Long-term follow-up of the randomized trial of mesorectal excision with or without lateral lymph node dissection in rectal cancer (JCOG0212)

BACKGROUND

Japan Clinical Oncology Group (JCOG) 0212 (ClinicalTrials.gov NCT00190541) was a non-inferiority phase III trial of patients with clinical stage II-III rectal cancer without lateral pelvic lymph node enlargement. The trial compared mesorectal excision (ME) with ME and lateral lymph node dissection (LLND), with a primary endpoint of recurrence-free survival (RFS). The planned primary analysis at 5 years failed to confirm the non-inferiority of ME alone compared with ME and LLND. The present study aimed to compare ME alone and ME with LLND using long-term follow-up data from JCOG0212.

METHODS

Patients with clinical stage II-III rectal cancer below the peritoneal reflection and no lateral pelvic lymph node enlargement were included in this study. After surgeons confirmed R0 resection by ME, patients were randomized to receive ME alone or ME with LLND. The primary endpoint was RFS.

RESULTS

A total of 701 patients from 33 institutions were assigned to ME with LLND (351) or ME alone (350) between June 2003 and August 2010. The 7-year RFS rate was 71.1 per cent for ME with LLND and 70·7 per cent for ME alone (hazard ratio (HR) 1·09, 95 per cent c.i. 0·84 to 1·42; non-inferiority P = 0·064). Subgroup analysis showed improved RFS among patients with clinical stage III disease who underwent ME with LLND compared with ME alone (HR 1·49, 1·02 to 2·17).

CONCLUSION

Long-term follow-up data did not support the non-inferiority of ME alone compared with ME and LLND. ME with LLND is recommended for patients with clinical stage III disease, whereas LLND could be omitted in those with clinical stage II tumours.

Male sexual dysfunction after rectal cancer surgery: Results of a randomized trial comparing mesorectal excision with and without lateral lymph node dissection for patients with lower rectal cancer: Japan Clinical Oncology Group Study JCOG0212

BACKGROUND

We conducted a randomized controlled trial (JCOG0212) to determine whether the outcome of mesorectal excision (ME) alone for rectal cancer is not inferior to that of ME with lateral lymph node dissection (LLND). The present study focused on male sexual dysfunction after surgery.

METHODOLOGY

Eligibility criteria included clinical stage II/III rectal cancer, the lower margin of the lesion below the peritoneal reflection, the absence of lateral pelvic lymph node enlargement, and no preoperative radiotherapy. After confirmation of R0 resection by ME, patients were intraoperatively randomized. Questionnaires using the International Index of Erectile Function (IIEF-5) about the sexual function of men were collected before and 1 year after surgery. Sexual dysfunction incidence was defined as the ratio of patients showing sexual dysfunction after surgery relative to the number who had no erectile dysfunction before surgery.

RESULTS

Among 701 patients enrolled between June 2003 and August 2010, 472 males were included. Among them, 343 (73%) completed preoperative and postoperative questionnaires. According to the study protocol, the incidences of sexual dysfunction in patients who underwent ME alone and ME with LLND were 68% (17/25; 95%CI, 47-85%) and 79% (23/29; 95%CI, 60-92%), respectively (p = 0.37). Incidences of sexual dysfunction in patients with no or only mild erectile dysfunction before surgery who underwent ME alone and ME with LLND were 59% (48/81) and 71% (67/95), respectively (p = 0.15). Multivariate analysis identified age as the only risk factor for sexual dysfunction after surgery (p = 0.02).

CONCLUSIONS

LLND may not increase sexual dysfunction incidence after rectal cancer surgery. This incidence is associated with increased age. This trial is registered with ClinicalTrials.gov, number NCT00190541 and University Hospital Medical Information Network Clinical Trials Registry, number C000000034.

Cecal schwannoma with laparoscopic wedge resection: report of a case

Schwannomas of the large intestine are relatively rare. Here, we present a case of schwannoma of the cecum in a 59-year-old woman that was successfully resected by laparoscopic wedge resection. In a medical checkup, a colonoscopy revealed a 2 cm submucosal lesion, without mucosal changes, located in the cecum wall contralateral to Bauhin's valve. Abdominal contrast CT and contrast MRI indicated a smooth-surfaced, semi-round tumor of about 2 cm that gave an enhanced homogeneous signal in the cecum. Laparoscopic wedge resection was performed after the diagnosis of benign submucosal tumor. The lesion was 2.5 × 2.0 cm, was histologically composed of spindle neoplastic cells arranged in cords, was positive for S-100 and vimentin, and was diagnosed as schwannoma. The details of this case are reported herein and focus on the successful application of laparoscopic wedge resection for treatment of the colonic submucosal lesion.

Patterns of local recurrence in rectal cancer: a single-center experience

A cohort of patients operated at the National Cancer Center Hospital in Tokyo for rectal carcinoma, at or below the peritoneal reflection, was reviewed retrospectively. The purpose was to study the risk factors for local relapse and the patterns of local recurrence. Three hundred fifty-one patients operated between 1993 and 2002 for rectal carcinoma, at or below the peritoneal reflection, were analyzed. One hundred forty-five patients, with preoperatively staged T1 or T2 tumors without suspected lymph nodes, underwent total mesorectal excision (TME). Lateral lymph node dissection (LLND) was performed in suspected T3 or T4 disease, or when positive lymph nodes were seen; 73 patients received unilateral LLND and 133 patients received bilateral LLND. Of the 351 patients 6.6% developed local recurrence after 5 years. TME only resulted in 0.8% 5-year local recurrence. In lymph-node-positive patients, 33% of the unilateral LLND group had local relapse, significantly more (p = 0.04) than in the bilateral LLND group with 14% local recurrence. Local recurrence in the lateral, presacral, perineal, and anastomotic subsites was lower in the bilateral LLND group as compared with in the unilateral LLND group. We conclude that, in selected patients, surgery without LLND has a very low local recurrence rate. Bilateral LLND is more effective in reducing the chance of local recurrence than unilateral LLND. Either surgical approach, with or without LLND, requires reliable imaging during work-up.

