Increased expression of beta-catenin predicts better prognosis in nonsmall cell lung carcinomas

BACKGROUND: beta-Catenin has been shown to function as a Wnt signaling molecule to stimulate cyclin D1 expression and cell growth in several kinds of tumors. METHODS: The authors immunohistochemically examined specimens of 217 surgically resected primary nonsmall cell lung carcinomas (NSCLCs) for beta-catenin expression and classified them semiquantitatively into three categories, including those with high, moderate, and low scores of expression. RESULTS: High, moderate, and low scores of expression were found in 37 (17.1%), 145 (66.8%), and 35 (16.1%) tumors, respectively. beta-Catenin expression was not correlated with cyclin D1 expression, but was positively correlated with the Ki-67 cell growth fraction (P = 0.04). The direct sequencing analysis for the beta-catenin gene mutation of 13 specimens of 217 tumors for the current study revealed no mutations. The relation between survival and beta-catenin expression was evaluated in 148 potentially curatively resected tumors with pathologic Stages I-IIIA. A trend toward better survival was found in patients with tumors having higher scores. In multivariate analysis, high beta-catenin expression was a significant and independent favorable prognostic factor (hazards ratio, 0.31; P = 0.007) as was pathologic stage. Analyzed by cell type, in nonsquamous cell carcinomas, patients with tumors having high scores survived a significantly longer time than those with tumors having moderate or low scores (5-year survival rates, 84%, 55%, and 32%, respectively; P = 0.02), and high beta-catenin expression tended to be a favorable prognostic factor (hazards ratio, 0.32; P = 0.052). CONCLUSIONS: These results indicate that, in NSCLCs, increased expression of beta-catenin can predict favorable prognosis of patients with resected tumors, suggesting that accumulation of beta-catenin has no or little oncogenic effect via activation of the Wnt pathway, unlike in colon carcinomas or hepatomas.     

Three-dimensional intrafractional movement of prostate measured during real-time tumor-tracking radiotherapy in supine and prone treatment positions

To quantify three-dimensional (3D) movement of the prostate gland with the patient in the supine and prone positions and to analyze the movement frequency for each treatment position.

The real-time tumor-tracking radiotherapy (RTRT) system was developed to identify the 3D position of a 2-mm gold marker implanted in the prostate 30 times/s using two sets of fluoroscopic images. The linear accelerator was triggered to irradiate the tumor only when the gold marker was located within the region of the planned coordinates relative to the isocenter. Ten patients with prostate cancer treated with RTRT were the subjects of this study. The coordinates of the gold marker were recorded every 0.033 s during RTRT in the supine treatment position for 2 min. The patient was then moved to the prone position, and the marker was tracked for 2 min to acquire data regarding movement in this position. Measurements were taken 5 times for each patient (once a week); a total of 50 sets for the 10 patients was analyzed. The raw data from the RTRT system were filtered to reduce system noise, and the amplitude of movement was then calculated. The discrete Fourier transform of the unfiltered data was performed for the frequency analysis of prostate movement.

No apparent difference in movement was found among individuals. The amplitude of 3D movement was 0.1–2.7 mm in the supine and 0.4–24 mm in the prone positions. The amplitude in the supine position was statistically smaller in all directions than that in the prone position (p < 0.0001). The amplitude in the craniocaudal and AP directions was larger than in the left-right direction in the prone position (p < 0.0001). No characteristic movement frequency was detected in the supine position. The respiratory frequency was detected for all patients regarding movement in the craniocaudal and AP directions in the prone position. The results of the frequency analysis suggest that prostate movement is affected by the respiratory cycle and is influenced by bowel movement in the prone position.

The results of this study have confirmed that internal organ motion is less frequent in the supine position than in the prone position in the treatment of prostate cancer. RTRT would be useful in reducing uncertainty due to the effects of the respiratory cycle, especially in the prone position.     

