S100P, a calcium-binding protein, is preferentially associated with the growth of polypoid tumors in colorectal cancer

Colorectal cancer (CRC) is a genetically heterogeneous disease with distinct morphological patterns. It has been shown that polypoid and ulcerative CRC displays different genetic alterations. In the present study, we aimed to investigate genes with differential expression patterns between ulcerative and polypoid CRC. cDNA microarray analysis was performed to compare the gene expression profiles in samples of ulcerative and polypoid CRC with paired normal mucosa samples. Potential candidate genes were further validated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot analysis and immunohistochemistry. The epigenetic regulation of gene expression was investigated using methylation-specific PCR (MSP). cDNA microarray analysis identified 11 upregulated and 14 downregulated genes which were differentially expressed in samples from both tumor types compared to the matched normal mucosa samples. Among these, S100P was the only upregulated gene preferentially associated with polypoid CRC (P=0.032). The samples of polypoid CRC displayed significantly higher S100P protein and mRNA expression levels than the samples of ulcerative CRC (P<0.05, respectively). Using semi-quantitative immunohistochemical analyses, S100P overexpression was found to be preferentially associated with polypoid CRC (24/30 vs. 14/40, P<0.001). The relative methylation level determined by MSP did not differ significantly between the samples of polypoid and ulcerative CRC (43.36 vs. 49.10%, P=0.168), indicating that promoter hypomethylation was not directly related to the upregulation of S100P mRNA. Our results demonstrate that the upregulation of S100P mRNA and protein expression is a predominant characteristic in polypoid CRC, whereas ulcerative CRC presents with a wide range of expression levels, indicating that S100P overexpression is not a key determinant in conferring invasion properties. The clinicopathological significance of S100P in CRC requires further investigation in well-controlled studies.

Risk factors for lymph node metastasis in pT1 and pT2 rectal cancer: a single-institute experience in 943 patients and literature review

BACKGROUND

Local excision has become an alternative for radical resection in rectal cancer for selected patients. The purpose of this study was to assess the clinicopathologic factors determining lymph node metastasis (LNM) in patients with T1-2 rectal cancer.

METHODS

Between January 1995 and December 2009, a total of 943 patients with pT1 or pT2 rectal adenocarcinoma received radical resection at a single institution. Clinicopathologic factors were evaluated by univariate and multivariate analyses to identify risk factors for LNM.

RESULTS

A total of 943 patients (544 men and 399 women) treated for T1-2 rectal cancer were included in this study. LNM was found in 188 patients (19.9%). In multivariate analysis, lymphovascular invasion (LVI; P < 0.001, hazard ratio 11.472), poor differentiation (PD; P = 0.007, hazard ratio 3.218), and depth of invasion (presence of pT2; P = 0.032, hazard ratio 1.694) were significantly related to nodal involvement. The incidence for LNM lesions in the presence of LVI, PD, and pT2 was 68.8, 50.0, and 23.1%, respectively, while that for pT1 carcinomas with no LVI or PD was 7.5%.

CONCLUSIONS

LVI, PD, and pT2 are independent risk factors predicting LNM in pT1-2 rectal carcinoma.

Long-term survival benefits of adjuvant chemotherapy by decreasing incidence of tumor recurrence without delaying relapse in stage III colorectal cancer

BACKGROUNDS AND AIMS

To elucidate the survival benefits of adjuvant chemotherapy by decreasing incidence or by delaying time of tumor recurrence, we reported the long-term results of a nonrandomized prospective study comparing the adjuvant chemotherapy to no chemotherapy in stage III colorectal cancer.

PATIENTS

From 1991 to 1995, 463 patients with stage III colorectal cancer were divided to three groups which were no chemotherapy, weekly chemotherapy, and monthly chemotherapy (5-FU plus levamisole).

RESULTS

The recurrent incidence was significantly decreased in patients with chemotherapy (47.8% vs. 63.9% of no chemotherapy, P = 0.001), resulting into better survival. The 10-year cancer-specific and overall survival rates of patients with chemotherapy vs. no chemotherapy were 52.1% vs. 37.8% and 46.9% vs. 29.9%, respectively (P < 0.001). Weekly chemotherapy had better survival than monthly chemotherapy (P < 0.05). There was no significant difference in recurrent time or types between the patients with and without chemotherapy. The percentages of patients with recurrence happened within 3 years were 85.2% and 84.6% of those with and without chemotherapy, respectively. Patients with advanced stage of T4b invasion depth, N2, and central node invasion had no significant survival benefits by adjuvant chemotherapy.

CONCLUSIONS

Long-term survival benefits achieved by adjuvant chemotherapy is through decreasing recurrent incidence, not through postponing tumor recurrent time. That means adjuvant chemotherapy indeed cures some patients by eradicating occult tumor. In adjuvant setting, more powerful regimen for eradicating occult tumor is the keystone to improve long-term survival of stage III colorectal cancer.

Mutation analysis of the APC gene in Taiwanese FAP families: low incidence of APC germline mutation in a distinct subgroup of FAP families

Familial adenomatous polyposis (FAP) is an autosomal-dominant disease caused by germline mutations in the adenomatous polyposis coli (APC) gene. The affected individuals develop colorectal polyposis and show various extra-colonic manifestations. In this study, we aimed to investigate the genetic and clinical characteristics of FAP in Taiwanese families and analyze the genotype-phenotype correlations. Blood samples were obtained from 66 FAP patients registered in the hereditary colorectal cancer database. Then, germline mutations in the APC genes of these 66 polyposis patients from 47 unrelated FAP families were analyzed. The germline-mutation-negative cases were analyzed by performing multiplex ligation-dependent probe amplification (MLPA) and single-strand conformation polymorphism (SSCP) analysis of the MUTYH gene. Among the analyzed families, 79% (37/47) of the families showed 28 APC mutations, including 19 frameshift mutations, 4 nonsense mutations, 3 genomic deletion mutations, 1 missense mutation, and 1 splice-site mutation. In addition, we identified 15 novel mutations in 32% (15/47) of the families. The cases in which APC mutations were not identified showed significantly lower incidence of profuse polyposis (P = 0.034) and gastroduodenal polyps (P = 0.027). Furthermore, FAP families in which some affected individuals had less than 100 polyps showed significant association with low incidence of APC germline mutations (P = 0.002). We have added the APC germline-mutation data for Taiwanese FAP patients and indicated the presence of an FAP subgroup comprising affected individuals with nonadenomatous polyps or less than 100 adenomatous polyps; this form of FAP is less frequently caused by germline mutations of the APC gene.