Diazepam attenuates the post-traumatic hyperactivity of excitatory synapses in rat hippocampal CA1 neurons

The effect of diazepam, a benzodiazepine derivative, on the post-traumatic hyperactivity of excitatory synaptic transmission was examined in rat hippocampal CA1 area. Optical recordings showed that the activity of hippocampal neurons was enhanced in rats treated with fluid percussion injury (FPI) as compared with that of sham-operated rats. The optical response was characterized by fast and slow components. FPI did not affect the fast component that reflects presynaptic action potentials, but enhanced the slow component that reflects excitatory synaptic responses. Intracellular recordings showed that the amplitude and duration of the excitatory postsynaptic potential (EPSP) were increased after FPI. However, FPI did not affect the resting membrane potential and action potentials of hippocampal neurons. Intraperitoneal (i.p.) administration of diazepam (30 and 90 min after FPI) attenuated the post-traumatic hyperactivity of the slow optical response. The slope of input-to-output relation of excitatory synapses was decreased by acute administration of diazepam to FPI rats, but not by delayed administration of diazepam (4 and 5 h after FPI). The fast optical responses were not affected by either FPI or i.p. administration of diazepam. These results suggest that administration of diazepam at early post-traumatic period prevents the FPI-induced delayed enhancement of excitatory synaptic transmission in rat hippocampal CA1 neurons.

Clinicopathological significance of fibrous tissue around fixed recurrent rectal cancer in the pelvis

Background

Fibrous tissue around a locally recurrent rectal tumour is an interesting histological feature, but its clinicopathological significance has not been investigated.

Methods

This retrospective study examined clinicopathological findings in 48 patients who underwent curative total pelvic exenteration with distal sacrectomy (TPES) between 1992 and 2004. Data were analysed with respect to fibrosis around the recurrent tumour, categorized into one of three groups: no fibrosis (f0), partial fibrosis (f1) or circumferential fibrosis (f2).

Results

Ten, 17 and 21 patients had f0, f1 and f2 fibrosis respectively, with 5-year survival of none, four and eight patients respectively. The overall survival of patients with circumferential fibrosis was significantly better than that in patients with no fibrosis (P = 0·003). Univariable analysis showed that a high level of sacrectomy (P = 0·036), absence of lymphatic invasion (P = 0·031) and circumferential fibrosis (P = 0·039) were significantly associated with better overall survival. In multivariable analysis, circumferential fibrosis (P = 0·031) and low serum carcinoembryonic antigen levels (P = 0·044) were independent factors for a favourable outcome.

Conclusion

The outcome of patients with locally recurrent rectal cancer after curative TPES appears to be better when circumferential fibrosis is present around the tumour.

Clinicopathological significance of microscopic abscess formation at the invasive margin of advanced low rectal cancer

BACKGROUND

The aim of this study was to evaluate the clinicopathological significance of microscopic abscess formation (MAF) at the invasive front of advanced low rectal cancer.

METHODS

The clinicopathological features of 226 consecutive patients with low rectal cancer, who underwent curative resection between May 1997 and December 2002, were analysed.

RESULTS

Fifty-seven (25.2 per cent) of the 226 tumours had MAF and 169 (74.8 per cent) did not. Patients with tumours showing MAF were more likely to have extended surgery than those without MAF: 47 versus 31.4 per cent respectively underwent non-sphincter-preserving surgery (P=0.029) and 82 versus 60.9 per cent underwent lateral lymph node dissection (P=0.003). The incidence of lymph node metastases was lower in patients with MAF (30 versus 53.3 per cent; P=0.002). Univariable analysis of disease-free survival revealed that depth of invasion (P<0.001), lymph node status (P<0.001), histological type (P=0.035), lymphatic invasion (P<0.001), venous invasion (P<0.001), perineural invasion (P<0.001), focal dedifferentiation (P<0.001) and MAF (P<0.001) were significant prognostic factors. Multivariable analysis showed that lymph node status (P<0.001), perineural invasion (P=0.002), venous invasion (P=0.033) and MAF (P=0.012) remained independent prognostic factors.

CONCLUSION

MAF may reflect indolent tumour behaviour and a more favourable outcome in patients with advanced low rectal cancer.

Reduction of prolonged postoperative hospital stay after laparoscopic surgery for colorectal carcinoma

BACKGROUND

In evaluating the quality of laparoscopic surgery (LS) for colorectal carcinoma, many previous reports have used median or range values to assess the length of postoperative hospital stay and to show the complication and conversion rates separately. However, with this method, it is impossible to assess the proportion of patients who required prolonged postoperative hospital stay because of perioperative morbidities. This study investigated the proportion of patients who benefited from LS as minimally invasive surgery by assessing the percentage of patients who required prolonged postoperative hospital stay because of major perioperative morbidities.

METHODS

A review of 202 patients who underwent LS for colorectal carcinoma at the authors' hospital between January 2002 and December 2004 was performed. Short-term outcomes were compared among the patients who underwent LS in 2002, 2003, and 2004.

RESULTS

No significant differences were observed in baseline characteristics among the groups, and all the procedures in this study were completed laparoscopically. There were no significant differences in the operative times and intraoperative blood losses among the groups. Most of the patients resumed liquid intake on postoperative day 1 and solid food on day 3. However, there was a significant difference in the rate of postoperative prolonged hospital stays by year of surgery. In 2004, 97.3% of the patients (72/74) undergoing LS could be discharged to home within 8 days postoperatively. Major complications occurred at a low rate of 1.4% (1/74) in 2004. Regarding the reasons for prolonged postoperative hospital stay, inappropriate judgment of the physician in charge, based primarily on requests from patients without medical necessity, disappeared in 2004.

CONCLUSIONS

When LS is performed properly by specialists who have accumulated sufficient experience in both LS and conventional open surgery for colorectal carcinoma, up to 97% of patients undergoing LS can benefit from minimally invasive surgery.

A comparison of the complication rates between laparoscopic colectomy and laparoscopic low anterior resection

BACKGROUND

This study compared the short-term outcomes, including the complication rate and minimum surgical invasiveness, between patients with colon and rectal carcinomas, who underwent laparoscopic surgery.

METHODS

A review evaluated 151 patients who underwent laparoscopic colectomy (Lap-colectomy; n = 120) and laparoscopic low anterior resection (Lap-LAR; n = 31) between July 2001 and December 2003. The short-term outcomes were compared between the two groups.

RESULTS

The mean operative time and blood loss were significantly greater in the Lap-LAR group. However, the complication rates and postoperative course between the two approaches were similar, and no anastomotic leakage was observed. There was no significant difference in the serum C-reactive protein level and white blood cell count between the two groups in the early postoperative period.

CONCLUSIONS

Lap-LAR for rectal carcinoma can be performed safely without increased morbidity or mortality, and its short-term benefits are comparable with those conferred by Lap-colectomy.

Lateral pelvic lymph node dissection for advanced lower rectal cancer

BACKGROUND

The oncological outcome of patients who underwent curative surgery for lower rectal cancer was investigated to clarify whether lateral pelvic lymph node dissection (LPLD) conferred any benefit.

