On 12/14/2007
Nealie wrote:
Have any of you been in this situation? And if so what was your specialists protocol/recommendation?
Multiple scondary carcinoid tumours discovered in liver - "probably" inoperable, depending on site of primary.
Octreotide (Sandostatin) imaging can't detect primary source.
Endoscopy to be scheduled + more imaging using different isotope (MIGB?) in hopes a primary source will be located.
The specialist has recommended waiting for further testing to find primary before doing anything at all. Tumours in liver are beginning to grow more rapidly.
I've noticed some on here in similar situations but still taking something to slow growth of liver mets......My guess is the sandostatin may not be a good choice because of cancers non-uptake at imaging????
Any thoughts anyone....I'm going crazy with the lack of action.
Thnx in advance for your time.
Hi Nealie
I've only just seen your post and noticed you did not get a response (at least a public one). It seems you have an Octreotide-negative tumour like I have. There are other more specialised scans which can detect the mets even if Octreoscan doesn't work.
The general advice given by many patients is to get to a centre where they specialise in treatment of NETs. In the United States, one of the lead figures is Dr Eugene Woltering - there is a Yahoo Group called NET_ISLETCELL which gives you access to a lot of useful information and Dr Woltering pitches in from time to time.
I have been reading a lot about peptide receptor radionuclide therapy (PRRT) whih is used as a treatment for NETs in Basel (Switzerland), Rotterdam and London. It is expensive but I know several US patients have undergone treatment in Europe. I think also that one of the US hospitals is making this therapy available now.
This is my layperson take on the state of play. So far, the gateway
to this treatment is the expression (i.e. number and activity) of
somatostatin receptors (SSTR) on the cell surface of the tumor and
metastatic lesions. If you are not up to speed on this, so far five
SSTRs have been identified. Of these SSRT2 and (to a lesser extent)
SSRT5 are targeted by the octreotide-based agents in PRRT.
There is now good understanding of the role these different SSRT
types play in cellular activity. SSRT2 and SSRT5 for example are
active in the control of peptide secretions - that is why sandostatin
helps to control carcinoid syndrome. What is not yet fully
understood is why SSTR expression should vary so much between
otherwise similar cancer cell types. Or why SSRT expression seems to
decline as metastases become more aggressive.
The Octreoscan using Indium 111 - pentetreotide as the radioligand is
the imaging technique used to demonstrate the presence and activity
of SSRT2 and SSRT5. Conventional wisdom has been that a pentetrotide-
positive scan opens up the option of PRRT and a negative scan is a
strong indicator that PRRT won't be successful.
What is fairly recent news is that radioligands called lanreotide,
depreotide and SOM-230 offer hope for those patients with
pentetreotide-negative scans. These radioligands are the bit
that copy the body's own somatostatin's affinity to the receptor
sites and deliver their cancer-killing radioactivity. These newer
ones are not widely used yet but surely will be in the next couple of
years.
A recent paper from Dr Caplin's group in London makes very interesting
reading. About one third of the pentetrotide-negative patients were
found to give a positive scan using depreotide. If you search on
PUBMED for depreotide, you can get more information.
Here is the Caplin abstract:-
"Background
111In-pentetreotide scan (OctreoScan) is a widely available agent
with high sensitivity for imaging neuroendocrine tumours. Negative
111In-pentetreotide poses diagnostic as well as therapeutic problems
in terms of staging and consideration of targeted radionuclide
therapy.
Aim
To assess the role of 99mTc-depreotide in patients with negative or
weakly positive OctreoScan (Krenning score 0 or 1; measured on a
scale range 0–4). To determine the usefulness of 99mTc-depreotide
scintigraphy for highlighting lesions that may be missed by OctreoScan
and/or CT/MRI imaging.
Study design
Prospective analysis of 25 patients with neuroendocrine tumours, with
negative or weakly positive 111In-pentetreotide scans, who were
consecutively enrolled to undergo 111In-pentetreotide and 99mTc-
depreotide imaging. The results were compared with either CT or MRI
scans.
Results
Histology was available for 20 of 25 patients: of these 40% had high-
grade tumours (cellular proliferation marker Ki-67 score >20%), a
further 35% had intermediate-grade tumours (Ki-67 2–20%), and the
remaining 25% had low-grade tumours (Ki-67 < 2%).
Fifty-two percent of patients had completely negative and
48% had weakly positive OctreoScan results. Thirty-two
percent of these same patients had significantly positive
99mTc-depreotide scans (Krenning score 2, 3 or 4), with the histology
demonstrating intermediate-grade or high-grade
tumours."
I hope this is helpful.
"You must never confuse faith that you will prevail in the end –
which you can never afford to lose – with the discipline to confront
the most brutal facts of your current reality, whatever they might
be." (Admiral James Stockdale)
Best wishes
Tim