Serum p53 antibody as tumor marker for follow-up of colorectal cancer after curative resection

BACKGROUND

No large-scale studies have examined the use of serial measurements of serum p53 antibodies (s-p53Abs) combined with carcinoembryonic antigen (CEA) measurements during the follow-up of colorectal cancer (CRC) patients after curative resection.

METHODS

A highly specific enzyme-linked immunosorbent assay was used to analyze s-p53Abs levels in 305 CRC patients before and after curative resection at a single institution. Agreement between recurrence and serial s-p53Ab and CEA measurements was evaluated by diagnostic accuracy odds ratio (DOR), kappa, and area under receiver operating characteristic curve (AUC).

RESULTS

Among 305 patients, 76 (25%) patients had disease recurrence during follow-up. None of the 168 s-p53Ab seronegative patients (s-p53Ab < 10 U/microL) without recurrence had an abnormal s-p53Ab test during follow-up. Among the remaining low-level (10 U/microL <or= s-p53Ab <or= 76 U/microL, n = 103) and high-level (s-p53Ab titer > 76 U/microL, n = 34) seropositive patients, recurrence defined by s-p53Ab tests resulted in a DOR of 4.3 and infinity, a kappa of 0.35 and 1.00, and an AUC of 0.633 [95% confidence interval (CI), 0.495 to 0.772; P = 0.047], and 1.0 (95% CI, 1.000 to 1.000; P < 0.0001), respectively. Recurrence defined by CEA tests had an AUC of 0.781 (95% CI, 0.654 to 0.909) for low-level and 0.796 (95% CI, 0.611 to 0.982) for high-level seropositive patients.

CONCLUSIONS

Agreement between clinical recurrence and serial s-p53Ab test was dependent upon preoperative s-p53Ab level. Serial s-p53Ab testing outperformed CEA testing when predicting clinical recurrence in colorectal cancer patients with an abnormal preoperative s-p53Ab level.

Postoperative fever and survival in patients after open resection for colorectal cancer: a long-term follow-up study of 2,311 prospectively enrolled patients

PURPOSE

Two reports on the impact of postoperative fever on survival after surgery in patients with colorectal cancer yielded contradictory results. Our study examined possible associations between postoperative fever and long-term survival of patients who underwent resection of colorectal cancer.

METHODS

We investigated 2,311 consecutive patients who underwent elective open colorectal resection for primary colorectal cancer at a single institution between 1995 and 1998. The primary end points were cancer-specific and overall survival. Multiple covariate impact of risk factors on survival rates was assessed by Cox regression analysis.

RESULTS

A total of 252 patients (12.2 percent) developed postoperative fever. The most important independent risk factor for postoperative fever was postoperative morbidity (odds ratio, 4.9; 95 percent confidence interval, 3.7-6.6) followed by blood transfusion (1.7; 1.2-2.2), Stage IV disease (1.6; 1.1-2.2), male gender (1.4; 1.0-1.9), and rectal cancer (1.4; 1.0-1.8). Cox regression modeling indicated that stage, histology, tumor location, and blood transfusion were statistically significant covariate predictors for cancer-specific survival. Postoperative fever was not independently associated with cancer-specific or overall survival.

CONCLUSIONS

This study did not support the hypothesis that postoperative fever is an independent prognostic factor after colorectal resection for primary colorectal cancer.

Mismatch repair protein expression in Amsterdam II criteria-positive patients in Taiwan

BACKGROUND

Hereditary non-polyposis colorectal cancer (HNPCC) is characterized genetically by germline mutations in DNA mismatch repair (MMR) genes. Immunohistochemistry (IHC) has high sensitivity and specificity for identifying MMR-deficient tumours. This study investigated the clinical presentations and frequency of HNPCC in Taiwan by combined Amsterdam II criteria (AC-II) and IHC.

METHODS

In 1995-2003, 7108 patients with primary colorectal cancer registered in Chang Gung Memorial Hospital's Colorectal Cancer Registry were screened using AC-II. Tumour specimens were analysed for MMR protein expression by IHC, and relevant clinicopathological details were documented.

RESULTS

Some 83 patients fulfilled the AC-II. Clinicopathologically, 43 patients (52 per cent) had proximal tumours, ten (12 per cent) had poorly differentiated cancers, 17 (20 per cent) had mucinous adenocarcinoma and 51 (61 per cent) had stage I-II tumours. Seventeen patients developed second primary colonic and extracolonic cancers over a mean 7.2-year follow-up. Immunohistochemically, 58 patients were MMR protein deficient. They had a significantly earlier age of onset (P < 0.001), more proximal tumour location (P = 0.002), less advanced tumour stage (P = 0.008) and more second primary cancers (P = 0.017) compared with MMR-competent patients.

CONCLUSION

These data show significant differences in clinical features between MMR protein-deficient and MMR competent subgroups.

Postoperative urinary retention after primary colorectal cancer resection via laparotomy: a prospective study of 2,355 consecutive patients

PURPOSE

The risk factors for postoperative urinary retention after colorectal carcinoma surgery can be clearly defined. This study was designed to determine risk factors for postoperative urinary retention after colorectal cancer surgery.

METHODS

A total of 2,355 consecutive patients with colorectal cancer who underwent open resection for colorectal cancer during a four-year period were included. The association between dependent and independent variables (including 19 clinicopathologic and surgical factors) was analyzed by using the chi-squared test or Fisher's exact test, as appropriate. The significant variables in the univariate analyses were included in multivariate analysis.

RESULTS

The overall prevalence of postoperative urinary retention was 5.5 percent (colon cancer, 1.7 percent; rectal cancer, 9.1 percent, P < 0.0001). Multivariate analysis showed an independent association between postoperative urinary retention and age, lung disease, tumor location, operation duration, and additional pelvic procedure. Of the 121 patients with postoperative urinary retention, urine catheterization was required in 42 patients one month postoperatively. Discriminate analysis showed that gender, American Society of Anesthesiologists' score, tumor location, presence of drainage, and pelvic infection were best able to discriminate between prolonged (>1 month) and transient urinary dysfunction.

CONCLUSIONS

Older patients, lung disease, rectal cancer, longer operation duration, and additional pelvic procedure were at greater risk. There is a time-dependent change in postoperative urinary dysfunction. Male gender, American Society of Anesthesiologists' score of 2 or 3, rectal tumor, surgical drain, and pelvic infection can identify patients at risk for prolonged urinary dysfunction.

Inverse effects of mucin on survival of matched hereditary nonpolyposis colorectal cancer and sporadic colorectal cancer patients

PURPOSE

To compare survival and histologic features of hereditary nonpolyposis colorectal cancer (HNPCC; Lynch syndrome) cases to well-matched sporadic colon cancers from the same patient population.