METHODS

A total of 246 patients who underwent curative surgery for stage II and III lower rectal cancer (below the peritoneal reflection) between 1985 and 1998 was reviewed. Forty-two of these patients did not undergo LPLD.

RESULTS

Patients who did not undergo LPLD were older, more likely to have anterior resection and pelvic nerve preservation, and had smaller tumours and lymph node metastasis at an earlier stage than those who underwent LPLD. There was no difference in survival among patients with stage II and III disease between the two groups. However, in patients with pathological N1 lymph node metastasis, the 5-year disease-free survival rate was 73.3 per cent in patients who had LPLD compared with 35.3 per cent among those who did not (P = 0.013). Multivariate analysis showed that LPLD was a significant prognostic factor.

CONCLUSION

LPLD improved the prognosis of patients with stage III disease and a small number of lymph node metastases. A randomized clinical trial is needed to verify the benefit of LPLD.

Aggressive surgical treatment for patients with T4 rectal cancer

OBJECTIVE

To investigate the outcome of surgical treatment for patients with T4 rectal cancer and to evaluate prognostic factors influencing 5-year disease-free survival.

PATIENTS

Of 1600 rectal cancers seen between 1985 and 1998, there were 197 patients with T4 of whom 128 were treated with curative intent. In this retrospective study organ invaded, the type of treatment and outcome were analysed.

RESULTS

Of the 128 patients, 89% had visceral involvement and 11% had pelvic wall involvement. The most frequently involved organ was bladder, followed by prostate and vagina. Low anterior resection was performed in 52, abdomino-perineal resection in 35 and total pelvic exenteration in 41 patients. Of 81 with urinary tract invasion, 50% were treated with bladder-sparing surgery. Pathological examinations showed bladder involvement in only 44 of these and overall 5-year disease-free survival was 57%. Multivariate analysis revealed that body mass index, lymph node metastasis and inflammatory reaction were significant predictors of survival.

CONCLUSION

Completeness of resection is the essential factor influencing oncological outcome.

Development of an aggressive depressed cancer in a case of familial adenomatous polyposis

In 1977, Kariya et al. reported a case of a small depressed cancer in a patient with familial adenomatous polyposis (FAP) raising the possibility that not all cancers in FAP develop from polypoid adenomas. It is now becoming widely recognized that colonic adenomas may appear as flat or depressed lesions. However, colorectal cancers developing in patients with familial adenomatous polyposis (FAP) are still thought to evolve from adenomatous polyps following the polyp-carcinoma sequence. We report the case of a patient with FAP in whom rectal carcinoma developed 23 years after subtotal colectomy and ileorectal anastomosis. We suggest that this malignancy may have developed de novo because of the depressed shape of the lesion and the aggressive growth pattern. This case raises the possibility that carcinomas may not always evolve from polyps in FAP. Aggressive cancers with a depressed appearance should be searched for when surveying the rectal stump in patients with FAP.

Activation of inhibitory pathways suppresses the induction of long-term potentiation in neurons of the rat lateral septal nucleus

Long-term potentiation of the hippocampal-septal pathway was examined by intracellular recording techniques. High frequency stimulation (two 100-Hz 1-s trains with a 20-s interval between them) of the hippocampal CA3 area resulted in a transient depolarization in rat lateral septal nucleus neurons. High frequency stimulation was followed by a facilitation of fast and slow inhibitory postsynaptic potentials, lasting for more than 2 h, but not by a long-lasting increase in the excitatory postsynaptic potential in the normal solution. Long-term potentiation (>2 h) of the excitatory postsynaptic potential did not appear in 74% of neurons tested, even when the fast inhibitory postsynaptic potential was blocked by bicuculline (30 microM), a GABA(A) receptor antagonist. High frequency stimulation produced long-term potentiation of the excitatory postsynaptic potential in the Mg(2+)-free solution containing bicuculline. When the fast and slow inhibitory postsynaptic potentials were blocked by GABA(A) and GABA(B) receptor antagonists (bicuculline and CGP 55845A respectively), high frequency stimulation produced a large and sustained depolarization followed by long-term potentiation of the excitatory postsynaptic potential. However, the excitatory postsynaptic potential was not enhanced by administration of these drugs after termination of high frequency stimulation. Pretreatment with 2-amino-5-phosphonopentanoate, a NMDA receptor antagonist, resulted in loss of long-term potentiation in both sets of experiments. Paired-pulse stimulation of the hippocampal CA3 region with interstimulus intervals between 200 and 800 ms depressed the second excitatory postsynaptic potential in the presence of bicuculline. CGP 35348, a GABA(B) receptor antagonist, reversed the depression of excitatory postsynaptic potentials to facilitation. These data suggest that high frequency stimulation of hippocampal CA3 neurons enhances the efficacy of GABAergic inhibitory circuits which, in turn, depress the ability of lateral septal nucleus neurons to express long-term potentiation.

Optical recording of the spatiotemporal propagation of neuronal excitation in the rat hippocampal CA2-CA1 pathway

Changes in the membrane potential of neurons in the hippocampal CA2 and CA1 regions were recorded by optical recording techniques. After stimulation of the Schaffer collaterals at the hippocampal CA2 region, excitatory optical signals first occurred adjacent stimulus electrode and then flamed-up signals spread toward the hippocampal CA1 region. The optical signal was blocked by tetrodotoxin (TTX) (1 microM). Propagation of the optical signal was blocked in an artificial cerebrospinal fluid (ACSF) containing 0 mM Ca2+ and 6 mM Mg2+. 6,7-Dinitroquinoxaline-2,3 (1H,4H)-dione (DNQX) (20 microM) also blocked the optical signals that spread to the hippocampal CA1 region. The time course of the optical signal recorded at a unit area (49 pixels) on the propagation pathway was characterized by fast and slow components. TTX (1 microM) blocked both fast and slow components of the optical signal. The slow component of the optical signal was preferentially depressed by either removal of external Ca2+ or by bath-application of DNQX (20 microM). When bicuculline (15 microM) was applied to the bath-solution, the intensity and propagation area of the optical signal were increased. The results indicate that stimulation of the Schaffer collaterals in the hippocampal CA2 region produces the propagation of the optical signal to the hippocampal CA1 region, and that the optical signal involves the action potential and excitatory and inhibitory postsynaptic potentials.

