Melatonin for PT or malignant mammary tumours?

[victoria]

Has anyone ever tried Melatonin to treat tumours in rats? I was reading up on Bromocroptin and Cabergoline, I read somewhere (I could have sworn it was Rat Guide but I can't find the source again) that Melatonin was a cheaper alternative. I researched it a little bit and found that melatonin reduces mammary ademocarcinoma (malignant mammary tumours), possibly because they are linked to exposure to too much light, which in turn reduces the production of Melatonin by the pineal gland.

One of my rats has many malignant tumours so I was wondering if this might help. I don't know if any of them are mammary, the vet aspirated one last time we were in and she said it was malignant and I understood it wasn't mammary, but there is at least one that is likely mammary. If I do give it I will talk to my vet first, (FML another recheck) but I'm wondering about people's experiences or opinions.

What would the effect to the sleep cycle be? Possibly unwanted effects/risks? I have Melatonin at home but the pills are sublingual, would it be ok to give those or should I find a different type? (Anyone have suggestions on brands?) Would the Melatonin even have an effect on existing tumours or just reduce the risk of new ones?

 

[jorats]

Have you discussed this with your vet? Also... was there a biopsy and histopathology done? If not, that would be your first step. Although vet can gauge the cells they still can't tell for sure if it's malignant or not without it analyzed at a lab.
I believe the Bromocriptine and Cabergoline has an effect on the prolactin which is what they are now believing is fuelling PTs.
Have you given Tamoxifen a try? Tamoxifen is ineffective with benign mammary tumours but in humans it is effective with malignant mammary tumours, perhaps that would be the way to go?
I haven't heard of using Melatonin to treat cancers in rats... haven't researched it either but I think this might be something to discuss with your vet. I would think he would have greater information.

Results indicate that daily administration of melatonin increased significantly the survival time of tumor bearing animals compared to the control non-melatonin receiving rats. However, the lengthened survival time did not correlate with changes in either tumor multiplicity or growth rates. Animals with mammary tumors exhibited increased levels of prolactin and catecholamine concentrations compared to the healthy animals. The administration of melatonin stabilized the hormone levels, returning them to the levels of the healthy animals. Rats with mammary tumors also presented lower percentages of NK cells, however these levels were not increased with the administration of melatonin. Researchers concluded that melatonin is beneficial during advanced breast cancer. It increases survival time, perhaps by improving the homeostatic and neuroendocrine equilibrium which is imbalanced during advanced breast cancer.

Learn more: http://www.naturalnews.com/022981_melat ... z1EDyJ1Do0

The main problem with this study is that the rats were induced with tumours, not naturally grown tumours.
Is this the rat with the implant?
My vet also discussed another drug: lupron for malignancies... although it's shown to work in ferrets, there's not much study on rats. But it's something to try or at least discuss with your vet? My vet told me it's a slim chance...but.
My mom has a rat with a tumour, my vet believes it's malignant. Ideally we'd like it removed but her lungs are so bad... we discussed the implant but that's a no go. She said it would do nothing on a tumour of that size, (small walnut) She said those implants should be done before or during the very beginning of a tumour. The implants are not licensed in Canada, apparently, there's a great deal of paper work to bring them in???

 

[victoria]

Yes, she is one of my rats with an implant. She has 6 tumours - one teeny on each of her sides, below her ribs, one on her neck, one by her hind leg (just above the hip), one in her armpit, and one near her urethrae. She also had another in her opposite armpit removed last year. I lost her sister to PT last summer and shortly before she passed we found a lump near her urethrae similar to Sophie's in feel and colour (dark purple/blue). The one on her throat we suspected was an abscess for a long time because she had an lump in the same area removed earlier that turned out to be an abscess even though we treated with antibiotics for at least 6 weeks before surgery. Last week I went in to get it aspirated and the vet looked at it under the microscope said it was a tumour and it was full of lymphocytes (I think that's what she said) meaning it was malignant. The tumour on her armpit (that looks and feels like so many others I have had) is very likely mammary and benign and it is very slow growing, as are any tumours on my other girls with implants. It's the one on her belly that I am worried about because I think it's starting to affect her ability to pass waste. If there is anything I can do, especially if it has few side effects, I want to try.