EXPERIMENTAL DESIGN

Between January 1995 and March 2002, a total of 5,138 consecutive patients underwent resection of primary colorectal adenocarcinoma in a single institution. According to the Amsterdam criteria, 56 HNPCC patients were matched to 147 sporadic colorectal cancer (SCRC) with no family history of cancer and with the same gender, tumor location, and age within 3 years. Immunohistochemical analyses were done for MUC1, MUC2, MUC3, and MUC5AC.

RESULTS

The HNPCC group had a marginally significantly better long-term outcome than the SCRC group (P = 0.058). The trend disappeared after adjustment by tumor-node-metastasis stage in a Cox model (P = 0.774). We noted a difference of >50% in the 5-year cancer-specific survival rates of HNPCC- and SCRC-mucinous groups (92% versus 31%, P = 0.0003). Interaction between mucin and HNPCC and its effects on survival were further confirmed by comparing the Cox models with and without interaction terms (hazard ratio, 0.1; P = 0.034 with adjusting stage). Patients with tumors showing dual expression of mucin and MUC1, which appeared in 11% of those with HNPCC and 50% of those with SCRC, had a lower 5-year cancer-specific survival rate than patients without (30% versus 60%; P = 0.004 by log-rank test; P = 0.039 with adjustment for tumor-node-metastasis stage).

CONCLUSIONS

These results suggest that mucin has an inverse effect on survival in patients with HNPCC and SCRC, which might be partly explained by a lower prevalence of MUC1 expression in the mucinous HNPCC group than in the SCRC groups.

Preoperative plasma vascular endothelial growth factor but not nitrite is a useful complementary tumor marker in patients with colorectal cancer

PURPOSE

Vascular endothelial growth factor and nitric oxide are both related to tumor progression. This study was designed to measure preoperative plasma vascular endothelial growth factor and nitrite levels in patients with colorectal cancer to evaluate their clinical applications as tumor markers.

METHODS

In total, 279 patients with primary colorectal cancer and 20 patients with hemorrhoids (as a control) were included in this study. Plasma vascular endothelial growth factor was measured by quantitative, solid-phase, enzyme-linked immunosorbent assay (R&D Systems), whereas nitrite was measured by a high-performance liquid chromatographic method.

RESULTS

The vascular endothelial growth factor (mean, 220.6 pg/ml, P < 0.005) and nitrite (mean, 29.4 microM, P = 0.043) levels of patients with cancer were significantly higher than those of controls (mean vascular endothelial growth factor, 67 pg/ml; mean nitrite, 23 microM). Preoperative plasma vascular endothelial growth factor levels were positively correlated with tumor stage, T class, M class, and tumor size (Spearman correlation, P < 0.01), but were not associated with gender, N class, tumor location, histology type, or grade. There were no statistical differences in nitrite levels among different groups of patients with cancer. Higher vascular endothelial growth factor levels also were correlated with leukocytosis, elevated carcinoembryonic antigen, and a higher platelet count. The positive rates of vascular endothelial growth factor elevation (>148.6 pg/ml) compared with carcinoembryonic antigen elevation were 36.9 to 14.6 percent in Stage I, 60.9 to 33 percent in Stage II, 62.9 to 48.7 percent in Stage III, and 86 to 70.2 percent in Stage IV, respectively. The overall positive rate of vascular endothelial growth factor elevation also was higher than that of carcinoembryonic antigen elevation (63 percent for vascular endothelial growth factor vs. 42.5 percent for carcinoembryonic antigen, P = 0.016). More than one-half of the patients without carcinoembryonic antigen elevation still had elevated vascular endothelial growth factor levels. The combined assessment using vascular endothelial growth factor and carcinoembryonic antigen was superior to individual assessment using vascular endothelial growth factor or carcinoembryonic antigen. In node-negative tumor, the patients with vascular endothelial growth factor elevation had worse disease-free survival than those without vascular endothelial growth factor elevation (P = 0.0367). There was no association of vascular endothelial growth factor elevation with survival in patients with node-positive tumor.

CONCLUSIONS

Plasma vascular endothelial growth factor is a useful complementary tumor marker; however, synchronous measurement of white blood cells, platelets, and carcinoembryonic antigen is suggested in the clinical application of vascular endothelial growth factor to colorectal cancer.

Impact of the cyclin D1 A870G polymorphism on susceptibility to sporadic colorectal cancer in Taiwan

PURPOSE

Cyclin D1 is a regulatory protein involved in the cell cycle of both normal and neoplastic cells. Polymorphism of this gene at codon 242 in exon 4 has impacts on risk of the early-age onset in several malignant neoplasms, including colorectal cancer. This investigation was designed to evaluate the effect of cyclin D1 gene polymorphism on the risk of colorectal cancer in Chinese migrants of the Taiwanese population.

METHODS

We enrolled 831 primary sporadic colorectal cancer patients as the study group and 1,052 age-gender matched healthy individuals as the control group (1,883 total cases) for present study. Cyclin D1 genotypes (AA, AG, GG) were determined using PCR-RFLP analysis on genomic DNA.

RESULTS

The frequency of G allele was 39.89 percent and 40.96 percent in the study group and the control group, respectively (P = 0.02). The patients were divided into three age groups for statistical analysis. The younger male patients had a higher frequency of AA/AG genotype compared with the controls (odds ratio, 2.75; 95 percent confidence interval, 1-7.9). The effect of AA/AG genotype on colorectal cancer risk was statistically significant for male patients (odds ratio, 1.34; 95 percent confidence interval, 1.04-1.72), but such phenomenon was not observed in female patients.

CONCLUSIONS

Our study suggests that the effect of cyclin D1 gene polymorphism on colorectal cancer risk is only observed in males and AA/AG genotype of cyclin D1 gene is associated with a higher risk of colorectal cancer in the younger patients within the Taiwanese population.

Pelvic drainage and other risk factors for leakage after elective anterior resection in rectal cancer patients: a prospective study of 978 patients

OBJECTIVE

The objective of this study was to investigate prophylactic pelvic drainage and other factors that might be associated with anastomotic leakage after elective anterior resection of primary rectal cancer.

SUMMARY BACKGROUND DATA

Anastomotic leak after anterior resection for primary rectal cancer leads to significant postoperative morbidity and mortality. The role of pelvic drainage in the prevention of anastomotic leakage is controversial.