Non-ischemic nephron-sparing surgery for small renal cell carcinoma: complete tumor enucleation using a microwave tissue coagulator

OBJECTIVE: To determine the methodological usefulness of non-ischemic complete enucleation for small renal cell carcinomas (RCC) using a microwave tissue coagulator (MTC). METHODS: Fifty-nine patients (61 kidneys) underwent non-ischemic complete tumor enucleation by MTC. Of the 59 patients, 46 had an elective indication and 15 kidneys of 13 patients had an imperative indication. RCC was exposed with minimal peri-renal detachment. The demarcation line, 7-10 mm from the tumor, was coagulated at 8-10 mm intervals with a microwave antenna needle for 30-40 s at 50-60 W. The renal tumor was excised along the coagulated zone with normal surrounding tissue. The enucleation bed was covered with fibrin glue or fat tissue without approximation. RESULTS: The operations were successfully completed in all intended cases. The mean operation time was 160 +/- 43 (median: 160) min and the mean blood loss was 313 +/- 370 (median: 158) ml. No major bleeding or urine leakage from the enucleation bed was observed in 62.2 and 88.5% of cases, respectively. The minor bleeding and urine leakage were controlled easily with absorbable sutures. None of the cases presented with postoperative bleeding or urine leakage from the enucleation bed. Severe impairment of the renal function was not observed in any case evaluated by means of serum creatinine, creatinine clearance and radioisotope examination. The 5-year overall survival rate was 87% without recurrence up to 23.1 +/- 19.5 months of the mean follow-up. CONCLUSION: Non-ischemic complete tumor enucleation using MTC constitutes a simple, reliable and less invasive alternative to ordinary nephron-sparing surgeries for small RCC.     

Prognostic factors in patients with hepatocellular carcinoma treated by transcatheter arterial embolization

BACKGROUND: Transcatheter arterial embolization induces marked antitumor response in patients with hepatocellular carcinoma, but the survival benefit of transcatheter arterial embolization remains to be determined. This study investigated prognostic factors in patients with advanced hepatocellular carcinoma treated by transcatheter arterial embolization. METHODS: A total of 128 consecutive patients with non-resectable hepatocellular carcinoma, who had undergone transcatheter arterial embolization between May 1990 and August 1998, were analyzed to investigate prognostic factors. RESULTS: Median survival time and survival proportions at 1, 3 and 5 years were 3.3 years, 92.0, 54.6 and 23.4%, respectively. By multivariate analysis using the accelerated failure time model, age <60 years, hepatitis C virus antibody positivity, serum albumin >3.5 g/dl, absence of portal vein invasion and serum alpha-fetoprotein level <400 ng/ml were significantly associated with favorable survival. For clinical application, we also propose a prognostic equation with combination of specific prognostic factors, by which survival curves of each patient could be predicted directly. CONCLUSION: The findings of the current study may be helpful in predicting the life expectancy of hepatocellular carcinoma patients treated by transcatheter arterial embolization and in designing future clinical trials of transcatheter arterial embolization for hepatocellular carcinoma.     

Indications and limits of breast conserving treatment

In Japan, 41% of surgeries for breast cancer were breast conserving treatment (BCT) in 2000. The indications for BCT in the guidelines of the Japanese Breast Cancer Society (1999) are as follows: (1) tumor size is 3 cm or less, (2) image diagnosis indicates no sign of extensive intraductal spread, (3) cases with multiple tumor are excluded, (4) radiation therapy is possible, (5) the patient wants to receive BCT. The pathological negative margin is favorable in BCT; however, we estimate based on our study that only about 30% of all breast cancers can be completely resected by partial mastectomy. To extend the indications for BCT, the roles of postoperative radiotherapy, endocrine therapy and preoperative chemotherapy will be important. Patients with ipsilateral breast tumor recurrence (IBTR) have increased risk of distant metastases, and the presence of IBTR is an important predictive factor for distant metastases. When we discuss the indications and limits of BCT, we have to take the rate of IBTR into careful consideration.     