I also took in another girl who has a scary tumour on her throat (she has no implant, although no one thinks it's a mammary tumour) and did ask the vet about Bromocriptine and Cabergoline but she said it would only work on PT and not other types of tumours. She said the other chemotherapy drugs have really toxic side effects (I have read this about Tamoxifen many times and would not use it) so I didn't inquire further because I really don't think the extra weeks/months they would give us are worth the cost.

I was intrigued by Melatonin as a treatment for PT and was looking into it when I found this abstract that indicated it reduced malignant mammary tumours in rats when it was induced but also in the group just given Melatonin. It doesn't say what the incidence of tumours was in the control group or if they were malignant or benign or if they were exposed to excessive light levels.:

http://cancerres.aacrjournals.org/conte ... 4432.short

The effects of the pineal hormone, melatonin, and of pinealectomy on the incidence of mammary adenocarcinoma in Sprague-Dawley rats treated with 7,12-dimethylbenz(α)-anthracene (DMBA) were investigated. Melatonin (2.5 mg/kg), begun on the same day as DMBA (15 mg) treatment and given daily in the afternoon for 90 days, significantly reduced the incidence of mammary tumors from 79% (control) to 20% (treated) (p < 0.002). Rats pinealectomized at 20 days of age and treated with 7 mg of DMBA at 50 days of age had a higher incidence of tumors (88%) compared to control animals (22%). Fifteen mg of DMBA, which resulted in a higher incidence of tumors, reduced the difference between pinealectomized and control animals. Melatonin only partially reversed the effects of pinealectomy, reducing the incidence from 87% (pinealectomy alone) to 63% (pinealectomy plus melatonin); however, the tumor incidence was still lower (27%) in nonpinealectomized, melatonin-treated animals. Assessment of plasma prolactin, luteinizing hormone, follicle-stimulating hormone, estradiol, and cortisol in DMBA-treated tumor-free and tumor-bearing animals revealed a significantly lower plasma prolactin concentration [27 ± 5 (S.E.) ng/ml] in melatonin-treated animals as compared to vehicle-treated animals [65 ± 8 ng/ml]. The concentration of plasma prolactin was less in melatonin-treated, pinealectomized rats (55 ± 10 ng/ml) as compared to vehicle-treated, pinealectomized animals (101 ± 13 ng/ml). Other hormones were not affected by melatonin treatment. These data support the hypothesis that melatonin inhibits the development of DMBA-induced mammary tumors in the rat while removal of the pineal gland stimulates development of such tumors. Additionally, these experiments provide evidence that these effects may be mediated by a suppression of plasma prolactin levels.

I'm left unsure as to why Bromocriptine and Cabergoline wouldn't work the same way as Melatonin if they both affect prolactin levels. I haven't discussed it with my vet yet, I wanted to know if anyone here had any experience with it first. I also doubt that it's smart to do a biopsy on Sophie now (although I'm not sure what it entails) because she is really not healing from simple cuts and scratches (tiny scratches keep growing because she keeps grooming them and her body is not healing fast enough to keep up) and I don't want to add more punctures. Also part of the reason why I'm reluctant to get Pred to reduce the size of the lumps.

 

[jorats]

Your poor girl. It must be hard to do nothing.

Reading that part... it seems to me that Melatonin might be worth a shot on typical mammary tumours, those fed by prolactin? It's weird that bromo or cabergoline won't work when it seems to do the same thing?

 

[lilspaz68]

Dr Munn has a ratgirl on bromo for a small tumour. I haven't heard much about it, but I think its been over a month now. I will try to remember to ask.

 

[ChrisK]

Hi Victoria... just wondering if you have any update .. i.e. if you've spoken with your vet about Melatonin yet?

 

[victoria]

I was at the vet on Monday and I showed my vet the abstracts I found. He looked at them and said they were interesting but said he would not have time to go through them and related research right away. He said Melatonin (and the other chemo meds that act on prolactin) would have a similar effect as the Deslorelin implants, so he doesn't know how beneficial they will be since Sophie has one, but there wouldn't be any harm in trying. She weighs about 440g right now, so I am quartering my 5mg sublingual pills and mixing them with something soft to give her each evening. I haven't seen a huge improvement, but I haven't seen any ill effects either. She does seem happier (although that's likely attributed to the Metacam I also started this week) and is a bit more active and responsive. The one contraindication I know of with Melatonin is Pred, so it wouldn't be something to give in combination with it. I'll keep poking my vet about it when I go in and I'll update the thread when he gives me more info.