METHODS

We investigated 978 consecutive patients undergoing elective anterior resection for primary rectal cancer between February 1995 and December 1998 in a single institution. Use of a drain and type of drainage were at the surgeon's preference. Data were prospectively collected during hospitalization. Twenty-five independent tumor-, patient-, and treatment-related variables were analyzed. The dependent variable was clinical anastomotic leakage. A binary logistic regression analysis was used to assess the independent association of variables with the dependent variable.

RESULTS

The clinical anastomotic leakage rate was 2.8%. Independent risk factors for anastomotic leakage were use of an irrigation-suction drain (odds ratio [OR], 9.13; 95% confidence interval [CI], 1.16-71.76), blood transfusion, poor colon preparation (OR, 2.58; 95% CI, 1.10-5.88), and anastomotic level 5 cm or less from the anal verge (OR, 2.38; 95% CI, 1.03-5.46).

CONCLUSIONS

Routine use of pelvic drainage is not justified and should be discouraged. In cases in which pelvic drainage is required such as in difficult operations or to prevent pelvic hematoma, pelvic drainage other than irrigation-suction should be considered.

Evaluation of prognosis for malignant rectal gastrointestinal stromal tumor by clinical parameters and immunohistochemical staining

PURPOSE

The aim of this study was to identify associated prognostic factors influencing the outcome of curative resection of rectal gastrointestinal stromal tumor.

PATIENTS AND METHODS

Diagnostic immunohistochemical staining with CD34, CD117, S-100, desmin, and muscle-specific actin was performed in 46 consecutive patients with previously diagnosed rectal leiomyosarcoma who underwent curative resection from 1979 to 1999. CD44, Bcl-2, P53, and Ki-67 staining were performed on tumors rediagnosed as gastrointestinal stromal tumor for the prognostic evaluation.

RESULTS

There were 42 (91.3 percent) patients with rectal gastrointestinal stromal tumor (18 females and 24 males; mean age, 58.4 years). Twenty-nine patients underwent radical surgical resections, such as abdominoperineal resection or low anterior resection, whereas the other 13 patients underwent wide local excision, such as transrectal excision or Kraske's operation. Sixteen tumors were classified as high-grade gastrointestinal stromal tumors, and 26 as low-grade. No tumor had a positive P53 stain. Twenty-seven patients (64.3 percent) developed recurrence or metastasis postoperatively (median follow-up, 52 months). The one-year, two-year, and five-year disease-free survival rates were 90.2 percent, 76.7 percent, and 43.9 percent, respectively. Of these patients with recurrence, subsequent resections in 12 patients with local recurrence, transarterial tumor embolism or STI-571 chemotherapies in 3 patients with distant mestastases were performed. The one-year, two-year, and five-year overall survival rates were 97.4 percent, 94.3 percent, and 83.7 percent, respectively. Bcl-2 (P = 0.007) and histologic grade (P = 0.05) in disease-free survival analysis and age < 50 years (P = 0.03) and tumor size > 5 cm (P = 0.02) in overall survival analysis were independent prognostic factors. The group with wide local excision had a higher local recurrence rate than that of the radical resection group (77 percent vs. 31 percent, P = 0.006), despite smaller tumors (4.5 vs. 7.2 cm, P = 0.05). There was no difference in the incidence of distant metastasis between the two groups.

CONCLUSION

Younger age (< 50 years), higher histologic tumor grade, positive Bcl-2 status, and larger tumors (> 5 cm) were factors associated with significantly poorer prognoses for rectal gastrointestinal stromal tumor. Radical resection was superior to wide local excision in the prevention of local recurrence, but not that of distant metastases.

Humoral response to p53 is associated with conserved domains II and IV mutations in human colorectal cancer: a case-control study in Taiwan

To explore the relationship between mutations of the p53 gene, p53 protein accumulation in tumor tissues and the presence of anti-p53 antibodies (Ab) in sera, a matched case-control study with 63 colorectal cancer patients positive for p53-Ab was carried out. These control patients were matched for age, gender, as well as tumor site and stage with 63 colorectal cancer patients positive for p53-Ab. The study was designed to analyze their p53 gene mutations in exons 4-9 by the single strand conformation polymorphism (SSCP) followed by direct sequencing, as well as measuring p53 protein accumulation by immunohistochemistry. A significantly higher frequency of p53 mutations in exon 4-9 and positive immunohistochemical staining of p53 protein was observed in tumors from p53-Ab positive patients (55.56 and 84.13%, respectively) than in tumors from p53-Ab negative patients (22.22 and 60.32%, respectively). Using a conditional logistic regression model, the humoral response to p53 was found to be associated with p53 gene mutation (OR = 3.34; 95% CI, 1.31-8.54, p=0.012) and p53 protein accumulation (OR = 3.80; 95% CI, 1.02-14.14, p=0.047). Further analysis showed that the frequency of p53 mutations located in the conserved domains II (codons 112-141) and IV (codons 234-258) was significantly higher in p53-Ab positive patients than in p53-Ab negative patients (50.00% (16/32) vs. 8.33% (1/12), p=0.015, Fisher's exact test). Thus, our study demonstrated that the generation of p53 antibodies was usually correlated with the p53 protein accumulation and p53 gene mutation, especially mutations located in conserved domains II and IV.

p53 is an independent pre-treatment markers for long-term survival in stage II and III colorectal cancers: an analysis of interaction between genetic markers and fluorouracil-based adjuvant therapy

One hundred and thirty-eight stage II and III colorectal cancer patients were included to evaluate the prognostic significance of genetic markers (including mutations of the p53, K-ras genes, and microsatellite instability) on the response to 5-fluorouracil (FU)-based post-operative adjuvant therapies (PAT). When stratified by PAT and adjusting for other prognostic variables, presence of p53 mutation was associated with a poor outcome (hazard ratio (HR)=3.1, 95% confidence interval (CI), 0.9-11.0) among patients without PAT. Our data confirmed that p53 mutation is an independent pre-treatment factor in stage II and III colorectal cancer after curative resection.