5-Hydroxytryptamine facilitates spatiotemporal propagation of optical signals in the hippocampal-septal pathway

The role of 5-hydroxytryptamine (5-HT) on the propagation of neuronal excitation in the hippocampal-septal pathway was examined in a brain slice by optical and electrophysiological recording techniques. After electrical stimulation of the fimbrial pathway, optical signals first occurred at the caudal region of lateral septal nucleus (LSN), then propagated toward the rostral region of LSN. All of the evoked optical signals were blocked by tetrodotoxin (TTX). The optical signal that propagated to the LSN was blocked by either the removal of external Ca(2+) or bath-application of 6-cyano-7-nitroquinoxaline-2,3-(1H,4H)-dione (CNQX). Bath-application of 5-HT (1-50 microM) to the LSN for 10 min produced an increase in the propagation area of the optical signal and prolonged the falling phase of the optical signal. Bicuculline blocked the 5-HT-induced facilitation of the optical signal. 8-Hydroxy-di-n-propylamino tetralin (8-OH-DPAT), a selective 5-HT(1A) agonist, mimicked the facilitation of 5-HT. 1-(2-Methoxyphenyl)-4-(4-phthalimidobutyl)piperazine (NAN-190), a 5-HT(1A) antagonist, blocked the facilitation induced by 5-HT. 5-HT enhanced the amplitude of the field potential in septal slices, where the optical signals had been enhanced. These results indicate that 5-HT increases the efficacy of excitatory synaptic transmission in the hippocampal-septal circuit via 5-HT(1A) receptors of LSN neurons.

Detection of cytokeratin 19 and 20 mRNA in peripheral and mesenteric blood from colorectal cancer patients and their prognosis

To detect the presence of cancer cells in peripheral and mesenteric blood and to examine their relationship to prognosis in colorectal cancer patients undergoing curative surgery, we examined cytokeratin 19 and 20 mRNA in peripheral and mesenteric venous blood. Using reverse transcriptase polymerase chain reaction, cytokeratin 19 and 20 mRNA was amplified in peripheral and mesenteric blood samples obtained from 35 colorectal cancer patients who underwent curative surgery. Cytokeratin 19 or 20 mRNA in peripheral or mesenteric blood samples was detected in 18 of 35 cases (51%). There was no significant difference in Dukes' staging between the positive and negative groups. The median follow-up period was 56 months. In the positive group six patients (33%) showed recurrences. One patient (6%) showed recurrence in the negative group. The recurrence rate was significantly higher in the positive group than in the negative group. Five-year disease-free survival was significantly better in the negative group than in the positive group (94% vs. 65%). The detection of cytokeratin 19 or 20 mRNA in peripheral or mesenteric blood is thus associated with the prognosis for colorectal cancer patients undergoing curative surgery. Although the presence of these mRNAs in blood samples is a prognostic marker, the clinical utility of this assay is questionable because of the low recurrence rate in the positive group.

[Surgical treatment of liver metastases from colorectal cancer patient selection and oncological outcome]

The indications for surgical resection of liver metastases from colorectal cancer remain controversial. Clinical, pathological, and outcome data for 418 consecutive patients undergoing hepatectomy between 1984 and 1998 were examined. The over-all 5-year survival rate was 42%, and the 10-year survival rate was 31%. The 5-year survival rate of patients with four or more nodules was 24%, with 20 patients surviving for more than 5 years. Five factors were found to be significant and independent predictors of poor long-term outcome by multivariate analysis. The preoperative scoring system reported by Fong et al was double-checked in our 418 patients and was found to be useful to predict long-term outcome after hepatectomy. It is clear that liver resection alone has limitations. Therefore clinical risk scoring (CRS) and effective intravenous systemic chemotherapy to prevent recurrence both in the remaining liver and lung should be established to improve survival outcome in patients with poor prognostic factors after liver resection.

Characterization of outward currents induced by 5-HT in neurons of rat dorsolateral septal nucleus

Properties of the 5-hydroxytryptamine (5-HT)-induced current (I(5-HT)) were examined in neurons of rat dorsolateral septal nucleus (DLSN) by using whole cell patch-clamp techniques. I(5-HT) was associated with an increase in the membrane conductance of DLSN neurons. The reversal potential of I(5-HT) was -93 +/- 6 (SE) mV (n = 7) in the artificial cerebrospinal fluid (ACSF) and was changed by 54 mV per decade change in the external K(+) concentration, indicating that I(5-HT) is carried exclusively by K(+). Voltage dependency of the K(+) conductance underlying I(5-HT) was investigated by using current-voltage relationship. I(5-HT) showed a linear I-V relation in 63%, inward rectification in 21%, and outward rectification in 16% of DLSN neurons. (+/-)-8-Hydroxy-dipropylaminotetralin hydrobromide (30 microM), a selective 5-HT(1A) receptor agonist, also produced outward currents with three types of voltage dependency. Ba(2+) (100 microM) blocked the inward rectifier I(5-HT) but not the outward rectifier I(5-HT). In I(5-HT) with linear I-V relation, blockade of the inward rectifier K(+) current by Ba(2+) (100 microM) unmasked the outward rectifier current in DLSN neurons. These results suggest that I(5-HT) with linear I-V relation is the sum of inward rectifier and outward rectifier K(+) currents in DLSN neurons. Intracellular application of guanosine-5'-O-(3-thiotriphosphate) (300 microM) and guanosine-5'-O-(2-thiodiphosphate) (5 mM), blockers of G protein, irreversibly depressed I(5-HT). Protein kinase C (PKC) 19-36 (20 microM), a specific PKC inhibitor, depressed the outward rectifier I(5-HT) but not the inward rectifier I(5-HT). I(5-HT) was depressed by N-ethylmaleimide, which uncouples the G-protein-coupled receptor from pertussis-toxin-sensitive G proteins. H-89 (10 microM) and adenosine 3',5'-cyclic monophosphothioate Rp-isomer (300 microM), protein kinase A inhibitors, did not depress I(5-HT). Phorbol 12-myristate 13-acetate (10 microM), an activator of PKC, produced an outward rectifying K(+) current. These results suggest that both 5-HT-induced inward and outward rectifying currents are mediated by a G protein and that PKC is probably involved in the transduction pathway of the outward rectifying I(5-HT) in DLSN neurons.

Long-term outcome of urinary function after extended lymphadenectomy in patients with distal rectal cancer

AIMS

Extended lymphadenectomy for rectal cancer has been superseded by autonomic nerve-sparing surgery, but it still has historical significance. It is useful to document the long-term outcome of urinary function in cases who had resection of the inferior hypogastric nerve plexus (pelvic nerve plexus).

