Final Outcome in Growth Hormone-Secreting Adenomas After Combination of Maximal Tumor Resection and Medical Treatment.

[OBJECTIVE] Gross total resection (GTR) is not always possible in acromegalic patients, especially in patients with invasive growth hormone-secreting adenomas. We analyzed the biochemical remission outcome in relation to extent of tumor resection and effectiveness of medical treatment in cases of remnant tumor.

[METHODS] Retrospective analysis was performed of acromegalic patients operated on between 2002 and 2017. Preoperative imaging, tumor invasiveness, extent of resection, and biochemical remission were collected. Patients with tumor remnant not amenable to second surgery began medical treatment. The relationship between pituitary adenoma remnant volume and final biochemical outcome was analyzed.

[RESULTS] Of 120 acromegalic patients operated on, 82 underwent transsphenoidal microsurgery and 38 underwent endonasal endoscopic approach. GTR was achieved in 72 cases (60%); subtotal resection (STR), 21 (17.5%) cases; and partial resection, 27 (22.5%) cases. There was a nonsignificant higher rate of GTR/STR in patients who underwent endonasal endoscopic approach. However, a significantly higher remission rate (89.45% vs. 67.1%) was achieved in these patients (P < 0.01). Greater tumor volume and invasiveness were associated with a lower remission (P < 0.05). Patients with tumor remnant who achieved biochemical remission with added medical therapy had a significantly smaller tumor volume (P < 0.001).

[CONCLUSIONS] The more aggressive surgical resection is, the greater the chance of attaining final biochemical remission, whether or not GTR is achieved. Medical therapy effectiveness is enhanced in cases with STR. Invasive growth hormone-secreting macroadenomas that are not surgically amenable to total resection are best managed with a combination of safe STR and medical treatment.