Colorectal cancer without high microsatellite instability and chromosomal instability--an alternative genetic pathway to human colorectal cancer

At least two forms of genomic instability have been described in colorectal cancers (CRCs): microsatellite instability (MIN), which is characterized by a high frequency of microsatellite instability (MSI-H) and chromosomal instability (CIN), which is characterized by losses and gains of chromosomes (aneuploidy), as well as chromosome rearrangements. Morphological and molecular heterogeneity within MIN(-) CRCs have been described, but the distinctions between MIN(-) tumors with CIN and those without CIN remain largely unknown. We studied 179 colorectal cancers to elucidate the clinicopathological characteristics and molecular events in CRCs arising along these pathways. Loss of heterozygosity, MIN, DNA content, mutation of p53 and K-ras, and expression of p53, hMLH1 and hMSH2 were examined. We found that a subtype of tumors (17%) with MIN(-) and CIN(-), differed from MIN(-)CIN(+) tumors with respect to clinicopathological and genetic characteristics. This subtype was associated with a greater frequency of poorly differentiated and/or mucinous tumors (26%). This subtype of tumors had an extremely low p53 gene mutation rate (11%) and a relatively high p53 protein accumulation rate (55%). The dissociation between the p53 gene mutation and protein accumulation suggests that stabilization of p53 protein in the absence of p53 gene mutation may be an important event on a distinct pathway.

Favorable influence of age on tumor characteristics of sporadic colorectal adenocarcinoma: patients 30 years of age or younger may be a distinct patient group

PURPOSE

Age is reported as a risk factor for carcinogenesis, even though age can affect cancer behavior both positively and negatively. Young patients with colorectal cancer reveal different tumor characteristics than average-age and older-age groups, although few studies report the influence of age among the entire range of patient ages. The influence of age on clinicopathologic characteristics of sporadic colorectal cancer was analyzed. Whether an age group with distinct tumor characteristics was present was determined.

METHODS

A total of 5,436 patients who underwent colectomy in a single institute within a seven-year period were studied. Data on clinical and histopathologic features of colorectal cancer were collected from the cancer registry and medical records. These characteristics were analyzed according to ten-year age groups.

RESULTS

Eighty-three patients (1.6 percent) were 30 years of age or younger, whereas 285 (5.5 percent) were 31 to 40 years of age. Most patients (74.6 percent) were 51 to 80 years of age. The proportion of localized tumors (Dukes A and Dukes B) significantly increased as age increased, from 31.3 percent in the 30 years or younger age group to 49 percent in the 80 years or older group (P < 0.001). The proportion of poorly differentiated tumors tended to decreased as age increased (from 16.9 percent in the 30 years or younger group to 6.2 percent in the 80 years or older group; P = 0.009). A similar trend in the proportion of mucin-producing tumors was also observed (36 percent in the younger group vs. 7.5 percent in the older group; P < 0.001). There was no significantly different distribution of tumor locations among the different age groups.

CONCLUSIONS

Age appears to favorably influence the clinicopathological characteristics of sporadic colorectal cancer. As age increased, the characteristics of tumor stage at diagnosis, tumor differentiation, and mucin production improved.

Comparing results of preoperative staging of rectal tumor using endorectal ultrasonography and histopathology

BACKGROUND

Preoperative clinical staging of rectal tumors is very important to allow surgeons make informed decisions about the types of surgeries that should be performed. Endorectal ultrasonography (ERUS) is one of the tools that has been commonly used in clinical staging of rectal tumors. The aim of this study was to evaluate the accuracy of the preoperative rectal tumor staging using endorectal ultrasonography in comparison with the postoperative histopathological staging.

METHODS

The histopathology findings of the 67 patients with rectal tumors who underwent preoperative ERUS were reviewed and compared.

RESULTS

The overall accuracy of the ERUS assessment in the depth of tumor invasion was 88%, with overstaging at 9% and understaging at 3%. In determining perirectal nodal involvement of the 59 patients that were treated by radical rectal resection, the accuracy was 73%, with sensitivity of 77% and specificity of 70%.

CONCLUSION

ERUS is an objective, convenient, and highly accurate tool for preoperative rectal tumor staging, thus helping surgeons to determine the appropriate treatment modalities.

Risk factors associated with posthemorrhoidectomy secondary hemorrhage: a single-institution prospective study of 4,880 consecutive closed hemorrhoidectomies

PURPOSE

Posthemorrhoidectomy secondary hemorrhage is a rare but serious complication after hemorrhoidectomy. The determination of risk factors for this complication may provide information to improve outcome. A prospective study was conducted to determine the risk factors associated with posthemorrhoidectomy secondary hemorrhage.

METHODS

We studied 4,880 patients who underwent an elective closed hemorrhoidectomy by 9 proctologists in a single institution between January 1994 and July 1996. The variables analyzed included age, gender, surgeon, surgeon's seniority, suture material, aseptic preparation, and use of antibiotics. The logistic regression model was used to assess the independent association of variables with posthemorrhoidectomy secondary hemorrhage.

RESULTS

Among the 4,880 patients, 45 (0.9 percent) developed posthemorrhoidectomy secondary hemorrhage. The mean interval from operation to the onset of secondary hemorrhage was 8.8 (range, 5-19) days. Multivariate analysis revealed that patient's gender and individual surgeons were both independently associated with risk of hemorrhage. Male patients were more likely than females to develop posthemorrhoidectomy secondary hemorrhage (relative risk, 2.1; 95 percent confidence interval, 1.1-4.1; P = 0.021). The posthemorrhoidectomy secondary hemorrhage rates among individual surgeons ranged from 0.2 to 2.4 percent (P = 0.003).

CONCLUSION

Our data suggest that male patients are more likely to develop posthemorrhoidectomy secondary hemorrhage than female patients and that intersurgeon variability is highly correlated with this risk.

Effective management of posthemorrhoidectomy secondary hemorrhage using rectal irrigation

PURPOSE

How to manage posthemorrhoidectomy secondary hemorrhage, a rare but serious complication, effectively remains controversial. This study evaluated the effectiveness of using rectal irrigation as an initial treatment for posthemorrhoidectomy secondary hemorrhage.

METHODS

Among 4,880 patients on whom elective closed hemorrhoidectomy for symptomatic hemorrhoidal disease was performed, 45 (0.9 percent) developed posthemorrhoidectomy secondary hemorrhage. The 45 patients were divided into two groups based on the initial treatment in the stoma therapy room (n = 25) or in the operating room (n = 20). Patients in the stoma therapy room group were treated with rectal irrigation, whereas those in the operating room group were examined under anesthesia and the bleeding point (if any) was under-run using a suture. The two groups were then compared with respect to the cost-effectiveness of treatment, rehospitalization stay, and satisfaction with treatment.

RESULTS

The two groups (stoma therapy room vs. operating room groups) were comparable with respect to the mean age of patients (44 vs. 38 years), interval of hemorrhage (9.4 vs. 7.8 days), and estimated amount of blood loss (560 vs. 520 ml). Bleeding effectively stopped in 22 (88 percent) patients in the stoma therapy room group but only in 12 (60 percent) patients in the operating room group (P = 0.010). The rehospitalization stay was three days in the stoma therapy room and 4.9 days in the operating room group (P = 0.016). In addition, the stoma therapy room group had a greater satisfaction rate than the operating room group did (80 vs. 10 percent, P < 0.001). Moreover, the average cost of treatment in the operating room group was six-fold higher than that in the stoma therapy room group.