METHODS

The long-term urinary function following extended lymphadenectomy was studied retrospectively through the medical records of 83 patients who had been followed-up for more than 5 years after surgery.

RESULTS

Forty-four per cent of the male patients and 17% of the female patients had to perform clean intermittent self-catheterization (CIC) for more than 1 year; these rates were almost the same at 3 years after the procedure. Urinary incontinence was reported in 34% of the male patients and 45% of the female patients. Complicated cystitis (eight patients), complicated pyelonephritis (two patients), bladder stones (five patients) that required surgical treatment, and chronic renal failure (two patients) were considered as adverse outcomes of extended surgery. In particular, one case needed to undergo urinary diversion.

CONCLUSIONS

A surprisingly large proportion of patients suffered various urinary tract problems due to extended lymphadenectomy. The findings demonstrate the importance of selection of well-balanced operations that can encompass both radicality and quality of life. The extent of resection should be decided by the extent of the cancer and routine excision of the inferior hypogastric nerve plexus should not be performed.

Dermatomyositis accompanied by rectal cancer: report of a case

Dermatomyositis (DM) is a rare inflammatory disorder of the skin and muscles associated with an increased incidence of malignancy. We describe herein the case of a 59-year-old woman with DM accompanied by rectal cancer. Following excision of the rectal cancer, the characteristic features of the skin rash such as the heliotrope eyelid rash and Gottron's papules, and proximal muscle weakness, improved. Moreover, the elevated preoperative serum levels of muscle-associated enzymes, including aspartate transaminase, creatine phosphokinase, lactate dehydrogenase, and aldolase, decreased from 38 to 16 (IU/1), 138 to 42 (IU/1), 672 to 515 (IU/1), and 32.2 to 4.3 (IU/1), respectively. The current concepts of the correlation between DM and malignancy are discussed with regard to the present case.

Endorectal ultrasonography and treatment of early stage rectal cancer

The purpose of this study was to evaluate the accuracy of preoperative staging by endorectal ultrasonography (EUS) and its contribution to treatment of early stage rectal cancer (ESRC). The results of EUS for 154 consecutive patients with ESRC (pTis to pT2) were compared prospectively with histologic findings, assessed according to the TNM classification. Results of treatment selection and long-term outcomes were analyzed retrospectively. There were 35 patients histologically staged as pTis, 8 as pT1-slight (invasion confined to the superficial one-third of the submucosa), 37 as pT1-massive (invasion extending to the deeper submucosa), and 74 as pT2. The equipment used was an echoendoscope GF-UM2 or GF-UM3 (Olympus, Tokyo, Japan). Sensitivity/specificity/overall accuracy rates for detection of slight submucosal invasion, massive submucosal invasion, and muscularis propria invasion were 99%/74%/96%, 98%/88%/97%, and 97%/93%/96%, respectively. Incidences of lymph node metastasis in pTis, pTis to pT1-slight, pT1, pT1-massive, and pT2 cases were 0%, 0%, 18%, 22%, and 30%, respectively. Incidences of lymph node metastasis in ESRCs staged by EUS (u) as uTis, uT1-slight, uT1-massive, uT2, and uT3 by EUS were 0%, 0%, 26%, 36%, and 64%, respectively. Sensitivity, specificity, and overall accuracy rates for detection of positive nodes in overall ESRCs were 53%, 77%, and 72%, respectively. Of the 43 patients with pTis to pT1-slight tumors, 22 underwent endoscopic polypectomy or local excision, 20 radical surgery, and 1 radical surgery after endoscopic polypectomy due to vascular invasion. All these patients are alive and all but one (who refused radical surgery due to vascular invasion after local excision and developed liver and lung metastases) are disease-free. Of the 37 patients with pT1-massive tumors, 34 underwent radical surgery and 3 transcoccygeal segmental resection. All these patients are alive disease-free except for one who died of peritoneal carcinomatosis after radical surgery. All patients with pT2 tumors underwent radical surgery. The overall 5-year survival rates for pTis, pT1, and pT2 cases were 100%, 98%, and 97%, respectively. EUS is an accurate method for evaluating invasion depth in ESRC. Patients with uTis or uT1-slight tumors staged by EUS are at low risk of positive nodes and good candidates for endoscopic polypectomy or local excision. Those with uT1-massive or uT2 lesions should be treated with a radical operation because of the high incidence of positive nodes.

5-Hydroxytryptamine-induced outward currents mediated via 5-HT(1A) receptors in neurons of the rat dorsolateral septal nucleus

Effects of 5-hydroxytryptamine (5-HT) on neurons of the rat dorsolateral septal nucleus (DLSN) were examined by intracellular and whole-cell patch-clamp recording techniques. An outward current was induced by 5-HT (1-100 microM) in a concentration-dependent manner. The EC(50) for 5-HT was 4.8 microM. Also, 8-OH-DPAT (10-100 microM) produced the outward current an EC(50) of 17 microM. Amplitudes of the outward currents produced by 5-HT (100 microM) and 8-OH-DPAT (100 microM) were 117+/-4 (n=6) and 58+/-8 pA (n=6), respectively. Fluvoxamine (200 nM), a specific serotonin re-uptake inhibitor, enhanced the 5-HT (1 microM)-induced outward current: the EC(50) for 5-HT was 0.5 microM in the presence of fluvoxamine (200 nM). L-694247 (100 microM) and CP 93129 (100 microM) also produced outward currents with amplitudes of 33+/-3 (n=4) and 18+/-5 pA (n=4), respectively in DLSN neurons. DOI (100 microM) and RS 67333 (100 microM) did not produce outward currents. NAN-190 shifted, in a parallel manner, the concentration-response relationship of 5-HT to the right. The Lineweaver-Burk plot of the concentration-response curve showed that NAN-190 depressed the 5-HT-induced current in a competitive manner. The current-voltage relationship indicates that the 5-HT-induced current reversed polarity at a potential close to the equilibrium potential of K(+). Ba(2+) (100 microM-1 mM) partially depressed the outward current produced by 5-HT. These results suggest that 5-HT induces multiple K(+) currents via 5-HT(1A) receptors in DLSN neurons.

