Tumor doubling time of renal cell carcinoma measured by CT: collaboration of Japanese Society of Renal Cancer.
OBJECTIVE
This study was conducted to examine the natural history of renal cell carcinoma (RCC).


METHODS
Inclusion criteria were the following: (1) patients who received diagnostic imaging of the kidney (CT, MRI) at two points in time before the diagnosis of RCC or patients who were followed, without treatment, after a diagnosis of RCC; and (2) patients in whom changes in tumor size were followed by the same modality of diagnostic imaging and who did not receive any treatment which could exert anti-tumor activity on the primary or metastatic lesions. The tumor doubling time (DT) and the growth rate of maximum tumor diameter (R) were determined. DT was calculated using the equation DT = (T - T(0)) x log2/logV - logV(0) (where T - T(0) indicates the length of time between two measurements and V(0) and V denote the tumor volume at two points of measurement). R was calculated using the equation R = (phi - f(0))/(T - T(0)) x 100 (where phi(0) and f indicate the maximum diameter at two points). Fifty-six cases registered with the Japanese Society of Renal Cancer were included in the evaluation.


RESULTS
DT was 603.1 +/- 510.1 days, which did not correlate with V(0). R was 0.263 +/- 0.346 cm/day x 100. In cases where the tumor diameter was >/=4 cm, a significant correlation was noted between f(0) and R.


CONCLUSIONS
Elucidation of the natural history of RCC will contribute to facilitation of differential diagnosis and determination of optimum therapeutic strategy.
Ozono
Seiichiro
S
Department of Urology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan. ozn@hama-med.ac.jp
Miyao
Noriomi
N
Igarashi
Tatsuo
T
Marumo
Ken
K
Nakazawa
Hayakazu
H
Fukuda
Momokuni
M
Tsushima
Tomoyasu
T
Tokuda
Noriaki
N
Kawamura
Juichi
J
Murai
Masaru
M
D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007668:Kidney / Q000473:pathology; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012042:Registries; D014057:Tomography, X-Ray Computed