Growth hormone treatment linked to carcinoid tumours in HIV patient

Doctors at Beth Israel Deaconess Medical Center in Boston have reported that a 40 year old male patient who received recombinant human growth hormone (rHGH) treatment for lipodystrophy developed carcinoid tumours expressing high levels of human growth hormone receptor.

The tumours were identified after the patient reported rectal bleeding; two polyps were discovered which proved to express high levels of human growth hormone receptor.

The patient had undergone surgery for removal of a rectal polyp 14 months previously, and had received eight months of rHGH treatment (4mg a day).

Carcinoid tumours occur rarely in comparison to other tumours; they are neuroendocrine tumours, which means that they emerge in hormone producing cells. They occur predominantly in the gut, and early symptoms, other than rectal bleeding, may be mistaken for irritable bowel syndrome.

The authors suggest that because human growth hormone stimulates the production of high levels of insulin-line growth factor 1 (a hormone that reduces apoptosis), the substance might be expected to have the potential to cause cancers.

Some malignant tumours have been observed to express human growth hormone receptors, and the risk of developing breast cancer has been correlated with higher IGF-1 levels. However, the authors say that they believe this to be the first report of a carcinoid tumour that expresses human growth hormone receptors.

In HIV-negative people who receive rHGH, IGF-1’s antiproliferative effect is offset by a corresponding rise in levels of IGF-binding protein-3 (IGFBP-3), but this does not occur in HIV-positive people, according to a 1999 report.

The authors suggest that monitoring of IGF-1 levels may be warranted in people with HIV receiving HGH therapy, and that careful surveillance for malignancies should also be carried out.

Further information

Human growth hormone