Enhanced detection of deleterious and other germline mutations of hMSH2 and hMLH1 in Japanese hereditary nonpolyposis colorectal cancer kindreds

Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal, dominantly inherited cancer-prone syndrome. Here, we describe a novel and efficient approach for screening mutations of two major HNPCC susceptibility genes, hMSH2 and hMLH1. The system consists of RNA extraction from whole blood treated with the translation inhibitor, followed by long RT-PCR of the entire coding regions combined with direct sequencing. In analysis of 15 kindreds suspicious for HNPCC, 8 samples were subjected to analysis after puromycin treatment and 7 samples were analyzed without puromycin treatment. Three deleterious mutations were detected in the kindreds with puromycin treatment, while none were observed in those without puromycin. Signals from mutated alleles were enhanced after puromycin treatment and easily distinguished from the wild-type allele, achieved by suppression of nonsense-mediated mRNA decay. Furthermore, 12 other mutations were detected in 15 kindreds. The system is considered to be a reliable and useful approach for detecting germline mutations of hMSH2 and hMLH1 in HNPCC kindreds.

En bloc surgery for colon cancer: report of a case

We report herein the case of a 57-year-old woman in whom successful en bloc surgery was performed for locally advanced colon cancer. A fixed tumor was palpable in the right subcostal region, and computed tomography (CT) showed that it originated in the ascending colon and invaded the right kidney, duodenum, head of the pancreas, and liver. A right hemicolectomy with D3 lymphadenectomy was performed combined with resection of the right kidney, duodenum, head of the pancreas, and liver. On microscopic examination, well-differentiated adenocarcinoma of the ascending colon widely invaded the parenchyma of the kidney, the parenchyma of the pancreatic head, and the duodenal wall. Lymph node metastasis was found in one paracolic node. This case report outlines the procedures involved in this extended surgery.

Effects of corticosteroids on synaptic transmission in rat dorsolateral septal nucleus

The effects of corticosteroids on synaptic transmission in the rat dorsolateral septal nucleus (DLSN) were examined, in vitro, by using intracellular and voltage-clamp recording methods. Prednisolone (100 microM) increased the amplitude of excitatory postsynaptic potential (EPSP) and depressed both fast and slow inhibitory postsynaptic potentials (IPSP). Under voltage-clamp conditions, prednisolone (100 microM) increased the amplitude of excitatory postsynaptic current (EPSC) and depressed the fast and slow inhibitory postsynaptic currents (IPSCs). Corticosterone (100 microM) mimicked the effects of prednisolone on the postsynaptic currents (PSCs). To examine the direct effects of prednisolone on the EPSC and slow IPSC, the fast IPSC was blocked by bicuculline (20 microM). Under these experimental conditions, prednisolone (100 microM) did not alter the isolated EPSC but depressed slow IPSC by 22 +/- 3% (n = 10). The fast IPSC was isolated by pretreatment with kynurenic acid and CGP55845A, where the EPSC and slow IPSC were blocked. Prednisolone (100 microM) depressed the isolated fast IPSC in DLSN neurons. Prednisolone (100 microM) did not change either the inward current produced by glutamate or the outward current produced by gamma-aminobutyric acid (GABA). The results suggest that corticosteroids facilitate excitatory synaptic transmission in the DLSN by reducing the release of GABA from the presynaptic nerve terminals of interneurons.

Effects of interleukin-1 beta on neurons in mammalian pelvic ganglia

The effects of interleukin-1 beta (IL-1 beta) on the membrane potential and synaptic transmission were examined in neurons of mammalian pelvic ganglia. Bath-application of recombinant human IL-1 beta (6-300 pM) for 10 s-5 min produced a long-lasting hyperpolarization associated with increased input resistance in 11 neurons of rat major pelvic ganglia (MPG). In other 8 neurons, IL-1 beta (300 pM) produced a biphasic response that consists of an initial depolarization followed by a long-lasting hyperpolarization. IL-1 beta 163-171 (10-100 pM), a synthetic nonapeptide analog that contains the active domain of human IL-1 beta, mimicked the effect of IL-1 beta in MPG neurons. gamma-Aminobutyric acid (GABA, 300 microM) produced a depolarization followed by a hyperpolarization that was blocked by picrotoxin (100 microM). Db-cyclic guanosine monophosphate (db-cyclic GMP, 100 microM) also produced an initial depolarization followed by a long-lasting hyperpolarization. These results suggest that the IL-1 beta-induced biphasic response is mediated by a GABA receptor-cyclic GMP pathway. IL-1 beta and IL-1 beta 163-171 caused an initial facilitation followed by a long-lasting depression of the excitatory postsynaptic potential (EPSP) in rabbit VPG. The data suggest that IL-1 beta presynaptically depressed the EPSP by reducing the release of acetylcholine (ACh) from the pelvic nerve terminals.

Resection of synchronous liver metastases from colorectal cancer

BACKGROUND

The prognosis for patients with liver metastases from colorectal cancer is still poor. Thus, patient selection for hepatic resection is essential to improve the poor results of the procedure. Some reports have shown that the prognosis for patients with synchronous liver metastases is worse than that for those with metachronous liver metastases. Therefore, determination of the factors that influence outcome after resection of synchronous liver metastases is more important than with metachronous liver metastasis.

METHOD

We studied patients who had been followed for more than 5 years after undergoing resection of synchronous liver metastases from colorectal cancer.

RESULTS

Among the 12 prognostic factors studied (age, gender, adjuvant chemotherapy, tumor site, CEA level, tumor differentiation, tumor size, regional lymph node metastatic status, distribution of liver metastases, number of liver metastases, tumor size and pathological margin), regional lymph node metastatic status and pathological margin were significant prognostic factors by univariate analysis (p = 0.0002 and 0.005, respectively). Regional lymph node metastatic status was a significant prognostic factor by multivariate analysis (p = 0.031). The survival curve of patients with six or more regional lymph node metastases was similar to that of patients with non-resectable liver metastasis.

CONCLUSION

The resection of synchronous liver metastases in patients with six or more regional lymph node metastases is relatively contraindicated. For these patients, other treatment modalities should be considered.

Macroscopic intrabiliary growth of liver metastases from colorectal cancer

BACKGROUND

The clinicopathologic features of colorectal liver metastases that invade the bile duct were evaluated.

METHODS

From 1992 to 1996, 149 patients who underwent a first hepatic resection were studied for a total of 377 colorectal liver metastases. Twenty-one second hepatic resections in these patients were also analyzed.

RESULTS

Bile duct invasion was histologically observed in 62 (42%) of 149 patients with first colorectal liver metastasis. Eighteen patients (12%) had gross extension of the tumor in the bile duct ranging from 4 mm to 42 mm (median 17.0 mm). Histologically, two thirds (12 of 18) of the tumors with macroscopic bile duct invasion were well-differentiated adenocarcinomas with a tendency for less vascular involvement. The actuarial 3- and 5-year survivals were 62% and 57% for patients with no bile duct invasion, 56% and 48% for patients with microscopic bile duct invasion, and 94% and 80% for patients with macroscopic bile duct invasion. The 5-year survival rate was better for patients with macroscopic bile duct invasion than for those with only microscopic (P = .02) or no bile duct invasion (P = .03). In a multivariate analysis, macroscopic bile duct invasion was an independent prognostic variable for favorable outcome after hepatic resection.