CONCLUSIONS

Our data suggest that rectal irrigation is an effective initial treatment for posthemorrhoidectomy secondary hemorrhage and offers a high rate of patient satisfaction with a reduced hospital cost.

Humoral response to p53 in human colorectal tumors: a prospective study of 1,209 patients

p53 Antibodies (p53-Abs) have been detected in the serum of a proportion of colorectal cancer (CRC) patients. It is not yet known at which stage during colorectal tumor progression p53-Abs appear in the serum. The utility of these antibodies as markers for CRC prognosis remains to be clarified. Using a quantitative enzyme-linked immunosorbent assay, we analyzed serum samples from 998 CRC patients and from 211 patients with polyp. Levels of p53-Abs were defined as negative (<10 U/microL), low (10-76 U/microL) and high (>76 U/microL). Overall, 13.0% of CRC patients and less than 1% of polyp patients had increased serum p53-Ab levels. High p53-Ab levels were only seen in patients with invasive carcinomas. The parameters that were significantly and independently associated with a greater frequency of high p53-Ab levels were the left colon (odds ratio [OR] = 3.4; 95% CI = 1.1-10.5), the rectum (OR = 2.9; 95% CI, 1.0-8.8) and advanced lymph node metastasis (OR = 4.6; 95% CI, 2.2-9.6). In univariate analysis, patients with high p53-Ab levels had a shorter survival times than did those without (p = 0.007). However, the significant effect disappeared in a Cox regression model adjusting for sex, age, tumor location, carcinoembryonic antigen levels, gross findings, histologic grade, mucin production and TNM stage. Thus, autoantibodies against p53 occur with tumor progression in multistep colorectal carcinogenesis and increase with advanced node metastasis. Furthermore, the seemingly adverse effect of high p53-Ab levels on the survival of CRC patients may be explained by other prognostic factors.

Risk factors for surgical site infection after elective resection of the colon and rectum: a single-center prospective study of 2,809 consecutive patients

OBJECTIVE

To identify the risk factors for surgical site infection (SSI) in patients undergoing elective resection of the colon and rectum.

SUMMARY BACKGROUND DATA

SSI causes a substantial number of deaths and complications. Determining risk factors for SSI may provide information on reducing complications and improving outcome.

METHODS

The authors performed a prospective study of 2,809 consecutive patients undergoing elective colorectal resection via laparotomy between February 1995 and December 1998 at a single institution. The outcome of interest was SSI, which was classified as being incisional or organ/space with or without clinical leakage. A likelihood ratio forward regression model was used to assess the independent association of variables with SSIs.

RESULTS

The overall SSI, incisional SSI, and organ/space SSI with and without clinical anastomotic leakage rates were 4.7%, 3%, 2%, and 0.8%, respectively. Risk factors for overall SSI were American Society of Anesthesiology (ASA) score 2 or 3 (odd ratio [OR] = 1.7), male gender (OR = 1.5), surgeons (OR = 1.3-3.3), types of operation (OR = 0.3-2.1), creation of ostomy (OR = 2.1), contaminated wound (OR = 2.9), use of drainage (OR = 1.6), and intra- or postoperative blood transfusion (1-3 units, OR = 5.3; >/=4 units, OR = 6.2). However, SSIs at specific sites differed from each other with respect to the risk factors. Among a variety of risk factors, only blood transfusion was consistently associated with a risk of SSI at any specific site.

CONCLUSIONS

In addition to ASA score and surgical wound class, blood transfusion, creation of ostomy, types of operation, use of drainage, sex, and surgeons were important in predicting SSIs after elective colorectal resection.

Primary colorectal lymphoma

PURPOSE

The purpose of this study was to review the clinical presentation and characteristics of primary colorectal lymphoma, analyze the prognostic factors, and assess the results of treatment with adjuvant chemotherapy.

METHODS

We identified 37 cases at our institution between 1980 and 1996. They comprised 0.48 percent of all cases of colon malignancies (37/7,658) during this period. The following clinical information was obtained: age, gender, signs and symptoms, tumor site, tumor size, histology grade, pathology, and adjuvant chemotherapy.

RESULTS

The most common presenting signs and symptoms were abdominal pain (62 percent), abdominal mass (54 percent), and weight loss (43 percent). The most frequent site of involvement was the cecum (45 percent). Histologically, 29 (78 percent) were classified as high-grade, and 8 (22 percent) as intermediate-grade-to-low-grade lymphoma. Nine (24.3 percent) of the cases were Stage EI, 23 (62.2 percent) were Stage EII, and 5 (13.5 percent) were Stage EIV. Twenty-one (57 percent) cases received adjuvant chemotherapy. The five-year survival rate was 33 percent for all patients and 39 percent for patients treated with combination chemotherapy. Overall median survival time was 24 months and 36 months for those with adjuvant chemotherapy. Only histology grade, among the factors examined, was a significant prognostic factor for survival. The mean survival time of the patients with Stage II disease who received chemotherapy was 117.4 months, and it was 47.9 months for the patients with Stage II disease who did not received chemotherapy.

CONCLUSIONS

In our retrospective study high-grade lymphoma was the only significant adverse prognostic factor for survival. Receiving adjuvant chemotherapy significantly improved survival in patients with Stage II disease. Patients with diffuse large-cell type had better survival than patients with small noncleaved-cell type in Stage II high-grade lymphoma.

A simplified regimen of weekly high dose 5-fluorouracil and leucovorin as a 24-hour infusion in patients with advanced colorectal carcinoma

BACKGROUND

Reports of in vitro experiments in colorectal carcinoma cells suggest that prolonged cellular exposure to 5-fluorouracil (5-FU) combined with relatively low concentrations of leucovorin (LV) provides optimal enhancement of 5-FU efficacy. In this study, a simplified regimen of weekly 24-hour infusion of high dose 5-FU combined with a relatively low dose of LV was used to treat patients with advanced colorectal carcinoma.

METHODS

Thirty-six patients with advanced colorectal carcinoma received 5-FU, 2600 mg/m2, admixed with LV, 100 mg/m2, in a portable infusion pump administered intravenously over a 24-hour period. High dose 5-FU/LV was delivered once a week for 5 consecutive weeks followed by a 1-week recovery period. All patients were assessable for toxicity and response.

