[Methods for time trend analysis of cancer incidence rates].
ABSTRACT To introduce statistical methods of time trend analysis on cancer rates.
Cancer incidence data collected by the Shanghai Cancer Registry during 1991 to 1999 was used in the analysis to calculate the crude and age-adjusted rates, percent changes (PCs) and annual percent changes (APCs). APCs were estimated by a linear regression of the logarithm on the incidence rates during the nine years. It also introduced a method for partitioning a linear trend in age-adjusted rates into site-specific contributions to the overall floating trend. 95% confidence intervals for the APCs and contributions were described in the paper.
A decreasing rates were observed for cancers of stomach and esophagus among both men and women in urban Shanghai from 1991 to 1999. The increasing rates among men would include cancers of colon, rectum, gall bladder, pancreas, prostate, urinary bladder, kidney and leukemia. The rates of cancers among women increased for colon, rectum, lung, breast, gall bladder, endometrium, ovary, urinary bladder and kidney. The changes of above cancers over time were statistically significant (P < 0.05 or P < 0.01), but rates for other cancer sites changed little. The APCs (weighted method) and contributions for the cancers of stomach, esophagus, colon, rectum and prostate were -2.99% and -65.72%, -2.90% and -17.07%, 12.30% and 21.46%, 2.94% and 18.62%, and 3.11% and 15.09% among men, and -6.05% and -39.55%, -1.08% and -35.19%, 2.81% and 28.64%, and 3.69% and 15.70% for the cancers of stomach, esophagus, breast and colon in women, respectively.
APC, and related statistics could be used to describe and analyze the time trend of cancer rates rather than PC or/and graphical method alone.
- [show abstract] [hide abstract]
ABSTRACT: Chromatin remodeling agents such as histone deacetylase inhibitors have been shown to modulate gene expression in tumor cells and inhibit tumor growth and angiogenesis. We investigated the mechanisms of chronic valproic acid (VPA) inhibiting PC3 cell growth in the study. We established tumor xenografts of the PC3 cell line and investigated the effect of VPA chronic administration on tumor growth. Apoptosis in tumor tissue was measured using the TUNEL Detection Kit. We detected the effect of VPA chronic administration on histone acetylation; p21CIP1/WAF1 gene expression; vascular endothelial growth factor (VEGF) expression by reverse-transcription Polymerase Chain Reaction (PCR) analysis; immunohistochemistry; and Western Blotting. In mouse models with established subcutaneous prostate (PC3), VPA treatment induced 70% inhibition of tumor growth without overt toxicity. Our result showed that chronic administration of VPA has an effect on tumor growth arrest and the effect was associated with increased histone acetylation, p21CIP1/WAF1 up-regulation, and VEGF down-regulation. We conclude that chronic VPA results in profound decreases in the proliferation of PC3 cells, not only by increasing histone H3 acetylation and up-regulating p21CIP1/WAF1 expression, but also by down-regulating VEGF.International Journal of Urology 10/2007; 14(9):838-45. · 1.73 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: Knowledge concerning concordance of epidermal growth factor receptor 2 (HER2) expression between primary breast cancers and asynchronous local-regional recurrences is sparse. Receptor characteristics could be altered with time and may be affected by anticancer treatment. It remains uncertain whether recurrences have the identical or similar HER2 receptor expression pattern as the primary breast cancer. The aim of the present study was to evaluate whether HER2 is stable during the process of recurrence. Expression of HER2 was investigated immunohistochemically in paired samples of primary breast cancers and corresponding asynchronous local-regional recurrences (n=35). HER2 expression was scored as 0, 1+, 2+ or 3+. HER2 overexpression (2+ or 3+) was found in 48.57% (17/35) of the primary breast cancers and 45.71% (16/35) of the corresponding local-regional recurrences. A concordance of HER2 overexpression between the primary lesions and matching regional recurrences was observed in 85.71% of the breast cancer cases. Five out of the 35 paired samples (14.28%) were discordant. Only 3 patients who had 2+ HER2 expression in the primary tumors showed HER2 down-regulation (0 or 1+) in the recurrences, while the HER2 score in 2 patients changed oppositely. Moreover, all of the cases with 3+ HER2 staining in the primary lesions retained HER2 overexpression in the recurrences. The HER2 is commonly expressed in breast cancer, and its expression in the primary tumors and the corresponding recurrences was concordant in the majority of the cases. As the receptor expression may lose or gain in recurrences at a probability of approximately 10%, assessment of the receptor status in recurrences is still encouraged.Experimental and therapeutic medicine 01/2011; 2(6):1187-1191. · 0.34 Impact Factor