CONCLUSIONS

Macroscopic bile duct invasion of colorectal liver metastases may reflect an indolent biologic behavior, warrants an aggressive surgical approach, and confers a better prognosis.

Interleukin-1beta causes a biphasic response in neurons of rat major pelvic ganglia

The effect of interleukin-1beta (IL-1beta) on peripheral autonomic neurons was examined with intracellular microelectrodes, in vitro. Recombinant human IL-1beta (6-300 pM) produced a depolarization, associated with decrease in input resistance, followed by a hyperpolarization, associated with increase in input resistance, in neurons of rat major pelvic ganglia (MPG). IL-1beta 163-171 (10-100 pM), the active domain of human IL-1beta, also produced a biphasic response. The IL-1beta-induced responses reversed polarity at the equilibrium potential for Cl-. The IL-1beta-induced responses were blocked by picrotoxin (100 microM) but not by bicuculline (20 microM). Imidazole-4-acetic acid (14AA, 100 microM), a GABA(C) receptor antagonist, reduced the IL-1beta-induced responses. The results suggest that the IL-1beta-induced biphasic response is mediated through GABA(C) receptors in rat MPG neurons.

Role of GABAA and GABAC receptors in the biphasic GABA responses in neurons of the rat major pelvic ganglia

The role of gamma-aminobutyric acid-A (GABAA) and GABAC receptors in the GABA-induced biphasic response in neurons of the rat major pelvic ganglia (MPG) were examined in vitro. Application of GABA (100 microM) to MPG neurons produced a biphasic response, an initial depolarization (GABAd) followed by a hyperpolarization (GABAh). The input resistance of the MPG neurons was decreased during the GABAd, whereas it was increased during the GABAh. The GABAd could be further separated into the early component (early GABAd) with a duration of 27 +/- 5 s (mean +/- SE; n = 11) and the late component (late GABAd) with a duration of 109 +/- 11 s (n = 11). The duration of the GABAh was 516 +/- 64 s (n = 11). The effects of GABA (5-500 microM) in producing the depolarization and the hyperpolarization were concentration-dependent. GABA (5-30 microM) induced only late depolarizations. The early component of the depolarization appeared when the concentration of GABA was >50 microM. Muscimol produced only early depolarizing responses. Baclofen (100 microM) had no effect on the membrane potential and input resistance of MPG neurons. Bicuculline (60 microM) blocked the early GABAd but not the late GABAd and the GABAh. Application of picrotoxin (100 microM) with bicuculline (60 microM) blocked both the late GABAd and the GABAh. CGP55845A (3 microM), a selective GABAB receptor antagonist, did not affect the GABA-induced responses. cis-4-Aminocrotonic acid (CACA, 1 mM) and trans-4-aminocrotonic acid (TACA, 1 mM), selective GABAC receptor agonists, produced late biphasic responses in the MPG neurons. The duration of the CACA responses was almost the same as those of the late GABAd and GABAh obtained in the presence of bicuculline. Imidazole-4-acetic acid (I4AA, 100 microM), a GABAC receptor antagonist, depressed the late GABAd and the GABAh but not the early GABAd. I4AA (100 microM) and picrotoxin (100 microM) also suppressed the biphasic response to CACA. The early GABAd and the late GABAd were reversed in polarity at -32 +/- 3 mV (n = 7) and -38 +/- 2 mV (n = 4), respectively, in the Krebs solution. The reversal potential of the GABAh was -34 +/- 2 mV (n = 4) in the Krebs solution. The reversal potentials of the late GABAd and the GABAh shifted to -20 +/- 3 mV (n = 5) and -22 +/- 3 mV (n = 5), respectively, in 85 mM Cl- solution. These results indicate that the late GABA(d) and the GABAh are mediated predominantly by bicuculline-insensitive, picrotoxin-sensitive GABA receptors, GABAC (or GABAAOr) receptors, in neurons of the rat MPG.

The relationship between prognosis and CEA-dt after hepatic resection in patients with colorectal carcinomas

AIMS

CEA-doubling time (CEA-dt) was calculated by measuring serum CEA at two voluntary points. As CEA-dt is correlated with tumour doubling time the growth rate of liver metastasis could be determined. We investigated the relationship between CEA-dt and prognosis to determine the indications for resection of liver metastasis.

METHODS

We examined 334 patients diagnosed with resected liver metastasis of colorectal carcinoma. Patients were divided into three categories based on CEA-dt; Group A, CEA-dt <30 days; Group B, 30 days </=cCEA-dt <80 days; and Group C, CEA-dt >/=s80 days. Clinicopathological parameters, the 3-year or 5-year survival rate and the rate of recurrence were compared among the three groups.

RESULTS

In Group A, the survival time after hepatic resection was significantly shorter compared to the other groups. Furthermore, multiple liver metastasis showed slightly reduced CEA-dt levels compared with solitary metastasis, but even in patients with solitary liver metastasis, the rate of survival was poor. In 70% of Group A patients, recurrent tumour was recognized within 1 year of hepatic resection.

CONCLUSION

When surgery for liver metastasis of colorectal cancer is considered. Group A patients should be recognized as having a poor prognosis and a high rate of recurrence after hepatic resection, and CEA-dt should be employed as a prognostic factor.

GABAC receptors mediate slow membrane potentials in neurons of the rat major pelvic ganglia

Effects of gamma-aminobutyric acid (GABA) on the neuronal membrane of the rat major pelvic ganglia (MPG) were studied using intracellular recording techniques, in vitro. Application of GABA (100 microM) to MPG neurons induced a depolarization (GABAd) associated with a decreased membrane input resistance and a slow hyperpolarization (s-GABAh) associated with an increased membrane input resistance. The GABA depolarization had two phases, a fast depolarization (f-GABAd) and a subsequent slow depolarization (s-GABAd). Bicuculline (60 microM) blocked the f-GABAd but not the s-GABAd and s-GABAh. Picrotoxin (100 microM) blocked all the GABA responses. Imidazole-4-acetic acid (I4AA, 100 microM), a GABAc receptor antagonist, depressed the s-GABAd and s-GABAh, but did not block the f-GABAd. Cis-4-aminocrotonic acid (CACA), a GABAc receptor agonist, produced a depolarization followed by a hyperpolarization in MPG neurons. I4AA (100 microM) depressed the CACA-induced responses. It was concluded that GABAA receptors mediate the f-GABAd and that GABAc receptors mediate the s-GABAd and s-GABAh, in neurons of the rat MPG.