RESULTS

Two complete responses and 15 partial responses were observed (response rate of 47.2%; 95% confidence interval, 30.1-64.4%). The median response duration was 9.6 months. The median survival and time to progression were 11.9 months and 7.1 months, respectively. The toxicity was mild and acceptable. The major dose-limiting factors were hand-foot syndrome and fatigue.

CONCLUSIONS

This simplified regimen of weekly 24-hour continuous infusion of high dose 5-FU/LV is an effective regimen in the treatment of patients with advanced colorectal carcinoma. Further study of the pharmacokinetics of combination therapy with 5-FU and LV as used in this regimen and its correlation with response and toxicity is warranted.

Segmental colectomy in the management of colonic inertia

Subtotal colectomy with ileorectostomy has been proposed for the management of colon inertia-type constipation. However, many patients experience frequent bowel movements, watery diarrhea, or both after such a treatment. The purpose of this study is to determine the proper colectomy with which to treat colon dysmotility constipation without the negative side effects of frequent bowel movements, watery diarrhea, or both. Forty idiopathic constipation patients were studied. All of the patients showed a prolonged right or left colon transit time and normal transit time of the sigmoid and rectum. They received different types of colectomies (left, right, and subtotal) according to the distribution or accumulation of markers in the colon. Within 3 months of surgery, all of the patients experienced a dramatic improvement of their symptoms without frequent bowel movements or watery diarrhea. No significant complications developed after surgery. All the patients were followed up for at least 2 years. Most of them (37 cases) still had satisfactory bowel movements and no other constipation symptoms. However, 3 of the 40 cases developed symptoms of constipation 1 1/2 to 2 years after surgery. They all received subtotal colectomy with ileorectal anastomosis subsequently. They reobtained satisfactory bowel movements and experienced a subsidence of other constipation symptoms 3 months later. These results suggest that directed segmental colectomy can improve colonic inertia constipation without the consequence of frequent bowel movements and diarrhea.

Foley catheter-assisted endoscopic treatment of severe anastomotic stenosis following anterior resection of the rectum

Rectal stenosis following low anterior resection is common. Several methods of treatment have been described. We introduce a simple method for the treatment of anastomotic stenosis using a conventional proctoscope and an electric knife with a Foley catheter as an anvil. Under direct vision, this technique can afford accurate and safe incision of stenosis.

Primary diffusely infiltrative adenocarcinoma of the colon and rectum

BACKGROUND

Primary diffusely infiltrative colorectal adenocarcinoma is rare. About 100 cases have been reported in the literature. The mucosal alterations in this type of tumor and their clinicopathological characteristics in relation to survival are not clear.

METHODS

We retrospectively reviewed 30 cases of primary diffusely infiltrative colorectal adenocarcinoma operated upon in a single institution.

RESULTS

Eighteen (60%) of these 30 patients were women. The average age at diagnosis was 47.4 (SD, 19.3) years. Eighteen tumors (60%) were located in the rectum. The tumors could be classified into two major types. A type 1 tumor had minimal mucosal alteration and no discrete ulcer. A type 2 tumor was associated with a discrete ulcer. The type 1 tumor was more frequently associated with intracellular or extracellular mucin production and stage IV disease. Hematogenous spread (including peritoneal carcinomatosis) was more frequently seen in type 1 than in the type 2 tumors (61% vs. 18%, p = 0.013). The overall median cancer-specific survival time was 15 (SE, 3; 95% confidence interval, 10-21) months. TNM stage is the only significant factor in predicting outcome (p = 0.016). When compared with stages II and III, the odds of death for stage IV was 2.9 (95% confidence interval: 1.1-7.4).

CONCLUSION

Diffusely infiltrative colorectal cancer can be separated into two subtypes according to the presence of a discrete ulcer. The type 1 tumor (without a discrete ulcer) was associated with a higher frequency of hematogenous spread. TNM Stage was the only important clinicopathological factor in determining outcome.

Pathogenetic implications of DNA nondiploidy in colorectal cancers

PURPOSE

Several studies propose that proximal and distal colorectal cancers have a different pathogenesis. We tested the hypothesis using flow cytometric DNA analysis.

METHODS

DNA analysis was performed in 719 patients with colorectal cancer. In addition, histopathologic data were re-evaluated in a blinded fashion by a single pathologist.

RESULTS

Distal tumors were more often nondiploid than were proximal tumors (61 vs. 49 percent; P = 0.015). Compared with the proximal tumor, distal tumors were smaller (P = 0.0001) and had less desmoplastic reaction (39 vs. 53 percent; P = 0.0001). Tumor location had no significant associations with the remaining parameters, including mucin production, perineural invasion, blood/lymphatic vessel invasion, lymphocytic infiltration, histologic grade, tumor stage, gross appearance, age, and gender.

CONCLUSIONS

The unequal distribution of ploidy suggests distinct pathogenetic mechanisms at proximal and distal sites.

Internal iliac artery aneurysmo-rectal fistula associated with multiple aortoiliac aneurysms

Fistular communication between an internal iliac artery aneurysm and rectum presenting as massive lower gastrointestinal tract bleeding is a rare entity in clinical practice. Prompt diagnosis and experienced therapeutic application determine the outcome. Herein we report the successful management of such a complication. A 68-year-old male had multiple aneurysms over the abdominal aorta and bilateral iliac arteries. It was the largest aneurysm arising from the right internal iliac artery which ruptured into the rectum and resulted in massive hematochezia. After extraanatomical bypass with right axillo-femoral and femoro-femoral crossover grafts to restore the circulation to the bilateral lower limbs, the infrarenal abdominal aorta just immediately above the proximal aneurysm was transected and closed as a blind stump. All the aneurysms were included in this resection and as much of the infected aneurysm tissue was debrided as possible. The rectum was exteriorized using Hartmann's procedure. The patient survived the operation and was discharged in good condition.

Hemorrhoidectomy with self-retaining retraction

Hemorrhoidectomy is one of the most effective treatments for significantly symptomatic hemorrhoids. By placing the patient in the Sims' position and appropriately using the Hill-Ferguson retractor and towel clip, the surgeon can get good exposure and perform a Ferguson closed hemorrhoidectomy without any assistance.

Resection of liver metastases from colorectal cancer: are there any truly significant clinical prognosticators?

PURPOSE

This study was designed to evaluate the prognostic significance of various prognostic factors affecting recurrence after resection of colorectal hepatic metastases.

