Sustained clinical inactivity and stabilization of GH/IGF-1 levels in an acromegalic patient after discontinuation of somatostatin analogue treatment

Persistent remission of acromegaly in a patient with GH-secreting pituitary adenoma: Effect of treatment with pasireotide long-acting release and consequence of treatment withdrawal

WHAT IS KNOWN AND OBJECTIVE

Somatostatin analogues (SSAs) have been used for the treatment of acromegaly for several decades. However, a unified conclusion on the duration of SSAs therapy or the possibility of medication withdrawal is still missing. We aimed to report a case of acromegaly cured by pasireotide long-acting release (PAS-LAR) and provide some information on the withdrawal of SSAs after stable regression in acromegalic patients.

CASE SUMMARY

A 55-year-old male patient, who was diagnosed with acromegaly and refused surgery and received PAS-LAR as initial treatment, had maintained stability for ten years under the regular treatment with PAS-LAR. The pituitary microadenoma was also decreased during the treatment. After the PAS-LAR discontinuation for 21 months, no evidence of biochemical or clinical recurrence was found in this patient.

WHAT IS NEW AND CONCLUSION

The use of PAS-LAR in a subset of naive-treatment patients is promising to induce long-term regression. A subgroup of patients with mild and well-controlled acromegaly might hope for perpetual remission after the withdrawal of medication.

Active postoperative acromegaly: sustained remission after discontinuation of somatostatin analogues

In patients with active acromegaly after pituitary surgery, somatostatin analogues are effective in controlling the disease and can even be curative in some cases. After treatment discontinuation, the likelihood of disease recurrence is high. However, a small subset of patients remains symptom-free after discontinuation, with normalized growth hormone (GH) and insulin-like growth factor (IGF1) levels. The characteristics of patients most likely to achieve sustained remission after treatment discontinuation are not well understood, although limited evidence suggests that sustained remission is more likely in patients with lower GH and IGF1 levels before treatment withdrawal, in those who respond well to low-dose treatment, in those without evidence of adenoma on an MRI scan and/or in patients who receive long-term treatment. In this report, we describe the case of a 56-year-old female patient treated with lanreotide Autogel for 11 years. Treatment was successfully discontinued, and the patient is currently disease-free on all relevant parameters (clinical, biochemical and tumour status). The successful outcome in this case adds to the small body of literature suggesting that some well-selected patients who receive long-term treatment with somatostatin analogues may achieve sustained remission.

A case of fugitive acromegaly, initially presented as invasive prolactinoma

Fugitive acromegaly is most commonly caused by pituitary acidophil stem cell adenomas, and is characterized by a relatively short clinical history, a large and locally invasive tumor, and relatively low hormonal activity. Here, we report an unusual case of fugitive acromegaly that initially presented as invasive prolactinoma. A 48-year-old man with a huge pituitary mass extending to the suprasellar area was referred to our hospital in December 2007. He had undergone transsphenoidal surgery in November 1999 because of a large invasive prolactinoma. The tumor had grown progressively, despite therapy with dopamine agonists. Subtle features of acromegaly were noted and serum IGF-1 levels were high (733 ng/ml). An oral glucose tolerance test revealed that basal and nadir levels of growth hormone (GH) were 1.56 and 1 ng/ml, respectively. As a therapeutic trial, long-acting octreotide (20 mg IM, monthly) was added, and the tumor size markedly reduced within 6 months on magnetic resonance imaging examination. Immunohistochemical staining of the tumor tissue obtained at the surgery in 1999 showed positive staining for GH and prolactin (PRL). Double immunofluorescence staining showed a mixed positivity for GH and PRL in the majority of tumor cells; however, the two hormones colocalized in a minority of tumor cells, indicating that the tumor was composed of three different cell types (GH, PRL, and GH/PRL). The diagnosis of fugitive acromegaly was initially overlooked in this patient because of normal serum GH levels and a lack of acromegalic features, although histological evidence for GH production was present. IGF-1 determinations would be helpful for the diagnosis of fugitive acromegaly.

Complete disappearance of a GH-secreting pituitary macroadenoma in a patient with acromegaly: effect of treatment with lanreotide Autogel and consequence of treatment withdrawal

BACKGROUND

Somatostatin analogs (SA) are the cornerstone in the medical treatment of acromegaly, used as either primary or adjunctive therapy. In particular, SA are effective in inducing the biochemical remission of the disease and tumor shrinkage, although only few cases of complete disappearance of the pituitary tumor in patients treated with SA as long-acting formulations have been reported. SA withdrawal has been demonstrated to keep safe levels of GH and IGF1 at least in a small subset of patients well responsive to SA, although it is generally followed by disease recurrence after several months.

CASE REPORT

A 61-year-old female patient bearing a very large GH-secreting pituitary macroadenoma was treated with 12-month lanreotide Autogel (ATG), at the initial dose of 120 mg/28 days. After 3 months, GH and IGF1 levels were fully normalized, to prolong the administration interval from 28 to 56 days. After 6 months of treatment, a significant tumor shrinkage (90% of baseline size) was observed, whereas GH and IGF1 excess was still well controlled. After 12-month therapy, a complete disappearance of the pituitary tumor was observed, and the hormonal evaluation confirmed the complete biochemical remission of acromegaly. Lanreotide ATG treatment was withdrawn. The clinical, biochemical, and radiological remission of acromegaly was maintained 24 months after lanreotide ATG treatment discontinuation, without evidence of disease recurrence.

CONCLUSIONS

This report represents an exemplary case of the potentiality of treatment with lanreotide ATG in inducing a complete remission of acromegalic disease, persistent after a long period of time from treatment withdrawal.