Resection of both hepatic and pulmonary metastases in patients with colorectal carcinoma

BACKGROUND

More than 40% of patients who undergo curative resection of advanced colorectal carcinoma can be expected to have recurrence of the disease. The most frequent sites of recurrence are the liver (33% of patients) and lung (22%). Interest has therefore focused on treating hepatic or pulmonary metastases, or both, to improve the outcomes of these patients. Although surgical resection has become an increasingly accepted treatment for resectable localized hepatic or localized pulmonary metastases from colorectal carcinoma, the value of aggressive surgery for the removal of both hepatic and pulmonary metastases from patients with primary colorectal carcinoma remains to be clarified.

METHODS

Data on 30 patients who had undergone resection of both hepatic and pulmonary metastases from colorectal carcinoma were included in the study.

RESULTS

Independent, significant prognostic features were found to be the time that hepatic or pulmonary metastases occurred and the distribution of pulmonary metastases. Median survival times were 30 months (range, 7-108 months) after resection of both hepatic and pulmonary metastases and 48.5 months (range, 11-149 months) after excision of the primary colorectal tumor. Actuarial 1-, 3-, and 5-year survival after resection of both hepatic and pulmonary metastases was 86.7%, 49.3%, and 43.8%, respectively. No perioperative mortality occurred. There were three cases of minor morbidity, which the authors considered acceptable.

CONCLUSIONS

Resection of both hepatic and pulmonary metastases from colorectal carcinoma may help to prolong the survival of a small group of patients with these metastases.

Resection of both hepatic and pulmonary metastases in patients with colorectal carcinoma

BACKGROUND

More than 40% of patients who undergo curative resection of advanced colorectal carcinoma can be expected to have recurrence of the disease. The most frequent sites of recurrence are the liver (33% of patients) and lung (22%). Interest has therefore focused on treating hepatic or pulmonary metastases, or both, to improve the outcomes of these patients. Although surgical resection has become an increasingly accepted treatment for resectable localized hepatic or localized pulmonary metastases from colorectal carcinoma, the value of aggressive surgery for the removal of both hepatic and pulmonary metastases from patients with primary colorectal carcinoma remains to be clarified.

METHODS

Data on 30 patients who had undergone resection of both hepatic and pulmonary metastases from colorectal carcinoma were included in the study.

RESULTS

Independent, significant prognostic features were found to be the time that hepatic or pulmonary metastases occurred and the distribution of pulmonary metastases. Median survival times were 30 months (range, 7-108 months) after resection of both hepatic and pulmonary metastases and 48.5 months (range, 11-149 months) after excision of the primary colorectal tumor. Actuarial 1-, 3-, and 5-year survival after resection of both hepatic and pulmonary metastases was 86.7%, 49.3%, and 43.8%, respectively. No perioperative mortality occurred. There were three cases of minor morbidity, which the authors considered acceptable.

CONCLUSIONS

Resection of both hepatic and pulmonary metastases from colorectal carcinoma may help to prolong the survival of a small group of patients with these metastases.

Abnormal expression of CD44 variants in the exfoliated cells in the feces of patients with colorectal cancer

BACKGROUND & AIMS

Recent investigations have shown that CD44 variant exons are frequently overexpressed in human colorectal adenocarcinoma. The aim of this study was to investigate abnormal expression of the CD44 gene in exfoliated cells from patients with colorectal cancer.

METHODS

Exfoliated cells in feces from 25 patients with colorectal cancer before and after surgery and from 15 healthy volunteers were analyzed. CD44 standard, variant 6, and variant 10 messenger RNA (mRNA) expressions were examined in the exfoliated cells in feces by using reverse-transcription polymerase chain reaction followed by Southern hybridization with exon-specific probes.

RESULTS

CD44 standard mRNA was detected in all samples before and after surgery and in all healthy volunteers. CD44 variant 6 and variant 10 mRNA were detected in 17 of 25 patients (68%) and 15 of 25 patients (60%), respectively, in individual feces obtained before surgery. CD44 variant 6 mRNA and variant 10 mRNA were detected in postoperative samples in 3 of 25 patients (12%) and 7 of 25 patients (28%), respectively. Fifteen of 17 patients who were positive for CD44v6 based on preoperative fecal samples became negative after surgery (88.2%). Similarly, 12 of 15 patients who were CD44v10 positive in preoperative fecal samples were negative postoperatively (80%).

CONCLUSIONS

These results suggest that analysis of CD44 variant expression in the exfoliated cells in feces can provide a noninvasive diagnostic test for colorectal cancer.

[Effects of nonsteroidal anti-inflammatory drugs (NSAID) on colorectal polyps in patients with familial adenomatous polyposis: a review of clinical studies]

Experimental animal studies have demonstrated a protective effect of NSAIDs against intestinal tumorigenesis due to chemical carcinogens. Many epidemiological studies have also shown that regular aspirin use is associated with reduction of the risk of colorectal cancer. In familial adenomatous polyposis, numerous clinical studies have reported that sulindac and indomethacin are effective in reducing colorectal polyps. However, their effects are incomplete and they may cause severe toxicity. Therefore, they are unlikely to replace colectomy as primary treatment. Nevertheless, their unique effects on colorectal tumorigenesis warrant further basic and clinical research on NSAIDs, including COX-2-selective inhibitors.

Perianal Paget's disease associated with rectal carcinoma: a case report

A 58-year-old man was referred to us because of anal bleeding. Digital rectal examination revealed a 1.2 x 0.8 cm-sessile villous tumor located in the anal canal and lower rectum. Pruritus was lacking and there were no erythematous lesions or any skin lesion in the perianal region. Histologic examination of the excised lesion revealed the presence of an adenocarcinoma within a villous adenoma. The malignancy exhibited well, moderately and poorly differentiated areas with signet-ring cell elements. Because the carcinoma had massively invaded into the submucosa, additional abdominoperineal resection was performed. Microscopic examination of the obtained specimens showed incidental Paget's disease of the anal skin. Although perianal Paget's disease associated with rectal cancer is rare, cautious pathologic examination of the anal and perianal skin in cases with anorectal carcinoma is necessary, even if there are no suggestive clinical findings. If there is perianal Paget's disease, surgical resection with sufficient apparently normal skin and close follow-up are necessary.