Intrinsic angiotensin II-generating system in human pancreatic cancer tissues

To clarify whether an intrinsic angiotensin II-generating system exists in human advanced pancreatic cancer tissues, we measured angiotensin II concentration and angiotensin converting enzyme (ACE) activity in tissues of normal pancreas, pancreatic cancers, colon cancers and hepatocellular carcinomas. After the surgically resected specimens were homogenized, angiotensin II concentration and ACE activity in tissues were measured using the florisil method and Kasahara's method, respectively. Tissue angiotensin II levels in pancreatic cancers (n = 13) were significantly higher than those of normal pancreas (n = 7), colon cancers (n = 7), or hepatocellular carcinomas (n = 7). However, there was no significant difference in tissue ACE activity between them. This study provides in vivo evidence of ACE-independent angiotensin II-generating system in human pancreatic cancer tissues and suggests that this locally-formed angiotensin II influences the microenvironment of pancreatic cancer tissues in a paracrine fashion.     

Genetic alterations of the ornithine decarboxylase gene in human colorectal cancers

Ornithine decarboxylase (ODC), a critical regulatory enzyme for polyamine biosynthesis, is strictly regulated in human cells. Several studies suggested the importance of elevated enzymatic activity and altered biochemical characteristics of ODC in malignant cells. Because mutation of ODC in primary human hepatocellular carcinoma has been reported, we examined whether the genetic alterations, such as mutations or structural alterations of the gene, also account for the alteration of ODC activity in human colorectal cancer. No mutation or structural alteration in the ODC was detected in any of the colorectal tumors and normal tissues examined. These results suggest that a mutation or structural alteration of the ODC may not be involved in human colorectal carcinogenesis.     

Enhanced spontaneous and aflatoxin-induced liver tumorigenesis in xeroderma pigmentosum group A gene-deficient mice

Xeroderma pigmentosum (XP) is an autosomal recessive hereditary disease featuring defective nucleotide excision repair (NER). XP patients are highly sensitive to sunlight and develop skin cancer at an early age. While the fact that XP patients have a large increase in mortality from skin cancers has been extensively documented, the relation between XP and internal tumors has received little attention. We therefore analyzed development of spontaneous and aflatoxin B(1) (AFB(1))-induced liver tumors in XPA-deficient congenic mice, originally created by repeated back-crosses with inbred C3H/HeN mice. Spontaneous liver tumors were assessed at the age of 16 months in two separate experiments using F5 and F10 lines. The incidence of and average number of spontaneous tumors per mouse were significantly higher in XPA-/- than in XPA+/+ and +/- mice. Similarly, F10 XPA-/- mice receiving i.p. injection of 0.6 or 1.5 mg/kg b.w. AFB(1) at 7 days of age demonstrated more liver tumors than their heterozygous or homozygous positive counterparts when examined at month 11. These results demonstrate that XPA-deficient mice have increased susceptibility to both spontaneous liver tumor development and AFB(1)-induced hepatocarcinogenesis.     

Prognostic Value of Loss of Heterozygosity around three Candidate Tumor Suppressor Genes on Chromosome 10q in Astrocytomas

We thoroughly examined loss of heterozygosity (LOH) around three candidate tumor suppressor genes on chromosome 10q to determine whether LOH of each tumor suppressor gene is associated with the previously defined clinical prognostic indices. We also examined whether LOH can help predict prognostic variables in astrocytomas.We selected samples from 40 astrocytomas (grades 2–4), performed Ki-67 immunostaining, and counted positive cells. Using DNA from aliquots of tumor blocks and leukocytes, we investigated LOH around the PTEN, NEURL, and DMBT1 genes (10q23.3–26.1) with the silver staining procedure. We then statistically evaluated the relationship among histological features, regional LOH on chromosome 10q, and survival. The mean survival period for patients with LOH around PTEN was 7.2 months after surgery, while that for patients without LOH around PTEN was 21.4 months. Thus, LOH around PTEN was closely associated with a reduced overall survival (p = 0.0020) but LOH at NEURL or DMBT1 was not (p > 0.05).The combined features of an increase in histological grading and Ki-67-positive cells and the presence of LOH around PTEN significantly correlated with poor prognosis. These factors may be useful predictors of survival, and LOH analysis of tumor suppressor genes on chromosome 10q can contribute greatly to the treatment of patients with astrocytoma.