A male patient with acromegaly and breast cancer: treating acromegaly to control tumor progression

Background: Acromegaly is a rare disease associated with an increased risk of developing cancer. Case presentation: We report the case of a 72-year-old man who was diagnosed with acromegaly (IGF-1 770 ng/ml) and breast cancer. Four years before he suffered from a colon-rectal cancer. Pituitary surgery and octreotide-LAR treatment failed to control acromegaly. Normalization of IGF-1 (97 ng/ml) was obtained with pegvisomant therapy. Four years after breast cancer surgery, 2 pulmonary metastases were detected at chest CT. The patient was started on anastrozole, but, contrary to medical advice, he stopped pegvisomant treatment (IGF-I 453 ng/ml). Four months later, chest CT revealed an increase in size of the metastatic lesion of the left lung. The patient was shifted from anastrozole to tamoxifen and was restarted on pegvisomant, with normalization of serum IGF-1 levels (90 ng/ml). Four months later, a reduction in size of the metastatic lesion of the left lung was detected by CT. Subsequent CT scans throughout a 24-month follow-up showed a further reduction in size and then a stabilization of the metastasis. Conclusions: This is the first report of a male patient with acromegaly and breast cancer. The clinical course of breast cancer was closely related to the metabolic control of acromegaly. The rapid progression of metastatic lesion was temporally related to stopping pegvisomant treatment and paralleled a rise in serum IGF-1 levels. Normalization of IGF-1 after re-starting pegvisomant impressively reduced the progression of metastatic breast lesions. Control of acromegaly is mandatory in acromegalic patients with cancer.