) and invasive (53.9%). Biochemical remission was achieved in 69.9%, while 19.2% exhibited biochemical discrepancy. Univariate analysis identified overall medication (pre- and/or postoperative), irradiation, and invasive PAs as significant factors associated with biochemical discordance. Logistic regression confirmed medication as the most influential predictor, with irradiation as a potential contributing factor. Disease recurrence was the only distinguishing factor between persistent acromegaly and biochemical discrepancy.

CONCLUSION: Overall medication use is the strongest predictor of biochemical discrepancy, with irradiation potentially contributing. No clear distinguishing factors between biochemical discordance and persistent acromegaly were identified, except from disease recurrence. Managing patients with biochemical discrepancy similarly to those with persistent acromegaly may be advisable. Further research is needed to refine treatment strategies.