Hi Cleo

I suspect the problem with this subject is that:

- the formula is probably old (thus difficult to find)
- it has probably become 'a fact', thus the formula itself is not mentioned in 
the abstract but in the method-section or in books.
- doubling time may just be one parameter, others may include: tumor 
growth, -cell kinetics. Etcetera.

What I remembered from a previous life as researcher is that we used some 
kind of formula assuming that tumors would grow logaritmically (with the same 
speed).

So I (quickly and not exhaustively) searched Google scolar with the terms
<b>calculate doubling time log tumor</b> (so I would track the method 
section)

One of the first hits I found (just a case report) referred to a paper of 
Schwartz:
According to the formula of Schwartz [10], we calculated the
tumor doubling time on the basis of the tumor size measured by computed
tomography in 1995 and 2000: Doubling time = t/10(log d1 –
log d0), where d1, d0 and t are the latter diameter in cm, the former
diameter in cm, and the interval in days, respectively.

<b>Schwartz M: A biomathematical approach to clinical tumor growth. Cancer 
1961;14:1272–1294. (Note: this paper has no abstract and only 2 MeSH: 
Mathematics* - Neoplasms*, thus it is not readily found in PubMed!!).</b>

Next I quickly searched Abeloff: Clinical Oncology, 3rd ed. (electronic version) 
with the term doubling time and I found this statement in the section TUMOR 
CELL KINETICS AND THE USE OF CHEMOTHERAPY 

The heterogeneity of cancer cells includes their growth rate or cell cycle 
kinetic status and the biochemical characteristics of the cells that could 
determine drug resistance. Many of the concepts regarding cell growth that 
have helped guide the development of current chemotherapy were described 
by Skipper and Schabel[32][33] more than 30 years ago. Their model, based 
largely on work in murine leukemias, assumed that the growth rate of cancer 
cells in vivo is logarithmic. That is, growth rate and doubling time are constant 
and do not change with increasing or decreasing tumor size.

references: 
32. Skipper HE, Schabel Jr FM, Wilcox WS:  Experimental evaluation of 
potential anticancer agents. XII. On the criteria and kinetics associated with 
curability of experimental leukemia.   Cancer Chemother Rep  1964; 35:111.
33. Skipper HE:  Laboratory models: The historical perspective.   Cancer Treat 
Rep  1986; 70:3-7.
34. Shackney SE, McCormack GW, Cuchural GJ:  <b>Growth rate patterns of 
solid tumors</b> and their relation to responsiveness to therapy: An analytical 
review.   Ann Intern Med  1978; 89:107-121.
<b>35. Collins VP, Loeffler K, Tivey H:  Observations on growth rates of 
human tumors.   Am J Roentgenol  1956; 76:988-1000.
36. Tubiana M:  Tumor cell proliferation kinetics and tumor growth rate.   Acta 
Oncol  1989; 28:113-121</b>

As I said this is by no way exhaustive. But the principle of doubling time is 
simple. It just assumes that growth is logaritmic.

I didn't look for doubling times of malignant gastrointestinal tract tumors.

You could try Google scolar in the same way I did

or use broader terms for doubling time in PubMed together with GI tumor.
i.e. proliferation rate*;  kinetics* ; growth rate* : doubling time*
(MeSH Terms: Cell Cycle; Cell Division; Kinetics)

Combine with: Gastrointestinal Neoplasms"[Mesh] 

or consult a book on Gastrointestinal Neoplasms"[Mesh] 


Success!

"Laika" (Jacqueline)

http://laikaspoetnik.wordpress.com/




On Wed, 4 Jun 2008 15:43:18 +1000, Cleo Wilkinson 
<[log in to unmask]> wrote:

>Dear Colleagues ,
> 
>We are trying to find  the formula used   to estimate the growth rate
>"doubling  times " of tumors  . 
> 
>Also we  need the "doubling times " of malignant gastrointestinal tract
>tumors .
> 
>I have searched Pubmed , google and UptoDate without any success.
> 
>Many Thanks 
> 
>Cleo
> 
> 
> 
>Cleo Wilkinson | Library | Sullivan Nicolaides Pathology
>P +61 (07) 33778525 | E [log in to unmask]
> 
>