In a preliminary study conducted by June Chan at the Harvard School of Public Health, published in the prestigious Journal of Science January 23, 1998, IGF-1 was linked to a higher incidence of prostate cancer. The implication of this study was that men with a high PSA blood level or a strong family history of prostate cancer should think twice before starting growth hormone or growth hormone releasing agents. Of course, this would also mean IGF-1 or IGF-1 producing agents.
In the summer issue of the International Journal of Antiaging Medicine 1998 premier issue, Dr. L. Cass, M.D., Ph.D., Pharm.D., Medical College of Milwaukee, Wisconsin, and chief medical advisor to Cenegenics published a paper entitled “Insulin-Like Growth Factor-1 blood levels are not associated with prostate specific antigen (PSA) levels or prostate cancer a study of 749 men”. The incidence of prostate cancer increases with age in men whereas blood levels of IGF-1 decline significantly with age, at about 14% per decade after the age of 30. Therefore, it seems unlikely that IGF would have any causative relationship with prostate cancer. However, the question does arise that with supplementation with recombinant human growth hormone can it actually pose a risk for increased prostate cancer? The question also arises that IGF-1, if given as a supplement, would it do the same?
The purpose of the study conducted by Dr. Cass was to determine the IGF blood levels in men receiving recombinant growth hormone supplementation as a relationship to blood PSA levels as an indicator of prostate cancer. In this particular study as well as three others, circulating IGF-1 levels had no relationship to PSA levels or prostate cancer and did not appear to be a risk factor in patients with or without recombinant growth hormone administration. These findings are consistent with extensive studies on recombinant growth hormone replacement in growth hormone deficient adults resulting from pituitary or prepituitary tumors. Moreover, no increase in prostate cancer or any other malignancy was observed in approximately 3,000 patients during long term treatment with recombinant growth hormone.
Thus to date, the weight of scientific evidence shows that recombinant growth hormone or IGF-1 do not cause prostate cancer. Certainly more long term studies are essential to assess the benefits and risks of life long growth hormone replacement or IGF-1 supplementation. If anything, the tendency is that recombinant growth hormone and IGF-1 actually reduce the incidence of prostate cancer and PSA readings that are greater than 4, as evidenced by the results of this particular study.
In his book entitled Grow Young with HGH Dr. Ronald Klatz, president of the American Academy of Antiaging Medicine, reported on the patients treated by Drs. Chein and Terry with human growth hormone injections. Of 800 patients the only side effects that had been reported were minor joint aches and pains and some fluid retention. These symptoms disappeared in the first couple of months.
More significantly was the fact that there were no reported cases of cancer among all 800 patients treated at their clinic. It is very reassuring since some investigators have been concerned that growth hormone would cause undetected cancer cells to divide more rapidly.
Even so, you would think with 800 people over the age of 40-years-old, given the normal incidence of cancer, some of these people would certainly get the disease. It could be that there is some sort of protective effect of growth hormone replacement, probably through the immune system.
Even more compelling in this study was the act that PSA levels as a marker of prostate problems including cancer did not increase among any of the male patients. In one case study, with Chein and Terry, growth hormone actually seemed to have reversed the course of the prostate cancer. The patient came to see Dr. Chein with a PSA level of over 50, normal being 0 to 4 and men with cancer usually having a PSA level in the 10s or 20s. The diagnosis of adenocarcinoma was confirmed by a needle biopsy. Although existing cancer is normally a contraindication for hormone replacement therapy, the patient did refuse surgery and urged Dr. Chein to treat him with growth hormone as well as DHEA, melatonin, but not testosterone. In a short period of time the man’s PSA levels came down to between 5 and 7. This is absolutely spectacular as the disease has gone into remission. Dr. Chein speculates that through the immune stimulation of growth hormone, natural killer cells were effectively able to destroy the cancer cells.
Further clinical studies have similarly failed to link elevated GH and IGF-1 levels with cancer. In fact, arginine, a growth hormone increasing amino acid, has proven anti-tumour effects (chemotherapeutic), and it's use also reduces wasting (cachexia) associated with cancer.
In each of
these cases you can go to the Medline site
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi
and enter the PMID number to bring up the abstract.
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Orv Hetil 2002 Mar 24;143(12):601-5
[Serum tumor marker levels during a 12-months growth hormone replacement therapy in patients with adult growth hormone deficiency]
[Article in Hungarian]
Hubina E, Kovacs L, Szabolcs I, Rimanoczy E, Czirjak S, Goth M.
Egeszsegtudomanyi Kar, Belgyogyaszati es Geriatriai Klinika, Semmelweis Egyetem, Budapest.
CONCLUSION: The lack of increase of tumor marker levels does not indicate possible oncogenic effect of one-year GH treatment in hypopituitary adults. The authors can not draw any far-reaching conclusions because of the low patient number and the short follow-up, but the measurement of tumor marker levels may provide useful means to follow up long-term therapy and for the early diagnosis of possible occult malignancy.
PMID: 11963397 [PubMed - indexed for MEDLINE]
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Eur J Endocrinol 2002 Jul;147(1):59-63
Growth hormone replacement does not increase serum prostate-specific antigen in hypopituitary men over 50 years.
Department of Endocrinology, St Bartholomew's and the Royal London School of Medicine and Dentistry, St Bartholomew's Hospital, London EC1A 7BE, UK.
RESULTS: Mean serum PSA remained unchanged during rhGH replacement, with a median follow-up of 2 years. No correlation was found between the individual changes in serum IGF-I and changes in serum PSA. CONCLUSIONS: These data are reassuring thus far regarding the safety of GH replacement in relation to the prostate in this patient group.
PMID: 12088920 [PubMed - indexed for MEDLINE]
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Clin Endocrinol (Oxf) 2000 Apr;52(4):457-62
One year growth hormone replacement therapy does not alter colonic epithelial cell proliferation in growth hormone deficient adults.
Beentjes JA, van Gorkom BA, Sluiter WJ, de Vries EG, Kleibeuker JH, Dullaart RP.
Department of Internal Medicine, Divisions of; Endocrinology, University Hospital Groningen, The Netherlands.
CONCLUSIONS: Six to 12 months of GH replacement therapy, aimed to increase plasma IGF-I into the (high) physiological range, does not adversely affect colonic epithelial cell proliferation as a biomarker for the risk of development of colorectal cancer.
PMID: 10762288 [PubMed - indexed for MEDLINE]
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Lancet 2002 Jul 27;360(9329):268-9
Comment on:
Lancet. 2002 Jul 27;360(9329):273-7.
Risk of cancer in patients treated with human pituitary growth hormone in the UK, 1959-85: a cohort study.
Swerdlow AJ, Higgins CD, Adlard P, Preece MA.
Section of Epidemiology, Institute of Cancer Research, Sutton SM2 5NG, UK. a.swerdlow@icr.ac.uk
We have no evidence as to whether growth hormone in modern dosage regimens is associated with an increased risk of colorectal cancer.
Duncan Crow