PATIENTS AND METHODS

Records of 54 patients who had hepatic resection between 1986 and 1993 for metastatic liver tumor from colorectal cancer were reviewed. Factors analyzed were those reported to be of prognostic significance in other studies, including gender, primary tumor site, Dukes stage, diagnostic interval, grade, preoperative carcinoembryonic antigen (CEA) level, number of metastases, size of metastases, distribution of metastases, type of resection, resection margin, and estimated blood loss.

RESULTS

Average follow-up of surviving patients was 28 (range, 12-89) months. Average survival time from date of hepatic resection was 26 months, with an estimated actuarial survival rate of 25.5 percent at five years. Using the multivariate analysis of factors, gender and preoperative CEA level were shown to be significantly related to overall survival (P = 0.0455 and 0.054, respectively). Cancer of the right side colon had significant correlation with hepatic "recurrence" (P = 0.0071).

CONCLUSIONS

Female patients and those with peroperative CEA values higher than 20 ng/ml have a better chance of survival following hepatic resection. Cancer of the right colon has a greater tendency for hepatic recurrence than that of the left colon.

Prognostic evaluation of DNA flow cytometric and histopathologic parameters of colorectal cancer

BACKGROUND

The clinical value of DNA flow cytometry of colorectal cancer is unclear. The purpose of this retrospective study was to evaluate the relationship between tumor flow cytometry, histopathologic parameters, and survival.

METHODS

Flow cytometry was performed on paraffin embedded specimens from 653 patients who had surgery from 1980 to 1983.

RESULTS

Aneuploidy was associated with distal tumor, perineural invasion, desmoplastic reaction, and failure to secrete mucin. TNM Stage I tumors were more frequently diploid than were more advanced tumors (71% vs. 41%). An abnormal DNA content had a marginal impact on survival as evaluated by univariate analysis (69% vs. 61% 10-year survival rate, P = 0.06). Multivariate analysis revealed that significant predictors of outcome were lymph node metastasis (95% confidence interval of relative risks of death from recurrent disease, 1.50-2.92), rectal cancer (1.22-2.19), absence of lymphocytic infiltration (1.20-2.17), invasion through bowel wall (1.17-3.13), lymphatic vessel invasion outside bowel wall (1.05-2.69), perineural invasion (1.15-3.19), and male gender (1.00-1.79).

CONCLUSIONS

These findings suggest that ploidy is associated with some histopathologic parameters, but flow cytometry does not correlate with long term survival of patients with colorectal carcinoma.

Presacral tumor: a review of forty-five cases

Forty-five patients with primary presacral tumors underwent their treatment at Division of Colon Rectal Surgery, Chang Gung Memorial Hospital, from 1978 to 1992. These 45 patients, 20 male and 25 female, ranged from 15 to 76 years of age (mean, 41.1 years). Congenital tumors (47 per cent) were the most frequent histologic type, followed by miscellaneous tumors (36 per cent). Forty-eight per cent of patients had malignant tumors. All benign congenital cysts were in females. These tumors presented a variety of symptoms and signs. Diagnosis could be made by digital examination in 43 (96 per cent) of the patients. Computed tomographic scan was the most important diagnostic tool in determining the extent and degree of tumor invasion. The positive rate was 100 per cent in 21 patients. As for operative methods, abdominal approach was selected in 24 patients, transacral in 13 patients, abdominal/sacral combined in 6 patients, and biopsy only in two patients. Postoperative complications occurred in 16 patients (36 per cent), but there were no operative deaths. Of the tumors that underwent resection, 23 had total resection (18 benign and 5 malignant) and 22 incomplete (5 benign and 17 malignant). Benign tumors had a good chance with resection of the lesion (P < 0.05). For patients with malignant tumors, the 5-year survival rate was 40.7 per cent. Whenever possible, total resection could offer better results for presacral tumor, whether the lesions were benign or malignant.

An alternative treatment of anal squamous cell carcinoma: combined radiotherapy and chemotherapy

The conventional surgical treatment of anal squamous cell carcinoma is abdominoperineal resection. A new approach of combined radiotherapy and chemotherapy has been proposed following the observation of excellent local control. In this retrospective study, 40 cases of primary anal squamous cell carcinoma without distant metastasis were collected between 1979 and 1986 and the individual prognosis of the above two methods of treatment was evaluated. Group I (20 cases) received abdominoperineal resection with or without postoperative radiotherapy. Postoperative radiation was given if regional lymph node biopsy was positive. Group II (20 cases) received combined radiotherapy and chemotherapy with or without wide local excision. Radiation was delivered to the anus, pelvis, and bilateral inguinal nodal areas to a total dose of 5,500 rads. A continuous infusion of 5-FU was started on day 2 of the irradiation at a dose of 1,000 mg/m2 body surface/day for 5 days and a bolus injection of mitomycin was given on day 2 at a dose of 10 mg/m2 body surface. The second course was given 1 month later to complete the chemotherapy. The wide local excision was performed if the disease still persisted after completion of combined radiotherapy and chemotherapy. All 40 cases were followed up for at least 5 years. All cases (100%) in group I survived 1 year, 18 cases (90%) 2 years, 14 cases (70%) 3 years, 10 cases (50%) 4 years, and 6 cases (30%) 5 years. Twenty cases (100%) in group II survived 1 year, 17 cases (85%) 2 years, 13 cases (65%) 3 years, 8 cases (40%) 4 years, and 5 cases (25%) survived 5 years. All the mortalities in both groups died of distant metastasis or abdominal carcinomatosis. From the above results, the overall survival rate of combined radiotherapy and chemotherapy was not significantly worse than that of conventional abdominoperineal resection. In conclusion, combined radiotherapy and chemotherapy may be chosen as an alternative management in treating anal squamous cell carcinoma.

[The clinic diagnostic value of the rigid sigmoidoscopy]

Rigid sigmoidoscopy is beneficial as it detects rectal or distal sigmoidal lesions very efficiently and precisely. But it also has some complications, e. g. rectal injury, rectal perforation or transient bacteremia. In this prospective study, 800 cases were collected and divided into two groups. In group I, 400 O.P.D. symptomatic cases were chosen randomly and in group II 400 cases registered for routine physical examination were picked up. The positive detection rate was 7% in group I versus 2% in group II. The lesions detected in group I are 15 cases of cancer, 7 cases of polyp, 4 cases of irradiation proctitis, 2 cases of ulcerative colitis and 1 case of pseudomembranous colitis. Only 8 polyps are found in group II. The routine sigmoidoscopy is mandatory for symptomatic patients but it is not cost-effective for routine check-ups. The stool occult blood is the best screening test for detecting colorectal lesions. For routine physical examination, stool occult blood test is safe and easy to perform. If the stool occult blood test is positive, then further examinations will be necessary.